root/drivers/tty/serial/sh-sci.c

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DEFINITIONS

This source file includes following definitions.
  1. to_sci_port
  2. sci_serial_in
  3. sci_serial_out
  4. sci_port_enable
  5. sci_port_disable
  6. port_rx_irq_mask
  7. sci_start_tx
  8. sci_stop_tx
  9. sci_start_rx
  10. sci_stop_rx
  11. sci_clear_SCxSR
  12. sci_poll_get_char
  13. sci_poll_put_char
  14. sci_init_pins
  15. sci_txfill
  16. sci_txroom
  17. sci_rxfill
  18. sci_transmit_chars
  19. sci_receive_chars
  20. sci_handle_errors
  21. sci_handle_fifo_overrun
  22. sci_handle_breaks
  23. scif_set_rtrg
  24. scif_rtrg_enabled
  25. rx_fifo_timer_fn
  26. rx_fifo_trigger_show
  27. rx_fifo_trigger_store
  28. rx_fifo_timeout_show
  29. rx_fifo_timeout_store
  30. sci_dma_tx_complete
  31. sci_dma_rx_push
  32. sci_dma_rx_find_active
  33. sci_dma_rx_chan_invalidate
  34. sci_dma_rx_release
  35. start_hrtimer_us
  36. sci_dma_rx_reenable_irq
  37. sci_dma_rx_complete
  38. sci_dma_tx_release
  39. sci_dma_rx_submit
  40. sci_dma_tx_work_fn
  41. sci_dma_rx_timer_fn
  42. sci_request_dma_chan
  43. sci_request_dma
  44. sci_free_dma
  45. sci_flush_buffer
  46. sci_request_dma
  47. sci_free_dma
  48. sci_rx_interrupt
  49. sci_tx_interrupt
  50. sci_br_interrupt
  51. sci_er_interrupt
  52. sci_mpxed_interrupt
  53. sci_request_irq
  54. sci_free_irq
  55. sci_tx_empty
  56. sci_set_rts
  57. sci_get_cts
  58. sci_set_mctrl
  59. sci_get_mctrl
  60. sci_enable_ms
  61. sci_break_ctl
  62. sci_startup
  63. sci_shutdown
  64. sci_sck_calc
  65. sci_brg_calc
  66. sci_scbrr_calc
  67. sci_reset
  68. sci_set_termios
  69. sci_pm
  70. sci_type
  71. sci_remap_port
  72. sci_release_port
  73. sci_request_port
  74. sci_config_port
  75. sci_verify_port
  76. sci_init_clocks
  77. sci_probe_regmap
  78. sci_init_single
  79. sci_cleanup_single
  80. serial_console_putchar
  81. serial_console_write
  82. serial_console_setup
  83. sci_probe_earlyprintk
  84. sci_probe_earlyprintk
  85. sci_remove
  86. sci_parse_dt
  87. sci_probe_single
  88. sci_probe
  89. sci_suspend
  90. sci_resume
  91. sci_init
  92. sci_exit
  93. early_console_setup
  94. sci_early_console_setup
  95. scif_early_console_setup
  96. rzscifa_early_console_setup
  97. scifa_early_console_setup
  98. scifb_early_console_setup
  99. hscif_early_console_setup

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SuperH on-chip serial module support.  (SCI with no FIFO / with FIFO)
   4  *
   5  *  Copyright (C) 2002 - 2011  Paul Mundt
   6  *  Copyright (C) 2015 Glider bvba
   7  *  Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007).
   8  *
   9  * based off of the old drivers/char/sh-sci.c by:
  10  *
  11  *   Copyright (C) 1999, 2000  Niibe Yutaka
  12  *   Copyright (C) 2000  Sugioka Toshinobu
  13  *   Modified to support multiple serial ports. Stuart Menefy (May 2000).
  14  *   Modified to support SecureEdge. David McCullough (2002)
  15  *   Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003).
  16  *   Removed SH7300 support (Jul 2007).
  17  */
  18 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  19 #define SUPPORT_SYSRQ
  20 #endif
  21 
  22 #undef DEBUG
  23 
  24 #include <linux/clk.h>
  25 #include <linux/console.h>
  26 #include <linux/ctype.h>
  27 #include <linux/cpufreq.h>
  28 #include <linux/delay.h>
  29 #include <linux/dmaengine.h>
  30 #include <linux/dma-mapping.h>
  31 #include <linux/err.h>
  32 #include <linux/errno.h>
  33 #include <linux/init.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/ioport.h>
  36 #include <linux/ktime.h>
  37 #include <linux/major.h>
  38 #include <linux/module.h>
  39 #include <linux/mm.h>
  40 #include <linux/of.h>
  41 #include <linux/of_device.h>
  42 #include <linux/platform_device.h>
  43 #include <linux/pm_runtime.h>
  44 #include <linux/scatterlist.h>
  45 #include <linux/serial.h>
  46 #include <linux/serial_sci.h>
  47 #include <linux/sh_dma.h>
  48 #include <linux/slab.h>
  49 #include <linux/string.h>
  50 #include <linux/sysrq.h>
  51 #include <linux/timer.h>
  52 #include <linux/tty.h>
  53 #include <linux/tty_flip.h>
  54 
  55 #ifdef CONFIG_SUPERH
  56 #include <asm/sh_bios.h>
  57 #endif
  58 
  59 #include "serial_mctrl_gpio.h"
  60 #include "sh-sci.h"
  61 
  62 /* Offsets into the sci_port->irqs array */
  63 enum {
  64         SCIx_ERI_IRQ,
  65         SCIx_RXI_IRQ,
  66         SCIx_TXI_IRQ,
  67         SCIx_BRI_IRQ,
  68         SCIx_DRI_IRQ,
  69         SCIx_TEI_IRQ,
  70         SCIx_NR_IRQS,
  71 
  72         SCIx_MUX_IRQ = SCIx_NR_IRQS,    /* special case */
  73 };
  74 
  75 #define SCIx_IRQ_IS_MUXED(port)                 \
  76         ((port)->irqs[SCIx_ERI_IRQ] ==  \
  77          (port)->irqs[SCIx_RXI_IRQ]) || \
  78         ((port)->irqs[SCIx_ERI_IRQ] &&  \
  79          ((port)->irqs[SCIx_RXI_IRQ] < 0))
  80 
  81 enum SCI_CLKS {
  82         SCI_FCK,                /* Functional Clock */
  83         SCI_SCK,                /* Optional External Clock */
  84         SCI_BRG_INT,            /* Optional BRG Internal Clock Source */
  85         SCI_SCIF_CLK,           /* Optional BRG External Clock Source */
  86         SCI_NUM_CLKS
  87 };
  88 
  89 /* Bit x set means sampling rate x + 1 is supported */
  90 #define SCI_SR(x)               BIT((x) - 1)
  91 #define SCI_SR_RANGE(x, y)      GENMASK((y) - 1, (x) - 1)
  92 
  93 #define SCI_SR_SCIFAB           SCI_SR(5) | SCI_SR(7) | SCI_SR(11) | \
  94                                 SCI_SR(13) | SCI_SR(16) | SCI_SR(17) | \
  95                                 SCI_SR(19) | SCI_SR(27)
  96 
  97 #define min_sr(_port)           ffs((_port)->sampling_rate_mask)
  98 #define max_sr(_port)           fls((_port)->sampling_rate_mask)
  99 
 100 /* Iterate over all supported sampling rates, from high to low */
 101 #define for_each_sr(_sr, _port)                                         \
 102         for ((_sr) = max_sr(_port); (_sr) >= min_sr(_port); (_sr)--)    \
 103                 if ((_port)->sampling_rate_mask & SCI_SR((_sr)))
 104 
 105 struct plat_sci_reg {
 106         u8 offset, size;
 107 };
 108 
 109 struct sci_port_params {
 110         const struct plat_sci_reg regs[SCIx_NR_REGS];
 111         unsigned int fifosize;
 112         unsigned int overrun_reg;
 113         unsigned int overrun_mask;
 114         unsigned int sampling_rate_mask;
 115         unsigned int error_mask;
 116         unsigned int error_clear;
 117 };
 118 
 119 struct sci_port {
 120         struct uart_port        port;
 121 
 122         /* Platform configuration */
 123         const struct sci_port_params *params;
 124         const struct plat_sci_port *cfg;
 125         unsigned int            sampling_rate_mask;
 126         resource_size_t         reg_size;
 127         struct mctrl_gpios      *gpios;
 128 
 129         /* Clocks */
 130         struct clk              *clks[SCI_NUM_CLKS];
 131         unsigned long           clk_rates[SCI_NUM_CLKS];
 132 
 133         int                     irqs[SCIx_NR_IRQS];
 134         char                    *irqstr[SCIx_NR_IRQS];
 135 
 136         struct dma_chan                 *chan_tx;
 137         struct dma_chan                 *chan_rx;
 138 
 139 #ifdef CONFIG_SERIAL_SH_SCI_DMA
 140         struct dma_chan                 *chan_tx_saved;
 141         struct dma_chan                 *chan_rx_saved;
 142         dma_cookie_t                    cookie_tx;
 143         dma_cookie_t                    cookie_rx[2];
 144         dma_cookie_t                    active_rx;
 145         dma_addr_t                      tx_dma_addr;
 146         unsigned int                    tx_dma_len;
 147         struct scatterlist              sg_rx[2];
 148         void                            *rx_buf[2];
 149         size_t                          buf_len_rx;
 150         struct work_struct              work_tx;
 151         struct hrtimer                  rx_timer;
 152         unsigned int                    rx_timeout;     /* microseconds */
 153 #endif
 154         unsigned int                    rx_frame;
 155         int                             rx_trigger;
 156         struct timer_list               rx_fifo_timer;
 157         int                             rx_fifo_timeout;
 158         u16                             hscif_tot;
 159 
 160         bool has_rtscts;
 161         bool autorts;
 162 };
 163 
 164 #define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS
 165 
 166 static struct sci_port sci_ports[SCI_NPORTS];
 167 static unsigned long sci_ports_in_use;
 168 static struct uart_driver sci_uart_driver;
 169 
 170 static inline struct sci_port *
 171 to_sci_port(struct uart_port *uart)
 172 {
 173         return container_of(uart, struct sci_port, port);
 174 }
 175 
 176 static const struct sci_port_params sci_port_params[SCIx_NR_REGTYPES] = {
 177         /*
 178          * Common SCI definitions, dependent on the port's regshift
 179          * value.
 180          */
 181         [SCIx_SCI_REGTYPE] = {
 182                 .regs = {
 183                         [SCSMR]         = { 0x00,  8 },
 184                         [SCBRR]         = { 0x01,  8 },
 185                         [SCSCR]         = { 0x02,  8 },
 186                         [SCxTDR]        = { 0x03,  8 },
 187                         [SCxSR]         = { 0x04,  8 },
 188                         [SCxRDR]        = { 0x05,  8 },
 189                 },
 190                 .fifosize = 1,
 191                 .overrun_reg = SCxSR,
 192                 .overrun_mask = SCI_ORER,
 193                 .sampling_rate_mask = SCI_SR(32),
 194                 .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
 195                 .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
 196         },
 197 
 198         /*
 199          * Common definitions for legacy IrDA ports.
 200          */
 201         [SCIx_IRDA_REGTYPE] = {
 202                 .regs = {
 203                         [SCSMR]         = { 0x00,  8 },
 204                         [SCBRR]         = { 0x02,  8 },
 205                         [SCSCR]         = { 0x04,  8 },
 206                         [SCxTDR]        = { 0x06,  8 },
 207                         [SCxSR]         = { 0x08, 16 },
 208                         [SCxRDR]        = { 0x0a,  8 },
 209                         [SCFCR]         = { 0x0c,  8 },
 210                         [SCFDR]         = { 0x0e, 16 },
 211                 },
 212                 .fifosize = 1,
 213                 .overrun_reg = SCxSR,
 214                 .overrun_mask = SCI_ORER,
 215                 .sampling_rate_mask = SCI_SR(32),
 216                 .error_mask = SCI_DEFAULT_ERROR_MASK | SCI_ORER,
 217                 .error_clear = SCI_ERROR_CLEAR & ~SCI_ORER,
 218         },
 219 
 220         /*
 221          * Common SCIFA definitions.
 222          */
 223         [SCIx_SCIFA_REGTYPE] = {
 224                 .regs = {
 225                         [SCSMR]         = { 0x00, 16 },
 226                         [SCBRR]         = { 0x04,  8 },
 227                         [SCSCR]         = { 0x08, 16 },
 228                         [SCxTDR]        = { 0x20,  8 },
 229                         [SCxSR]         = { 0x14, 16 },
 230                         [SCxRDR]        = { 0x24,  8 },
 231                         [SCFCR]         = { 0x18, 16 },
 232                         [SCFDR]         = { 0x1c, 16 },
 233                         [SCPCR]         = { 0x30, 16 },
 234                         [SCPDR]         = { 0x34, 16 },
 235                 },
 236                 .fifosize = 64,
 237                 .overrun_reg = SCxSR,
 238                 .overrun_mask = SCIFA_ORER,
 239                 .sampling_rate_mask = SCI_SR_SCIFAB,
 240                 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 241                 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 242         },
 243 
 244         /*
 245          * Common SCIFB definitions.
 246          */
 247         [SCIx_SCIFB_REGTYPE] = {
 248                 .regs = {
 249                         [SCSMR]         = { 0x00, 16 },
 250                         [SCBRR]         = { 0x04,  8 },
 251                         [SCSCR]         = { 0x08, 16 },
 252                         [SCxTDR]        = { 0x40,  8 },
 253                         [SCxSR]         = { 0x14, 16 },
 254                         [SCxRDR]        = { 0x60,  8 },
 255                         [SCFCR]         = { 0x18, 16 },
 256                         [SCTFDR]        = { 0x38, 16 },
 257                         [SCRFDR]        = { 0x3c, 16 },
 258                         [SCPCR]         = { 0x30, 16 },
 259                         [SCPDR]         = { 0x34, 16 },
 260                 },
 261                 .fifosize = 256,
 262                 .overrun_reg = SCxSR,
 263                 .overrun_mask = SCIFA_ORER,
 264                 .sampling_rate_mask = SCI_SR_SCIFAB,
 265                 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 266                 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 267         },
 268 
 269         /*
 270          * Common SH-2(A) SCIF definitions for ports with FIFO data
 271          * count registers.
 272          */
 273         [SCIx_SH2_SCIF_FIFODATA_REGTYPE] = {
 274                 .regs = {
 275                         [SCSMR]         = { 0x00, 16 },
 276                         [SCBRR]         = { 0x04,  8 },
 277                         [SCSCR]         = { 0x08, 16 },
 278                         [SCxTDR]        = { 0x0c,  8 },
 279                         [SCxSR]         = { 0x10, 16 },
 280                         [SCxRDR]        = { 0x14,  8 },
 281                         [SCFCR]         = { 0x18, 16 },
 282                         [SCFDR]         = { 0x1c, 16 },
 283                         [SCSPTR]        = { 0x20, 16 },
 284                         [SCLSR]         = { 0x24, 16 },
 285                 },
 286                 .fifosize = 16,
 287                 .overrun_reg = SCLSR,
 288                 .overrun_mask = SCLSR_ORER,
 289                 .sampling_rate_mask = SCI_SR(32),
 290                 .error_mask = SCIF_DEFAULT_ERROR_MASK,
 291                 .error_clear = SCIF_ERROR_CLEAR,
 292         },
 293 
 294         /*
 295          * The "SCIFA" that is in RZ/T and RZ/A2.
 296          * It looks like a normal SCIF with FIFO data, but with a
 297          * compressed address space. Also, the break out of interrupts
 298          * are different: ERI/BRI, RXI, TXI, TEI, DRI.
 299          */
 300         [SCIx_RZ_SCIFA_REGTYPE] = {
 301                 .regs = {
 302                         [SCSMR]         = { 0x00, 16 },
 303                         [SCBRR]         = { 0x02,  8 },
 304                         [SCSCR]         = { 0x04, 16 },
 305                         [SCxTDR]        = { 0x06,  8 },
 306                         [SCxSR]         = { 0x08, 16 },
 307                         [SCxRDR]        = { 0x0A,  8 },
 308                         [SCFCR]         = { 0x0C, 16 },
 309                         [SCFDR]         = { 0x0E, 16 },
 310                         [SCSPTR]        = { 0x10, 16 },
 311                         [SCLSR]         = { 0x12, 16 },
 312                 },
 313                 .fifosize = 16,
 314                 .overrun_reg = SCLSR,
 315                 .overrun_mask = SCLSR_ORER,
 316                 .sampling_rate_mask = SCI_SR(32),
 317                 .error_mask = SCIF_DEFAULT_ERROR_MASK,
 318                 .error_clear = SCIF_ERROR_CLEAR,
 319         },
 320 
 321         /*
 322          * Common SH-3 SCIF definitions.
 323          */
 324         [SCIx_SH3_SCIF_REGTYPE] = {
 325                 .regs = {
 326                         [SCSMR]         = { 0x00,  8 },
 327                         [SCBRR]         = { 0x02,  8 },
 328                         [SCSCR]         = { 0x04,  8 },
 329                         [SCxTDR]        = { 0x06,  8 },
 330                         [SCxSR]         = { 0x08, 16 },
 331                         [SCxRDR]        = { 0x0a,  8 },
 332                         [SCFCR]         = { 0x0c,  8 },
 333                         [SCFDR]         = { 0x0e, 16 },
 334                 },
 335                 .fifosize = 16,
 336                 .overrun_reg = SCLSR,
 337                 .overrun_mask = SCLSR_ORER,
 338                 .sampling_rate_mask = SCI_SR(32),
 339                 .error_mask = SCIF_DEFAULT_ERROR_MASK,
 340                 .error_clear = SCIF_ERROR_CLEAR,
 341         },
 342 
 343         /*
 344          * Common SH-4(A) SCIF(B) definitions.
 345          */
 346         [SCIx_SH4_SCIF_REGTYPE] = {
 347                 .regs = {
 348                         [SCSMR]         = { 0x00, 16 },
 349                         [SCBRR]         = { 0x04,  8 },
 350                         [SCSCR]         = { 0x08, 16 },
 351                         [SCxTDR]        = { 0x0c,  8 },
 352                         [SCxSR]         = { 0x10, 16 },
 353                         [SCxRDR]        = { 0x14,  8 },
 354                         [SCFCR]         = { 0x18, 16 },
 355                         [SCFDR]         = { 0x1c, 16 },
 356                         [SCSPTR]        = { 0x20, 16 },
 357                         [SCLSR]         = { 0x24, 16 },
 358                 },
 359                 .fifosize = 16,
 360                 .overrun_reg = SCLSR,
 361                 .overrun_mask = SCLSR_ORER,
 362                 .sampling_rate_mask = SCI_SR(32),
 363                 .error_mask = SCIF_DEFAULT_ERROR_MASK,
 364                 .error_clear = SCIF_ERROR_CLEAR,
 365         },
 366 
 367         /*
 368          * Common SCIF definitions for ports with a Baud Rate Generator for
 369          * External Clock (BRG).
 370          */
 371         [SCIx_SH4_SCIF_BRG_REGTYPE] = {
 372                 .regs = {
 373                         [SCSMR]         = { 0x00, 16 },
 374                         [SCBRR]         = { 0x04,  8 },
 375                         [SCSCR]         = { 0x08, 16 },
 376                         [SCxTDR]        = { 0x0c,  8 },
 377                         [SCxSR]         = { 0x10, 16 },
 378                         [SCxRDR]        = { 0x14,  8 },
 379                         [SCFCR]         = { 0x18, 16 },
 380                         [SCFDR]         = { 0x1c, 16 },
 381                         [SCSPTR]        = { 0x20, 16 },
 382                         [SCLSR]         = { 0x24, 16 },
 383                         [SCDL]          = { 0x30, 16 },
 384                         [SCCKS]         = { 0x34, 16 },
 385                 },
 386                 .fifosize = 16,
 387                 .overrun_reg = SCLSR,
 388                 .overrun_mask = SCLSR_ORER,
 389                 .sampling_rate_mask = SCI_SR(32),
 390                 .error_mask = SCIF_DEFAULT_ERROR_MASK,
 391                 .error_clear = SCIF_ERROR_CLEAR,
 392         },
 393 
 394         /*
 395          * Common HSCIF definitions.
 396          */
 397         [SCIx_HSCIF_REGTYPE] = {
 398                 .regs = {
 399                         [SCSMR]         = { 0x00, 16 },
 400                         [SCBRR]         = { 0x04,  8 },
 401                         [SCSCR]         = { 0x08, 16 },
 402                         [SCxTDR]        = { 0x0c,  8 },
 403                         [SCxSR]         = { 0x10, 16 },
 404                         [SCxRDR]        = { 0x14,  8 },
 405                         [SCFCR]         = { 0x18, 16 },
 406                         [SCFDR]         = { 0x1c, 16 },
 407                         [SCSPTR]        = { 0x20, 16 },
 408                         [SCLSR]         = { 0x24, 16 },
 409                         [HSSRR]         = { 0x40, 16 },
 410                         [SCDL]          = { 0x30, 16 },
 411                         [SCCKS]         = { 0x34, 16 },
 412                         [HSRTRGR]       = { 0x54, 16 },
 413                         [HSTTRGR]       = { 0x58, 16 },
 414                 },
 415                 .fifosize = 128,
 416                 .overrun_reg = SCLSR,
 417                 .overrun_mask = SCLSR_ORER,
 418                 .sampling_rate_mask = SCI_SR_RANGE(8, 32),
 419                 .error_mask = SCIF_DEFAULT_ERROR_MASK,
 420                 .error_clear = SCIF_ERROR_CLEAR,
 421         },
 422 
 423         /*
 424          * Common SH-4(A) SCIF(B) definitions for ports without an SCSPTR
 425          * register.
 426          */
 427         [SCIx_SH4_SCIF_NO_SCSPTR_REGTYPE] = {
 428                 .regs = {
 429                         [SCSMR]         = { 0x00, 16 },
 430                         [SCBRR]         = { 0x04,  8 },
 431                         [SCSCR]         = { 0x08, 16 },
 432                         [SCxTDR]        = { 0x0c,  8 },
 433                         [SCxSR]         = { 0x10, 16 },
 434                         [SCxRDR]        = { 0x14,  8 },
 435                         [SCFCR]         = { 0x18, 16 },
 436                         [SCFDR]         = { 0x1c, 16 },
 437                         [SCLSR]         = { 0x24, 16 },
 438                 },
 439                 .fifosize = 16,
 440                 .overrun_reg = SCLSR,
 441                 .overrun_mask = SCLSR_ORER,
 442                 .sampling_rate_mask = SCI_SR(32),
 443                 .error_mask = SCIF_DEFAULT_ERROR_MASK,
 444                 .error_clear = SCIF_ERROR_CLEAR,
 445         },
 446 
 447         /*
 448          * Common SH-4(A) SCIF(B) definitions for ports with FIFO data
 449          * count registers.
 450          */
 451         [SCIx_SH4_SCIF_FIFODATA_REGTYPE] = {
 452                 .regs = {
 453                         [SCSMR]         = { 0x00, 16 },
 454                         [SCBRR]         = { 0x04,  8 },
 455                         [SCSCR]         = { 0x08, 16 },
 456                         [SCxTDR]        = { 0x0c,  8 },
 457                         [SCxSR]         = { 0x10, 16 },
 458                         [SCxRDR]        = { 0x14,  8 },
 459                         [SCFCR]         = { 0x18, 16 },
 460                         [SCFDR]         = { 0x1c, 16 },
 461                         [SCTFDR]        = { 0x1c, 16 }, /* aliased to SCFDR */
 462                         [SCRFDR]        = { 0x20, 16 },
 463                         [SCSPTR]        = { 0x24, 16 },
 464                         [SCLSR]         = { 0x28, 16 },
 465                 },
 466                 .fifosize = 16,
 467                 .overrun_reg = SCLSR,
 468                 .overrun_mask = SCLSR_ORER,
 469                 .sampling_rate_mask = SCI_SR(32),
 470                 .error_mask = SCIF_DEFAULT_ERROR_MASK,
 471                 .error_clear = SCIF_ERROR_CLEAR,
 472         },
 473 
 474         /*
 475          * SH7705-style SCIF(B) ports, lacking both SCSPTR and SCLSR
 476          * registers.
 477          */
 478         [SCIx_SH7705_SCIF_REGTYPE] = {
 479                 .regs = {
 480                         [SCSMR]         = { 0x00, 16 },
 481                         [SCBRR]         = { 0x04,  8 },
 482                         [SCSCR]         = { 0x08, 16 },
 483                         [SCxTDR]        = { 0x20,  8 },
 484                         [SCxSR]         = { 0x14, 16 },
 485                         [SCxRDR]        = { 0x24,  8 },
 486                         [SCFCR]         = { 0x18, 16 },
 487                         [SCFDR]         = { 0x1c, 16 },
 488                 },
 489                 .fifosize = 64,
 490                 .overrun_reg = SCxSR,
 491                 .overrun_mask = SCIFA_ORER,
 492                 .sampling_rate_mask = SCI_SR(16),
 493                 .error_mask = SCIF_DEFAULT_ERROR_MASK | SCIFA_ORER,
 494                 .error_clear = SCIF_ERROR_CLEAR & ~SCIFA_ORER,
 495         },
 496 };
 497 
 498 #define sci_getreg(up, offset)          (&to_sci_port(up)->params->regs[offset])
 499 
 500 /*
 501  * The "offset" here is rather misleading, in that it refers to an enum
 502  * value relative to the port mapping rather than the fixed offset
 503  * itself, which needs to be manually retrieved from the platform's
 504  * register map for the given port.
 505  */
 506 static unsigned int sci_serial_in(struct uart_port *p, int offset)
 507 {
 508         const struct plat_sci_reg *reg = sci_getreg(p, offset);
 509 
 510         if (reg->size == 8)
 511                 return ioread8(p->membase + (reg->offset << p->regshift));
 512         else if (reg->size == 16)
 513                 return ioread16(p->membase + (reg->offset << p->regshift));
 514         else
 515                 WARN(1, "Invalid register access\n");
 516 
 517         return 0;
 518 }
 519 
 520 static void sci_serial_out(struct uart_port *p, int offset, int value)
 521 {
 522         const struct plat_sci_reg *reg = sci_getreg(p, offset);
 523 
 524         if (reg->size == 8)
 525                 iowrite8(value, p->membase + (reg->offset << p->regshift));
 526         else if (reg->size == 16)
 527                 iowrite16(value, p->membase + (reg->offset << p->regshift));
 528         else
 529                 WARN(1, "Invalid register access\n");
 530 }
 531 
 532 static void sci_port_enable(struct sci_port *sci_port)
 533 {
 534         unsigned int i;
 535 
 536         if (!sci_port->port.dev)
 537                 return;
 538 
 539         pm_runtime_get_sync(sci_port->port.dev);
 540 
 541         for (i = 0; i < SCI_NUM_CLKS; i++) {
 542                 clk_prepare_enable(sci_port->clks[i]);
 543                 sci_port->clk_rates[i] = clk_get_rate(sci_port->clks[i]);
 544         }
 545         sci_port->port.uartclk = sci_port->clk_rates[SCI_FCK];
 546 }
 547 
 548 static void sci_port_disable(struct sci_port *sci_port)
 549 {
 550         unsigned int i;
 551 
 552         if (!sci_port->port.dev)
 553                 return;
 554 
 555         for (i = SCI_NUM_CLKS; i-- > 0; )
 556                 clk_disable_unprepare(sci_port->clks[i]);
 557 
 558         pm_runtime_put_sync(sci_port->port.dev);
 559 }
 560 
 561 static inline unsigned long port_rx_irq_mask(struct uart_port *port)
 562 {
 563         /*
 564          * Not all ports (such as SCIFA) will support REIE. Rather than
 565          * special-casing the port type, we check the port initialization
 566          * IRQ enable mask to see whether the IRQ is desired at all. If
 567          * it's unset, it's logically inferred that there's no point in
 568          * testing for it.
 569          */
 570         return SCSCR_RIE | (to_sci_port(port)->cfg->scscr & SCSCR_REIE);
 571 }
 572 
 573 static void sci_start_tx(struct uart_port *port)
 574 {
 575         struct sci_port *s = to_sci_port(port);
 576         unsigned short ctrl;
 577 
 578 #ifdef CONFIG_SERIAL_SH_SCI_DMA
 579         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 580                 u16 new, scr = serial_port_in(port, SCSCR);
 581                 if (s->chan_tx)
 582                         new = scr | SCSCR_TDRQE;
 583                 else
 584                         new = scr & ~SCSCR_TDRQE;
 585                 if (new != scr)
 586                         serial_port_out(port, SCSCR, new);
 587         }
 588 
 589         if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
 590             dma_submit_error(s->cookie_tx)) {
 591                 s->cookie_tx = 0;
 592                 schedule_work(&s->work_tx);
 593         }
 594 #endif
 595 
 596         if (!s->chan_tx || port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 597                 /* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
 598                 ctrl = serial_port_in(port, SCSCR);
 599                 serial_port_out(port, SCSCR, ctrl | SCSCR_TIE);
 600         }
 601 }
 602 
 603 static void sci_stop_tx(struct uart_port *port)
 604 {
 605         unsigned short ctrl;
 606 
 607         /* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
 608         ctrl = serial_port_in(port, SCSCR);
 609 
 610         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 611                 ctrl &= ~SCSCR_TDRQE;
 612 
 613         ctrl &= ~SCSCR_TIE;
 614 
 615         serial_port_out(port, SCSCR, ctrl);
 616 }
 617 
 618 static void sci_start_rx(struct uart_port *port)
 619 {
 620         unsigned short ctrl;
 621 
 622         ctrl = serial_port_in(port, SCSCR) | port_rx_irq_mask(port);
 623 
 624         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 625                 ctrl &= ~SCSCR_RDRQE;
 626 
 627         serial_port_out(port, SCSCR, ctrl);
 628 }
 629 
 630 static void sci_stop_rx(struct uart_port *port)
 631 {
 632         unsigned short ctrl;
 633 
 634         ctrl = serial_port_in(port, SCSCR);
 635 
 636         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
 637                 ctrl &= ~SCSCR_RDRQE;
 638 
 639         ctrl &= ~port_rx_irq_mask(port);
 640 
 641         serial_port_out(port, SCSCR, ctrl);
 642 }
 643 
 644 static void sci_clear_SCxSR(struct uart_port *port, unsigned int mask)
 645 {
 646         if (port->type == PORT_SCI) {
 647                 /* Just store the mask */
 648                 serial_port_out(port, SCxSR, mask);
 649         } else if (to_sci_port(port)->params->overrun_mask == SCIFA_ORER) {
 650                 /* SCIFA/SCIFB and SCIF on SH7705/SH7720/SH7721 */
 651                 /* Only clear the status bits we want to clear */
 652                 serial_port_out(port, SCxSR,
 653                                 serial_port_in(port, SCxSR) & mask);
 654         } else {
 655                 /* Store the mask, clear parity/framing errors */
 656                 serial_port_out(port, SCxSR, mask & ~(SCIF_FERC | SCIF_PERC));
 657         }
 658 }
 659 
 660 #if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
 661     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
 662 
 663 #ifdef CONFIG_CONSOLE_POLL
 664 static int sci_poll_get_char(struct uart_port *port)
 665 {
 666         unsigned short status;
 667         int c;
 668 
 669         do {
 670                 status = serial_port_in(port, SCxSR);
 671                 if (status & SCxSR_ERRORS(port)) {
 672                         sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
 673                         continue;
 674                 }
 675                 break;
 676         } while (1);
 677 
 678         if (!(status & SCxSR_RDxF(port)))
 679                 return NO_POLL_CHAR;
 680 
 681         c = serial_port_in(port, SCxRDR);
 682 
 683         /* Dummy read */
 684         serial_port_in(port, SCxSR);
 685         sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 686 
 687         return c;
 688 }
 689 #endif
 690 
 691 static void sci_poll_put_char(struct uart_port *port, unsigned char c)
 692 {
 693         unsigned short status;
 694 
 695         do {
 696                 status = serial_port_in(port, SCxSR);
 697         } while (!(status & SCxSR_TDxE(port)));
 698 
 699         serial_port_out(port, SCxTDR, c);
 700         sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port));
 701 }
 702 #endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE ||
 703           CONFIG_SERIAL_SH_SCI_EARLYCON */
 704 
 705 static void sci_init_pins(struct uart_port *port, unsigned int cflag)
 706 {
 707         struct sci_port *s = to_sci_port(port);
 708 
 709         /*
 710          * Use port-specific handler if provided.
 711          */
 712         if (s->cfg->ops && s->cfg->ops->init_pins) {
 713                 s->cfg->ops->init_pins(port, cflag);
 714                 return;
 715         }
 716 
 717         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
 718                 u16 data = serial_port_in(port, SCPDR);
 719                 u16 ctrl = serial_port_in(port, SCPCR);
 720 
 721                 /* Enable RXD and TXD pin functions */
 722                 ctrl &= ~(SCPCR_RXDC | SCPCR_TXDC);
 723                 if (to_sci_port(port)->has_rtscts) {
 724                         /* RTS# is output, active low, unless autorts */
 725                         if (!(port->mctrl & TIOCM_RTS)) {
 726                                 ctrl |= SCPCR_RTSC;
 727                                 data |= SCPDR_RTSD;
 728                         } else if (!s->autorts) {
 729                                 ctrl |= SCPCR_RTSC;
 730                                 data &= ~SCPDR_RTSD;
 731                         } else {
 732                                 /* Enable RTS# pin function */
 733                                 ctrl &= ~SCPCR_RTSC;
 734                         }
 735                         /* Enable CTS# pin function */
 736                         ctrl &= ~SCPCR_CTSC;
 737                 }
 738                 serial_port_out(port, SCPDR, data);
 739                 serial_port_out(port, SCPCR, ctrl);
 740         } else if (sci_getreg(port, SCSPTR)->size) {
 741                 u16 status = serial_port_in(port, SCSPTR);
 742 
 743                 /* RTS# is always output; and active low, unless autorts */
 744                 status |= SCSPTR_RTSIO;
 745                 if (!(port->mctrl & TIOCM_RTS))
 746                         status |= SCSPTR_RTSDT;
 747                 else if (!s->autorts)
 748                         status &= ~SCSPTR_RTSDT;
 749                 /* CTS# and SCK are inputs */
 750                 status &= ~(SCSPTR_CTSIO | SCSPTR_SCKIO);
 751                 serial_port_out(port, SCSPTR, status);
 752         }
 753 }
 754 
 755 static int sci_txfill(struct uart_port *port)
 756 {
 757         struct sci_port *s = to_sci_port(port);
 758         unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
 759         const struct plat_sci_reg *reg;
 760 
 761         reg = sci_getreg(port, SCTFDR);
 762         if (reg->size)
 763                 return serial_port_in(port, SCTFDR) & fifo_mask;
 764 
 765         reg = sci_getreg(port, SCFDR);
 766         if (reg->size)
 767                 return serial_port_in(port, SCFDR) >> 8;
 768 
 769         return !(serial_port_in(port, SCxSR) & SCI_TDRE);
 770 }
 771 
 772 static int sci_txroom(struct uart_port *port)
 773 {
 774         return port->fifosize - sci_txfill(port);
 775 }
 776 
 777 static int sci_rxfill(struct uart_port *port)
 778 {
 779         struct sci_port *s = to_sci_port(port);
 780         unsigned int fifo_mask = (s->params->fifosize << 1) - 1;
 781         const struct plat_sci_reg *reg;
 782 
 783         reg = sci_getreg(port, SCRFDR);
 784         if (reg->size)
 785                 return serial_port_in(port, SCRFDR) & fifo_mask;
 786 
 787         reg = sci_getreg(port, SCFDR);
 788         if (reg->size)
 789                 return serial_port_in(port, SCFDR) & fifo_mask;
 790 
 791         return (serial_port_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;
 792 }
 793 
 794 /* ********************************************************************** *
 795  *                   the interrupt related routines                       *
 796  * ********************************************************************** */
 797 
 798 static void sci_transmit_chars(struct uart_port *port)
 799 {
 800         struct circ_buf *xmit = &port->state->xmit;
 801         unsigned int stopped = uart_tx_stopped(port);
 802         unsigned short status;
 803         unsigned short ctrl;
 804         int count;
 805 
 806         status = serial_port_in(port, SCxSR);
 807         if (!(status & SCxSR_TDxE(port))) {
 808                 ctrl = serial_port_in(port, SCSCR);
 809                 if (uart_circ_empty(xmit))
 810                         ctrl &= ~SCSCR_TIE;
 811                 else
 812                         ctrl |= SCSCR_TIE;
 813                 serial_port_out(port, SCSCR, ctrl);
 814                 return;
 815         }
 816 
 817         count = sci_txroom(port);
 818 
 819         do {
 820                 unsigned char c;
 821 
 822                 if (port->x_char) {
 823                         c = port->x_char;
 824                         port->x_char = 0;
 825                 } else if (!uart_circ_empty(xmit) && !stopped) {
 826                         c = xmit->buf[xmit->tail];
 827                         xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 828                 } else {
 829                         break;
 830                 }
 831 
 832                 serial_port_out(port, SCxTDR, c);
 833 
 834                 port->icount.tx++;
 835         } while (--count > 0);
 836 
 837         sci_clear_SCxSR(port, SCxSR_TDxE_CLEAR(port));
 838 
 839         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 840                 uart_write_wakeup(port);
 841         if (uart_circ_empty(xmit))
 842                 sci_stop_tx(port);
 843 
 844 }
 845 
 846 /* On SH3, SCIF may read end-of-break as a space->mark char */
 847 #define STEPFN(c)  ({int __c = (c); (((__c-1)|(__c)) == -1); })
 848 
 849 static void sci_receive_chars(struct uart_port *port)
 850 {
 851         struct tty_port *tport = &port->state->port;
 852         int i, count, copied = 0;
 853         unsigned short status;
 854         unsigned char flag;
 855 
 856         status = serial_port_in(port, SCxSR);
 857         if (!(status & SCxSR_RDxF(port)))
 858                 return;
 859 
 860         while (1) {
 861                 /* Don't copy more bytes than there is room for in the buffer */
 862                 count = tty_buffer_request_room(tport, sci_rxfill(port));
 863 
 864                 /* If for any reason we can't copy more data, we're done! */
 865                 if (count == 0)
 866                         break;
 867 
 868                 if (port->type == PORT_SCI) {
 869                         char c = serial_port_in(port, SCxRDR);
 870                         if (uart_handle_sysrq_char(port, c))
 871                                 count = 0;
 872                         else
 873                                 tty_insert_flip_char(tport, c, TTY_NORMAL);
 874                 } else {
 875                         for (i = 0; i < count; i++) {
 876                                 char c;
 877 
 878                                 if (port->type == PORT_SCIF ||
 879                                     port->type == PORT_HSCIF) {
 880                                         status = serial_port_in(port, SCxSR);
 881                                         c = serial_port_in(port, SCxRDR);
 882                                 } else {
 883                                         c = serial_port_in(port, SCxRDR);
 884                                         status = serial_port_in(port, SCxSR);
 885                                 }
 886                                 if (uart_handle_sysrq_char(port, c)) {
 887                                         count--; i--;
 888                                         continue;
 889                                 }
 890 
 891                                 /* Store data and status */
 892                                 if (status & SCxSR_FER(port)) {
 893                                         flag = TTY_FRAME;
 894                                         port->icount.frame++;
 895                                         dev_notice(port->dev, "frame error\n");
 896                                 } else if (status & SCxSR_PER(port)) {
 897                                         flag = TTY_PARITY;
 898                                         port->icount.parity++;
 899                                         dev_notice(port->dev, "parity error\n");
 900                                 } else
 901                                         flag = TTY_NORMAL;
 902 
 903                                 tty_insert_flip_char(tport, c, flag);
 904                         }
 905                 }
 906 
 907                 serial_port_in(port, SCxSR); /* dummy read */
 908                 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 909 
 910                 copied += count;
 911                 port->icount.rx += count;
 912         }
 913 
 914         if (copied) {
 915                 /* Tell the rest of the system the news. New characters! */
 916                 tty_flip_buffer_push(tport);
 917         } else {
 918                 /* TTY buffers full; read from RX reg to prevent lockup */
 919                 serial_port_in(port, SCxRDR);
 920                 serial_port_in(port, SCxSR); /* dummy read */
 921                 sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
 922         }
 923 }
 924 
 925 static int sci_handle_errors(struct uart_port *port)
 926 {
 927         int copied = 0;
 928         unsigned short status = serial_port_in(port, SCxSR);
 929         struct tty_port *tport = &port->state->port;
 930         struct sci_port *s = to_sci_port(port);
 931 
 932         /* Handle overruns */
 933         if (status & s->params->overrun_mask) {
 934                 port->icount.overrun++;
 935 
 936                 /* overrun error */
 937                 if (tty_insert_flip_char(tport, 0, TTY_OVERRUN))
 938                         copied++;
 939 
 940                 dev_notice(port->dev, "overrun error\n");
 941         }
 942 
 943         if (status & SCxSR_FER(port)) {
 944                 /* frame error */
 945                 port->icount.frame++;
 946 
 947                 if (tty_insert_flip_char(tport, 0, TTY_FRAME))
 948                         copied++;
 949 
 950                 dev_notice(port->dev, "frame error\n");
 951         }
 952 
 953         if (status & SCxSR_PER(port)) {
 954                 /* parity error */
 955                 port->icount.parity++;
 956 
 957                 if (tty_insert_flip_char(tport, 0, TTY_PARITY))
 958                         copied++;
 959 
 960                 dev_notice(port->dev, "parity error\n");
 961         }
 962 
 963         if (copied)
 964                 tty_flip_buffer_push(tport);
 965 
 966         return copied;
 967 }
 968 
 969 static int sci_handle_fifo_overrun(struct uart_port *port)
 970 {
 971         struct tty_port *tport = &port->state->port;
 972         struct sci_port *s = to_sci_port(port);
 973         const struct plat_sci_reg *reg;
 974         int copied = 0;
 975         u16 status;
 976 
 977         reg = sci_getreg(port, s->params->overrun_reg);
 978         if (!reg->size)
 979                 return 0;
 980 
 981         status = serial_port_in(port, s->params->overrun_reg);
 982         if (status & s->params->overrun_mask) {
 983                 status &= ~s->params->overrun_mask;
 984                 serial_port_out(port, s->params->overrun_reg, status);
 985 
 986                 port->icount.overrun++;
 987 
 988                 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 989                 tty_flip_buffer_push(tport);
 990 
 991                 dev_dbg(port->dev, "overrun error\n");
 992                 copied++;
 993         }
 994 
 995         return copied;
 996 }
 997 
 998 static int sci_handle_breaks(struct uart_port *port)
 999 {
1000         int copied = 0;
1001         unsigned short status = serial_port_in(port, SCxSR);
1002         struct tty_port *tport = &port->state->port;
1003 
1004         if (uart_handle_break(port))
1005                 return 0;
1006 
1007         if (status & SCxSR_BRK(port)) {
1008                 port->icount.brk++;
1009 
1010                 /* Notify of BREAK */
1011                 if (tty_insert_flip_char(tport, 0, TTY_BREAK))
1012                         copied++;
1013 
1014                 dev_dbg(port->dev, "BREAK detected\n");
1015         }
1016 
1017         if (copied)
1018                 tty_flip_buffer_push(tport);
1019 
1020         copied += sci_handle_fifo_overrun(port);
1021 
1022         return copied;
1023 }
1024 
1025 static int scif_set_rtrg(struct uart_port *port, int rx_trig)
1026 {
1027         unsigned int bits;
1028 
1029         if (rx_trig < 1)
1030                 rx_trig = 1;
1031         if (rx_trig >= port->fifosize)
1032                 rx_trig = port->fifosize;
1033 
1034         /* HSCIF can be set to an arbitrary level. */
1035         if (sci_getreg(port, HSRTRGR)->size) {
1036                 serial_port_out(port, HSRTRGR, rx_trig);
1037                 return rx_trig;
1038         }
1039 
1040         switch (port->type) {
1041         case PORT_SCIF:
1042                 if (rx_trig < 4) {
1043                         bits = 0;
1044                         rx_trig = 1;
1045                 } else if (rx_trig < 8) {
1046                         bits = SCFCR_RTRG0;
1047                         rx_trig = 4;
1048                 } else if (rx_trig < 14) {
1049                         bits = SCFCR_RTRG1;
1050                         rx_trig = 8;
1051                 } else {
1052                         bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1053                         rx_trig = 14;
1054                 }
1055                 break;
1056         case PORT_SCIFA:
1057         case PORT_SCIFB:
1058                 if (rx_trig < 16) {
1059                         bits = 0;
1060                         rx_trig = 1;
1061                 } else if (rx_trig < 32) {
1062                         bits = SCFCR_RTRG0;
1063                         rx_trig = 16;
1064                 } else if (rx_trig < 48) {
1065                         bits = SCFCR_RTRG1;
1066                         rx_trig = 32;
1067                 } else {
1068                         bits = SCFCR_RTRG0 | SCFCR_RTRG1;
1069                         rx_trig = 48;
1070                 }
1071                 break;
1072         default:
1073                 WARN(1, "unknown FIFO configuration");
1074                 return 1;
1075         }
1076 
1077         serial_port_out(port, SCFCR,
1078                 (serial_port_in(port, SCFCR) &
1079                 ~(SCFCR_RTRG1 | SCFCR_RTRG0)) | bits);
1080 
1081         return rx_trig;
1082 }
1083 
1084 static int scif_rtrg_enabled(struct uart_port *port)
1085 {
1086         if (sci_getreg(port, HSRTRGR)->size)
1087                 return serial_port_in(port, HSRTRGR) != 0;
1088         else
1089                 return (serial_port_in(port, SCFCR) &
1090                         (SCFCR_RTRG0 | SCFCR_RTRG1)) != 0;
1091 }
1092 
1093 static void rx_fifo_timer_fn(struct timer_list *t)
1094 {
1095         struct sci_port *s = from_timer(s, t, rx_fifo_timer);
1096         struct uart_port *port = &s->port;
1097 
1098         dev_dbg(port->dev, "Rx timed out\n");
1099         scif_set_rtrg(port, 1);
1100 }
1101 
1102 static ssize_t rx_fifo_trigger_show(struct device *dev,
1103                                     struct device_attribute *attr, char *buf)
1104 {
1105         struct uart_port *port = dev_get_drvdata(dev);
1106         struct sci_port *sci = to_sci_port(port);
1107 
1108         return sprintf(buf, "%d\n", sci->rx_trigger);
1109 }
1110 
1111 static ssize_t rx_fifo_trigger_store(struct device *dev,
1112                                      struct device_attribute *attr,
1113                                      const char *buf, size_t count)
1114 {
1115         struct uart_port *port = dev_get_drvdata(dev);
1116         struct sci_port *sci = to_sci_port(port);
1117         int ret;
1118         long r;
1119 
1120         ret = kstrtol(buf, 0, &r);
1121         if (ret)
1122                 return ret;
1123 
1124         sci->rx_trigger = scif_set_rtrg(port, r);
1125         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1126                 scif_set_rtrg(port, 1);
1127 
1128         return count;
1129 }
1130 
1131 static DEVICE_ATTR_RW(rx_fifo_trigger);
1132 
1133 static ssize_t rx_fifo_timeout_show(struct device *dev,
1134                                struct device_attribute *attr,
1135                                char *buf)
1136 {
1137         struct uart_port *port = dev_get_drvdata(dev);
1138         struct sci_port *sci = to_sci_port(port);
1139         int v;
1140 
1141         if (port->type == PORT_HSCIF)
1142                 v = sci->hscif_tot >> HSSCR_TOT_SHIFT;
1143         else
1144                 v = sci->rx_fifo_timeout;
1145 
1146         return sprintf(buf, "%d\n", v);
1147 }
1148 
1149 static ssize_t rx_fifo_timeout_store(struct device *dev,
1150                                 struct device_attribute *attr,
1151                                 const char *buf,
1152                                 size_t count)
1153 {
1154         struct uart_port *port = dev_get_drvdata(dev);
1155         struct sci_port *sci = to_sci_port(port);
1156         int ret;
1157         long r;
1158 
1159         ret = kstrtol(buf, 0, &r);
1160         if (ret)
1161                 return ret;
1162 
1163         if (port->type == PORT_HSCIF) {
1164                 if (r < 0 || r > 3)
1165                         return -EINVAL;
1166                 sci->hscif_tot = r << HSSCR_TOT_SHIFT;
1167         } else {
1168                 sci->rx_fifo_timeout = r;
1169                 scif_set_rtrg(port, 1);
1170                 if (r > 0)
1171                         timer_setup(&sci->rx_fifo_timer, rx_fifo_timer_fn, 0);
1172         }
1173 
1174         return count;
1175 }
1176 
1177 static DEVICE_ATTR_RW(rx_fifo_timeout);
1178 
1179 
1180 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1181 static void sci_dma_tx_complete(void *arg)
1182 {
1183         struct sci_port *s = arg;
1184         struct uart_port *port = &s->port;
1185         struct circ_buf *xmit = &port->state->xmit;
1186         unsigned long flags;
1187 
1188         dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
1189 
1190         spin_lock_irqsave(&port->lock, flags);
1191 
1192         xmit->tail += s->tx_dma_len;
1193         xmit->tail &= UART_XMIT_SIZE - 1;
1194 
1195         port->icount.tx += s->tx_dma_len;
1196 
1197         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
1198                 uart_write_wakeup(port);
1199 
1200         if (!uart_circ_empty(xmit)) {
1201                 s->cookie_tx = 0;
1202                 schedule_work(&s->work_tx);
1203         } else {
1204                 s->cookie_tx = -EINVAL;
1205                 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1206                         u16 ctrl = serial_port_in(port, SCSCR);
1207                         serial_port_out(port, SCSCR, ctrl & ~SCSCR_TIE);
1208                 }
1209         }
1210 
1211         spin_unlock_irqrestore(&port->lock, flags);
1212 }
1213 
1214 /* Locking: called with port lock held */
1215 static int sci_dma_rx_push(struct sci_port *s, void *buf, size_t count)
1216 {
1217         struct uart_port *port = &s->port;
1218         struct tty_port *tport = &port->state->port;
1219         int copied;
1220 
1221         copied = tty_insert_flip_string(tport, buf, count);
1222         if (copied < count)
1223                 port->icount.buf_overrun++;
1224 
1225         port->icount.rx += copied;
1226 
1227         return copied;
1228 }
1229 
1230 static int sci_dma_rx_find_active(struct sci_port *s)
1231 {
1232         unsigned int i;
1233 
1234         for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1235                 if (s->active_rx == s->cookie_rx[i])
1236                         return i;
1237 
1238         return -1;
1239 }
1240 
1241 static void sci_dma_rx_chan_invalidate(struct sci_port *s)
1242 {
1243         unsigned int i;
1244 
1245         s->chan_rx = NULL;
1246         for (i = 0; i < ARRAY_SIZE(s->cookie_rx); i++)
1247                 s->cookie_rx[i] = -EINVAL;
1248         s->active_rx = 0;
1249 }
1250 
1251 static void sci_dma_rx_release(struct sci_port *s)
1252 {
1253         struct dma_chan *chan = s->chan_rx_saved;
1254 
1255         s->chan_rx_saved = NULL;
1256         sci_dma_rx_chan_invalidate(s);
1257         dmaengine_terminate_sync(chan);
1258         dma_free_coherent(chan->device->dev, s->buf_len_rx * 2, s->rx_buf[0],
1259                           sg_dma_address(&s->sg_rx[0]));
1260         dma_release_channel(chan);
1261 }
1262 
1263 static void start_hrtimer_us(struct hrtimer *hrt, unsigned long usec)
1264 {
1265         long sec = usec / 1000000;
1266         long nsec = (usec % 1000000) * 1000;
1267         ktime_t t = ktime_set(sec, nsec);
1268 
1269         hrtimer_start(hrt, t, HRTIMER_MODE_REL);
1270 }
1271 
1272 static void sci_dma_rx_reenable_irq(struct sci_port *s)
1273 {
1274         struct uart_port *port = &s->port;
1275         u16 scr;
1276 
1277         /* Direct new serial port interrupts back to CPU */
1278         scr = serial_port_in(port, SCSCR);
1279         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1280                 scr &= ~SCSCR_RDRQE;
1281                 enable_irq(s->irqs[SCIx_RXI_IRQ]);
1282         }
1283         serial_port_out(port, SCSCR, scr | SCSCR_RIE);
1284 }
1285 
1286 static void sci_dma_rx_complete(void *arg)
1287 {
1288         struct sci_port *s = arg;
1289         struct dma_chan *chan = s->chan_rx;
1290         struct uart_port *port = &s->port;
1291         struct dma_async_tx_descriptor *desc;
1292         unsigned long flags;
1293         int active, count = 0;
1294 
1295         dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line,
1296                 s->active_rx);
1297 
1298         spin_lock_irqsave(&port->lock, flags);
1299 
1300         active = sci_dma_rx_find_active(s);
1301         if (active >= 0)
1302                 count = sci_dma_rx_push(s, s->rx_buf[active], s->buf_len_rx);
1303 
1304         start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1305 
1306         if (count)
1307                 tty_flip_buffer_push(&port->state->port);
1308 
1309         desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[active], 1,
1310                                        DMA_DEV_TO_MEM,
1311                                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1312         if (!desc)
1313                 goto fail;
1314 
1315         desc->callback = sci_dma_rx_complete;
1316         desc->callback_param = s;
1317         s->cookie_rx[active] = dmaengine_submit(desc);
1318         if (dma_submit_error(s->cookie_rx[active]))
1319                 goto fail;
1320 
1321         s->active_rx = s->cookie_rx[!active];
1322 
1323         dma_async_issue_pending(chan);
1324 
1325         spin_unlock_irqrestore(&port->lock, flags);
1326         dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",
1327                 __func__, s->cookie_rx[active], active, s->active_rx);
1328         return;
1329 
1330 fail:
1331         spin_unlock_irqrestore(&port->lock, flags);
1332         dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");
1333         /* Switch to PIO */
1334         spin_lock_irqsave(&port->lock, flags);
1335         dmaengine_terminate_async(chan);
1336         sci_dma_rx_chan_invalidate(s);
1337         sci_dma_rx_reenable_irq(s);
1338         spin_unlock_irqrestore(&port->lock, flags);
1339 }
1340 
1341 static void sci_dma_tx_release(struct sci_port *s)
1342 {
1343         struct dma_chan *chan = s->chan_tx_saved;
1344 
1345         cancel_work_sync(&s->work_tx);
1346         s->chan_tx_saved = s->chan_tx = NULL;
1347         s->cookie_tx = -EINVAL;
1348         dmaengine_terminate_sync(chan);
1349         dma_unmap_single(chan->device->dev, s->tx_dma_addr, UART_XMIT_SIZE,
1350                          DMA_TO_DEVICE);
1351         dma_release_channel(chan);
1352 }
1353 
1354 static int sci_dma_rx_submit(struct sci_port *s, bool port_lock_held)
1355 {
1356         struct dma_chan *chan = s->chan_rx;
1357         struct uart_port *port = &s->port;
1358         unsigned long flags;
1359         int i;
1360 
1361         for (i = 0; i < 2; i++) {
1362                 struct scatterlist *sg = &s->sg_rx[i];
1363                 struct dma_async_tx_descriptor *desc;
1364 
1365                 desc = dmaengine_prep_slave_sg(chan,
1366                         sg, 1, DMA_DEV_TO_MEM,
1367                         DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1368                 if (!desc)
1369                         goto fail;
1370 
1371                 desc->callback = sci_dma_rx_complete;
1372                 desc->callback_param = s;
1373                 s->cookie_rx[i] = dmaengine_submit(desc);
1374                 if (dma_submit_error(s->cookie_rx[i]))
1375                         goto fail;
1376 
1377         }
1378 
1379         s->active_rx = s->cookie_rx[0];
1380 
1381         dma_async_issue_pending(chan);
1382         return 0;
1383 
1384 fail:
1385         /* Switch to PIO */
1386         if (!port_lock_held)
1387                 spin_lock_irqsave(&port->lock, flags);
1388         if (i)
1389                 dmaengine_terminate_async(chan);
1390         sci_dma_rx_chan_invalidate(s);
1391         sci_start_rx(port);
1392         if (!port_lock_held)
1393                 spin_unlock_irqrestore(&port->lock, flags);
1394         return -EAGAIN;
1395 }
1396 
1397 static void sci_dma_tx_work_fn(struct work_struct *work)
1398 {
1399         struct sci_port *s = container_of(work, struct sci_port, work_tx);
1400         struct dma_async_tx_descriptor *desc;
1401         struct dma_chan *chan = s->chan_tx;
1402         struct uart_port *port = &s->port;
1403         struct circ_buf *xmit = &port->state->xmit;
1404         unsigned long flags;
1405         dma_addr_t buf;
1406         int head, tail;
1407 
1408         /*
1409          * DMA is idle now.
1410          * Port xmit buffer is already mapped, and it is one page... Just adjust
1411          * offsets and lengths. Since it is a circular buffer, we have to
1412          * transmit till the end, and then the rest. Take the port lock to get a
1413          * consistent xmit buffer state.
1414          */
1415         spin_lock_irq(&port->lock);
1416         head = xmit->head;
1417         tail = xmit->tail;
1418         buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
1419         s->tx_dma_len = min_t(unsigned int,
1420                 CIRC_CNT(head, tail, UART_XMIT_SIZE),
1421                 CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
1422         if (!s->tx_dma_len) {
1423                 /* Transmit buffer has been flushed */
1424                 spin_unlock_irq(&port->lock);
1425                 return;
1426         }
1427 
1428         desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
1429                                            DMA_MEM_TO_DEV,
1430                                            DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1431         if (!desc) {
1432                 spin_unlock_irq(&port->lock);
1433                 dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
1434                 goto switch_to_pio;
1435         }
1436 
1437         dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
1438                                    DMA_TO_DEVICE);
1439 
1440         desc->callback = sci_dma_tx_complete;
1441         desc->callback_param = s;
1442         s->cookie_tx = dmaengine_submit(desc);
1443         if (dma_submit_error(s->cookie_tx)) {
1444                 spin_unlock_irq(&port->lock);
1445                 dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
1446                 goto switch_to_pio;
1447         }
1448 
1449         spin_unlock_irq(&port->lock);
1450         dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
1451                 __func__, xmit->buf, tail, head, s->cookie_tx);
1452 
1453         dma_async_issue_pending(chan);
1454         return;
1455 
1456 switch_to_pio:
1457         spin_lock_irqsave(&port->lock, flags);
1458         s->chan_tx = NULL;
1459         sci_start_tx(port);
1460         spin_unlock_irqrestore(&port->lock, flags);
1461         return;
1462 }
1463 
1464 static enum hrtimer_restart sci_dma_rx_timer_fn(struct hrtimer *t)
1465 {
1466         struct sci_port *s = container_of(t, struct sci_port, rx_timer);
1467         struct dma_chan *chan = s->chan_rx;
1468         struct uart_port *port = &s->port;
1469         struct dma_tx_state state;
1470         enum dma_status status;
1471         unsigned long flags;
1472         unsigned int read;
1473         int active, count;
1474 
1475         dev_dbg(port->dev, "DMA Rx timed out\n");
1476 
1477         spin_lock_irqsave(&port->lock, flags);
1478 
1479         active = sci_dma_rx_find_active(s);
1480         if (active < 0) {
1481                 spin_unlock_irqrestore(&port->lock, flags);
1482                 return HRTIMER_NORESTART;
1483         }
1484 
1485         status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1486         if (status == DMA_COMPLETE) {
1487                 spin_unlock_irqrestore(&port->lock, flags);
1488                 dev_dbg(port->dev, "Cookie %d #%d has already completed\n",
1489                         s->active_rx, active);
1490 
1491                 /* Let packet complete handler take care of the packet */
1492                 return HRTIMER_NORESTART;
1493         }
1494 
1495         dmaengine_pause(chan);
1496 
1497         /*
1498          * sometimes DMA transfer doesn't stop even if it is stopped and
1499          * data keeps on coming until transaction is complete so check
1500          * for DMA_COMPLETE again
1501          * Let packet complete handler take care of the packet
1502          */
1503         status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);
1504         if (status == DMA_COMPLETE) {
1505                 spin_unlock_irqrestore(&port->lock, flags);
1506                 dev_dbg(port->dev, "Transaction complete after DMA engine was stopped");
1507                 return HRTIMER_NORESTART;
1508         }
1509 
1510         /* Handle incomplete DMA receive */
1511         dmaengine_terminate_async(s->chan_rx);
1512         read = sg_dma_len(&s->sg_rx[active]) - state.residue;
1513 
1514         if (read) {
1515                 count = sci_dma_rx_push(s, s->rx_buf[active], read);
1516                 if (count)
1517                         tty_flip_buffer_push(&port->state->port);
1518         }
1519 
1520         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1521                 sci_dma_rx_submit(s, true);
1522 
1523         sci_dma_rx_reenable_irq(s);
1524 
1525         spin_unlock_irqrestore(&port->lock, flags);
1526 
1527         return HRTIMER_NORESTART;
1528 }
1529 
1530 static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
1531                                              enum dma_transfer_direction dir)
1532 {
1533         struct dma_chan *chan;
1534         struct dma_slave_config cfg;
1535         int ret;
1536 
1537         chan = dma_request_slave_channel(port->dev,
1538                                          dir == DMA_MEM_TO_DEV ? "tx" : "rx");
1539         if (!chan) {
1540                 dev_dbg(port->dev, "dma_request_slave_channel failed\n");
1541                 return NULL;
1542         }
1543 
1544         memset(&cfg, 0, sizeof(cfg));
1545         cfg.direction = dir;
1546         if (dir == DMA_MEM_TO_DEV) {
1547                 cfg.dst_addr = port->mapbase +
1548                         (sci_getreg(port, SCxTDR)->offset << port->regshift);
1549                 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1550         } else {
1551                 cfg.src_addr = port->mapbase +
1552                         (sci_getreg(port, SCxRDR)->offset << port->regshift);
1553                 cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1554         }
1555 
1556         ret = dmaengine_slave_config(chan, &cfg);
1557         if (ret) {
1558                 dev_warn(port->dev, "dmaengine_slave_config failed %d\n", ret);
1559                 dma_release_channel(chan);
1560                 return NULL;
1561         }
1562 
1563         return chan;
1564 }
1565 
1566 static void sci_request_dma(struct uart_port *port)
1567 {
1568         struct sci_port *s = to_sci_port(port);
1569         struct dma_chan *chan;
1570 
1571         dev_dbg(port->dev, "%s: port %d\n", __func__, port->line);
1572 
1573         /*
1574          * DMA on console may interfere with Kernel log messages which use
1575          * plain putchar(). So, simply don't use it with a console.
1576          */
1577         if (uart_console(port))
1578                 return;
1579 
1580         if (!port->dev->of_node)
1581                 return;
1582 
1583         s->cookie_tx = -EINVAL;
1584 
1585         /*
1586          * Don't request a dma channel if no channel was specified
1587          * in the device tree.
1588          */
1589         if (!of_find_property(port->dev->of_node, "dmas", NULL))
1590                 return;
1591 
1592         chan = sci_request_dma_chan(port, DMA_MEM_TO_DEV);
1593         dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);
1594         if (chan) {
1595                 /* UART circular tx buffer is an aligned page. */
1596                 s->tx_dma_addr = dma_map_single(chan->device->dev,
1597                                                 port->state->xmit.buf,
1598                                                 UART_XMIT_SIZE,
1599                                                 DMA_TO_DEVICE);
1600                 if (dma_mapping_error(chan->device->dev, s->tx_dma_addr)) {
1601                         dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
1602                         dma_release_channel(chan);
1603                 } else {
1604                         dev_dbg(port->dev, "%s: mapped %lu@%p to %pad\n",
1605                                 __func__, UART_XMIT_SIZE,
1606                                 port->state->xmit.buf, &s->tx_dma_addr);
1607 
1608                         INIT_WORK(&s->work_tx, sci_dma_tx_work_fn);
1609                         s->chan_tx_saved = s->chan_tx = chan;
1610                 }
1611         }
1612 
1613         chan = sci_request_dma_chan(port, DMA_DEV_TO_MEM);
1614         dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);
1615         if (chan) {
1616                 unsigned int i;
1617                 dma_addr_t dma;
1618                 void *buf;
1619 
1620                 s->buf_len_rx = 2 * max_t(size_t, 16, port->fifosize);
1621                 buf = dma_alloc_coherent(chan->device->dev, s->buf_len_rx * 2,
1622                                          &dma, GFP_KERNEL);
1623                 if (!buf) {
1624                         dev_warn(port->dev,
1625                                  "Failed to allocate Rx dma buffer, using PIO\n");
1626                         dma_release_channel(chan);
1627                         return;
1628                 }
1629 
1630                 for (i = 0; i < 2; i++) {
1631                         struct scatterlist *sg = &s->sg_rx[i];
1632 
1633                         sg_init_table(sg, 1);
1634                         s->rx_buf[i] = buf;
1635                         sg_dma_address(sg) = dma;
1636                         sg_dma_len(sg) = s->buf_len_rx;
1637 
1638                         buf += s->buf_len_rx;
1639                         dma += s->buf_len_rx;
1640                 }
1641 
1642                 hrtimer_init(&s->rx_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1643                 s->rx_timer.function = sci_dma_rx_timer_fn;
1644 
1645                 s->chan_rx_saved = s->chan_rx = chan;
1646 
1647                 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
1648                         sci_dma_rx_submit(s, false);
1649         }
1650 }
1651 
1652 static void sci_free_dma(struct uart_port *port)
1653 {
1654         struct sci_port *s = to_sci_port(port);
1655 
1656         if (s->chan_tx_saved)
1657                 sci_dma_tx_release(s);
1658         if (s->chan_rx_saved)
1659                 sci_dma_rx_release(s);
1660 }
1661 
1662 static void sci_flush_buffer(struct uart_port *port)
1663 {
1664         struct sci_port *s = to_sci_port(port);
1665 
1666         /*
1667          * In uart_flush_buffer(), the xmit circular buffer has just been
1668          * cleared, so we have to reset tx_dma_len accordingly, and stop any
1669          * pending transfers
1670          */
1671         s->tx_dma_len = 0;
1672         if (s->chan_tx) {
1673                 dmaengine_terminate_async(s->chan_tx);
1674                 s->cookie_tx = -EINVAL;
1675         }
1676 }
1677 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
1678 static inline void sci_request_dma(struct uart_port *port)
1679 {
1680 }
1681 
1682 static inline void sci_free_dma(struct uart_port *port)
1683 {
1684 }
1685 
1686 #define sci_flush_buffer        NULL
1687 #endif /* !CONFIG_SERIAL_SH_SCI_DMA */
1688 
1689 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
1690 {
1691         struct uart_port *port = ptr;
1692         struct sci_port *s = to_sci_port(port);
1693 
1694 #ifdef CONFIG_SERIAL_SH_SCI_DMA
1695         if (s->chan_rx) {
1696                 u16 scr = serial_port_in(port, SCSCR);
1697                 u16 ssr = serial_port_in(port, SCxSR);
1698 
1699                 /* Disable future Rx interrupts */
1700                 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
1701                         disable_irq_nosync(irq);
1702                         scr |= SCSCR_RDRQE;
1703                 } else {
1704                         if (sci_dma_rx_submit(s, false) < 0)
1705                                 goto handle_pio;
1706 
1707                         scr &= ~SCSCR_RIE;
1708                 }
1709                 serial_port_out(port, SCSCR, scr);
1710                 /* Clear current interrupt */
1711                 serial_port_out(port, SCxSR,
1712                                 ssr & ~(SCIF_DR | SCxSR_RDxF(port)));
1713                 dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u us\n",
1714                         jiffies, s->rx_timeout);
1715                 start_hrtimer_us(&s->rx_timer, s->rx_timeout);
1716 
1717                 return IRQ_HANDLED;
1718         }
1719 
1720 handle_pio:
1721 #endif
1722 
1723         if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {
1724                 if (!scif_rtrg_enabled(port))
1725                         scif_set_rtrg(port, s->rx_trigger);
1726 
1727                 mod_timer(&s->rx_fifo_timer, jiffies + DIV_ROUND_UP(
1728                           s->rx_frame * HZ * s->rx_fifo_timeout, 1000000));
1729         }
1730 
1731         /* I think sci_receive_chars has to be called irrespective
1732          * of whether the I_IXOFF is set, otherwise, how is the interrupt
1733          * to be disabled?
1734          */
1735         sci_receive_chars(port);
1736 
1737         return IRQ_HANDLED;
1738 }
1739 
1740 static irqreturn_t sci_tx_interrupt(int irq, void *ptr)
1741 {
1742         struct uart_port *port = ptr;
1743         unsigned long flags;
1744 
1745         spin_lock_irqsave(&port->lock, flags);
1746         sci_transmit_chars(port);
1747         spin_unlock_irqrestore(&port->lock, flags);
1748 
1749         return IRQ_HANDLED;
1750 }
1751 
1752 static irqreturn_t sci_br_interrupt(int irq, void *ptr)
1753 {
1754         struct uart_port *port = ptr;
1755 
1756         /* Handle BREAKs */
1757         sci_handle_breaks(port);
1758         sci_clear_SCxSR(port, SCxSR_BREAK_CLEAR(port));
1759 
1760         return IRQ_HANDLED;
1761 }
1762 
1763 static irqreturn_t sci_er_interrupt(int irq, void *ptr)
1764 {
1765         struct uart_port *port = ptr;
1766         struct sci_port *s = to_sci_port(port);
1767 
1768         if (s->irqs[SCIx_ERI_IRQ] == s->irqs[SCIx_BRI_IRQ]) {
1769                 /* Break and Error interrupts are muxed */
1770                 unsigned short ssr_status = serial_port_in(port, SCxSR);
1771 
1772                 /* Break Interrupt */
1773                 if (ssr_status & SCxSR_BRK(port))
1774                         sci_br_interrupt(irq, ptr);
1775 
1776                 /* Break only? */
1777                 if (!(ssr_status & SCxSR_ERRORS(port)))
1778                         return IRQ_HANDLED;
1779         }
1780 
1781         /* Handle errors */
1782         if (port->type == PORT_SCI) {
1783                 if (sci_handle_errors(port)) {
1784                         /* discard character in rx buffer */
1785                         serial_port_in(port, SCxSR);
1786                         sci_clear_SCxSR(port, SCxSR_RDxF_CLEAR(port));
1787                 }
1788         } else {
1789                 sci_handle_fifo_overrun(port);
1790                 if (!s->chan_rx)
1791                         sci_receive_chars(port);
1792         }
1793 
1794         sci_clear_SCxSR(port, SCxSR_ERROR_CLEAR(port));
1795 
1796         /* Kick the transmission */
1797         if (!s->chan_tx)
1798                 sci_tx_interrupt(irq, ptr);
1799 
1800         return IRQ_HANDLED;
1801 }
1802 
1803 static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr)
1804 {
1805         unsigned short ssr_status, scr_status, err_enabled, orer_status = 0;
1806         struct uart_port *port = ptr;
1807         struct sci_port *s = to_sci_port(port);
1808         irqreturn_t ret = IRQ_NONE;
1809 
1810         ssr_status = serial_port_in(port, SCxSR);
1811         scr_status = serial_port_in(port, SCSCR);
1812         if (s->params->overrun_reg == SCxSR)
1813                 orer_status = ssr_status;
1814         else if (sci_getreg(port, s->params->overrun_reg)->size)
1815                 orer_status = serial_port_in(port, s->params->overrun_reg);
1816 
1817         err_enabled = scr_status & port_rx_irq_mask(port);
1818 
1819         /* Tx Interrupt */
1820         if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) &&
1821             !s->chan_tx)
1822                 ret = sci_tx_interrupt(irq, ptr);
1823 
1824         /*
1825          * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /
1826          * DR flags
1827          */
1828         if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&
1829             (scr_status & SCSCR_RIE))
1830                 ret = sci_rx_interrupt(irq, ptr);
1831 
1832         /* Error Interrupt */
1833         if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
1834                 ret = sci_er_interrupt(irq, ptr);
1835 
1836         /* Break Interrupt */
1837         if ((ssr_status & SCxSR_BRK(port)) && err_enabled)
1838                 ret = sci_br_interrupt(irq, ptr);
1839 
1840         /* Overrun Interrupt */
1841         if (orer_status & s->params->overrun_mask) {
1842                 sci_handle_fifo_overrun(port);
1843                 ret = IRQ_HANDLED;
1844         }
1845 
1846         return ret;
1847 }
1848 
1849 static const struct sci_irq_desc {
1850         const char      *desc;
1851         irq_handler_t   handler;
1852 } sci_irq_desc[] = {
1853         /*
1854          * Split out handlers, the default case.
1855          */
1856         [SCIx_ERI_IRQ] = {
1857                 .desc = "rx err",
1858                 .handler = sci_er_interrupt,
1859         },
1860 
1861         [SCIx_RXI_IRQ] = {
1862                 .desc = "rx full",
1863                 .handler = sci_rx_interrupt,
1864         },
1865 
1866         [SCIx_TXI_IRQ] = {
1867                 .desc = "tx empty",
1868                 .handler = sci_tx_interrupt,
1869         },
1870 
1871         [SCIx_BRI_IRQ] = {
1872                 .desc = "break",
1873                 .handler = sci_br_interrupt,
1874         },
1875 
1876         [SCIx_DRI_IRQ] = {
1877                 .desc = "rx ready",
1878                 .handler = sci_rx_interrupt,
1879         },
1880 
1881         [SCIx_TEI_IRQ] = {
1882                 .desc = "tx end",
1883                 .handler = sci_tx_interrupt,
1884         },
1885 
1886         /*
1887          * Special muxed handler.
1888          */
1889         [SCIx_MUX_IRQ] = {
1890                 .desc = "mux",
1891                 .handler = sci_mpxed_interrupt,
1892         },
1893 };
1894 
1895 static int sci_request_irq(struct sci_port *port)
1896 {
1897         struct uart_port *up = &port->port;
1898         int i, j, w, ret = 0;
1899 
1900         for (i = j = 0; i < SCIx_NR_IRQS; i++, j++) {
1901                 const struct sci_irq_desc *desc;
1902                 int irq;
1903 
1904                 /* Check if already registered (muxed) */
1905                 for (w = 0; w < i; w++)
1906                         if (port->irqs[w] == port->irqs[i])
1907                                 w = i + 1;
1908                 if (w > i)
1909                         continue;
1910 
1911                 if (SCIx_IRQ_IS_MUXED(port)) {
1912                         i = SCIx_MUX_IRQ;
1913                         irq = up->irq;
1914                 } else {
1915                         irq = port->irqs[i];
1916 
1917                         /*
1918                          * Certain port types won't support all of the
1919                          * available interrupt sources.
1920                          */
1921                         if (unlikely(irq < 0))
1922                                 continue;
1923                 }
1924 
1925                 desc = sci_irq_desc + i;
1926                 port->irqstr[j] = kasprintf(GFP_KERNEL, "%s:%s",
1927                                             dev_name(up->dev), desc->desc);
1928                 if (!port->irqstr[j]) {
1929                         ret = -ENOMEM;
1930                         goto out_nomem;
1931                 }
1932 
1933                 ret = request_irq(irq, desc->handler, up->irqflags,
1934                                   port->irqstr[j], port);
1935                 if (unlikely(ret)) {
1936                         dev_err(up->dev, "Can't allocate %s IRQ\n", desc->desc);
1937                         goto out_noirq;
1938                 }
1939         }
1940 
1941         return 0;
1942 
1943 out_noirq:
1944         while (--i >= 0)
1945                 free_irq(port->irqs[i], port);
1946 
1947 out_nomem:
1948         while (--j >= 0)
1949                 kfree(port->irqstr[j]);
1950 
1951         return ret;
1952 }
1953 
1954 static void sci_free_irq(struct sci_port *port)
1955 {
1956         int i, j;
1957 
1958         /*
1959          * Intentionally in reverse order so we iterate over the muxed
1960          * IRQ first.
1961          */
1962         for (i = 0; i < SCIx_NR_IRQS; i++) {
1963                 int irq = port->irqs[i];
1964 
1965                 /*
1966                  * Certain port types won't support all of the available
1967                  * interrupt sources.
1968                  */
1969                 if (unlikely(irq < 0))
1970                         continue;
1971 
1972                 /* Check if already freed (irq was muxed) */
1973                 for (j = 0; j < i; j++)
1974                         if (port->irqs[j] == irq)
1975                                 j = i + 1;
1976                 if (j > i)
1977                         continue;
1978 
1979                 free_irq(port->irqs[i], port);
1980                 kfree(port->irqstr[i]);
1981 
1982                 if (SCIx_IRQ_IS_MUXED(port)) {
1983                         /* If there's only one IRQ, we're done. */
1984                         return;
1985                 }
1986         }
1987 }
1988 
1989 static unsigned int sci_tx_empty(struct uart_port *port)
1990 {
1991         unsigned short status = serial_port_in(port, SCxSR);
1992         unsigned short in_tx_fifo = sci_txfill(port);
1993 
1994         return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;
1995 }
1996 
1997 static void sci_set_rts(struct uart_port *port, bool state)
1998 {
1999         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2000                 u16 data = serial_port_in(port, SCPDR);
2001 
2002                 /* Active low */
2003                 if (state)
2004                         data &= ~SCPDR_RTSD;
2005                 else
2006                         data |= SCPDR_RTSD;
2007                 serial_port_out(port, SCPDR, data);
2008 
2009                 /* RTS# is output */
2010                 serial_port_out(port, SCPCR,
2011                                 serial_port_in(port, SCPCR) | SCPCR_RTSC);
2012         } else if (sci_getreg(port, SCSPTR)->size) {
2013                 u16 ctrl = serial_port_in(port, SCSPTR);
2014 
2015                 /* Active low */
2016                 if (state)
2017                         ctrl &= ~SCSPTR_RTSDT;
2018                 else
2019                         ctrl |= SCSPTR_RTSDT;
2020                 serial_port_out(port, SCSPTR, ctrl);
2021         }
2022 }
2023 
2024 static bool sci_get_cts(struct uart_port *port)
2025 {
2026         if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2027                 /* Active low */
2028                 return !(serial_port_in(port, SCPDR) & SCPDR_CTSD);
2029         } else if (sci_getreg(port, SCSPTR)->size) {
2030                 /* Active low */
2031                 return !(serial_port_in(port, SCSPTR) & SCSPTR_CTSDT);
2032         }
2033 
2034         return true;
2035 }
2036 
2037 /*
2038  * Modem control is a bit of a mixed bag for SCI(F) ports. Generally
2039  * CTS/RTS is supported in hardware by at least one port and controlled
2040  * via SCSPTR (SCxPCR for SCIFA/B parts), or external pins (presently
2041  * handled via the ->init_pins() op, which is a bit of a one-way street,
2042  * lacking any ability to defer pin control -- this will later be
2043  * converted over to the GPIO framework).
2044  *
2045  * Other modes (such as loopback) are supported generically on certain
2046  * port types, but not others. For these it's sufficient to test for the
2047  * existence of the support register and simply ignore the port type.
2048  */
2049 static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
2050 {
2051         struct sci_port *s = to_sci_port(port);
2052 
2053         if (mctrl & TIOCM_LOOP) {
2054                 const struct plat_sci_reg *reg;
2055 
2056                 /*
2057                  * Standard loopback mode for SCFCR ports.
2058                  */
2059                 reg = sci_getreg(port, SCFCR);
2060                 if (reg->size)
2061                         serial_port_out(port, SCFCR,
2062                                         serial_port_in(port, SCFCR) |
2063                                         SCFCR_LOOP);
2064         }
2065 
2066         mctrl_gpio_set(s->gpios, mctrl);
2067 
2068         if (!s->has_rtscts)
2069                 return;
2070 
2071         if (!(mctrl & TIOCM_RTS)) {
2072                 /* Disable Auto RTS */
2073                 serial_port_out(port, SCFCR,
2074                                 serial_port_in(port, SCFCR) & ~SCFCR_MCE);
2075 
2076                 /* Clear RTS */
2077                 sci_set_rts(port, 0);
2078         } else if (s->autorts) {
2079                 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) {
2080                         /* Enable RTS# pin function */
2081                         serial_port_out(port, SCPCR,
2082                                 serial_port_in(port, SCPCR) & ~SCPCR_RTSC);
2083                 }
2084 
2085                 /* Enable Auto RTS */
2086                 serial_port_out(port, SCFCR,
2087                                 serial_port_in(port, SCFCR) | SCFCR_MCE);
2088         } else {
2089                 /* Set RTS */
2090                 sci_set_rts(port, 1);
2091         }
2092 }
2093 
2094 static unsigned int sci_get_mctrl(struct uart_port *port)
2095 {
2096         struct sci_port *s = to_sci_port(port);
2097         struct mctrl_gpios *gpios = s->gpios;
2098         unsigned int mctrl = 0;
2099 
2100         mctrl_gpio_get(gpios, &mctrl);
2101 
2102         /*
2103          * CTS/RTS is handled in hardware when supported, while nothing
2104          * else is wired up.
2105          */
2106         if (s->autorts) {
2107                 if (sci_get_cts(port))
2108                         mctrl |= TIOCM_CTS;
2109         } else if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) {
2110                 mctrl |= TIOCM_CTS;
2111         }
2112         if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR))
2113                 mctrl |= TIOCM_DSR;
2114         if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD))
2115                 mctrl |= TIOCM_CAR;
2116 
2117         return mctrl;
2118 }
2119 
2120 static void sci_enable_ms(struct uart_port *port)
2121 {
2122         mctrl_gpio_enable_ms(to_sci_port(port)->gpios);
2123 }
2124 
2125 static void sci_break_ctl(struct uart_port *port, int break_state)
2126 {
2127         unsigned short scscr, scsptr;
2128         unsigned long flags;
2129 
2130         /* check wheter the port has SCSPTR */
2131         if (!sci_getreg(port, SCSPTR)->size) {
2132                 /*
2133                  * Not supported by hardware. Most parts couple break and rx
2134                  * interrupts together, with break detection always enabled.
2135                  */
2136                 return;
2137         }
2138 
2139         spin_lock_irqsave(&port->lock, flags);
2140         scsptr = serial_port_in(port, SCSPTR);
2141         scscr = serial_port_in(port, SCSCR);
2142 
2143         if (break_state == -1) {
2144                 scsptr = (scsptr | SCSPTR_SPB2IO) & ~SCSPTR_SPB2DT;
2145                 scscr &= ~SCSCR_TE;
2146         } else {
2147                 scsptr = (scsptr | SCSPTR_SPB2DT) & ~SCSPTR_SPB2IO;
2148                 scscr |= SCSCR_TE;
2149         }
2150 
2151         serial_port_out(port, SCSPTR, scsptr);
2152         serial_port_out(port, SCSCR, scscr);
2153         spin_unlock_irqrestore(&port->lock, flags);
2154 }
2155 
2156 static int sci_startup(struct uart_port *port)
2157 {
2158         struct sci_port *s = to_sci_port(port);
2159         int ret;
2160 
2161         dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2162 
2163         sci_request_dma(port);
2164 
2165         ret = sci_request_irq(s);
2166         if (unlikely(ret < 0)) {
2167                 sci_free_dma(port);
2168                 return ret;
2169         }
2170 
2171         return 0;
2172 }
2173 
2174 static void sci_shutdown(struct uart_port *port)
2175 {
2176         struct sci_port *s = to_sci_port(port);
2177         unsigned long flags;
2178         u16 scr;
2179 
2180         dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
2181 
2182         s->autorts = false;
2183         mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
2184 
2185         spin_lock_irqsave(&port->lock, flags);
2186         sci_stop_rx(port);
2187         sci_stop_tx(port);
2188         /*
2189          * Stop RX and TX, disable related interrupts, keep clock source
2190          * and HSCIF TOT bits
2191          */
2192         scr = serial_port_in(port, SCSCR);
2193         serial_port_out(port, SCSCR, scr &
2194                         (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot));
2195         spin_unlock_irqrestore(&port->lock, flags);
2196 
2197 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2198         if (s->chan_rx_saved) {
2199                 dev_dbg(port->dev, "%s(%d) deleting rx_timer\n", __func__,
2200                         port->line);
2201                 hrtimer_cancel(&s->rx_timer);
2202         }
2203 #endif
2204 
2205         if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0)
2206                 del_timer_sync(&s->rx_fifo_timer);
2207         sci_free_irq(s);
2208         sci_free_dma(port);
2209 }
2210 
2211 static int sci_sck_calc(struct sci_port *s, unsigned int bps,
2212                         unsigned int *srr)
2213 {
2214         unsigned long freq = s->clk_rates[SCI_SCK];
2215         int err, min_err = INT_MAX;
2216         unsigned int sr;
2217 
2218         if (s->port.type != PORT_HSCIF)
2219                 freq *= 2;
2220 
2221         for_each_sr(sr, s) {
2222                 err = DIV_ROUND_CLOSEST(freq, sr) - bps;
2223                 if (abs(err) >= abs(min_err))
2224                         continue;
2225 
2226                 min_err = err;
2227                 *srr = sr - 1;
2228 
2229                 if (!err)
2230                         break;
2231         }
2232 
2233         dev_dbg(s->port.dev, "SCK: %u%+d bps using SR %u\n", bps, min_err,
2234                 *srr + 1);
2235         return min_err;
2236 }
2237 
2238 static int sci_brg_calc(struct sci_port *s, unsigned int bps,
2239                         unsigned long freq, unsigned int *dlr,
2240                         unsigned int *srr)
2241 {
2242         int err, min_err = INT_MAX;
2243         unsigned int sr, dl;
2244 
2245         if (s->port.type != PORT_HSCIF)
2246                 freq *= 2;
2247 
2248         for_each_sr(sr, s) {
2249                 dl = DIV_ROUND_CLOSEST(freq, sr * bps);
2250                 dl = clamp(dl, 1U, 65535U);
2251 
2252                 err = DIV_ROUND_CLOSEST(freq, sr * dl) - bps;
2253                 if (abs(err) >= abs(min_err))
2254                         continue;
2255 
2256                 min_err = err;
2257                 *dlr = dl;
2258                 *srr = sr - 1;
2259 
2260                 if (!err)
2261                         break;
2262         }
2263 
2264         dev_dbg(s->port.dev, "BRG: %u%+d bps using DL %u SR %u\n", bps,
2265                 min_err, *dlr, *srr + 1);
2266         return min_err;
2267 }
2268 
2269 /* calculate sample rate, BRR, and clock select */
2270 static int sci_scbrr_calc(struct sci_port *s, unsigned int bps,
2271                           unsigned int *brr, unsigned int *srr,
2272                           unsigned int *cks)
2273 {
2274         unsigned long freq = s->clk_rates[SCI_FCK];
2275         unsigned int sr, br, prediv, scrate, c;
2276         int err, min_err = INT_MAX;
2277 
2278         if (s->port.type != PORT_HSCIF)
2279                 freq *= 2;
2280 
2281         /*
2282          * Find the combination of sample rate and clock select with the
2283          * smallest deviation from the desired baud rate.
2284          * Prefer high sample rates to maximise the receive margin.
2285          *
2286          * M: Receive margin (%)
2287          * N: Ratio of bit rate to clock (N = sampling rate)
2288          * D: Clock duty (D = 0 to 1.0)
2289          * L: Frame length (L = 9 to 12)
2290          * F: Absolute value of clock frequency deviation
2291          *
2292          *  M = |(0.5 - 1 / 2 * N) - ((L - 0.5) * F) -
2293          *      (|D - 0.5| / N * (1 + F))|
2294          *  NOTE: Usually, treat D for 0.5, F is 0 by this calculation.
2295          */
2296         for_each_sr(sr, s) {
2297                 for (c = 0; c <= 3; c++) {
2298                         /* integerized formulas from HSCIF documentation */
2299                         prediv = sr * (1 << (2 * c + 1));
2300 
2301                         /*
2302                          * We need to calculate:
2303                          *
2304                          *     br = freq / (prediv * bps) clamped to [1..256]
2305                          *     err = freq / (br * prediv) - bps
2306                          *
2307                          * Watch out for overflow when calculating the desired
2308                          * sampling clock rate!
2309                          */
2310                         if (bps > UINT_MAX / prediv)
2311                                 break;
2312 
2313                         scrate = prediv * bps;
2314                         br = DIV_ROUND_CLOSEST(freq, scrate);
2315                         br = clamp(br, 1U, 256U);
2316 
2317                         err = DIV_ROUND_CLOSEST(freq, br * prediv) - bps;
2318                         if (abs(err) >= abs(min_err))
2319                                 continue;
2320 
2321                         min_err = err;
2322                         *brr = br - 1;
2323                         *srr = sr - 1;
2324                         *cks = c;
2325 
2326                         if (!err)
2327                                 goto found;
2328                 }
2329         }
2330 
2331 found:
2332         dev_dbg(s->port.dev, "BRR: %u%+d bps using N %u SR %u cks %u\n", bps,
2333                 min_err, *brr, *srr + 1, *cks);
2334         return min_err;
2335 }
2336 
2337 static void sci_reset(struct uart_port *port)
2338 {
2339         const struct plat_sci_reg *reg;
2340         unsigned int status;
2341         struct sci_port *s = to_sci_port(port);
2342 
2343         serial_port_out(port, SCSCR, s->hscif_tot);     /* TE=0, RE=0, CKE1=0 */
2344 
2345         reg = sci_getreg(port, SCFCR);
2346         if (reg->size)
2347                 serial_port_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
2348 
2349         sci_clear_SCxSR(port,
2350                         SCxSR_RDxF_CLEAR(port) & SCxSR_ERROR_CLEAR(port) &
2351                         SCxSR_BREAK_CLEAR(port));
2352         if (sci_getreg(port, SCLSR)->size) {
2353                 status = serial_port_in(port, SCLSR);
2354                 status &= ~(SCLSR_TO | SCLSR_ORER);
2355                 serial_port_out(port, SCLSR, status);
2356         }
2357 
2358         if (s->rx_trigger > 1) {
2359                 if (s->rx_fifo_timeout) {
2360                         scif_set_rtrg(port, 1);
2361                         timer_setup(&s->rx_fifo_timer, rx_fifo_timer_fn, 0);
2362                 } else {
2363                         if (port->type == PORT_SCIFA ||
2364                             port->type == PORT_SCIFB)
2365                                 scif_set_rtrg(port, 1);
2366                         else
2367                                 scif_set_rtrg(port, s->rx_trigger);
2368                 }
2369         }
2370 }
2371 
2372 static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
2373                             struct ktermios *old)
2374 {
2375         unsigned int baud, smr_val = SCSMR_ASYNC, scr_val = 0, i, bits;
2376         unsigned int brr = 255, cks = 0, srr = 15, dl = 0, sccks = 0;
2377         unsigned int brr1 = 255, cks1 = 0, srr1 = 15, dl1 = 0;
2378         struct sci_port *s = to_sci_port(port);
2379         const struct plat_sci_reg *reg;
2380         int min_err = INT_MAX, err;
2381         unsigned long max_freq = 0;
2382         int best_clk = -1;
2383         unsigned long flags;
2384 
2385         if ((termios->c_cflag & CSIZE) == CS7)
2386                 smr_val |= SCSMR_CHR;
2387         if (termios->c_cflag & PARENB)
2388                 smr_val |= SCSMR_PE;
2389         if (termios->c_cflag & PARODD)
2390                 smr_val |= SCSMR_PE | SCSMR_ODD;
2391         if (termios->c_cflag & CSTOPB)
2392                 smr_val |= SCSMR_STOP;
2393 
2394         /*
2395          * earlyprintk comes here early on with port->uartclk set to zero.
2396          * the clock framework is not up and running at this point so here
2397          * we assume that 115200 is the maximum baud rate. please note that
2398          * the baud rate is not programmed during earlyprintk - it is assumed
2399          * that the previous boot loader has enabled required clocks and
2400          * setup the baud rate generator hardware for us already.
2401          */
2402         if (!port->uartclk) {
2403                 baud = uart_get_baud_rate(port, termios, old, 0, 115200);
2404                 goto done;
2405         }
2406 
2407         for (i = 0; i < SCI_NUM_CLKS; i++)
2408                 max_freq = max(max_freq, s->clk_rates[i]);
2409 
2410         baud = uart_get_baud_rate(port, termios, old, 0, max_freq / min_sr(s));
2411         if (!baud)
2412                 goto done;
2413 
2414         /*
2415          * There can be multiple sources for the sampling clock.  Find the one
2416          * that gives us the smallest deviation from the desired baud rate.
2417          */
2418 
2419         /* Optional Undivided External Clock */
2420         if (s->clk_rates[SCI_SCK] && port->type != PORT_SCIFA &&
2421             port->type != PORT_SCIFB) {
2422                 err = sci_sck_calc(s, baud, &srr1);
2423                 if (abs(err) < abs(min_err)) {
2424                         best_clk = SCI_SCK;
2425                         scr_val = SCSCR_CKE1;
2426                         sccks = SCCKS_CKS;
2427                         min_err = err;
2428                         srr = srr1;
2429                         if (!err)
2430                                 goto done;
2431                 }
2432         }
2433 
2434         /* Optional BRG Frequency Divided External Clock */
2435         if (s->clk_rates[SCI_SCIF_CLK] && sci_getreg(port, SCDL)->size) {
2436                 err = sci_brg_calc(s, baud, s->clk_rates[SCI_SCIF_CLK], &dl1,
2437                                    &srr1);
2438                 if (abs(err) < abs(min_err)) {
2439                         best_clk = SCI_SCIF_CLK;
2440                         scr_val = SCSCR_CKE1;
2441                         sccks = 0;
2442                         min_err = err;
2443                         dl = dl1;
2444                         srr = srr1;
2445                         if (!err)
2446                                 goto done;
2447                 }
2448         }
2449 
2450         /* Optional BRG Frequency Divided Internal Clock */
2451         if (s->clk_rates[SCI_BRG_INT] && sci_getreg(port, SCDL)->size) {
2452                 err = sci_brg_calc(s, baud, s->clk_rates[SCI_BRG_INT], &dl1,
2453                                    &srr1);
2454                 if (abs(err) < abs(min_err)) {
2455                         best_clk = SCI_BRG_INT;
2456                         scr_val = SCSCR_CKE1;
2457                         sccks = SCCKS_XIN;
2458                         min_err = err;
2459                         dl = dl1;
2460                         srr = srr1;
2461                         if (!min_err)
2462                                 goto done;
2463                 }
2464         }
2465 
2466         /* Divided Functional Clock using standard Bit Rate Register */
2467         err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1);
2468         if (abs(err) < abs(min_err)) {
2469                 best_clk = SCI_FCK;
2470                 scr_val = 0;
2471                 min_err = err;
2472                 brr = brr1;
2473                 srr = srr1;
2474                 cks = cks1;
2475         }
2476 
2477 done:
2478         if (best_clk >= 0)
2479                 dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n",
2480                         s->clks[best_clk], baud, min_err);
2481 
2482         sci_port_enable(s);
2483 
2484         /*
2485          * Program the optional External Baud Rate Generator (BRG) first.
2486          * It controls the mux to select (H)SCK or frequency divided clock.
2487          */
2488         if (best_clk >= 0 && sci_getreg(port, SCCKS)->size) {
2489                 serial_port_out(port, SCDL, dl);
2490                 serial_port_out(port, SCCKS, sccks);
2491         }
2492 
2493         spin_lock_irqsave(&port->lock, flags);
2494 
2495         sci_reset(port);
2496 
2497         uart_update_timeout(port, termios->c_cflag, baud);
2498 
2499         /* byte size and parity */
2500         switch (termios->c_cflag & CSIZE) {
2501         case CS5:
2502                 bits = 7;
2503                 break;
2504         case CS6:
2505                 bits = 8;
2506                 break;
2507         case CS7:
2508                 bits = 9;
2509                 break;
2510         default:
2511                 bits = 10;
2512                 break;
2513         }
2514 
2515         if (termios->c_cflag & CSTOPB)
2516                 bits++;
2517         if (termios->c_cflag & PARENB)
2518                 bits++;
2519 
2520         if (best_clk >= 0) {
2521                 if (port->type == PORT_SCIFA || port->type == PORT_SCIFB)
2522                         switch (srr + 1) {
2523                         case 5:  smr_val |= SCSMR_SRC_5;  break;
2524                         case 7:  smr_val |= SCSMR_SRC_7;  break;
2525                         case 11: smr_val |= SCSMR_SRC_11; break;
2526                         case 13: smr_val |= SCSMR_SRC_13; break;
2527                         case 16: smr_val |= SCSMR_SRC_16; break;
2528                         case 17: smr_val |= SCSMR_SRC_17; break;
2529                         case 19: smr_val |= SCSMR_SRC_19; break;
2530                         case 27: smr_val |= SCSMR_SRC_27; break;
2531                         }
2532                 smr_val |= cks;
2533                 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2534                 serial_port_out(port, SCSMR, smr_val);
2535                 serial_port_out(port, SCBRR, brr);
2536                 if (sci_getreg(port, HSSRR)->size) {
2537                         unsigned int hssrr = srr | HSCIF_SRE;
2538                         /* Calculate deviation from intended rate at the
2539                          * center of the last stop bit in sampling clocks.
2540                          */
2541                         int last_stop = bits * 2 - 1;
2542                         int deviation = DIV_ROUND_CLOSEST(min_err * last_stop *
2543                                                           (int)(srr + 1),
2544                                                           2 * (int)baud);
2545 
2546                         if (abs(deviation) >= 2) {
2547                                 /* At least two sampling clocks off at the
2548                                  * last stop bit; we can increase the error
2549                                  * margin by shifting the sampling point.
2550                                  */
2551                                 int shift = clamp(deviation / 2, -8, 7);
2552 
2553                                 hssrr |= (shift << HSCIF_SRHP_SHIFT) &
2554                                          HSCIF_SRHP_MASK;
2555                                 hssrr |= HSCIF_SRDE;
2556                         }
2557                         serial_port_out(port, HSSRR, hssrr);
2558                 }
2559 
2560                 /* Wait one bit interval */
2561                 udelay((1000000 + (baud - 1)) / baud);
2562         } else {
2563                 /* Don't touch the bit rate configuration */
2564                 scr_val = s->cfg->scscr & (SCSCR_CKE1 | SCSCR_CKE0);
2565                 smr_val |= serial_port_in(port, SCSMR) &
2566                            (SCSMR_CKEDG | SCSMR_SRC_MASK | SCSMR_CKS);
2567                 serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2568                 serial_port_out(port, SCSMR, smr_val);
2569         }
2570 
2571         sci_init_pins(port, termios->c_cflag);
2572 
2573         port->status &= ~UPSTAT_AUTOCTS;
2574         s->autorts = false;
2575         reg = sci_getreg(port, SCFCR);
2576         if (reg->size) {
2577                 unsigned short ctrl = serial_port_in(port, SCFCR);
2578 
2579                 if ((port->flags & UPF_HARD_FLOW) &&
2580                     (termios->c_cflag & CRTSCTS)) {
2581                         /* There is no CTS interrupt to restart the hardware */
2582                         port->status |= UPSTAT_AUTOCTS;
2583                         /* MCE is enabled when RTS is raised */
2584                         s->autorts = true;
2585                 }
2586 
2587                 /*
2588                  * As we've done a sci_reset() above, ensure we don't
2589                  * interfere with the FIFOs while toggling MCE. As the
2590                  * reset values could still be set, simply mask them out.
2591                  */
2592                 ctrl &= ~(SCFCR_RFRST | SCFCR_TFRST);
2593 
2594                 serial_port_out(port, SCFCR, ctrl);
2595         }
2596         if (port->flags & UPF_HARD_FLOW) {
2597                 /* Refresh (Auto) RTS */
2598                 sci_set_mctrl(port, port->mctrl);
2599         }
2600 
2601         scr_val |= SCSCR_RE | SCSCR_TE |
2602                    (s->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0));
2603         serial_port_out(port, SCSCR, scr_val | s->hscif_tot);
2604         if ((srr + 1 == 5) &&
2605             (port->type == PORT_SCIFA || port->type == PORT_SCIFB)) {
2606                 /*
2607                  * In asynchronous mode, when the sampling rate is 1/5, first
2608                  * received data may become invalid on some SCIFA and SCIFB.
2609                  * To avoid this problem wait more than 1 serial data time (1
2610                  * bit time x serial data number) after setting SCSCR.RE = 1.
2611                  */
2612                 udelay(DIV_ROUND_UP(10 * 1000000, baud));
2613         }
2614 
2615         /*
2616          * Calculate delay for 2 DMA buffers (4 FIFO).
2617          * See serial_core.c::uart_update_timeout().
2618          * With 10 bits (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above
2619          * function calculates 1 jiffie for the data plus 5 jiffies for the
2620          * "slop(e)." Then below we calculate 5 jiffies (20ms) for 2 DMA
2621          * buffers (4 FIFO sizes), but when performing a faster transfer, the
2622          * value obtained by this formula is too small. Therefore, if the value
2623          * is smaller than 20ms, use 20ms as the timeout value for DMA.
2624          */
2625         s->rx_frame = (10000 * bits) / (baud / 100);
2626 #ifdef CONFIG_SERIAL_SH_SCI_DMA
2627         s->rx_timeout = s->buf_len_rx * 2 * s->rx_frame;
2628         if (s->rx_timeout < 20)
2629                 s->rx_timeout = 20;
2630 #endif
2631 
2632         if ((termios->c_cflag & CREAD) != 0)
2633                 sci_start_rx(port);
2634 
2635         spin_unlock_irqrestore(&port->lock, flags);
2636 
2637         sci_port_disable(s);
2638 
2639         if (UART_ENABLE_MS(port, termios->c_cflag))
2640                 sci_enable_ms(port);
2641 }
2642 
2643 static void sci_pm(struct uart_port *port, unsigned int state,
2644                    unsigned int oldstate)
2645 {
2646         struct sci_port *sci_port = to_sci_port(port);
2647 
2648         switch (state) {
2649         case UART_PM_STATE_OFF:
2650                 sci_port_disable(sci_port);
2651                 break;
2652         default:
2653                 sci_port_enable(sci_port);
2654                 break;
2655         }
2656 }
2657 
2658 static const char *sci_type(struct uart_port *port)
2659 {
2660         switch (port->type) {
2661         case PORT_IRDA:
2662                 return "irda";
2663         case PORT_SCI:
2664                 return "sci";
2665         case PORT_SCIF:
2666                 return "scif";
2667         case PORT_SCIFA:
2668                 return "scifa";
2669         case PORT_SCIFB:
2670                 return "scifb";
2671         case PORT_HSCIF:
2672                 return "hscif";
2673         }
2674 
2675         return NULL;
2676 }
2677 
2678 static int sci_remap_port(struct uart_port *port)
2679 {
2680         struct sci_port *sport = to_sci_port(port);
2681 
2682         /*
2683          * Nothing to do if there's already an established membase.
2684          */
2685         if (port->membase)
2686                 return 0;
2687 
2688         if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2689                 port->membase = ioremap_nocache(port->mapbase, sport->reg_size);
2690                 if (unlikely(!port->membase)) {
2691                         dev_err(port->dev, "can't remap port#%d\n", port->line);
2692                         return -ENXIO;
2693                 }
2694         } else {
2695                 /*
2696                  * For the simple (and majority of) cases where we don't
2697                  * need to do any remapping, just cast the cookie
2698                  * directly.
2699                  */
2700                 port->membase = (void __iomem *)(uintptr_t)port->mapbase;
2701         }
2702 
2703         return 0;
2704 }
2705 
2706 static void sci_release_port(struct uart_port *port)
2707 {
2708         struct sci_port *sport = to_sci_port(port);
2709 
2710         if (port->dev->of_node || (port->flags & UPF_IOREMAP)) {
2711                 iounmap(port->membase);
2712                 port->membase = NULL;
2713         }
2714 
2715         release_mem_region(port->mapbase, sport->reg_size);
2716 }
2717 
2718 static int sci_request_port(struct uart_port *port)
2719 {
2720         struct resource *res;
2721         struct sci_port *sport = to_sci_port(port);
2722         int ret;
2723 
2724         res = request_mem_region(port->mapbase, sport->reg_size,
2725                                  dev_name(port->dev));
2726         if (unlikely(res == NULL)) {
2727                 dev_err(port->dev, "request_mem_region failed.");
2728                 return -EBUSY;
2729         }
2730 
2731         ret = sci_remap_port(port);
2732         if (unlikely(ret != 0)) {
2733                 release_resource(res);
2734                 return ret;
2735         }
2736 
2737         return 0;
2738 }
2739 
2740 static void sci_config_port(struct uart_port *port, int flags)
2741 {
2742         if (flags & UART_CONFIG_TYPE) {
2743                 struct sci_port *sport = to_sci_port(port);
2744 
2745                 port->type = sport->cfg->type;
2746                 sci_request_port(port);
2747         }
2748 }
2749 
2750 static int sci_verify_port(struct uart_port *port, struct serial_struct *ser)
2751 {
2752         if (ser->baud_base < 2400)
2753                 /* No paper tape reader for Mitch.. */
2754                 return -EINVAL;
2755 
2756         return 0;
2757 }
2758 
2759 static const struct uart_ops sci_uart_ops = {
2760         .tx_empty       = sci_tx_empty,
2761         .set_mctrl      = sci_set_mctrl,
2762         .get_mctrl      = sci_get_mctrl,
2763         .start_tx       = sci_start_tx,
2764         .stop_tx        = sci_stop_tx,
2765         .stop_rx        = sci_stop_rx,
2766         .enable_ms      = sci_enable_ms,
2767         .break_ctl      = sci_break_ctl,
2768         .startup        = sci_startup,
2769         .shutdown       = sci_shutdown,
2770         .flush_buffer   = sci_flush_buffer,
2771         .set_termios    = sci_set_termios,
2772         .pm             = sci_pm,
2773         .type           = sci_type,
2774         .release_port   = sci_release_port,
2775         .request_port   = sci_request_port,
2776         .config_port    = sci_config_port,
2777         .verify_port    = sci_verify_port,
2778 #ifdef CONFIG_CONSOLE_POLL
2779         .poll_get_char  = sci_poll_get_char,
2780         .poll_put_char  = sci_poll_put_char,
2781 #endif
2782 };
2783 
2784 static int sci_init_clocks(struct sci_port *sci_port, struct device *dev)
2785 {
2786         const char *clk_names[] = {
2787                 [SCI_FCK] = "fck",
2788                 [SCI_SCK] = "sck",
2789                 [SCI_BRG_INT] = "brg_int",
2790                 [SCI_SCIF_CLK] = "scif_clk",
2791         };
2792         struct clk *clk;
2793         unsigned int i;
2794 
2795         if (sci_port->cfg->type == PORT_HSCIF)
2796                 clk_names[SCI_SCK] = "hsck";
2797 
2798         for (i = 0; i < SCI_NUM_CLKS; i++) {
2799                 clk = devm_clk_get(dev, clk_names[i]);
2800                 if (PTR_ERR(clk) == -EPROBE_DEFER)
2801                         return -EPROBE_DEFER;
2802 
2803                 if (IS_ERR(clk) && i == SCI_FCK) {
2804                         /*
2805                          * "fck" used to be called "sci_ick", and we need to
2806                          * maintain DT backward compatibility.
2807                          */
2808                         clk = devm_clk_get(dev, "sci_ick");
2809                         if (PTR_ERR(clk) == -EPROBE_DEFER)
2810                                 return -EPROBE_DEFER;
2811 
2812                         if (!IS_ERR(clk))
2813                                 goto found;
2814 
2815                         /*
2816                          * Not all SH platforms declare a clock lookup entry
2817                          * for SCI devices, in which case we need to get the
2818                          * global "peripheral_clk" clock.
2819                          */
2820                         clk = devm_clk_get(dev, "peripheral_clk");
2821                         if (!IS_ERR(clk))
2822                                 goto found;
2823 
2824                         dev_err(dev, "failed to get %s (%ld)\n", clk_names[i],
2825                                 PTR_ERR(clk));
2826                         return PTR_ERR(clk);
2827                 }
2828 
2829 found:
2830                 if (IS_ERR(clk))
2831                         dev_dbg(dev, "failed to get %s (%ld)\n", clk_names[i],
2832                                 PTR_ERR(clk));
2833                 else
2834                         dev_dbg(dev, "clk %s is %pC rate %lu\n", clk_names[i],
2835                                 clk, clk_get_rate(clk));
2836                 sci_port->clks[i] = IS_ERR(clk) ? NULL : clk;
2837         }
2838         return 0;
2839 }
2840 
2841 static const struct sci_port_params *
2842 sci_probe_regmap(const struct plat_sci_port *cfg)
2843 {
2844         unsigned int regtype;
2845 
2846         if (cfg->regtype != SCIx_PROBE_REGTYPE)
2847                 return &sci_port_params[cfg->regtype];
2848 
2849         switch (cfg->type) {
2850         case PORT_SCI:
2851                 regtype = SCIx_SCI_REGTYPE;
2852                 break;
2853         case PORT_IRDA:
2854                 regtype = SCIx_IRDA_REGTYPE;
2855                 break;
2856         case PORT_SCIFA:
2857                 regtype = SCIx_SCIFA_REGTYPE;
2858                 break;
2859         case PORT_SCIFB:
2860                 regtype = SCIx_SCIFB_REGTYPE;
2861                 break;
2862         case PORT_SCIF:
2863                 /*
2864                  * The SH-4 is a bit of a misnomer here, although that's
2865                  * where this particular port layout originated. This
2866                  * configuration (or some slight variation thereof)
2867                  * remains the dominant model for all SCIFs.
2868                  */
2869                 regtype = SCIx_SH4_SCIF_REGTYPE;
2870                 break;
2871         case PORT_HSCIF:
2872                 regtype = SCIx_HSCIF_REGTYPE;
2873                 break;
2874         default:
2875                 pr_err("Can't probe register map for given port\n");
2876                 return NULL;
2877         }
2878 
2879         return &sci_port_params[regtype];
2880 }
2881 
2882 static int sci_init_single(struct platform_device *dev,
2883                            struct sci_port *sci_port, unsigned int index,
2884                            const struct plat_sci_port *p, bool early)
2885 {
2886         struct uart_port *port = &sci_port->port;
2887         const struct resource *res;
2888         unsigned int i;
2889         int ret;
2890 
2891         sci_port->cfg   = p;
2892 
2893         port->ops       = &sci_uart_ops;
2894         port->iotype    = UPIO_MEM;
2895         port->line      = index;
2896 
2897         res = platform_get_resource(dev, IORESOURCE_MEM, 0);
2898         if (res == NULL)
2899                 return -ENOMEM;
2900 
2901         port->mapbase = res->start;
2902         sci_port->reg_size = resource_size(res);
2903 
2904         for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
2905                 if (i)
2906                         sci_port->irqs[i] = platform_get_irq_optional(dev, i);
2907                 else
2908                         sci_port->irqs[i] = platform_get_irq(dev, i);
2909         }
2910 
2911         /* The SCI generates several interrupts. They can be muxed together or
2912          * connected to different interrupt lines. In the muxed case only one
2913          * interrupt resource is specified as there is only one interrupt ID.
2914          * In the non-muxed case, up to 6 interrupt signals might be generated
2915          * from the SCI, however those signals might have their own individual
2916          * interrupt ID numbers, or muxed together with another interrupt.
2917          */
2918         if (sci_port->irqs[0] < 0)
2919                 return -ENXIO;
2920 
2921         if (sci_port->irqs[1] < 0)
2922                 for (i = 1; i < ARRAY_SIZE(sci_port->irqs); i++)
2923                         sci_port->irqs[i] = sci_port->irqs[0];
2924 
2925         sci_port->params = sci_probe_regmap(p);
2926         if (unlikely(sci_port->params == NULL))
2927                 return -EINVAL;
2928 
2929         switch (p->type) {
2930         case PORT_SCIFB:
2931                 sci_port->rx_trigger = 48;
2932                 break;
2933         case PORT_HSCIF:
2934                 sci_port->rx_trigger = 64;
2935                 break;
2936         case PORT_SCIFA:
2937                 sci_port->rx_trigger = 32;
2938                 break;
2939         case PORT_SCIF:
2940                 if (p->regtype == SCIx_SH7705_SCIF_REGTYPE)
2941                         /* RX triggering not implemented for this IP */
2942                         sci_port->rx_trigger = 1;
2943                 else
2944                         sci_port->rx_trigger = 8;
2945                 break;
2946         default:
2947                 sci_port->rx_trigger = 1;
2948                 break;
2949         }
2950 
2951         sci_port->rx_fifo_timeout = 0;
2952         sci_port->hscif_tot = 0;
2953 
2954         /* SCIFA on sh7723 and sh7724 need a custom sampling rate that doesn't
2955          * match the SoC datasheet, this should be investigated. Let platform
2956          * data override the sampling rate for now.
2957          */
2958         sci_port->sampling_rate_mask = p->sampling_rate
2959                                      ? SCI_SR(p->sampling_rate)
2960                                      : sci_port->params->sampling_rate_mask;
2961 
2962         if (!early) {
2963                 ret = sci_init_clocks(sci_port, &dev->dev);
2964                 if (ret < 0)
2965                         return ret;
2966 
2967                 port->dev = &dev->dev;
2968 
2969                 pm_runtime_enable(&dev->dev);
2970         }
2971 
2972         port->type              = p->type;
2973         port->flags             = UPF_FIXED_PORT | UPF_BOOT_AUTOCONF | p->flags;
2974         port->fifosize          = sci_port->params->fifosize;
2975 
2976         if (port->type == PORT_SCI) {
2977                 if (sci_port->reg_size >= 0x20)
2978                         port->regshift = 2;
2979                 else
2980                         port->regshift = 1;
2981         }
2982 
2983         /*
2984          * The UART port needs an IRQ value, so we peg this to the RX IRQ
2985          * for the multi-IRQ ports, which is where we are primarily
2986          * concerned with the shutdown path synchronization.
2987          *
2988          * For the muxed case there's nothing more to do.
2989          */
2990         port->irq               = sci_port->irqs[SCIx_RXI_IRQ];
2991         port->irqflags          = 0;
2992 
2993         port->serial_in         = sci_serial_in;
2994         port->serial_out        = sci_serial_out;
2995 
2996         return 0;
2997 }
2998 
2999 static void sci_cleanup_single(struct sci_port *port)
3000 {
3001         pm_runtime_disable(port->port.dev);
3002 }
3003 
3004 #if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) || \
3005     defined(CONFIG_SERIAL_SH_SCI_EARLYCON)
3006 static void serial_console_putchar(struct uart_port *port, int ch)
3007 {
3008         sci_poll_put_char(port, ch);
3009 }
3010 
3011 /*
3012  *      Print a string to the serial port trying not to disturb
3013  *      any possible real use of the port...
3014  */
3015 static void serial_console_write(struct console *co, const char *s,
3016                                  unsigned count)
3017 {
3018         struct sci_port *sci_port = &sci_ports[co->index];
3019         struct uart_port *port = &sci_port->port;
3020         unsigned short bits, ctrl, ctrl_temp;
3021         unsigned long flags;
3022         int locked = 1;
3023 
3024 #if defined(SUPPORT_SYSRQ)
3025         if (port->sysrq)
3026                 locked = 0;
3027         else
3028 #endif
3029         if (oops_in_progress)
3030                 locked = spin_trylock_irqsave(&port->lock, flags);
3031         else
3032                 spin_lock_irqsave(&port->lock, flags);
3033 
3034         /* first save SCSCR then disable interrupts, keep clock source */
3035         ctrl = serial_port_in(port, SCSCR);
3036         ctrl_temp = SCSCR_RE | SCSCR_TE |
3037                     (sci_port->cfg->scscr & ~(SCSCR_CKE1 | SCSCR_CKE0)) |
3038                     (ctrl & (SCSCR_CKE1 | SCSCR_CKE0));
3039         serial_port_out(port, SCSCR, ctrl_temp | sci_port->hscif_tot);
3040 
3041         uart_console_write(port, s, count, serial_console_putchar);
3042 
3043         /* wait until fifo is empty and last bit has been transmitted */
3044         bits = SCxSR_TDxE(port) | SCxSR_TEND(port);
3045         while ((serial_port_in(port, SCxSR) & bits) != bits)
3046                 cpu_relax();
3047 
3048         /* restore the SCSCR */
3049         serial_port_out(port, SCSCR, ctrl);
3050 
3051         if (locked)
3052                 spin_unlock_irqrestore(&port->lock, flags);
3053 }
3054 
3055 static int serial_console_setup(struct console *co, char *options)
3056 {
3057         struct sci_port *sci_port;
3058         struct uart_port *port;
3059         int baud = 115200;
3060         int bits = 8;
3061         int parity = 'n';
3062         int flow = 'n';
3063         int ret;
3064 
3065         /*
3066          * Refuse to handle any bogus ports.
3067          */
3068         if (co->index < 0 || co->index >= SCI_NPORTS)
3069                 return -ENODEV;
3070 
3071         sci_port = &sci_ports[co->index];
3072         port = &sci_port->port;
3073 
3074         /*
3075          * Refuse to handle uninitialized ports.
3076          */
3077         if (!port->ops)
3078                 return -ENODEV;
3079 
3080         ret = sci_remap_port(port);
3081         if (unlikely(ret != 0))
3082                 return ret;
3083 
3084         if (options)
3085                 uart_parse_options(options, &baud, &parity, &bits, &flow);
3086 
3087         return uart_set_options(port, co, baud, parity, bits, flow);
3088 }
3089 
3090 static struct console serial_console = {
3091         .name           = "ttySC",
3092         .device         = uart_console_device,
3093         .write          = serial_console_write,
3094         .setup          = serial_console_setup,
3095         .flags          = CON_PRINTBUFFER,
3096         .index          = -1,
3097         .data           = &sci_uart_driver,
3098 };
3099 
3100 static struct console early_serial_console = {
3101         .name           = "early_ttySC",
3102         .write          = serial_console_write,
3103         .flags          = CON_PRINTBUFFER,
3104         .index          = -1,
3105 };
3106 
3107 static char early_serial_buf[32];
3108 
3109 static int sci_probe_earlyprintk(struct platform_device *pdev)
3110 {
3111         const struct plat_sci_port *cfg = dev_get_platdata(&pdev->dev);
3112 
3113         if (early_serial_console.data)
3114                 return -EEXIST;
3115 
3116         early_serial_console.index = pdev->id;
3117 
3118         sci_init_single(pdev, &sci_ports[pdev->id], pdev->id, cfg, true);
3119 
3120         serial_console_setup(&early_serial_console, early_serial_buf);
3121 
3122         if (!strstr(early_serial_buf, "keep"))
3123                 early_serial_console.flags |= CON_BOOT;
3124 
3125         register_console(&early_serial_console);
3126         return 0;
3127 }
3128 
3129 #define SCI_CONSOLE     (&serial_console)
3130 
3131 #else
3132 static inline int sci_probe_earlyprintk(struct platform_device *pdev)
3133 {
3134         return -EINVAL;
3135 }
3136 
3137 #define SCI_CONSOLE     NULL
3138 
3139 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE || CONFIG_SERIAL_SH_SCI_EARLYCON */
3140 
3141 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
3142 
3143 static DEFINE_MUTEX(sci_uart_registration_lock);
3144 static struct uart_driver sci_uart_driver = {
3145         .owner          = THIS_MODULE,
3146         .driver_name    = "sci",
3147         .dev_name       = "ttySC",
3148         .major          = SCI_MAJOR,
3149         .minor          = SCI_MINOR_START,
3150         .nr             = SCI_NPORTS,
3151         .cons           = SCI_CONSOLE,
3152 };
3153 
3154 static int sci_remove(struct platform_device *dev)
3155 {
3156         struct sci_port *port = platform_get_drvdata(dev);
3157         unsigned int type = port->port.type;    /* uart_remove_... clears it */
3158 
3159         sci_ports_in_use &= ~BIT(port->port.line);
3160         uart_remove_one_port(&sci_uart_driver, &port->port);
3161 
3162         sci_cleanup_single(port);
3163 
3164         if (port->port.fifosize > 1)
3165                 device_remove_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3166         if (type == PORT_SCIFA || type == PORT_SCIFB || type == PORT_HSCIF)
3167                 device_remove_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3168 
3169         return 0;
3170 }
3171 
3172 
3173 #define SCI_OF_DATA(type, regtype)      (void *)((type) << 16 | (regtype))
3174 #define SCI_OF_TYPE(data)               ((unsigned long)(data) >> 16)
3175 #define SCI_OF_REGTYPE(data)            ((unsigned long)(data) & 0xffff)
3176 
3177 static const struct of_device_id of_sci_match[] = {
3178         /* SoC-specific types */
3179         {
3180                 .compatible = "renesas,scif-r7s72100",
3181                 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH2_SCIF_FIFODATA_REGTYPE),
3182         },
3183         {
3184                 .compatible = "renesas,scif-r7s9210",
3185                 .data = SCI_OF_DATA(PORT_SCIF, SCIx_RZ_SCIFA_REGTYPE),
3186         },
3187         /* Family-specific types */
3188         {
3189                 .compatible = "renesas,rcar-gen1-scif",
3190                 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3191         }, {
3192                 .compatible = "renesas,rcar-gen2-scif",
3193                 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3194         }, {
3195                 .compatible = "renesas,rcar-gen3-scif",
3196                 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_BRG_REGTYPE),
3197         },
3198         /* Generic types */
3199         {
3200                 .compatible = "renesas,scif",
3201                 .data = SCI_OF_DATA(PORT_SCIF, SCIx_SH4_SCIF_REGTYPE),
3202         }, {
3203                 .compatible = "renesas,scifa",
3204                 .data = SCI_OF_DATA(PORT_SCIFA, SCIx_SCIFA_REGTYPE),
3205         }, {
3206                 .compatible = "renesas,scifb",
3207                 .data = SCI_OF_DATA(PORT_SCIFB, SCIx_SCIFB_REGTYPE),
3208         }, {
3209                 .compatible = "renesas,hscif",
3210                 .data = SCI_OF_DATA(PORT_HSCIF, SCIx_HSCIF_REGTYPE),
3211         }, {
3212                 .compatible = "renesas,sci",
3213                 .data = SCI_OF_DATA(PORT_SCI, SCIx_SCI_REGTYPE),
3214         }, {
3215                 /* Terminator */
3216         },
3217 };
3218 MODULE_DEVICE_TABLE(of, of_sci_match);
3219 
3220 static struct plat_sci_port *sci_parse_dt(struct platform_device *pdev,
3221                                           unsigned int *dev_id)
3222 {
3223         struct device_node *np = pdev->dev.of_node;
3224         struct plat_sci_port *p;
3225         struct sci_port *sp;
3226         const void *data;
3227         int id;
3228 
3229         if (!IS_ENABLED(CONFIG_OF) || !np)
3230                 return NULL;
3231 
3232         data = of_device_get_match_data(&pdev->dev);
3233 
3234         p = devm_kzalloc(&pdev->dev, sizeof(struct plat_sci_port), GFP_KERNEL);
3235         if (!p)
3236                 return NULL;
3237 
3238         /* Get the line number from the aliases node. */
3239         id = of_alias_get_id(np, "serial");
3240         if (id < 0 && ~sci_ports_in_use)
3241                 id = ffz(sci_ports_in_use);
3242         if (id < 0) {
3243                 dev_err(&pdev->dev, "failed to get alias id (%d)\n", id);
3244                 return NULL;
3245         }
3246         if (id >= ARRAY_SIZE(sci_ports)) {
3247                 dev_err(&pdev->dev, "serial%d out of range\n", id);
3248                 return NULL;
3249         }
3250 
3251         sp = &sci_ports[id];
3252         *dev_id = id;
3253 
3254         p->type = SCI_OF_TYPE(data);
3255         p->regtype = SCI_OF_REGTYPE(data);
3256 
3257         sp->has_rtscts = of_property_read_bool(np, "uart-has-rtscts");
3258 
3259         return p;
3260 }
3261 
3262 static int sci_probe_single(struct platform_device *dev,
3263                                       unsigned int index,
3264                                       struct plat_sci_port *p,
3265                                       struct sci_port *sciport)
3266 {
3267         int ret;
3268 
3269         /* Sanity check */
3270         if (unlikely(index >= SCI_NPORTS)) {
3271                 dev_notice(&dev->dev, "Attempting to register port %d when only %d are available\n",
3272                            index+1, SCI_NPORTS);
3273                 dev_notice(&dev->dev, "Consider bumping CONFIG_SERIAL_SH_SCI_NR_UARTS!\n");
3274                 return -EINVAL;
3275         }
3276         BUILD_BUG_ON(SCI_NPORTS > sizeof(sci_ports_in_use) * 8);
3277         if (sci_ports_in_use & BIT(index))
3278                 return -EBUSY;
3279 
3280         mutex_lock(&sci_uart_registration_lock);
3281         if (!sci_uart_driver.state) {
3282                 ret = uart_register_driver(&sci_uart_driver);
3283                 if (ret) {
3284                         mutex_unlock(&sci_uart_registration_lock);
3285                         return ret;
3286                 }
3287         }
3288         mutex_unlock(&sci_uart_registration_lock);
3289 
3290         ret = sci_init_single(dev, sciport, index, p, false);
3291         if (ret)
3292                 return ret;
3293 
3294         sciport->gpios = mctrl_gpio_init(&sciport->port, 0);
3295         if (IS_ERR(sciport->gpios))
3296                 return PTR_ERR(sciport->gpios);
3297 
3298         if (sciport->has_rtscts) {
3299                 if (mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_CTS) ||
3300                     mctrl_gpio_to_gpiod(sciport->gpios, UART_GPIO_RTS)) {
3301                         dev_err(&dev->dev, "Conflicting RTS/CTS config\n");
3302                         return -EINVAL;
3303                 }
3304                 sciport->port.flags |= UPF_HARD_FLOW;
3305         }
3306 
3307         ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
3308         if (ret) {
3309                 sci_cleanup_single(sciport);
3310                 return ret;
3311         }
3312 
3313         return 0;
3314 }
3315 
3316 static int sci_probe(struct platform_device *dev)
3317 {
3318         struct plat_sci_port *p;
3319         struct sci_port *sp;
3320         unsigned int dev_id;
3321         int ret;
3322 
3323         /*
3324          * If we've come here via earlyprintk initialization, head off to
3325          * the special early probe. We don't have sufficient device state
3326          * to make it beyond this yet.
3327          */
3328         if (is_early_platform_device(dev))
3329                 return sci_probe_earlyprintk(dev);
3330 
3331         if (dev->dev.of_node) {
3332                 p = sci_parse_dt(dev, &dev_id);
3333                 if (p == NULL)
3334                         return -EINVAL;
3335         } else {
3336                 p = dev->dev.platform_data;
3337                 if (p == NULL) {
3338                         dev_err(&dev->dev, "no platform data supplied\n");
3339                         return -EINVAL;
3340                 }
3341 
3342                 dev_id = dev->id;
3343         }
3344 
3345         sp = &sci_ports[dev_id];
3346         platform_set_drvdata(dev, sp);
3347 
3348         ret = sci_probe_single(dev, dev_id, p, sp);
3349         if (ret)
3350                 return ret;
3351 
3352         if (sp->port.fifosize > 1) {
3353                 ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_trigger);
3354                 if (ret)
3355                         return ret;
3356         }
3357         if (sp->port.type == PORT_SCIFA || sp->port.type == PORT_SCIFB ||
3358             sp->port.type == PORT_HSCIF) {
3359                 ret = device_create_file(&dev->dev, &dev_attr_rx_fifo_timeout);
3360                 if (ret) {
3361                         if (sp->port.fifosize > 1) {
3362                                 device_remove_file(&dev->dev,
3363                                                    &dev_attr_rx_fifo_trigger);
3364                         }
3365                         return ret;
3366                 }
3367         }
3368 
3369 #ifdef CONFIG_SH_STANDARD_BIOS
3370         sh_bios_gdb_detach();
3371 #endif
3372 
3373         sci_ports_in_use |= BIT(dev_id);
3374         return 0;
3375 }
3376 
3377 static __maybe_unused int sci_suspend(struct device *dev)
3378 {
3379         struct sci_port *sport = dev_get_drvdata(dev);
3380 
3381         if (sport)
3382                 uart_suspend_port(&sci_uart_driver, &sport->port);
3383 
3384         return 0;
3385 }
3386 
3387 static __maybe_unused int sci_resume(struct device *dev)
3388 {
3389         struct sci_port *sport = dev_get_drvdata(dev);
3390 
3391         if (sport)
3392                 uart_resume_port(&sci_uart_driver, &sport->port);
3393 
3394         return 0;
3395 }
3396 
3397 static SIMPLE_DEV_PM_OPS(sci_dev_pm_ops, sci_suspend, sci_resume);
3398 
3399 static struct platform_driver sci_driver = {
3400         .probe          = sci_probe,
3401         .remove         = sci_remove,
3402         .driver         = {
3403                 .name   = "sh-sci",
3404                 .pm     = &sci_dev_pm_ops,
3405                 .of_match_table = of_match_ptr(of_sci_match),
3406         },
3407 };
3408 
3409 static int __init sci_init(void)
3410 {
3411         pr_info("%s\n", banner);
3412 
3413         return platform_driver_register(&sci_driver);
3414 }
3415 
3416 static void __exit sci_exit(void)
3417 {
3418         platform_driver_unregister(&sci_driver);
3419 
3420         if (sci_uart_driver.state)
3421                 uart_unregister_driver(&sci_uart_driver);
3422 }
3423 
3424 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
3425 early_platform_init_buffer("earlyprintk", &sci_driver,
3426                            early_serial_buf, ARRAY_SIZE(early_serial_buf));
3427 #endif
3428 #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON
3429 static struct plat_sci_port port_cfg __initdata;
3430 
3431 static int __init early_console_setup(struct earlycon_device *device,
3432                                       int type)
3433 {
3434         if (!device->port.membase)
3435                 return -ENODEV;
3436 
3437         device->port.serial_in = sci_serial_in;
3438         device->port.serial_out = sci_serial_out;
3439         device->port.type = type;
3440         memcpy(&sci_ports[0].port, &device->port, sizeof(struct uart_port));
3441         port_cfg.type = type;
3442         sci_ports[0].cfg = &port_cfg;
3443         sci_ports[0].params = sci_probe_regmap(&port_cfg);
3444         port_cfg.scscr = sci_serial_in(&sci_ports[0].port, SCSCR);
3445         sci_serial_out(&sci_ports[0].port, SCSCR,
3446                        SCSCR_RE | SCSCR_TE | port_cfg.scscr);
3447 
3448         device->con->write = serial_console_write;
3449         return 0;
3450 }
3451 static int __init sci_early_console_setup(struct earlycon_device *device,
3452                                           const char *opt)
3453 {
3454         return early_console_setup(device, PORT_SCI);
3455 }
3456 static int __init scif_early_console_setup(struct earlycon_device *device,
3457                                           const char *opt)
3458 {
3459         return early_console_setup(device, PORT_SCIF);
3460 }
3461 static int __init rzscifa_early_console_setup(struct earlycon_device *device,
3462                                           const char *opt)
3463 {
3464         port_cfg.regtype = SCIx_RZ_SCIFA_REGTYPE;
3465         return early_console_setup(device, PORT_SCIF);
3466 }
3467 static int __init scifa_early_console_setup(struct earlycon_device *device,
3468                                           const char *opt)
3469 {
3470         return early_console_setup(device, PORT_SCIFA);
3471 }
3472 static int __init scifb_early_console_setup(struct earlycon_device *device,
3473                                           const char *opt)
3474 {
3475         return early_console_setup(device, PORT_SCIFB);
3476 }
3477 static int __init hscif_early_console_setup(struct earlycon_device *device,
3478                                           const char *opt)
3479 {
3480         return early_console_setup(device, PORT_HSCIF);
3481 }
3482 
3483 OF_EARLYCON_DECLARE(sci, "renesas,sci", sci_early_console_setup);
3484 OF_EARLYCON_DECLARE(scif, "renesas,scif", scif_early_console_setup);
3485 OF_EARLYCON_DECLARE(scif, "renesas,scif-r7s9210", rzscifa_early_console_setup);
3486 OF_EARLYCON_DECLARE(scifa, "renesas,scifa", scifa_early_console_setup);
3487 OF_EARLYCON_DECLARE(scifb, "renesas,scifb", scifb_early_console_setup);
3488 OF_EARLYCON_DECLARE(hscif, "renesas,hscif", hscif_early_console_setup);
3489 #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */
3490 
3491 module_init(sci_init);
3492 module_exit(sci_exit);
3493 
3494 MODULE_LICENSE("GPL");
3495 MODULE_ALIAS("platform:sh-sci");
3496 MODULE_AUTHOR("Paul Mundt");
3497 MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");

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