root/drivers/tty/serial/rda-uart.c

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DEFINITIONS

This source file includes following definitions.
  1. rda_uart_write
  2. rda_uart_read
  3. rda_uart_tx_empty
  4. rda_uart_get_mctrl
  5. rda_uart_set_mctrl
  6. rda_uart_stop_tx
  7. rda_uart_stop_rx
  8. rda_uart_start_tx
  9. rda_uart_change_baudrate
  10. rda_uart_set_termios
  11. rda_uart_send_chars
  12. rda_uart_receive_chars
  13. rda_interrupt
  14. rda_uart_startup
  15. rda_uart_shutdown
  16. rda_uart_type
  17. rda_uart_request_port
  18. rda_uart_config_port
  19. rda_uart_release_port
  20. rda_uart_verify_port
  21. rda_console_putchar
  22. rda_uart_port_write
  23. rda_uart_console_write
  24. rda_uart_console_setup
  25. rda_uart_console_init
  26. rda_uart_early_console_write
  27. rda_uart_early_console_setup
  28. rda_uart_probe
  29. rda_uart_remove
  30. rda_uart_init
  31. rda_uart_exit

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * RDA8810PL serial device driver
   4  *
   5  * Copyright RDA Microelectronics Company Limited
   6  * Copyright (c) 2017 Andreas Färber
   7  * Copyright (c) 2018 Manivannan Sadhasivam
   8  */
   9 
  10 #include <linux/clk.h>
  11 #include <linux/console.h>
  12 #include <linux/delay.h>
  13 #include <linux/io.h>
  14 #include <linux/module.h>
  15 #include <linux/of.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/serial.h>
  18 #include <linux/serial_core.h>
  19 #include <linux/tty.h>
  20 #include <linux/tty_flip.h>
  21 
  22 #define RDA_UART_PORT_NUM 3
  23 #define RDA_UART_DEV_NAME "ttyRDA"
  24 
  25 #define RDA_UART_CTRL           0x00
  26 #define RDA_UART_STATUS         0x04
  27 #define RDA_UART_RXTX_BUFFER    0x08
  28 #define RDA_UART_IRQ_MASK       0x0c
  29 #define RDA_UART_IRQ_CAUSE      0x10
  30 #define RDA_UART_IRQ_TRIGGERS   0x14
  31 #define RDA_UART_CMD_SET        0x18
  32 #define RDA_UART_CMD_CLR        0x1c
  33 
  34 /* UART_CTRL Bits */
  35 #define RDA_UART_ENABLE                 BIT(0)
  36 #define RDA_UART_DBITS_8                BIT(1)
  37 #define RDA_UART_TX_SBITS_2             BIT(2)
  38 #define RDA_UART_PARITY_EN              BIT(3)
  39 #define RDA_UART_PARITY(x)              (((x) & 0x3) << 4)
  40 #define RDA_UART_PARITY_ODD             RDA_UART_PARITY(0)
  41 #define RDA_UART_PARITY_EVEN            RDA_UART_PARITY(1)
  42 #define RDA_UART_PARITY_SPACE           RDA_UART_PARITY(2)
  43 #define RDA_UART_PARITY_MARK            RDA_UART_PARITY(3)
  44 #define RDA_UART_DIV_MODE               BIT(20)
  45 #define RDA_UART_IRDA_EN                BIT(21)
  46 #define RDA_UART_DMA_EN                 BIT(22)
  47 #define RDA_UART_FLOW_CNT_EN            BIT(23)
  48 #define RDA_UART_LOOP_BACK_EN           BIT(24)
  49 #define RDA_UART_RX_LOCK_ERR            BIT(25)
  50 #define RDA_UART_RX_BREAK_LEN(x)        (((x) & 0xf) << 28)
  51 
  52 /* UART_STATUS Bits */
  53 #define RDA_UART_RX_FIFO(x)             (((x) & 0x7f) << 0)
  54 #define RDA_UART_RX_FIFO_MASK           (0x7f << 0)
  55 #define RDA_UART_TX_FIFO(x)             (((x) & 0x1f) << 8)
  56 #define RDA_UART_TX_FIFO_MASK           (0x1f << 8)
  57 #define RDA_UART_TX_ACTIVE              BIT(14)
  58 #define RDA_UART_RX_ACTIVE              BIT(15)
  59 #define RDA_UART_RX_OVERFLOW_ERR        BIT(16)
  60 #define RDA_UART_TX_OVERFLOW_ERR        BIT(17)
  61 #define RDA_UART_RX_PARITY_ERR          BIT(18)
  62 #define RDA_UART_RX_FRAMING_ERR         BIT(19)
  63 #define RDA_UART_RX_BREAK_INT           BIT(20)
  64 #define RDA_UART_DCTS                   BIT(24)
  65 #define RDA_UART_CTS                    BIT(25)
  66 #define RDA_UART_DTR                    BIT(28)
  67 #define RDA_UART_CLK_ENABLED            BIT(31)
  68 
  69 /* UART_RXTX_BUFFER Bits */
  70 #define RDA_UART_RX_DATA(x)             (((x) & 0xff) << 0)
  71 #define RDA_UART_TX_DATA(x)             (((x) & 0xff) << 0)
  72 
  73 /* UART_IRQ_MASK Bits */
  74 #define RDA_UART_TX_MODEM_STATUS        BIT(0)
  75 #define RDA_UART_RX_DATA_AVAILABLE      BIT(1)
  76 #define RDA_UART_TX_DATA_NEEDED         BIT(2)
  77 #define RDA_UART_RX_TIMEOUT             BIT(3)
  78 #define RDA_UART_RX_LINE_ERR            BIT(4)
  79 #define RDA_UART_TX_DMA_DONE            BIT(5)
  80 #define RDA_UART_RX_DMA_DONE            BIT(6)
  81 #define RDA_UART_RX_DMA_TIMEOUT         BIT(7)
  82 #define RDA_UART_DTR_RISE               BIT(8)
  83 #define RDA_UART_DTR_FALL               BIT(9)
  84 
  85 /* UART_IRQ_CAUSE Bits */
  86 #define RDA_UART_TX_MODEM_STATUS_U      BIT(16)
  87 #define RDA_UART_RX_DATA_AVAILABLE_U    BIT(17)
  88 #define RDA_UART_TX_DATA_NEEDED_U       BIT(18)
  89 #define RDA_UART_RX_TIMEOUT_U           BIT(19)
  90 #define RDA_UART_RX_LINE_ERR_U          BIT(20)
  91 #define RDA_UART_TX_DMA_DONE_U          BIT(21)
  92 #define RDA_UART_RX_DMA_DONE_U          BIT(22)
  93 #define RDA_UART_RX_DMA_TIMEOUT_U       BIT(23)
  94 #define RDA_UART_DTR_RISE_U             BIT(24)
  95 #define RDA_UART_DTR_FALL_U             BIT(25)
  96 
  97 /* UART_TRIGGERS Bits */
  98 #define RDA_UART_RX_TRIGGER(x)          (((x) & 0x1f) << 0)
  99 #define RDA_UART_TX_TRIGGER(x)          (((x) & 0xf) << 8)
 100 #define RDA_UART_AFC_LEVEL(x)           (((x) & 0x1f) << 16)
 101 
 102 /* UART_CMD_SET Bits */
 103 #define RDA_UART_RI                     BIT(0)
 104 #define RDA_UART_DCD                    BIT(1)
 105 #define RDA_UART_DSR                    BIT(2)
 106 #define RDA_UART_TX_BREAK_CONTROL       BIT(3)
 107 #define RDA_UART_TX_FINISH_N_WAIT       BIT(4)
 108 #define RDA_UART_RTS                    BIT(5)
 109 #define RDA_UART_RX_FIFO_RESET          BIT(6)
 110 #define RDA_UART_TX_FIFO_RESET          BIT(7)
 111 
 112 #define RDA_UART_TX_FIFO_SIZE   16
 113 
 114 static struct uart_driver rda_uart_driver;
 115 
 116 struct rda_uart_port {
 117         struct uart_port port;
 118         struct clk *clk;
 119 };
 120 
 121 #define to_rda_uart_port(port) container_of(port, struct rda_uart_port, port)
 122 
 123 static struct rda_uart_port *rda_uart_ports[RDA_UART_PORT_NUM];
 124 
 125 static inline void rda_uart_write(struct uart_port *port, u32 val,
 126                                   unsigned int off)
 127 {
 128         writel(val, port->membase + off);
 129 }
 130 
 131 static inline u32 rda_uart_read(struct uart_port *port, unsigned int off)
 132 {
 133         return readl(port->membase + off);
 134 }
 135 
 136 static unsigned int rda_uart_tx_empty(struct uart_port *port)
 137 {
 138         unsigned long flags;
 139         unsigned int ret;
 140         u32 val;
 141 
 142         spin_lock_irqsave(&port->lock, flags);
 143 
 144         val = rda_uart_read(port, RDA_UART_STATUS);
 145         ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0;
 146 
 147         spin_unlock_irqrestore(&port->lock, flags);
 148 
 149         return ret;
 150 }
 151 
 152 static unsigned int rda_uart_get_mctrl(struct uart_port *port)
 153 {
 154         unsigned int mctrl = 0;
 155         u32 cmd_set, status;
 156 
 157         cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
 158         status = rda_uart_read(port, RDA_UART_STATUS);
 159         if (cmd_set & RDA_UART_RTS)
 160                 mctrl |= TIOCM_RTS;
 161         if (!(status & RDA_UART_CTS))
 162                 mctrl |= TIOCM_CTS;
 163 
 164         return mctrl;
 165 }
 166 
 167 static void rda_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 168 {
 169         u32 val;
 170 
 171         if (mctrl & TIOCM_RTS) {
 172                 val = rda_uart_read(port, RDA_UART_CMD_SET);
 173                 rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_SET);
 174         } else {
 175                 /* Clear RTS to stop to receive. */
 176                 val = rda_uart_read(port, RDA_UART_CMD_CLR);
 177                 rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_CLR);
 178         }
 179 
 180         val = rda_uart_read(port, RDA_UART_CTRL);
 181 
 182         if (mctrl & TIOCM_LOOP)
 183                 val |= RDA_UART_LOOP_BACK_EN;
 184         else
 185                 val &= ~RDA_UART_LOOP_BACK_EN;
 186 
 187         rda_uart_write(port, val, RDA_UART_CTRL);
 188 }
 189 
 190 static void rda_uart_stop_tx(struct uart_port *port)
 191 {
 192         u32 val;
 193 
 194         val = rda_uart_read(port, RDA_UART_IRQ_MASK);
 195         val &= ~RDA_UART_TX_DATA_NEEDED;
 196         rda_uart_write(port, val, RDA_UART_IRQ_MASK);
 197 
 198         val = rda_uart_read(port, RDA_UART_CMD_SET);
 199         val |= RDA_UART_TX_FIFO_RESET;
 200         rda_uart_write(port, val, RDA_UART_CMD_SET);
 201 }
 202 
 203 static void rda_uart_stop_rx(struct uart_port *port)
 204 {
 205         u32 val;
 206 
 207         val = rda_uart_read(port, RDA_UART_IRQ_MASK);
 208         val &= ~(RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
 209         rda_uart_write(port, val, RDA_UART_IRQ_MASK);
 210 
 211         /* Read Rx buffer before reset to avoid Rx timeout interrupt */
 212         val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
 213 
 214         val = rda_uart_read(port, RDA_UART_CMD_SET);
 215         val |= RDA_UART_RX_FIFO_RESET;
 216         rda_uart_write(port, val, RDA_UART_CMD_SET);
 217 }
 218 
 219 static void rda_uart_start_tx(struct uart_port *port)
 220 {
 221         u32 val;
 222 
 223         if (uart_tx_stopped(port)) {
 224                 rda_uart_stop_tx(port);
 225                 return;
 226         }
 227 
 228         val = rda_uart_read(port, RDA_UART_IRQ_MASK);
 229         val |= RDA_UART_TX_DATA_NEEDED;
 230         rda_uart_write(port, val, RDA_UART_IRQ_MASK);
 231 }
 232 
 233 static void rda_uart_change_baudrate(struct rda_uart_port *rda_port,
 234                                      unsigned long baud)
 235 {
 236         clk_set_rate(rda_port->clk, baud * 8);
 237 }
 238 
 239 static void rda_uart_set_termios(struct uart_port *port,
 240                                  struct ktermios *termios,
 241                                  struct ktermios *old)
 242 {
 243         struct rda_uart_port *rda_port = to_rda_uart_port(port);
 244         unsigned long flags;
 245         unsigned int ctrl, cmd_set, cmd_clr, triggers;
 246         unsigned int baud;
 247         u32 irq_mask;
 248 
 249         spin_lock_irqsave(&port->lock, flags);
 250 
 251         baud = uart_get_baud_rate(port, termios, old, 9600, port->uartclk / 4);
 252         rda_uart_change_baudrate(rda_port, baud);
 253 
 254         ctrl = rda_uart_read(port, RDA_UART_CTRL);
 255         cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
 256         cmd_clr = rda_uart_read(port, RDA_UART_CMD_CLR);
 257 
 258         switch (termios->c_cflag & CSIZE) {
 259         case CS5:
 260         case CS6:
 261                 dev_warn(port->dev, "bit size not supported, using 7 bits\n");
 262                 /* Fall through */
 263         case CS7:
 264                 ctrl &= ~RDA_UART_DBITS_8;
 265                 break;
 266         default:
 267                 ctrl |= RDA_UART_DBITS_8;
 268                 break;
 269         }
 270 
 271         /* stop bits */
 272         if (termios->c_cflag & CSTOPB)
 273                 ctrl |= RDA_UART_TX_SBITS_2;
 274         else
 275                 ctrl &= ~RDA_UART_TX_SBITS_2;
 276 
 277         /* parity check */
 278         if (termios->c_cflag & PARENB) {
 279                 ctrl |= RDA_UART_PARITY_EN;
 280 
 281                 /* Mark or Space parity */
 282                 if (termios->c_cflag & CMSPAR) {
 283                         if (termios->c_cflag & PARODD)
 284                                 ctrl |= RDA_UART_PARITY_MARK;
 285                         else
 286                                 ctrl |= RDA_UART_PARITY_SPACE;
 287                 } else if (termios->c_cflag & PARODD) {
 288                         ctrl |= RDA_UART_PARITY_ODD;
 289                 } else {
 290                         ctrl |= RDA_UART_PARITY_EVEN;
 291                 }
 292         } else {
 293                 ctrl &= ~RDA_UART_PARITY_EN;
 294         }
 295 
 296         /* Hardware handshake (RTS/CTS) */
 297         if (termios->c_cflag & CRTSCTS) {
 298                 ctrl   |= RDA_UART_FLOW_CNT_EN;
 299                 cmd_set |= RDA_UART_RTS;
 300         } else {
 301                 ctrl   &= ~RDA_UART_FLOW_CNT_EN;
 302                 cmd_clr |= RDA_UART_RTS;
 303         }
 304 
 305         ctrl |= RDA_UART_ENABLE;
 306         ctrl &= ~RDA_UART_DMA_EN;
 307 
 308         triggers  = (RDA_UART_AFC_LEVEL(20) | RDA_UART_RX_TRIGGER(16));
 309         irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
 310         rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
 311 
 312         rda_uart_write(port, triggers, RDA_UART_IRQ_TRIGGERS);
 313         rda_uart_write(port, ctrl, RDA_UART_CTRL);
 314         rda_uart_write(port, cmd_set, RDA_UART_CMD_SET);
 315         rda_uart_write(port, cmd_clr, RDA_UART_CMD_CLR);
 316 
 317         rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
 318 
 319         /* Don't rewrite B0 */
 320         if (tty_termios_baud_rate(termios))
 321                 tty_termios_encode_baud_rate(termios, baud, baud);
 322 
 323         /* update the per-port timeout */
 324         uart_update_timeout(port, termios->c_cflag, baud);
 325 
 326         spin_unlock_irqrestore(&port->lock, flags);
 327 }
 328 
 329 static void rda_uart_send_chars(struct uart_port *port)
 330 {
 331         struct circ_buf *xmit = &port->state->xmit;
 332         unsigned int ch;
 333         u32 val;
 334 
 335         if (uart_tx_stopped(port))
 336                 return;
 337 
 338         if (port->x_char) {
 339                 while (!(rda_uart_read(port, RDA_UART_STATUS) &
 340                          RDA_UART_TX_FIFO_MASK))
 341                         cpu_relax();
 342 
 343                 rda_uart_write(port, port->x_char, RDA_UART_RXTX_BUFFER);
 344                 port->icount.tx++;
 345                 port->x_char = 0;
 346         }
 347 
 348         while (rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK) {
 349                 if (uart_circ_empty(xmit))
 350                         break;
 351 
 352                 ch = xmit->buf[xmit->tail];
 353                 rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
 354                 xmit->tail = (xmit->tail + 1) & (SERIAL_XMIT_SIZE - 1);
 355                 port->icount.tx++;
 356         }
 357 
 358         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 359                 uart_write_wakeup(port);
 360 
 361         if (!uart_circ_empty(xmit)) {
 362                 /* Re-enable Tx FIFO interrupt */
 363                 val = rda_uart_read(port, RDA_UART_IRQ_MASK);
 364                 val |= RDA_UART_TX_DATA_NEEDED;
 365                 rda_uart_write(port, val, RDA_UART_IRQ_MASK);
 366         }
 367 }
 368 
 369 static void rda_uart_receive_chars(struct uart_port *port)
 370 {
 371         u32 status, val;
 372 
 373         status = rda_uart_read(port, RDA_UART_STATUS);
 374         while ((status & RDA_UART_RX_FIFO_MASK)) {
 375                 char flag = TTY_NORMAL;
 376 
 377                 if (status & RDA_UART_RX_PARITY_ERR) {
 378                         port->icount.parity++;
 379                         flag = TTY_PARITY;
 380                 }
 381 
 382                 if (status & RDA_UART_RX_FRAMING_ERR) {
 383                         port->icount.frame++;
 384                         flag = TTY_FRAME;
 385                 }
 386 
 387                 if (status & RDA_UART_RX_OVERFLOW_ERR) {
 388                         port->icount.overrun++;
 389                         flag = TTY_OVERRUN;
 390                 }
 391 
 392                 val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
 393                 val &= 0xff;
 394 
 395                 port->icount.rx++;
 396                 tty_insert_flip_char(&port->state->port, val, flag);
 397 
 398                 status = rda_uart_read(port, RDA_UART_STATUS);
 399         }
 400 
 401         spin_unlock(&port->lock);
 402         tty_flip_buffer_push(&port->state->port);
 403         spin_lock(&port->lock);
 404 }
 405 
 406 static irqreturn_t rda_interrupt(int irq, void *dev_id)
 407 {
 408         struct uart_port *port = dev_id;
 409         unsigned long flags;
 410         u32 val, irq_mask;
 411 
 412         spin_lock_irqsave(&port->lock, flags);
 413 
 414         /* Clear IRQ cause */
 415         val = rda_uart_read(port, RDA_UART_IRQ_CAUSE);
 416         rda_uart_write(port, val, RDA_UART_IRQ_CAUSE);
 417 
 418         if (val & (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT))
 419                 rda_uart_receive_chars(port);
 420 
 421         if (val & (RDA_UART_TX_DATA_NEEDED)) {
 422                 irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
 423                 irq_mask &= ~RDA_UART_TX_DATA_NEEDED;
 424                 rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
 425 
 426                 rda_uart_send_chars(port);
 427         }
 428 
 429         spin_unlock_irqrestore(&port->lock, flags);
 430 
 431         return IRQ_HANDLED;
 432 }
 433 
 434 static int rda_uart_startup(struct uart_port *port)
 435 {
 436         unsigned long flags;
 437         int ret;
 438         u32 val;
 439 
 440         spin_lock_irqsave(&port->lock, flags);
 441         rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
 442         spin_unlock_irqrestore(&port->lock, flags);
 443 
 444         ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND,
 445                           "rda-uart", port);
 446         if (ret)
 447                 return ret;
 448 
 449         spin_lock_irqsave(&port->lock, flags);
 450 
 451         val = rda_uart_read(port, RDA_UART_CTRL);
 452         val |= RDA_UART_ENABLE;
 453         rda_uart_write(port, val, RDA_UART_CTRL);
 454 
 455         /* enable rx interrupt */
 456         val = rda_uart_read(port, RDA_UART_IRQ_MASK);
 457         val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
 458         rda_uart_write(port, val, RDA_UART_IRQ_MASK);
 459 
 460         spin_unlock_irqrestore(&port->lock, flags);
 461 
 462         return 0;
 463 }
 464 
 465 static void rda_uart_shutdown(struct uart_port *port)
 466 {
 467         unsigned long flags;
 468         u32 val;
 469 
 470         spin_lock_irqsave(&port->lock, flags);
 471 
 472         rda_uart_stop_tx(port);
 473         rda_uart_stop_rx(port);
 474 
 475         val = rda_uart_read(port, RDA_UART_CTRL);
 476         val &= ~RDA_UART_ENABLE;
 477         rda_uart_write(port, val, RDA_UART_CTRL);
 478 
 479         spin_unlock_irqrestore(&port->lock, flags);
 480 }
 481 
 482 static const char *rda_uart_type(struct uart_port *port)
 483 {
 484         return (port->type == PORT_RDA) ? "rda-uart" : NULL;
 485 }
 486 
 487 static int rda_uart_request_port(struct uart_port *port)
 488 {
 489         struct platform_device *pdev = to_platform_device(port->dev);
 490         struct resource *res;
 491 
 492         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 493         if (!res)
 494                 return -ENXIO;
 495 
 496         if (!devm_request_mem_region(port->dev, port->mapbase,
 497                                      resource_size(res), dev_name(port->dev)))
 498                 return -EBUSY;
 499 
 500         if (port->flags & UPF_IOREMAP) {
 501                 port->membase = devm_ioremap_nocache(port->dev, port->mapbase,
 502                                                      resource_size(res));
 503                 if (!port->membase)
 504                         return -EBUSY;
 505         }
 506 
 507         return 0;
 508 }
 509 
 510 static void rda_uart_config_port(struct uart_port *port, int flags)
 511 {
 512         unsigned long irq_flags;
 513 
 514         if (flags & UART_CONFIG_TYPE) {
 515                 port->type = PORT_RDA;
 516                 rda_uart_request_port(port);
 517         }
 518 
 519         spin_lock_irqsave(&port->lock, irq_flags);
 520 
 521         /* Clear mask, so no surprise interrupts. */
 522         rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
 523 
 524         /* Clear status register */
 525         rda_uart_write(port, 0, RDA_UART_STATUS);
 526 
 527         spin_unlock_irqrestore(&port->lock, irq_flags);
 528 }
 529 
 530 static void rda_uart_release_port(struct uart_port *port)
 531 {
 532         struct platform_device *pdev = to_platform_device(port->dev);
 533         struct resource *res;
 534 
 535         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 536         if (!res)
 537                 return;
 538 
 539         if (port->flags & UPF_IOREMAP) {
 540                 devm_release_mem_region(port->dev, port->mapbase,
 541                                         resource_size(res));
 542                 devm_iounmap(port->dev, port->membase);
 543                 port->membase = NULL;
 544         }
 545 }
 546 
 547 static int rda_uart_verify_port(struct uart_port *port,
 548                                 struct serial_struct *ser)
 549 {
 550         if (port->type != PORT_RDA)
 551                 return -EINVAL;
 552 
 553         if (port->irq != ser->irq)
 554                 return -EINVAL;
 555 
 556         return 0;
 557 }
 558 
 559 static const struct uart_ops rda_uart_ops = {
 560         .tx_empty       = rda_uart_tx_empty,
 561         .get_mctrl      = rda_uart_get_mctrl,
 562         .set_mctrl      = rda_uart_set_mctrl,
 563         .start_tx       = rda_uart_start_tx,
 564         .stop_tx        = rda_uart_stop_tx,
 565         .stop_rx        = rda_uart_stop_rx,
 566         .startup        = rda_uart_startup,
 567         .shutdown       = rda_uart_shutdown,
 568         .set_termios    = rda_uart_set_termios,
 569         .type           = rda_uart_type,
 570         .request_port   = rda_uart_request_port,
 571         .release_port   = rda_uart_release_port,
 572         .config_port    = rda_uart_config_port,
 573         .verify_port    = rda_uart_verify_port,
 574 };
 575 
 576 #ifdef CONFIG_SERIAL_RDA_CONSOLE
 577 
 578 static void rda_console_putchar(struct uart_port *port, int ch)
 579 {
 580         if (!port->membase)
 581                 return;
 582 
 583         while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
 584                 cpu_relax();
 585 
 586         rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
 587 }
 588 
 589 static void rda_uart_port_write(struct uart_port *port, const char *s,
 590                                 u_int count)
 591 {
 592         u32 old_irq_mask;
 593         unsigned long flags;
 594         int locked;
 595 
 596         local_irq_save(flags);
 597 
 598         if (port->sysrq) {
 599                 locked = 0;
 600         } else if (oops_in_progress) {
 601                 locked = spin_trylock(&port->lock);
 602         } else {
 603                 spin_lock(&port->lock);
 604                 locked = 1;
 605         }
 606 
 607         old_irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
 608         rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
 609 
 610         uart_console_write(port, s, count, rda_console_putchar);
 611 
 612         /* wait until all contents have been sent out */
 613         while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
 614                 cpu_relax();
 615 
 616         rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK);
 617 
 618         if (locked)
 619                 spin_unlock(&port->lock);
 620 
 621         local_irq_restore(flags);
 622 }
 623 
 624 static void rda_uart_console_write(struct console *co, const char *s,
 625                                    u_int count)
 626 {
 627         struct rda_uart_port *rda_port;
 628 
 629         rda_port = rda_uart_ports[co->index];
 630         if (!rda_port)
 631                 return;
 632 
 633         rda_uart_port_write(&rda_port->port, s, count);
 634 }
 635 
 636 static int rda_uart_console_setup(struct console *co, char *options)
 637 {
 638         struct rda_uart_port *rda_port;
 639         int baud = 921600;
 640         int bits = 8;
 641         int parity = 'n';
 642         int flow = 'n';
 643 
 644         if (co->index < 0 || co->index >= RDA_UART_PORT_NUM)
 645                 return -EINVAL;
 646 
 647         rda_port = rda_uart_ports[co->index];
 648         if (!rda_port || !rda_port->port.membase)
 649                 return -ENODEV;
 650 
 651         if (options)
 652                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 653 
 654         return uart_set_options(&rda_port->port, co, baud, parity, bits, flow);
 655 }
 656 
 657 static struct console rda_uart_console = {
 658         .name = RDA_UART_DEV_NAME,
 659         .write = rda_uart_console_write,
 660         .device = uart_console_device,
 661         .setup = rda_uart_console_setup,
 662         .flags = CON_PRINTBUFFER,
 663         .index = -1,
 664         .data = &rda_uart_driver,
 665 };
 666 
 667 static int __init rda_uart_console_init(void)
 668 {
 669         register_console(&rda_uart_console);
 670 
 671         return 0;
 672 }
 673 console_initcall(rda_uart_console_init);
 674 
 675 static void rda_uart_early_console_write(struct console *co,
 676                                          const char *s,
 677                                          u_int count)
 678 {
 679         struct earlycon_device *dev = co->data;
 680 
 681         rda_uart_port_write(&dev->port, s, count);
 682 }
 683 
 684 static int __init
 685 rda_uart_early_console_setup(struct earlycon_device *device, const char *opt)
 686 {
 687         if (!device->port.membase)
 688                 return -ENODEV;
 689 
 690         device->con->write = rda_uart_early_console_write;
 691 
 692         return 0;
 693 }
 694 
 695 OF_EARLYCON_DECLARE(rda, "rda,8810pl-uart",
 696                     rda_uart_early_console_setup);
 697 
 698 #define RDA_UART_CONSOLE (&rda_uart_console)
 699 #else
 700 #define RDA_UART_CONSOLE NULL
 701 #endif /* CONFIG_SERIAL_RDA_CONSOLE */
 702 
 703 static struct uart_driver rda_uart_driver = {
 704         .owner = THIS_MODULE,
 705         .driver_name = "rda-uart",
 706         .dev_name = RDA_UART_DEV_NAME,
 707         .nr = RDA_UART_PORT_NUM,
 708         .cons = RDA_UART_CONSOLE,
 709 };
 710 
 711 static const struct of_device_id rda_uart_dt_matches[] = {
 712         { .compatible = "rda,8810pl-uart" },
 713         { }
 714 };
 715 MODULE_DEVICE_TABLE(of, rda_uart_dt_matches);
 716 
 717 static int rda_uart_probe(struct platform_device *pdev)
 718 {
 719         struct resource *res_mem;
 720         struct rda_uart_port *rda_port;
 721         int ret, irq;
 722 
 723         if (pdev->dev.of_node)
 724                 pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
 725 
 726         if (pdev->id < 0 || pdev->id >= RDA_UART_PORT_NUM) {
 727                 dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
 728                 return -EINVAL;
 729         }
 730 
 731         res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 732         if (!res_mem) {
 733                 dev_err(&pdev->dev, "could not get mem\n");
 734                 return -ENODEV;
 735         }
 736 
 737         irq = platform_get_irq(pdev, 0);
 738         if (irq < 0)
 739                 return irq;
 740 
 741         if (rda_uart_ports[pdev->id]) {
 742                 dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
 743                 return -EBUSY;
 744         }
 745 
 746         rda_port = devm_kzalloc(&pdev->dev, sizeof(*rda_port), GFP_KERNEL);
 747         if (!rda_port)
 748                 return -ENOMEM;
 749 
 750         rda_port->clk = devm_clk_get(&pdev->dev, NULL);
 751         if (IS_ERR(rda_port->clk)) {
 752                 dev_err(&pdev->dev, "could not get clk\n");
 753                 return PTR_ERR(rda_port->clk);
 754         }
 755 
 756         rda_port->port.dev = &pdev->dev;
 757         rda_port->port.regshift = 0;
 758         rda_port->port.line = pdev->id;
 759         rda_port->port.type = PORT_RDA;
 760         rda_port->port.iotype = UPIO_MEM;
 761         rda_port->port.mapbase = res_mem->start;
 762         rda_port->port.irq = irq;
 763         rda_port->port.uartclk = clk_get_rate(rda_port->clk);
 764         if (rda_port->port.uartclk == 0) {
 765                 dev_err(&pdev->dev, "clock rate is zero\n");
 766                 return -EINVAL;
 767         }
 768         rda_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
 769                                UPF_LOW_LATENCY;
 770         rda_port->port.x_char = 0;
 771         rda_port->port.fifosize = RDA_UART_TX_FIFO_SIZE;
 772         rda_port->port.ops = &rda_uart_ops;
 773 
 774         rda_uart_ports[pdev->id] = rda_port;
 775         platform_set_drvdata(pdev, rda_port);
 776 
 777         ret = uart_add_one_port(&rda_uart_driver, &rda_port->port);
 778         if (ret)
 779                 rda_uart_ports[pdev->id] = NULL;
 780 
 781         return ret;
 782 }
 783 
 784 static int rda_uart_remove(struct platform_device *pdev)
 785 {
 786         struct rda_uart_port *rda_port = platform_get_drvdata(pdev);
 787 
 788         uart_remove_one_port(&rda_uart_driver, &rda_port->port);
 789         rda_uart_ports[pdev->id] = NULL;
 790 
 791         return 0;
 792 }
 793 
 794 static struct platform_driver rda_uart_platform_driver = {
 795         .probe = rda_uart_probe,
 796         .remove = rda_uart_remove,
 797         .driver = {
 798                 .name = "rda-uart",
 799                 .of_match_table = rda_uart_dt_matches,
 800         },
 801 };
 802 
 803 static int __init rda_uart_init(void)
 804 {
 805         int ret;
 806 
 807         ret = uart_register_driver(&rda_uart_driver);
 808         if (ret)
 809                 return ret;
 810 
 811         ret = platform_driver_register(&rda_uart_platform_driver);
 812         if (ret)
 813                 uart_unregister_driver(&rda_uart_driver);
 814 
 815         return ret;
 816 }
 817 
 818 static void __exit rda_uart_exit(void)
 819 {
 820         platform_driver_unregister(&rda_uart_platform_driver);
 821         uart_unregister_driver(&rda_uart_driver);
 822 }
 823 
 824 module_init(rda_uart_init);
 825 module_exit(rda_uart_exit);
 826 
 827 MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
 828 MODULE_DESCRIPTION("RDA8810PL serial device driver");
 829 MODULE_LICENSE("GPL");

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