drivers/tty/serial/omap-serial.c

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This source file includes following definitions.
serial_in
serial_out
serial_omap_clear_fifos
serial_omap_get_context_loss_count
serial_omap_enable_wakeup
calculate_baud_abs_diff
serial_omap_baud_is_mode16
serial_omap_get_divisor
serial_omap_enable_ms
serial_omap_stop_tx
serial_omap_stop_rx
transmit_chars
serial_omap_enable_ier_thri
serial_omap_start_tx
serial_omap_throttle
serial_omap_unthrottle
check_modem_status
serial_omap_rlsi
serial_omap_rdi
serial_omap_irq
serial_omap_tx_empty
serial_omap_get_mctrl
serial_omap_set_mctrl
serial_omap_break_ctl
serial_omap_startup
serial_omap_shutdown
serial_omap_uart_qos_work
serial_omap_set_termios
serial_omap_pm
serial_omap_release_port
serial_omap_request_port
serial_omap_config_port
serial_omap_verify_port
serial_omap_type
wait_for_xmitr
serial_omap_poll_put_char
serial_omap_poll_get_char
omap_serial_early_in
omap_serial_early_out
omap_serial_early_putc
early_omap_serial_write
early_omap_serial_setup
serial_omap_console_putchar
serial_omap_console_write
serial_omap_console_setup
serial_omap_add_console_port
serial_omap_add_console_port
serial_omap_config_rs485
serial_omap_prepare
serial_omap_complete
serial_omap_suspend
serial_omap_resume
omap_serial_fill_features_erratas
of_get_uart_port_info
serial_omap_probe_rs485
serial_omap_probe
serial_omap_remove
serial_omap_mdr1_errataset
serial_omap_restore_context
serial_omap_runtime_suspend
serial_omap_runtime_resume
serial_omap_init
serial_omap_exit
   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Driver for OMAP-UART controller.
   4  * Based on drivers/serial/8250.c
   5  *
   6  * Copyright (C) 2010 Texas Instruments.
   7  *
   8  * Authors:
   9  *      Govindraj R     <govindraj.raja@ti.com>
  10  *      Thara Gopinath  <thara@ti.com>
  11  *
  12  * Note: This driver is made separate from 8250 driver as we cannot
  13  * over load 8250 driver with omap platform specific configuration for
  14  * features like DMA, it makes easier to implement features like DMA and
  15  * hardware flow control and software flow control configuration with
  16  * this driver as required for the omap-platform.
  17  */
  18 
  19 #if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  20 #define SUPPORT_SYSRQ
  21 #endif
  22 
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/console.h>
  26 #include <linux/serial_reg.h>
  27 #include <linux/delay.h>
  28 #include <linux/slab.h>
  29 #include <linux/tty.h>
  30 #include <linux/tty_flip.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/io.h>
  33 #include <linux/clk.h>
  34 #include <linux/serial_core.h>
  35 #include <linux/irq.h>
  36 #include <linux/pm_runtime.h>
  37 #include <linux/pm_wakeirq.h>
  38 #include <linux/of.h>
  39 #include <linux/of_irq.h>
  40 #include <linux/gpio.h>
  41 #include <linux/of_gpio.h>
  42 #include <linux/platform_data/serial-omap.h>
  43 
  44 #include <dt-bindings/gpio/gpio.h>
  45 
  46 #define OMAP_MAX_HSUART_PORTS   10
  47 
  48 #define UART_BUILD_REVISION(x, y)       (((x) << 8) | (y))
  49 
  50 #define OMAP_UART_REV_42 0x0402
  51 #define OMAP_UART_REV_46 0x0406
  52 #define OMAP_UART_REV_52 0x0502
  53 #define OMAP_UART_REV_63 0x0603
  54 
  55 #define OMAP_UART_TX_WAKEUP_EN          BIT(7)
  56 
  57 /* Feature flags */
  58 #define OMAP_UART_WER_HAS_TX_WAKEUP     BIT(0)
  59 
  60 #define UART_ERRATA_i202_MDR1_ACCESS    BIT(0)
  61 #define UART_ERRATA_i291_DMA_FORCEIDLE  BIT(1)
  62 
  63 #define DEFAULT_CLK_SPEED 48000000 /* 48Mhz */
  64 
  65 /* SCR register bitmasks */
  66 #define OMAP_UART_SCR_RX_TRIG_GRANU1_MASK               (1 << 7)
  67 #define OMAP_UART_SCR_TX_TRIG_GRANU1_MASK               (1 << 6)
  68 #define OMAP_UART_SCR_TX_EMPTY                  (1 << 3)
  69 
  70 /* FCR register bitmasks */
  71 #define OMAP_UART_FCR_RX_FIFO_TRIG_MASK                 (0x3 << 6)
  72 #define OMAP_UART_FCR_TX_FIFO_TRIG_MASK                 (0x3 << 4)
  73 
  74 /* MVR register bitmasks */
  75 #define OMAP_UART_MVR_SCHEME_SHIFT      30
  76 
  77 #define OMAP_UART_LEGACY_MVR_MAJ_MASK   0xf0
  78 #define OMAP_UART_LEGACY_MVR_MAJ_SHIFT  4
  79 #define OMAP_UART_LEGACY_MVR_MIN_MASK   0x0f
  80 
  81 #define OMAP_UART_MVR_MAJ_MASK          0x700
  82 #define OMAP_UART_MVR_MAJ_SHIFT         8
  83 #define OMAP_UART_MVR_MIN_MASK          0x3f
  84 
  85 #define OMAP_UART_DMA_CH_FREE   -1
  86 
  87 #define MSR_SAVE_FLAGS          UART_MSR_ANY_DELTA
  88 #define OMAP_MODE13X_SPEED      230400
  89 
  90 /* WER = 0x7F
  91  * Enable module level wakeup in WER reg
  92  */
  93 #define OMAP_UART_WER_MOD_WKUP  0x7F
  94 
  95 /* Enable XON/XOFF flow control on output */
  96 #define OMAP_UART_SW_TX         0x08
  97 
  98 /* Enable XON/XOFF flow control on input */
  99 #define OMAP_UART_SW_RX         0x02
 100 
 101 #define OMAP_UART_SW_CLR        0xF0
 102 
 103 #define OMAP_UART_TCR_TRIG      0x0F
 104 
 105 struct uart_omap_dma {
 106         u8                      uart_dma_tx;
 107         u8                      uart_dma_rx;
 108         int                     rx_dma_channel;
 109         int                     tx_dma_channel;
 110         dma_addr_t              rx_buf_dma_phys;
 111         dma_addr_t              tx_buf_dma_phys;
 112         unsigned int            uart_base;
 113         /*
 114          * Buffer for rx dma. It is not required for tx because the buffer
 115          * comes from port structure.
 116          */
 117         unsigned char           *rx_buf;
 118         unsigned int            prev_rx_dma_pos;
 119         int                     tx_buf_size;
 120         int                     tx_dma_used;
 121         int                     rx_dma_used;
 122         spinlock_t              tx_lock;
 123         spinlock_t              rx_lock;
 124         /* timer to poll activity on rx dma */
 125         struct timer_list       rx_timer;
 126         unsigned int            rx_buf_size;
 127         unsigned int            rx_poll_rate;
 128         unsigned int            rx_timeout;
 129 };
 130 
 131 struct uart_omap_port {
 132         struct uart_port        port;
 133         struct uart_omap_dma    uart_dma;
 134         struct device           *dev;
 135         int                     wakeirq;
 136 
 137         unsigned char           ier;
 138         unsigned char           lcr;
 139         unsigned char           mcr;
 140         unsigned char           fcr;
 141         unsigned char           efr;
 142         unsigned char           dll;
 143         unsigned char           dlh;
 144         unsigned char           mdr1;
 145         unsigned char           scr;
 146         unsigned char           wer;
 147 
 148         int                     use_dma;
 149         /*
 150          * Some bits in registers are cleared on a read, so they must
 151          * be saved whenever the register is read, but the bits will not
 152          * be immediately processed.
 153          */
 154         unsigned int            lsr_break_flag;
 155         unsigned char           msr_saved_flags;
 156         char                    name[20];
 157         unsigned long           port_activity;
 158         int                     context_loss_cnt;
 159         u32                     errata;
 160         u32                     features;
 161 
 162         int                     rts_gpio;
 163 
 164         struct pm_qos_request   pm_qos_request;
 165         u32                     latency;
 166         u32                     calc_latency;
 167         struct work_struct      qos_work;
 168         bool                    is_suspending;
 169 };
 170 
 171 #define to_uart_omap_port(p) ((container_of((p), struct uart_omap_port, port)))
 172 
 173 static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS];
 174 
 175 /* Forward declaration of functions */
 176 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1);
 177 
 178 static inline unsigned int serial_in(struct uart_omap_port *up, int offset)
 179 {
 180         offset <<= up->port.regshift;
 181         return readw(up->port.membase + offset);
 182 }
 183 
 184 static inline void serial_out(struct uart_omap_port *up, int offset, int value)
 185 {
 186         offset <<= up->port.regshift;
 187         writew(value, up->port.membase + offset);
 188 }
 189 
 190 static inline void serial_omap_clear_fifos(struct uart_omap_port *up)
 191 {
 192         serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
 193         serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO |
 194                        UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
 195         serial_out(up, UART_FCR, 0);
 196 }
 197 
 198 #ifdef CONFIG_PM
 199 static int serial_omap_get_context_loss_count(struct uart_omap_port *up)
 200 {
 201         struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
 202 
 203         if (!pdata || !pdata->get_context_loss_count)
 204                 return -EINVAL;
 205 
 206         return pdata->get_context_loss_count(up->dev);
 207 }
 208 
 209 /* REVISIT: Remove this when omap3 boots in device tree only mode */
 210 static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
 211 {
 212         struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
 213 
 214         if (!pdata || !pdata->enable_wakeup)
 215                 return;
 216 
 217         pdata->enable_wakeup(up->dev, enable);
 218 }
 219 #endif /* CONFIG_PM */
 220 
 221 /*
 222  * Calculate the absolute difference between the desired and actual baud
 223  * rate for the given mode.
 224  */
 225 static inline int calculate_baud_abs_diff(struct uart_port *port,
 226                                 unsigned int baud, unsigned int mode)
 227 {
 228         unsigned int n = port->uartclk / (mode * baud);
 229         int abs_diff;
 230 
 231         if (n == 0)
 232                 n = 1;
 233 
 234         abs_diff = baud - (port->uartclk / (mode * n));
 235         if (abs_diff < 0)
 236                 abs_diff = -abs_diff;
 237 
 238         return abs_diff;
 239 }
 240 
 241 /*
 242  * serial_omap_baud_is_mode16 - check if baud rate is MODE16X
 243  * @port: uart port info
 244  * @baud: baudrate for which mode needs to be determined
 245  *
 246  * Returns true if baud rate is MODE16X and false if MODE13X
 247  * Original table in OMAP TRM named "UART Mode Baud Rates, Divisor Values,
 248  * and Error Rates" determines modes not for all common baud rates.
 249  * E.g. for 1000000 baud rate mode must be 16x, but according to that
 250  * table it's determined as 13x.
 251  */
 252 static bool
 253 serial_omap_baud_is_mode16(struct uart_port *port, unsigned int baud)
 254 {
 255         int abs_diff_13 = calculate_baud_abs_diff(port, baud, 13);
 256         int abs_diff_16 = calculate_baud_abs_diff(port, baud, 16);
 257 
 258         return (abs_diff_13 >= abs_diff_16);
 259 }
 260 
 261 /*
 262  * serial_omap_get_divisor - calculate divisor value
 263  * @port: uart port info
 264  * @baud: baudrate for which divisor needs to be calculated.
 265  */
 266 static unsigned int
 267 serial_omap_get_divisor(struct uart_port *port, unsigned int baud)
 268 {
 269         unsigned int mode;
 270 
 271         if (!serial_omap_baud_is_mode16(port, baud))
 272                 mode = 13;
 273         else
 274                 mode = 16;
 275         return port->uartclk/(mode * baud);
 276 }
 277 
 278 static void serial_omap_enable_ms(struct uart_port *port)
 279 {
 280         struct uart_omap_port *up = to_uart_omap_port(port);
 281 
 282         dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->port.line);
 283 
 284         pm_runtime_get_sync(up->dev);
 285         up->ier |= UART_IER_MSI;
 286         serial_out(up, UART_IER, up->ier);
 287         pm_runtime_mark_last_busy(up->dev);
 288         pm_runtime_put_autosuspend(up->dev);
 289 }
 290 
 291 static void serial_omap_stop_tx(struct uart_port *port)
 292 {
 293         struct uart_omap_port *up = to_uart_omap_port(port);
 294         int res;
 295 
 296         pm_runtime_get_sync(up->dev);
 297 
 298         /* Handle RS-485 */
 299         if (port->rs485.flags & SER_RS485_ENABLED) {
 300                 if (up->scr & OMAP_UART_SCR_TX_EMPTY) {
 301                         /* THR interrupt is fired when both TX FIFO and TX
 302                          * shift register are empty. This means there's nothing
 303                          * left to transmit now, so make sure the THR interrupt
 304                          * is fired when TX FIFO is below the trigger level,
 305                          * disable THR interrupts and toggle the RS-485 GPIO
 306                          * data direction pin if needed.
 307                          */
 308                         up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
 309                         serial_out(up, UART_OMAP_SCR, up->scr);
 310                         res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ?
 311                                 1 : 0;
 312                         if (gpio_get_value(up->rts_gpio) != res) {
 313                                 if (port->rs485.delay_rts_after_send > 0)
 314                                         mdelay(
 315                                         port->rs485.delay_rts_after_send);
 316                                 gpio_set_value(up->rts_gpio, res);
 317                         }
 318                 } else {
 319                         /* We're asked to stop, but there's still stuff in the
 320                          * UART FIFO, so make sure the THR interrupt is fired
 321                          * when both TX FIFO and TX shift register are empty.
 322                          * The next THR interrupt (if no transmission is started
 323                          * in the meantime) will indicate the end of a
 324                          * transmission. Therefore we _don't_ disable THR
 325                          * interrupts in this situation.
 326                          */
 327                         up->scr |= OMAP_UART_SCR_TX_EMPTY;
 328                         serial_out(up, UART_OMAP_SCR, up->scr);
 329                         return;
 330                 }
 331         }
 332 
 333         if (up->ier & UART_IER_THRI) {
 334                 up->ier &= ~UART_IER_THRI;
 335                 serial_out(up, UART_IER, up->ier);
 336         }
 337 
 338         if ((port->rs485.flags & SER_RS485_ENABLED) &&
 339             !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
 340                 /*
 341                  * Empty the RX FIFO, we are not interested in anything
 342                  * received during the half-duplex transmission.
 343                  */
 344                 serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_RCVR);
 345                 /* Re-enable RX interrupts */
 346                 up->ier |= UART_IER_RLSI | UART_IER_RDI;
 347                 up->port.read_status_mask |= UART_LSR_DR;
 348                 serial_out(up, UART_IER, up->ier);
 349         }
 350 
 351         pm_runtime_mark_last_busy(up->dev);
 352         pm_runtime_put_autosuspend(up->dev);
 353 }
 354 
 355 static void serial_omap_stop_rx(struct uart_port *port)
 356 {
 357         struct uart_omap_port *up = to_uart_omap_port(port);
 358 
 359         pm_runtime_get_sync(up->dev);
 360         up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
 361         up->port.read_status_mask &= ~UART_LSR_DR;
 362         serial_out(up, UART_IER, up->ier);
 363         pm_runtime_mark_last_busy(up->dev);
 364         pm_runtime_put_autosuspend(up->dev);
 365 }
 366 
 367 static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
 368 {
 369         struct circ_buf *xmit = &up->port.state->xmit;
 370         int count;
 371 
 372         if (up->port.x_char) {
 373                 serial_out(up, UART_TX, up->port.x_char);
 374                 up->port.icount.tx++;
 375                 up->port.x_char = 0;
 376                 return;
 377         }
 378         if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
 379                 serial_omap_stop_tx(&up->port);
 380                 return;
 381         }
 382         count = up->port.fifosize / 4;
 383         do {
 384                 serial_out(up, UART_TX, xmit->buf[xmit->tail]);
 385                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 386                 up->port.icount.tx++;
 387                 if (uart_circ_empty(xmit))
 388                         break;
 389         } while (--count > 0);
 390 
 391         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 392                 uart_write_wakeup(&up->port);
 393 
 394         if (uart_circ_empty(xmit))
 395                 serial_omap_stop_tx(&up->port);
 396 }
 397 
 398 static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up)
 399 {
 400         if (!(up->ier & UART_IER_THRI)) {
 401                 up->ier |= UART_IER_THRI;
 402                 serial_out(up, UART_IER, up->ier);
 403         }
 404 }
 405 
 406 static void serial_omap_start_tx(struct uart_port *port)
 407 {
 408         struct uart_omap_port *up = to_uart_omap_port(port);
 409         int res;
 410 
 411         pm_runtime_get_sync(up->dev);
 412 
 413         /* Handle RS-485 */
 414         if (port->rs485.flags & SER_RS485_ENABLED) {
 415                 /* Fire THR interrupts when FIFO is below trigger level */
 416                 up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
 417                 serial_out(up, UART_OMAP_SCR, up->scr);
 418 
 419                 /* if rts not already enabled */
 420                 res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
 421                 if (gpio_get_value(up->rts_gpio) != res) {
 422                         gpio_set_value(up->rts_gpio, res);
 423                         if (port->rs485.delay_rts_before_send > 0)
 424                                 mdelay(port->rs485.delay_rts_before_send);
 425                 }
 426         }
 427 
 428         if ((port->rs485.flags & SER_RS485_ENABLED) &&
 429             !(port->rs485.flags & SER_RS485_RX_DURING_TX))
 430                 serial_omap_stop_rx(port);
 431 
 432         serial_omap_enable_ier_thri(up);
 433         pm_runtime_mark_last_busy(up->dev);
 434         pm_runtime_put_autosuspend(up->dev);
 435 }
 436 
 437 static void serial_omap_throttle(struct uart_port *port)
 438 {
 439         struct uart_omap_port *up = to_uart_omap_port(port);
 440         unsigned long flags;
 441 
 442         pm_runtime_get_sync(up->dev);
 443         spin_lock_irqsave(&up->port.lock, flags);
 444         up->ier &= ~(UART_IER_RLSI | UART_IER_RDI);
 445         serial_out(up, UART_IER, up->ier);
 446         spin_unlock_irqrestore(&up->port.lock, flags);
 447         pm_runtime_mark_last_busy(up->dev);
 448         pm_runtime_put_autosuspend(up->dev);
 449 }
 450 
 451 static void serial_omap_unthrottle(struct uart_port *port)
 452 {
 453         struct uart_omap_port *up = to_uart_omap_port(port);
 454         unsigned long flags;
 455 
 456         pm_runtime_get_sync(up->dev);
 457         spin_lock_irqsave(&up->port.lock, flags);
 458         up->ier |= UART_IER_RLSI | UART_IER_RDI;
 459         serial_out(up, UART_IER, up->ier);
 460         spin_unlock_irqrestore(&up->port.lock, flags);
 461         pm_runtime_mark_last_busy(up->dev);
 462         pm_runtime_put_autosuspend(up->dev);
 463 }
 464 
 465 static unsigned int check_modem_status(struct uart_omap_port *up)
 466 {
 467         unsigned int status;
 468 
 469         status = serial_in(up, UART_MSR);
 470         status |= up->msr_saved_flags;
 471         up->msr_saved_flags = 0;
 472         if ((status & UART_MSR_ANY_DELTA) == 0)
 473                 return status;
 474 
 475         if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI &&
 476             up->port.state != NULL) {
 477                 if (status & UART_MSR_TERI)
 478                         up->port.icount.rng++;
 479                 if (status & UART_MSR_DDSR)
 480                         up->port.icount.dsr++;
 481                 if (status & UART_MSR_DDCD)
 482                         uart_handle_dcd_change
 483                                 (&up->port, status & UART_MSR_DCD);
 484                 if (status & UART_MSR_DCTS)
 485                         uart_handle_cts_change
 486                                 (&up->port, status & UART_MSR_CTS);
 487                 wake_up_interruptible(&up->port.state->port.delta_msr_wait);
 488         }
 489 
 490         return status;
 491 }
 492 
 493 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
 494 {
 495         unsigned int flag;
 496         unsigned char ch = 0;
 497 
 498         if (likely(lsr & UART_LSR_DR))
 499                 ch = serial_in(up, UART_RX);
 500 
 501         up->port.icount.rx++;
 502         flag = TTY_NORMAL;
 503 
 504         if (lsr & UART_LSR_BI) {
 505                 flag = TTY_BREAK;
 506                 lsr &= ~(UART_LSR_FE | UART_LSR_PE);
 507                 up->port.icount.brk++;
 508                 /*
 509                  * We do the SysRQ and SAK checking
 510                  * here because otherwise the break
 511                  * may get masked by ignore_status_mask
 512                  * or read_status_mask.
 513                  */
 514                 if (uart_handle_break(&up->port))
 515                         return;
 516 
 517         }
 518 
 519         if (lsr & UART_LSR_PE) {
 520                 flag = TTY_PARITY;
 521                 up->port.icount.parity++;
 522         }
 523 
 524         if (lsr & UART_LSR_FE) {
 525                 flag = TTY_FRAME;
 526                 up->port.icount.frame++;
 527         }
 528 
 529         if (lsr & UART_LSR_OE)
 530                 up->port.icount.overrun++;
 531 
 532 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
 533         if (up->port.line == up->port.cons->index) {
 534                 /* Recover the break flag from console xmit */
 535                 lsr |= up->lsr_break_flag;
 536         }
 537 #endif
 538         uart_insert_char(&up->port, lsr, UART_LSR_OE, 0, flag);
 539 }
 540 
 541 static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
 542 {
 543         unsigned char ch = 0;
 544         unsigned int flag;
 545 
 546         if (!(lsr & UART_LSR_DR))
 547                 return;
 548 
 549         ch = serial_in(up, UART_RX);
 550         flag = TTY_NORMAL;
 551         up->port.icount.rx++;
 552 
 553         if (uart_handle_sysrq_char(&up->port, ch))
 554                 return;
 555 
 556         uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
 557 }
 558 
 559 /**
 560  * serial_omap_irq() - This handles the interrupt from one port
 561  * @irq: uart port irq number
 562  * @dev_id: uart port info
 563  */
 564 static irqreturn_t serial_omap_irq(int irq, void *dev_id)
 565 {
 566         struct uart_omap_port *up = dev_id;
 567         unsigned int iir, lsr;
 568         unsigned int type;
 569         irqreturn_t ret = IRQ_NONE;
 570         int max_count = 256;
 571 
 572         spin_lock(&up->port.lock);
 573         pm_runtime_get_sync(up->dev);
 574 
 575         do {
 576                 iir = serial_in(up, UART_IIR);
 577                 if (iir & UART_IIR_NO_INT)
 578                         break;
 579 
 580                 ret = IRQ_HANDLED;
 581                 lsr = serial_in(up, UART_LSR);
 582 
 583                 /* extract IRQ type from IIR register */
 584                 type = iir & 0x3e;
 585 
 586                 switch (type) {
 587                 case UART_IIR_MSI:
 588                         check_modem_status(up);
 589                         break;
 590                 case UART_IIR_THRI:
 591                         transmit_chars(up, lsr);
 592                         break;
 593                 case UART_IIR_RX_TIMEOUT:
 594                         /* FALLTHROUGH */
 595                 case UART_IIR_RDI:
 596                         serial_omap_rdi(up, lsr);
 597                         break;
 598                 case UART_IIR_RLSI:
 599                         serial_omap_rlsi(up, lsr);
 600                         break;
 601                 case UART_IIR_CTS_RTS_DSR:
 602                         /* simply try again */
 603                         break;
 604                 case UART_IIR_XOFF:
 605                         /* FALLTHROUGH */
 606                 default:
 607                         break;
 608                 }
 609         } while (max_count--);
 610 
 611         spin_unlock(&up->port.lock);
 612 
 613         tty_flip_buffer_push(&up->port.state->port);
 614 
 615         pm_runtime_mark_last_busy(up->dev);
 616         pm_runtime_put_autosuspend(up->dev);
 617         up->port_activity = jiffies;
 618 
 619         return ret;
 620 }
 621 
 622 static unsigned int serial_omap_tx_empty(struct uart_port *port)
 623 {
 624         struct uart_omap_port *up = to_uart_omap_port(port);
 625         unsigned long flags = 0;
 626         unsigned int ret = 0;
 627 
 628         pm_runtime_get_sync(up->dev);
 629         dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->port.line);
 630         spin_lock_irqsave(&up->port.lock, flags);
 631         ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
 632         spin_unlock_irqrestore(&up->port.lock, flags);
 633         pm_runtime_mark_last_busy(up->dev);
 634         pm_runtime_put_autosuspend(up->dev);
 635         return ret;
 636 }
 637 
 638 static unsigned int serial_omap_get_mctrl(struct uart_port *port)
 639 {
 640         struct uart_omap_port *up = to_uart_omap_port(port);
 641         unsigned int status;
 642         unsigned int ret = 0;
 643 
 644         pm_runtime_get_sync(up->dev);
 645         status = check_modem_status(up);
 646         pm_runtime_mark_last_busy(up->dev);
 647         pm_runtime_put_autosuspend(up->dev);
 648 
 649         dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->port.line);
 650 
 651         if (status & UART_MSR_DCD)
 652                 ret |= TIOCM_CAR;
 653         if (status & UART_MSR_RI)
 654                 ret |= TIOCM_RNG;
 655         if (status & UART_MSR_DSR)
 656                 ret |= TIOCM_DSR;
 657         if (status & UART_MSR_CTS)
 658                 ret |= TIOCM_CTS;
 659         return ret;
 660 }
 661 
 662 static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl)
 663 {
 664         struct uart_omap_port *up = to_uart_omap_port(port);
 665         unsigned char mcr = 0, old_mcr, lcr;
 666 
 667         dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->port.line);
 668         if (mctrl & TIOCM_RTS)
 669                 mcr |= UART_MCR_RTS;
 670         if (mctrl & TIOCM_DTR)
 671                 mcr |= UART_MCR_DTR;
 672         if (mctrl & TIOCM_OUT1)
 673                 mcr |= UART_MCR_OUT1;
 674         if (mctrl & TIOCM_OUT2)
 675                 mcr |= UART_MCR_OUT2;
 676         if (mctrl & TIOCM_LOOP)
 677                 mcr |= UART_MCR_LOOP;
 678 
 679         pm_runtime_get_sync(up->dev);
 680         old_mcr = serial_in(up, UART_MCR);
 681         old_mcr &= ~(UART_MCR_LOOP | UART_MCR_OUT2 | UART_MCR_OUT1 |
 682                      UART_MCR_DTR | UART_MCR_RTS);
 683         up->mcr = old_mcr | mcr;
 684         serial_out(up, UART_MCR, up->mcr);
 685 
 686         /* Turn off autoRTS if RTS is lowered; restore autoRTS if RTS raised */
 687         lcr = serial_in(up, UART_LCR);
 688         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 689         if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
 690                 up->efr |= UART_EFR_RTS;
 691         else
 692                 up->efr &= ~UART_EFR_RTS;
 693         serial_out(up, UART_EFR, up->efr);
 694         serial_out(up, UART_LCR, lcr);
 695 
 696         pm_runtime_mark_last_busy(up->dev);
 697         pm_runtime_put_autosuspend(up->dev);
 698 }
 699 
 700 static void serial_omap_break_ctl(struct uart_port *port, int break_state)
 701 {
 702         struct uart_omap_port *up = to_uart_omap_port(port);
 703         unsigned long flags = 0;
 704 
 705         dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->port.line);
 706         pm_runtime_get_sync(up->dev);
 707         spin_lock_irqsave(&up->port.lock, flags);
 708         if (break_state == -1)
 709                 up->lcr |= UART_LCR_SBC;
 710         else
 711                 up->lcr &= ~UART_LCR_SBC;
 712         serial_out(up, UART_LCR, up->lcr);
 713         spin_unlock_irqrestore(&up->port.lock, flags);
 714         pm_runtime_mark_last_busy(up->dev);
 715         pm_runtime_put_autosuspend(up->dev);
 716 }
 717 
 718 static int serial_omap_startup(struct uart_port *port)
 719 {
 720         struct uart_omap_port *up = to_uart_omap_port(port);
 721         unsigned long flags = 0;
 722         int retval;
 723 
 724         /*
 725          * Allocate the IRQ
 726          */
 727         retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags,
 728                                 up->name, up);
 729         if (retval)
 730                 return retval;
 731 
 732         /* Optional wake-up IRQ */
 733         if (up->wakeirq) {
 734                 retval = dev_pm_set_dedicated_wake_irq(up->dev, up->wakeirq);
 735                 if (retval) {
 736                         free_irq(up->port.irq, up);
 737                         return retval;
 738                 }
 739         }
 740 
 741         dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line);
 742 
 743         pm_runtime_get_sync(up->dev);
 744         /*
 745          * Clear the FIFO buffers and disable them.
 746          * (they will be reenabled in set_termios())
 747          */
 748         serial_omap_clear_fifos(up);
 749 
 750         /*
 751          * Clear the interrupt registers.
 752          */
 753         (void) serial_in(up, UART_LSR);
 754         if (serial_in(up, UART_LSR) & UART_LSR_DR)
 755                 (void) serial_in(up, UART_RX);
 756         (void) serial_in(up, UART_IIR);
 757         (void) serial_in(up, UART_MSR);
 758 
 759         /*
 760          * Now, initialize the UART
 761          */
 762         serial_out(up, UART_LCR, UART_LCR_WLEN8);
 763         spin_lock_irqsave(&up->port.lock, flags);
 764         /*
 765          * Most PC uarts need OUT2 raised to enable interrupts.
 766          */
 767         up->port.mctrl |= TIOCM_OUT2;
 768         serial_omap_set_mctrl(&up->port, up->port.mctrl);
 769         spin_unlock_irqrestore(&up->port.lock, flags);
 770 
 771         up->msr_saved_flags = 0;
 772         /*
 773          * Finally, enable interrupts. Note: Modem status interrupts
 774          * are set via set_termios(), which will be occurring imminently
 775          * anyway, so we don't enable them here.
 776          */
 777         up->ier = UART_IER_RLSI | UART_IER_RDI;
 778         serial_out(up, UART_IER, up->ier);
 779 
 780         /* Enable module level wake up */
 781         up->wer = OMAP_UART_WER_MOD_WKUP;
 782         if (up->features & OMAP_UART_WER_HAS_TX_WAKEUP)
 783                 up->wer |= OMAP_UART_TX_WAKEUP_EN;
 784 
 785         serial_out(up, UART_OMAP_WER, up->wer);
 786 
 787         pm_runtime_mark_last_busy(up->dev);
 788         pm_runtime_put_autosuspend(up->dev);
 789         up->port_activity = jiffies;
 790         return 0;
 791 }
 792 
 793 static void serial_omap_shutdown(struct uart_port *port)
 794 {
 795         struct uart_omap_port *up = to_uart_omap_port(port);
 796         unsigned long flags = 0;
 797 
 798         dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->port.line);
 799 
 800         pm_runtime_get_sync(up->dev);
 801         /*
 802          * Disable interrupts from this port
 803          */
 804         up->ier = 0;
 805         serial_out(up, UART_IER, 0);
 806 
 807         spin_lock_irqsave(&up->port.lock, flags);
 808         up->port.mctrl &= ~TIOCM_OUT2;
 809         serial_omap_set_mctrl(&up->port, up->port.mctrl);
 810         spin_unlock_irqrestore(&up->port.lock, flags);
 811 
 812         /*
 813          * Disable break condition and FIFOs
 814          */
 815         serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC);
 816         serial_omap_clear_fifos(up);
 817 
 818         /*
 819          * Read data port to reset things, and then free the irq
 820          */
 821         if (serial_in(up, UART_LSR) & UART_LSR_DR)
 822                 (void) serial_in(up, UART_RX);
 823 
 824         pm_runtime_mark_last_busy(up->dev);
 825         pm_runtime_put_autosuspend(up->dev);
 826         free_irq(up->port.irq, up);
 827         dev_pm_clear_wake_irq(up->dev);
 828 }
 829 
 830 static void serial_omap_uart_qos_work(struct work_struct *work)
 831 {
 832         struct uart_omap_port *up = container_of(work, struct uart_omap_port,
 833                                                 qos_work);
 834 
 835         pm_qos_update_request(&up->pm_qos_request, up->latency);
 836 }
 837 
 838 static void
 839 serial_omap_set_termios(struct uart_port *port, struct ktermios *termios,
 840                         struct ktermios *old)
 841 {
 842         struct uart_omap_port *up = to_uart_omap_port(port);
 843         unsigned char cval = 0;
 844         unsigned long flags = 0;
 845         unsigned int baud, quot;
 846 
 847         switch (termios->c_cflag & CSIZE) {
 848         case CS5:
 849                 cval = UART_LCR_WLEN5;
 850                 break;
 851         case CS6:
 852                 cval = UART_LCR_WLEN6;
 853                 break;
 854         case CS7:
 855                 cval = UART_LCR_WLEN7;
 856                 break;
 857         default:
 858         case CS8:
 859                 cval = UART_LCR_WLEN8;
 860                 break;
 861         }
 862 
 863         if (termios->c_cflag & CSTOPB)
 864                 cval |= UART_LCR_STOP;
 865         if (termios->c_cflag & PARENB)
 866                 cval |= UART_LCR_PARITY;
 867         if (!(termios->c_cflag & PARODD))
 868                 cval |= UART_LCR_EPAR;
 869         if (termios->c_cflag & CMSPAR)
 870                 cval |= UART_LCR_SPAR;
 871 
 872         /*
 873          * Ask the core to calculate the divisor for us.
 874          */
 875 
 876         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13);
 877         quot = serial_omap_get_divisor(port, baud);
 878 
 879         /* calculate wakeup latency constraint */
 880         up->calc_latency = (USEC_PER_SEC * up->port.fifosize) / (baud / 8);
 881         up->latency = up->calc_latency;
 882         schedule_work(&up->qos_work);
 883 
 884         up->dll = quot & 0xff;
 885         up->dlh = quot >> 8;
 886         up->mdr1 = UART_OMAP_MDR1_DISABLE;
 887 
 888         up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 |
 889                         UART_FCR_ENABLE_FIFO;
 890 
 891         /*
 892          * Ok, we're now changing the port state. Do it with
 893          * interrupts disabled.
 894          */
 895         pm_runtime_get_sync(up->dev);
 896         spin_lock_irqsave(&up->port.lock, flags);
 897 
 898         /*
 899          * Update the per-port timeout.
 900          */
 901         uart_update_timeout(port, termios->c_cflag, baud);
 902 
 903         up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
 904         if (termios->c_iflag & INPCK)
 905                 up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
 906         if (termios->c_iflag & (BRKINT | PARMRK))
 907                 up->port.read_status_mask |= UART_LSR_BI;
 908 
 909         /*
 910          * Characters to ignore
 911          */
 912         up->port.ignore_status_mask = 0;
 913         if (termios->c_iflag & IGNPAR)
 914                 up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
 915         if (termios->c_iflag & IGNBRK) {
 916                 up->port.ignore_status_mask |= UART_LSR_BI;
 917                 /*
 918                  * If we're ignoring parity and break indicators,
 919                  * ignore overruns too (for real raw support).
 920                  */
 921                 if (termios->c_iflag & IGNPAR)
 922                         up->port.ignore_status_mask |= UART_LSR_OE;
 923         }
 924 
 925         /*
 926          * ignore all characters if CREAD is not set
 927          */
 928         if ((termios->c_cflag & CREAD) == 0)
 929                 up->port.ignore_status_mask |= UART_LSR_DR;
 930 
 931         /*
 932          * Modem status interrupts
 933          */
 934         up->ier &= ~UART_IER_MSI;
 935         if (UART_ENABLE_MS(&up->port, termios->c_cflag))
 936                 up->ier |= UART_IER_MSI;
 937         serial_out(up, UART_IER, up->ier);
 938         serial_out(up, UART_LCR, cval);         /* reset DLAB */
 939         up->lcr = cval;
 940         up->scr = 0;
 941 
 942         /* FIFOs and DMA Settings */
 943 
 944         /* FCR can be changed only when the
 945          * baud clock is not running
 946          * DLL_REG and DLH_REG set to 0.
 947          */
 948         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 949         serial_out(up, UART_DLL, 0);
 950         serial_out(up, UART_DLM, 0);
 951         serial_out(up, UART_LCR, 0);
 952 
 953         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 954 
 955         up->efr = serial_in(up, UART_EFR) & ~UART_EFR_ECB;
 956         up->efr &= ~UART_EFR_SCD;
 957         serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
 958 
 959         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 960         up->mcr = serial_in(up, UART_MCR) & ~UART_MCR_TCRTLR;
 961         serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
 962         /* FIFO ENABLE, DMA MODE */
 963 
 964         up->scr |= OMAP_UART_SCR_RX_TRIG_GRANU1_MASK;
 965         /*
 966          * NOTE: Setting OMAP_UART_SCR_RX_TRIG_GRANU1_MASK
 967          * sets Enables the granularity of 1 for TRIGGER RX
 968          * level. Along with setting RX FIFO trigger level
 969          * to 1 (as noted below, 16 characters) and TLR[3:0]
 970          * to zero this will result RX FIFO threshold level
 971          * to 1 character, instead of 16 as noted in comment
 972          * below.
 973          */
 974 
 975         /* Set receive FIFO threshold to 16 characters and
 976          * transmit FIFO threshold to 32 spaces
 977          */
 978         up->fcr &= ~OMAP_UART_FCR_RX_FIFO_TRIG_MASK;
 979         up->fcr &= ~OMAP_UART_FCR_TX_FIFO_TRIG_MASK;
 980         up->fcr |= UART_FCR6_R_TRIGGER_16 | UART_FCR6_T_TRIGGER_24 |
 981                 UART_FCR_ENABLE_FIFO;
 982 
 983         serial_out(up, UART_FCR, up->fcr);
 984         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 985 
 986         serial_out(up, UART_OMAP_SCR, up->scr);
 987 
 988         /* Reset UART_MCR_TCRTLR: this must be done with the EFR_ECB bit set */
 989         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 990         serial_out(up, UART_MCR, up->mcr);
 991         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 992         serial_out(up, UART_EFR, up->efr);
 993         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
 994 
 995         /* Protocol, Baud Rate, and Interrupt Settings */
 996 
 997         if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
 998                 serial_omap_mdr1_errataset(up, up->mdr1);
 999         else
1000                 serial_out(up, UART_OMAP_MDR1, up->mdr1);
1001 
1002         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1003         serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
1004 
1005         serial_out(up, UART_LCR, 0);
1006         serial_out(up, UART_IER, 0);
1007         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1008 
1009         serial_out(up, UART_DLL, up->dll);      /* LS of divisor */
1010         serial_out(up, UART_DLM, up->dlh);      /* MS of divisor */
1011 
1012         serial_out(up, UART_LCR, 0);
1013         serial_out(up, UART_IER, up->ier);
1014         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1015 
1016         serial_out(up, UART_EFR, up->efr);
1017         serial_out(up, UART_LCR, cval);
1018 
1019         if (!serial_omap_baud_is_mode16(port, baud))
1020                 up->mdr1 = UART_OMAP_MDR1_13X_MODE;
1021         else
1022                 up->mdr1 = UART_OMAP_MDR1_16X_MODE;
1023 
1024         if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1025                 serial_omap_mdr1_errataset(up, up->mdr1);
1026         else
1027                 serial_out(up, UART_OMAP_MDR1, up->mdr1);
1028 
1029         /* Configure flow control */
1030         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1031 
1032         /* XON1/XOFF1 accessible mode B, TCRTLR=0, ECB=0 */
1033         serial_out(up, UART_XON1, termios->c_cc[VSTART]);
1034         serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]);
1035 
1036         /* Enable access to TCR/TLR */
1037         serial_out(up, UART_EFR, up->efr | UART_EFR_ECB);
1038         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1039         serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR);
1040 
1041         serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG);
1042 
1043         up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
1044 
1045         if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
1046                 /* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
1047                 up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
1048                 up->efr |= UART_EFR_CTS;
1049         } else {
1050                 /* Disable AUTORTS and AUTOCTS */
1051                 up->efr &= ~(UART_EFR_CTS | UART_EFR_RTS);
1052         }
1053 
1054         if (up->port.flags & UPF_SOFT_FLOW) {
1055                 /* clear SW control mode bits */
1056                 up->efr &= OMAP_UART_SW_CLR;
1057 
1058                 /*
1059                  * IXON Flag:
1060                  * Enable XON/XOFF flow control on input.
1061                  * Receiver compares XON1, XOFF1.
1062                  */
1063                 if (termios->c_iflag & IXON)
1064                         up->efr |= OMAP_UART_SW_RX;
1065 
1066                 /*
1067                  * IXOFF Flag:
1068                  * Enable XON/XOFF flow control on output.
1069                  * Transmit XON1, XOFF1
1070                  */
1071                 if (termios->c_iflag & IXOFF) {
1072                         up->port.status |= UPSTAT_AUTOXOFF;
1073                         up->efr |= OMAP_UART_SW_TX;
1074                 }
1075 
1076                 /*
1077                  * IXANY Flag:
1078                  * Enable any character to restart output.
1079                  * Operation resumes after receiving any
1080                  * character after recognition of the XOFF character
1081                  */
1082                 if (termios->c_iflag & IXANY)
1083                         up->mcr |= UART_MCR_XONANY;
1084                 else
1085                         up->mcr &= ~UART_MCR_XONANY;
1086         }
1087         serial_out(up, UART_MCR, up->mcr);
1088         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1089         serial_out(up, UART_EFR, up->efr);
1090         serial_out(up, UART_LCR, up->lcr);
1091 
1092         serial_omap_set_mctrl(&up->port, up->port.mctrl);
1093 
1094         spin_unlock_irqrestore(&up->port.lock, flags);
1095         pm_runtime_mark_last_busy(up->dev);
1096         pm_runtime_put_autosuspend(up->dev);
1097         dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->port.line);
1098 }
1099 
1100 static void
1101 serial_omap_pm(struct uart_port *port, unsigned int state,
1102                unsigned int oldstate)
1103 {
1104         struct uart_omap_port *up = to_uart_omap_port(port);
1105         unsigned char efr;
1106 
1107         dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->port.line);
1108 
1109         pm_runtime_get_sync(up->dev);
1110         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1111         efr = serial_in(up, UART_EFR);
1112         serial_out(up, UART_EFR, efr | UART_EFR_ECB);
1113         serial_out(up, UART_LCR, 0);
1114 
1115         serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0);
1116         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
1117         serial_out(up, UART_EFR, efr);
1118         serial_out(up, UART_LCR, 0);
1119 
1120         pm_runtime_mark_last_busy(up->dev);
1121         pm_runtime_put_autosuspend(up->dev);
1122 }
1123 
1124 static void serial_omap_release_port(struct uart_port *port)
1125 {
1126         dev_dbg(port->dev, "serial_omap_release_port+\n");
1127 }
1128 
1129 static int serial_omap_request_port(struct uart_port *port)
1130 {
1131         dev_dbg(port->dev, "serial_omap_request_port+\n");
1132         return 0;
1133 }
1134 
1135 static void serial_omap_config_port(struct uart_port *port, int flags)
1136 {
1137         struct uart_omap_port *up = to_uart_omap_port(port);
1138 
1139         dev_dbg(up->port.dev, "serial_omap_config_port+%d\n",
1140                                                         up->port.line);
1141         up->port.type = PORT_OMAP;
1142         up->port.flags |= UPF_SOFT_FLOW | UPF_HARD_FLOW;
1143 }
1144 
1145 static int
1146 serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser)
1147 {
1148         /* we don't want the core code to modify any port params */
1149         dev_dbg(port->dev, "serial_omap_verify_port+\n");
1150         return -EINVAL;
1151 }
1152 
1153 static const char *
1154 serial_omap_type(struct uart_port *port)
1155 {
1156         struct uart_omap_port *up = to_uart_omap_port(port);
1157 
1158         dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->port.line);
1159         return up->name;
1160 }
1161 
1162 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
1163 
1164 static void __maybe_unused wait_for_xmitr(struct uart_omap_port *up)
1165 {
1166         unsigned int status, tmout = 10000;
1167 
1168         /* Wait up to 10ms for the character(s) to be sent. */
1169         do {
1170                 status = serial_in(up, UART_LSR);
1171 
1172                 if (status & UART_LSR_BI)
1173                         up->lsr_break_flag = UART_LSR_BI;
1174 
1175                 if (--tmout == 0)
1176                         break;
1177                 udelay(1);
1178         } while ((status & BOTH_EMPTY) != BOTH_EMPTY);
1179 
1180         /* Wait up to 1s for flow control if necessary */
1181         if (up->port.flags & UPF_CONS_FLOW) {
1182                 tmout = 1000000;
1183                 for (tmout = 1000000; tmout; tmout--) {
1184                         unsigned int msr = serial_in(up, UART_MSR);
1185 
1186                         up->msr_saved_flags |= msr & MSR_SAVE_FLAGS;
1187                         if (msr & UART_MSR_CTS)
1188                                 break;
1189 
1190                         udelay(1);
1191                 }
1192         }
1193 }
1194 
1195 #ifdef CONFIG_CONSOLE_POLL
1196 
1197 static void serial_omap_poll_put_char(struct uart_port *port, unsigned char ch)
1198 {
1199         struct uart_omap_port *up = to_uart_omap_port(port);
1200 
1201         pm_runtime_get_sync(up->dev);
1202         wait_for_xmitr(up);
1203         serial_out(up, UART_TX, ch);
1204         pm_runtime_mark_last_busy(up->dev);
1205         pm_runtime_put_autosuspend(up->dev);
1206 }
1207 
1208 static int serial_omap_poll_get_char(struct uart_port *port)
1209 {
1210         struct uart_omap_port *up = to_uart_omap_port(port);
1211         unsigned int status;
1212 
1213         pm_runtime_get_sync(up->dev);
1214         status = serial_in(up, UART_LSR);
1215         if (!(status & UART_LSR_DR)) {
1216                 status = NO_POLL_CHAR;
1217                 goto out;
1218         }
1219 
1220         status = serial_in(up, UART_RX);
1221 
1222 out:
1223         pm_runtime_mark_last_busy(up->dev);
1224         pm_runtime_put_autosuspend(up->dev);
1225 
1226         return status;
1227 }
1228 
1229 #endif /* CONFIG_CONSOLE_POLL */
1230 
1231 #ifdef CONFIG_SERIAL_OMAP_CONSOLE
1232 
1233 #ifdef CONFIG_SERIAL_EARLYCON
1234 static unsigned int omap_serial_early_in(struct uart_port *port, int offset)
1235 {
1236         offset <<= port->regshift;
1237         return readw(port->membase + offset);
1238 }
1239 
1240 static void omap_serial_early_out(struct uart_port *port, int offset,
1241                                   int value)
1242 {
1243         offset <<= port->regshift;
1244         writew(value, port->membase + offset);
1245 }
1246 
1247 static void omap_serial_early_putc(struct uart_port *port, int c)
1248 {
1249         unsigned int status;
1250 
1251         for (;;) {
1252                 status = omap_serial_early_in(port, UART_LSR);
1253                 if ((status & BOTH_EMPTY) == BOTH_EMPTY)
1254                         break;
1255                 cpu_relax();
1256         }
1257         omap_serial_early_out(port, UART_TX, c);
1258 }
1259 
1260 static void early_omap_serial_write(struct console *console, const char *s,
1261                                     unsigned int count)
1262 {
1263         struct earlycon_device *device = console->data;
1264         struct uart_port *port = &device->port;
1265 
1266         uart_console_write(port, s, count, omap_serial_early_putc);
1267 }
1268 
1269 static int __init early_omap_serial_setup(struct earlycon_device *device,
1270                                           const char *options)
1271 {
1272         struct uart_port *port = &device->port;
1273 
1274         if (!(device->port.membase || device->port.iobase))
1275                 return -ENODEV;
1276 
1277         port->regshift = 2;
1278         device->con->write = early_omap_serial_write;
1279         return 0;
1280 }
1281 
1282 OF_EARLYCON_DECLARE(omapserial, "ti,omap2-uart", early_omap_serial_setup);
1283 OF_EARLYCON_DECLARE(omapserial, "ti,omap3-uart", early_omap_serial_setup);
1284 OF_EARLYCON_DECLARE(omapserial, "ti,omap4-uart", early_omap_serial_setup);
1285 #endif /* CONFIG_SERIAL_EARLYCON */
1286 
1287 static struct uart_omap_port *serial_omap_console_ports[OMAP_MAX_HSUART_PORTS];
1288 
1289 static struct uart_driver serial_omap_reg;
1290 
1291 static void serial_omap_console_putchar(struct uart_port *port, int ch)
1292 {
1293         struct uart_omap_port *up = to_uart_omap_port(port);
1294 
1295         wait_for_xmitr(up);
1296         serial_out(up, UART_TX, ch);
1297 }
1298 
1299 static void
1300 serial_omap_console_write(struct console *co, const char *s,
1301                 unsigned int count)
1302 {
1303         struct uart_omap_port *up = serial_omap_console_ports[co->index];
1304         unsigned long flags;
1305         unsigned int ier;
1306         int locked = 1;
1307 
1308         pm_runtime_get_sync(up->dev);
1309 
1310         local_irq_save(flags);
1311         if (up->port.sysrq)
1312                 locked = 0;
1313         else if (oops_in_progress)
1314                 locked = spin_trylock(&up->port.lock);
1315         else
1316                 spin_lock(&up->port.lock);
1317 
1318         /*
1319          * First save the IER then disable the interrupts
1320          */
1321         ier = serial_in(up, UART_IER);
1322         serial_out(up, UART_IER, 0);
1323 
1324         uart_console_write(&up->port, s, count, serial_omap_console_putchar);
1325 
1326         /*
1327          * Finally, wait for transmitter to become empty
1328          * and restore the IER
1329          */
1330         wait_for_xmitr(up);
1331         serial_out(up, UART_IER, ier);
1332         /*
1333          * The receive handling will happen properly because the
1334          * receive ready bit will still be set; it is not cleared
1335          * on read.  However, modem control will not, we must
1336          * call it if we have saved something in the saved flags
1337          * while processing with interrupts off.
1338          */
1339         if (up->msr_saved_flags)
1340                 check_modem_status(up);
1341 
1342         pm_runtime_mark_last_busy(up->dev);
1343         pm_runtime_put_autosuspend(up->dev);
1344         if (locked)
1345                 spin_unlock(&up->port.lock);
1346         local_irq_restore(flags);
1347 }
1348 
1349 static int __init
1350 serial_omap_console_setup(struct console *co, char *options)
1351 {
1352         struct uart_omap_port *up;
1353         int baud = 115200;
1354         int bits = 8;
1355         int parity = 'n';
1356         int flow = 'n';
1357 
1358         if (serial_omap_console_ports[co->index] == NULL)
1359                 return -ENODEV;
1360         up = serial_omap_console_ports[co->index];
1361 
1362         if (options)
1363                 uart_parse_options(options, &baud, &parity, &bits, &flow);
1364 
1365         return uart_set_options(&up->port, co, baud, parity, bits, flow);
1366 }
1367 
1368 static struct console serial_omap_console = {
1369         .name           = OMAP_SERIAL_NAME,
1370         .write          = serial_omap_console_write,
1371         .device         = uart_console_device,
1372         .setup          = serial_omap_console_setup,
1373         .flags          = CON_PRINTBUFFER,
1374         .index          = -1,
1375         .data           = &serial_omap_reg,
1376 };
1377 
1378 static void serial_omap_add_console_port(struct uart_omap_port *up)
1379 {
1380         serial_omap_console_ports[up->port.line] = up;
1381 }
1382 
1383 #define OMAP_CONSOLE    (&serial_omap_console)
1384 
1385 #else
1386 
1387 #define OMAP_CONSOLE    NULL
1388 
1389 static inline void serial_omap_add_console_port(struct uart_omap_port *up)
1390 {}
1391 
1392 #endif
1393 
1394 /* Enable or disable the rs485 support */
1395 static int
1396 serial_omap_config_rs485(struct uart_port *port, struct serial_rs485 *rs485)
1397 {
1398         struct uart_omap_port *up = to_uart_omap_port(port);
1399         unsigned int mode;
1400         int val;
1401 
1402         pm_runtime_get_sync(up->dev);
1403 
1404         /* Disable interrupts from this port */
1405         mode = up->ier;
1406         up->ier = 0;
1407         serial_out(up, UART_IER, 0);
1408 
1409         /* Clamp the delays to [0, 100ms] */
1410         rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
1411         rs485->delay_rts_after_send  = min(rs485->delay_rts_after_send, 100U);
1412 
1413         /* store new config */
1414         port->rs485 = *rs485;
1415 
1416         /*
1417          * Just as a precaution, only allow rs485
1418          * to be enabled if the gpio pin is valid
1419          */
1420         if (gpio_is_valid(up->rts_gpio)) {
1421                 /* enable / disable rts */
1422                 val = (port->rs485.flags & SER_RS485_ENABLED) ?
1423                         SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
1424                 val = (port->rs485.flags & val) ? 1 : 0;
1425                 gpio_set_value(up->rts_gpio, val);
1426         } else
1427                 port->rs485.flags &= ~SER_RS485_ENABLED;
1428 
1429         /* Enable interrupts */
1430         up->ier = mode;
1431         serial_out(up, UART_IER, up->ier);
1432 
1433         /* If RS-485 is disabled, make sure the THR interrupt is fired when
1434          * TX FIFO is below the trigger level.
1435          */
1436         if (!(port->rs485.flags & SER_RS485_ENABLED) &&
1437             (up->scr & OMAP_UART_SCR_TX_EMPTY)) {
1438                 up->scr &= ~OMAP_UART_SCR_TX_EMPTY;
1439                 serial_out(up, UART_OMAP_SCR, up->scr);
1440         }
1441 
1442         pm_runtime_mark_last_busy(up->dev);
1443         pm_runtime_put_autosuspend(up->dev);
1444 
1445         return 0;
1446 }
1447 
1448 static const struct uart_ops serial_omap_pops = {
1449         .tx_empty       = serial_omap_tx_empty,
1450         .set_mctrl      = serial_omap_set_mctrl,
1451         .get_mctrl      = serial_omap_get_mctrl,
1452         .stop_tx        = serial_omap_stop_tx,
1453         .start_tx       = serial_omap_start_tx,
1454         .throttle       = serial_omap_throttle,
1455         .unthrottle     = serial_omap_unthrottle,
1456         .stop_rx        = serial_omap_stop_rx,
1457         .enable_ms      = serial_omap_enable_ms,
1458         .break_ctl      = serial_omap_break_ctl,
1459         .startup        = serial_omap_startup,
1460         .shutdown       = serial_omap_shutdown,
1461         .set_termios    = serial_omap_set_termios,
1462         .pm             = serial_omap_pm,
1463         .type           = serial_omap_type,
1464         .release_port   = serial_omap_release_port,
1465         .request_port   = serial_omap_request_port,
1466         .config_port    = serial_omap_config_port,
1467         .verify_port    = serial_omap_verify_port,
1468 #ifdef CONFIG_CONSOLE_POLL
1469         .poll_put_char  = serial_omap_poll_put_char,
1470         .poll_get_char  = serial_omap_poll_get_char,
1471 #endif
1472 };
1473 
1474 static struct uart_driver serial_omap_reg = {
1475         .owner          = THIS_MODULE,
1476         .driver_name    = "OMAP-SERIAL",
1477         .dev_name       = OMAP_SERIAL_NAME,
1478         .nr             = OMAP_MAX_HSUART_PORTS,
1479         .cons           = OMAP_CONSOLE,
1480 };
1481 
1482 #ifdef CONFIG_PM_SLEEP
1483 static int serial_omap_prepare(struct device *dev)
1484 {
1485         struct uart_omap_port *up = dev_get_drvdata(dev);
1486 
1487         up->is_suspending = true;
1488 
1489         return 0;
1490 }
1491 
1492 static void serial_omap_complete(struct device *dev)
1493 {
1494         struct uart_omap_port *up = dev_get_drvdata(dev);
1495 
1496         up->is_suspending = false;
1497 }
1498 
1499 static int serial_omap_suspend(struct device *dev)
1500 {
1501         struct uart_omap_port *up = dev_get_drvdata(dev);
1502 
1503         uart_suspend_port(&serial_omap_reg, &up->port);
1504         flush_work(&up->qos_work);
1505 
1506         if (device_may_wakeup(dev))
1507                 serial_omap_enable_wakeup(up, true);
1508         else
1509                 serial_omap_enable_wakeup(up, false);
1510 
1511         return 0;
1512 }
1513 
1514 static int serial_omap_resume(struct device *dev)
1515 {
1516         struct uart_omap_port *up = dev_get_drvdata(dev);
1517 
1518         if (device_may_wakeup(dev))
1519                 serial_omap_enable_wakeup(up, false);
1520 
1521         uart_resume_port(&serial_omap_reg, &up->port);
1522 
1523         return 0;
1524 }
1525 #else
1526 #define serial_omap_prepare NULL
1527 #define serial_omap_complete NULL
1528 #endif /* CONFIG_PM_SLEEP */
1529 
1530 static void omap_serial_fill_features_erratas(struct uart_omap_port *up)
1531 {
1532         u32 mvr, scheme;
1533         u16 revision, major, minor;
1534 
1535         mvr = readl(up->port.membase + (UART_OMAP_MVER << up->port.regshift));
1536 
1537         /* Check revision register scheme */
1538         scheme = mvr >> OMAP_UART_MVR_SCHEME_SHIFT;
1539 
1540         switch (scheme) {
1541         case 0: /* Legacy Scheme: OMAP2/3 */
1542                 /* MINOR_REV[0:4], MAJOR_REV[4:7] */
1543                 major = (mvr & OMAP_UART_LEGACY_MVR_MAJ_MASK) >>
1544                                         OMAP_UART_LEGACY_MVR_MAJ_SHIFT;
1545                 minor = (mvr & OMAP_UART_LEGACY_MVR_MIN_MASK);
1546                 break;
1547         case 1:
1548                 /* New Scheme: OMAP4+ */
1549                 /* MINOR_REV[0:5], MAJOR_REV[8:10] */
1550                 major = (mvr & OMAP_UART_MVR_MAJ_MASK) >>
1551                                         OMAP_UART_MVR_MAJ_SHIFT;
1552                 minor = (mvr & OMAP_UART_MVR_MIN_MASK);
1553                 break;
1554         default:
1555                 dev_warn(up->dev,
1556                         "Unknown %s revision, defaulting to highest\n",
1557                         up->name);
1558                 /* highest possible revision */
1559                 major = 0xff;
1560                 minor = 0xff;
1561         }
1562 
1563         /* normalize revision for the driver */
1564         revision = UART_BUILD_REVISION(major, minor);
1565 
1566         switch (revision) {
1567         case OMAP_UART_REV_46:
1568                 up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
1569                                 UART_ERRATA_i291_DMA_FORCEIDLE);
1570                 break;
1571         case OMAP_UART_REV_52:
1572                 up->errata |= (UART_ERRATA_i202_MDR1_ACCESS |
1573                                 UART_ERRATA_i291_DMA_FORCEIDLE);
1574                 up->features |= OMAP_UART_WER_HAS_TX_WAKEUP;
1575                 break;
1576         case OMAP_UART_REV_63:
1577                 up->errata |= UART_ERRATA_i202_MDR1_ACCESS;
1578                 up->features |= OMAP_UART_WER_HAS_TX_WAKEUP;
1579                 break;
1580         default:
1581                 break;
1582         }
1583 }
1584 
1585 static struct omap_uart_port_info *of_get_uart_port_info(struct device *dev)
1586 {
1587         struct omap_uart_port_info *omap_up_info;
1588 
1589         omap_up_info = devm_kzalloc(dev, sizeof(*omap_up_info), GFP_KERNEL);
1590         if (!omap_up_info)
1591                 return NULL; /* out of memory */
1592 
1593         of_property_read_u32(dev->of_node, "clock-frequency",
1594                                          &omap_up_info->uartclk);
1595 
1596         omap_up_info->flags = UPF_BOOT_AUTOCONF;
1597 
1598         return omap_up_info;
1599 }
1600 
1601 static int serial_omap_probe_rs485(struct uart_omap_port *up,
1602                                    struct device_node *np)
1603 {
1604         struct serial_rs485 *rs485conf = &up->port.rs485;
1605         int ret;
1606 
1607         rs485conf->flags = 0;
1608         up->rts_gpio = -EINVAL;
1609 
1610         if (!np)
1611                 return 0;
1612 
1613         uart_get_rs485_mode(up->dev, rs485conf);
1614 
1615         if (of_property_read_bool(np, "rs485-rts-active-high")) {
1616                 rs485conf->flags |= SER_RS485_RTS_ON_SEND;
1617                 rs485conf->flags &= ~SER_RS485_RTS_AFTER_SEND;
1618         } else {
1619                 rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
1620                 rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
1621         }
1622 
1623         /* check for tx enable gpio */
1624         up->rts_gpio = of_get_named_gpio(np, "rts-gpio", 0);
1625         if (gpio_is_valid(up->rts_gpio)) {
1626                 ret = devm_gpio_request(up->dev, up->rts_gpio, "omap-serial");
1627                 if (ret < 0)
1628                         return ret;
1629                 ret = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ? 1 : 0;
1630                 ret = gpio_direction_output(up->rts_gpio, ret);
1631                 if (ret < 0)
1632                         return ret;
1633         } else if (up->rts_gpio == -EPROBE_DEFER) {
1634                 return -EPROBE_DEFER;
1635         } else {
1636                 up->rts_gpio = -EINVAL;
1637         }
1638 
1639         return 0;
1640 }
1641 
1642 static int serial_omap_probe(struct platform_device *pdev)
1643 {
1644         struct omap_uart_port_info *omap_up_info = dev_get_platdata(&pdev->dev);
1645         struct uart_omap_port *up;
1646         struct resource *mem;
1647         void __iomem *base;
1648         int uartirq = 0;
1649         int wakeirq = 0;
1650         int ret;
1651 
1652         /* The optional wakeirq may be specified in the board dts file */
1653         if (pdev->dev.of_node) {
1654                 uartirq = irq_of_parse_and_map(pdev->dev.of_node, 0);
1655                 if (!uartirq)
1656                         return -EPROBE_DEFER;
1657                 wakeirq = irq_of_parse_and_map(pdev->dev.of_node, 1);
1658                 omap_up_info = of_get_uart_port_info(&pdev->dev);
1659                 pdev->dev.platform_data = omap_up_info;
1660         } else {
1661                 uartirq = platform_get_irq(pdev, 0);
1662                 if (uartirq < 0)
1663                         return -EPROBE_DEFER;
1664         }
1665 
1666         up = devm_kzalloc(&pdev->dev, sizeof(*up), GFP_KERNEL);
1667         if (!up)
1668                 return -ENOMEM;
1669 
1670         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1671         base = devm_ioremap_resource(&pdev->dev, mem);
1672         if (IS_ERR(base))
1673                 return PTR_ERR(base);
1674 
1675         up->dev = &pdev->dev;
1676         up->port.dev = &pdev->dev;
1677         up->port.type = PORT_OMAP;
1678         up->port.iotype = UPIO_MEM;
1679         up->port.irq = uartirq;
1680         up->port.regshift = 2;
1681         up->port.fifosize = 64;
1682         up->port.ops = &serial_omap_pops;
1683 
1684         if (pdev->dev.of_node)
1685                 ret = of_alias_get_id(pdev->dev.of_node, "serial");
1686         else
1687                 ret = pdev->id;
1688 
1689         if (ret < 0) {
1690                 dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n",
1691                         ret);
1692                 goto err_port_line;
1693         }
1694         up->port.line = ret;
1695 
1696         if (up->port.line >= OMAP_MAX_HSUART_PORTS) {
1697                 dev_err(&pdev->dev, "uart ID %d >  MAX %d.\n", up->port.line,
1698                         OMAP_MAX_HSUART_PORTS);
1699                 ret = -ENXIO;
1700                 goto err_port_line;
1701         }
1702 
1703         up->wakeirq = wakeirq;
1704         if (!up->wakeirq)
1705                 dev_info(up->port.dev, "no wakeirq for uart%d\n",
1706                          up->port.line);
1707 
1708         ret = serial_omap_probe_rs485(up, pdev->dev.of_node);
1709         if (ret < 0)
1710                 goto err_rs485;
1711 
1712         sprintf(up->name, "OMAP UART%d", up->port.line);
1713         up->port.mapbase = mem->start;
1714         up->port.membase = base;
1715         up->port.flags = omap_up_info->flags;
1716         up->port.uartclk = omap_up_info->uartclk;
1717         up->port.rs485_config = serial_omap_config_rs485;
1718         if (!up->port.uartclk) {
1719                 up->port.uartclk = DEFAULT_CLK_SPEED;
1720                 dev_warn(&pdev->dev,
1721                          "No clock speed specified: using default: %d\n",
1722                          DEFAULT_CLK_SPEED);
1723         }
1724 
1725         up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1726         up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1727         pm_qos_add_request(&up->pm_qos_request,
1728                 PM_QOS_CPU_DMA_LATENCY, up->latency);
1729         INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
1730 
1731         platform_set_drvdata(pdev, up);
1732         if (omap_up_info->autosuspend_timeout == 0)
1733                 omap_up_info->autosuspend_timeout = -1;
1734 
1735         device_init_wakeup(up->dev, true);
1736         pm_runtime_use_autosuspend(&pdev->dev);
1737         pm_runtime_set_autosuspend_delay(&pdev->dev,
1738                         omap_up_info->autosuspend_timeout);
1739 
1740         pm_runtime_irq_safe(&pdev->dev);
1741         pm_runtime_enable(&pdev->dev);
1742 
1743         pm_runtime_get_sync(&pdev->dev);
1744 
1745         omap_serial_fill_features_erratas(up);
1746 
1747         ui[up->port.line] = up;
1748         serial_omap_add_console_port(up);
1749 
1750         ret = uart_add_one_port(&serial_omap_reg, &up->port);
1751         if (ret != 0)
1752                 goto err_add_port;
1753 
1754         pm_runtime_mark_last_busy(up->dev);
1755         pm_runtime_put_autosuspend(up->dev);
1756         return 0;
1757 
1758 err_add_port:
1759         pm_runtime_dont_use_autosuspend(&pdev->dev);
1760         pm_runtime_put_sync(&pdev->dev);
1761         pm_runtime_disable(&pdev->dev);
1762         pm_qos_remove_request(&up->pm_qos_request);
1763         device_init_wakeup(up->dev, false);
1764 err_rs485:
1765 err_port_line:
1766         return ret;
1767 }
1768 
1769 static int serial_omap_remove(struct platform_device *dev)
1770 {
1771         struct uart_omap_port *up = platform_get_drvdata(dev);
1772 
1773         pm_runtime_get_sync(up->dev);
1774 
1775         uart_remove_one_port(&serial_omap_reg, &up->port);
1776 
1777         pm_runtime_dont_use_autosuspend(up->dev);
1778         pm_runtime_put_sync(up->dev);
1779         pm_runtime_disable(up->dev);
1780         pm_qos_remove_request(&up->pm_qos_request);
1781         device_init_wakeup(&dev->dev, false);
1782 
1783         return 0;
1784 }
1785 
1786 /*
1787  * Work Around for Errata i202 (2430, 3430, 3630, 4430 and 4460)
1788  * The access to uart register after MDR1 Access
1789  * causes UART to corrupt data.
1790  *
1791  * Need a delay =
1792  * 5 L4 clock cycles + 5 UART functional clock cycle (@48MHz = ~0.2uS)
1793  * give 10 times as much
1794  */
1795 static void serial_omap_mdr1_errataset(struct uart_omap_port *up, u8 mdr1)
1796 {
1797         u8 timeout = 255;
1798 
1799         serial_out(up, UART_OMAP_MDR1, mdr1);
1800         udelay(2);
1801         serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_XMIT |
1802                         UART_FCR_CLEAR_RCVR);
1803         /*
1804          * Wait for FIFO to empty: when empty, RX_FIFO_E bit is 0 and
1805          * TX_FIFO_E bit is 1.
1806          */
1807         while (UART_LSR_THRE != (serial_in(up, UART_LSR) &
1808                                 (UART_LSR_THRE | UART_LSR_DR))) {
1809                 timeout--;
1810                 if (!timeout) {
1811                         /* Should *never* happen. we warn and carry on */
1812                         dev_crit(up->dev, "Errata i202: timedout %x\n",
1813                                                 serial_in(up, UART_LSR));
1814                         break;
1815                 }
1816                 udelay(1);
1817         }
1818 }
1819 
1820 #ifdef CONFIG_PM
1821 static void serial_omap_restore_context(struct uart_omap_port *up)
1822 {
1823         if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1824                 serial_omap_mdr1_errataset(up, UART_OMAP_MDR1_DISABLE);
1825         else
1826                 serial_out(up, UART_OMAP_MDR1, UART_OMAP_MDR1_DISABLE);
1827 
1828         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1829         serial_out(up, UART_EFR, UART_EFR_ECB);
1830         serial_out(up, UART_LCR, 0x0); /* Operational mode */
1831         serial_out(up, UART_IER, 0x0);
1832         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1833         serial_out(up, UART_DLL, up->dll);
1834         serial_out(up, UART_DLM, up->dlh);
1835         serial_out(up, UART_LCR, 0x0); /* Operational mode */
1836         serial_out(up, UART_IER, up->ier);
1837         serial_out(up, UART_FCR, up->fcr);
1838         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_A);
1839         serial_out(up, UART_MCR, up->mcr);
1840         serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); /* Config B mode */
1841         serial_out(up, UART_OMAP_SCR, up->scr);
1842         serial_out(up, UART_EFR, up->efr);
1843         serial_out(up, UART_LCR, up->lcr);
1844         if (up->errata & UART_ERRATA_i202_MDR1_ACCESS)
1845                 serial_omap_mdr1_errataset(up, up->mdr1);
1846         else
1847                 serial_out(up, UART_OMAP_MDR1, up->mdr1);
1848         serial_out(up, UART_OMAP_WER, up->wer);
1849 }
1850 
1851 static int serial_omap_runtime_suspend(struct device *dev)
1852 {
1853         struct uart_omap_port *up = dev_get_drvdata(dev);
1854 
1855         if (!up)
1856                 return -EINVAL;
1857 
1858         /*
1859         * When using 'no_console_suspend', the console UART must not be
1860         * suspended. Since driver suspend is managed by runtime suspend,
1861         * preventing runtime suspend (by returning error) will keep device
1862         * active during suspend.
1863         */
1864         if (up->is_suspending && !console_suspend_enabled &&
1865             uart_console(&up->port))
1866                 return -EBUSY;
1867 
1868         up->context_loss_cnt = serial_omap_get_context_loss_count(up);
1869 
1870         serial_omap_enable_wakeup(up, true);
1871 
1872         up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1873         schedule_work(&up->qos_work);
1874 
1875         return 0;
1876 }
1877 
1878 static int serial_omap_runtime_resume(struct device *dev)
1879 {
1880         struct uart_omap_port *up = dev_get_drvdata(dev);
1881 
1882         int loss_cnt = serial_omap_get_context_loss_count(up);
1883 
1884         serial_omap_enable_wakeup(up, false);
1885 
1886         if (loss_cnt < 0) {
1887                 dev_dbg(dev, "serial_omap_get_context_loss_count failed : %d\n",
1888                         loss_cnt);
1889                 serial_omap_restore_context(up);
1890         } else if (up->context_loss_cnt != loss_cnt) {
1891                 serial_omap_restore_context(up);
1892         }
1893         up->latency = up->calc_latency;
1894         schedule_work(&up->qos_work);
1895 
1896         return 0;
1897 }
1898 #endif
1899 
1900 static const struct dev_pm_ops serial_omap_dev_pm_ops = {
1901         SET_SYSTEM_SLEEP_PM_OPS(serial_omap_suspend, serial_omap_resume)
1902         SET_RUNTIME_PM_OPS(serial_omap_runtime_suspend,
1903                                 serial_omap_runtime_resume, NULL)
1904         .prepare        = serial_omap_prepare,
1905         .complete       = serial_omap_complete,
1906 };
1907 
1908 #if defined(CONFIG_OF)
1909 static const struct of_device_id omap_serial_of_match[] = {
1910         { .compatible = "ti,omap2-uart" },
1911         { .compatible = "ti,omap3-uart" },
1912         { .compatible = "ti,omap4-uart" },
1913         {},
1914 };
1915 MODULE_DEVICE_TABLE(of, omap_serial_of_match);
1916 #endif
1917 
1918 static struct platform_driver serial_omap_driver = {
1919         .probe          = serial_omap_probe,
1920         .remove         = serial_omap_remove,
1921         .driver         = {
1922                 .name   = OMAP_SERIAL_DRIVER_NAME,
1923                 .pm     = &serial_omap_dev_pm_ops,
1924                 .of_match_table = of_match_ptr(omap_serial_of_match),
1925         },
1926 };
1927 
1928 static int __init serial_omap_init(void)
1929 {
1930         int ret;
1931 
1932         ret = uart_register_driver(&serial_omap_reg);
1933         if (ret != 0)
1934                 return ret;
1935         ret = platform_driver_register(&serial_omap_driver);
1936         if (ret != 0)
1937                 uart_unregister_driver(&serial_omap_reg);
1938         return ret;
1939 }
1940 
1941 static void __exit serial_omap_exit(void)
1942 {
1943         platform_driver_unregister(&serial_omap_driver);
1944         uart_unregister_driver(&serial_omap_reg);
1945 }
1946 
1947 module_init(serial_omap_init);
1948 module_exit(serial_omap_exit);
1949 
1950 MODULE_DESCRIPTION("OMAP High Speed UART driver");
1951 MODULE_LICENSE("GPL");
1952 MODULE_AUTHOR("Texas Instruments Inc");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/tty/serial/omap-serial.c

DEFINITIONS
