drivers/tty/serial/altera_uart.c

   1 /*
   2  * altera_uart.c -- Altera UART driver
   3  *
   4  * Based on mcf.c -- Freescale ColdFire UART driver
   5  *
   6  * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
   7  * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw>
   8  * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/timer.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/module.h>
  21 #include <linux/console.h>
  22 #include <linux/tty.h>
  23 #include <linux/tty_flip.h>
  24 #include <linux/serial.h>
  25 #include <linux/serial_core.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/of.h>
  28 #include <linux/io.h>
  29 #include <linux/altera_uart.h>
  30
  31 #define DRV_NAME "altera_uart"
  32 #define SERIAL_ALTERA_MAJOR 204
  33 #define SERIAL_ALTERA_MINOR 213
  34
  35 /*
  36  * Altera UART register definitions according to the Nios UART datasheet:
  37  * http://www.altera.com/literature/ds/ds_nios_uart.pdf
  38  */
  39
  40 #define ALTERA_UART_SIZE                32
  41
  42 #define ALTERA_UART_RXDATA_REG          0
  43 #define ALTERA_UART_TXDATA_REG          4
  44 #define ALTERA_UART_STATUS_REG          8
  45 #define ALTERA_UART_CONTROL_REG         12
  46 #define ALTERA_UART_DIVISOR_REG         16
  47 #define ALTERA_UART_EOP_REG             20
  48
  49 #define ALTERA_UART_STATUS_PE_MSK       0x0001  /* parity error */
  50 #define ALTERA_UART_STATUS_FE_MSK       0x0002  /* framing error */
  51 #define ALTERA_UART_STATUS_BRK_MSK      0x0004  /* break */
  52 #define ALTERA_UART_STATUS_ROE_MSK      0x0008  /* RX overrun error */
  53 #define ALTERA_UART_STATUS_TOE_MSK      0x0010  /* TX overrun error */
  54 #define ALTERA_UART_STATUS_TMT_MSK      0x0020  /* TX shift register state */
  55 #define ALTERA_UART_STATUS_TRDY_MSK     0x0040  /* TX ready */
  56 #define ALTERA_UART_STATUS_RRDY_MSK     0x0080  /* RX ready */
  57 #define ALTERA_UART_STATUS_E_MSK        0x0100  /* exception condition */
  58 #define ALTERA_UART_STATUS_DCTS_MSK     0x0400  /* CTS logic-level change */
  59 #define ALTERA_UART_STATUS_CTS_MSK      0x0800  /* CTS logic state */
  60 #define ALTERA_UART_STATUS_EOP_MSK      0x1000  /* EOP written/read */
  61
  62                                                 /* Enable interrupt on... */
  63 #define ALTERA_UART_CONTROL_PE_MSK      0x0001  /* ...parity error */
  64 #define ALTERA_UART_CONTROL_FE_MSK      0x0002  /* ...framing error */
  65 #define ALTERA_UART_CONTROL_BRK_MSK     0x0004  /* ...break */
  66 #define ALTERA_UART_CONTROL_ROE_MSK     0x0008  /* ...RX overrun */
  67 #define ALTERA_UART_CONTROL_TOE_MSK     0x0010  /* ...TX overrun */
  68 #define ALTERA_UART_CONTROL_TMT_MSK     0x0020  /* ...TX shift register empty */
  69 #define ALTERA_UART_CONTROL_TRDY_MSK    0x0040  /* ...TX ready */
  70 #define ALTERA_UART_CONTROL_RRDY_MSK    0x0080  /* ...RX ready */
  71 #define ALTERA_UART_CONTROL_E_MSK       0x0100  /* ...exception*/
  72
  73 #define ALTERA_UART_CONTROL_TRBK_MSK    0x0200  /* TX break */
  74 #define ALTERA_UART_CONTROL_DCTS_MSK    0x0400  /* Interrupt on CTS change */
  75 #define ALTERA_UART_CONTROL_RTS_MSK     0x0800  /* RTS signal */
  76 #define ALTERA_UART_CONTROL_EOP_MSK     0x1000  /* Interrupt on EOP */
  77
  78 /*
  79  * Local per-uart structure.
  80  */
  81 struct altera_uart {
  82         struct uart_port port;
  83         struct timer_list tmr;
  84         unsigned int sigs;      /* Local copy of line sigs */
  85         unsigned short imr;     /* Local IMR mirror */
  86 };
  87
  88 static u32 altera_uart_readl(struct uart_port *port, int reg)
  89 {
  90         return readl(port->membase + (reg << port->regshift));
  91 }
  92
  93 static void altera_uart_writel(struct uart_port *port, u32 dat, int reg)
  94 {
  95         writel(dat, port->membase + (reg << port->regshift));
  96 }
  97
  98 static unsigned int altera_uart_tx_empty(struct uart_port *port)
  99 {
 100         return (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 101                 ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
 102 }
 103
 104 static unsigned int altera_uart_get_mctrl(struct uart_port *port)
 105 {
 106         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 107         unsigned int sigs;
 108
 109         sigs = (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 110              ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
 111         sigs |= (pp->sigs & TIOCM_RTS);
 112
 113         return sigs;
 114 }
 115
 116 static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
 117 {
 118         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 119
 120         pp->sigs = sigs;
 121         if (sigs & TIOCM_RTS)
 122                 pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
 123         else
 124                 pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
 125         altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 126 }
 127
 128 static void altera_uart_start_tx(struct uart_port *port)
 129 {
 130         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 131
 132         pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
 133         altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 134 }
 135
 136 static void altera_uart_stop_tx(struct uart_port *port)
 137 {
 138         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 139
 140         pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
 141         altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 142 }
 143
 144 static void altera_uart_stop_rx(struct uart_port *port)
 145 {
 146         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 147
 148         pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
 149         altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 150 }
 151
 152 static void altera_uart_break_ctl(struct uart_port *port, int break_state)
 153 {
 154         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 155         unsigned long flags;
 156
 157         spin_lock_irqsave(&port->lock, flags);
 158         if (break_state == -1)
 159                 pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
 160         else
 161                 pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
 162         altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 163         spin_unlock_irqrestore(&port->lock, flags);
 164 }
 165
 166 static void altera_uart_enable_ms(struct uart_port *port)
 167 {
 168 }
 169
 170 static void altera_uart_set_termios(struct uart_port *port,
 171                                     struct ktermios *termios,
 172                                     struct ktermios *old)
 173 {
 174         unsigned long flags;
 175         unsigned int baud, baudclk;
 176
 177         baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 178         baudclk = port->uartclk / baud;
 179
 180         if (old)
 181                 tty_termios_copy_hw(termios, old);
 182         tty_termios_encode_baud_rate(termios, baud, baud);
 183
 184         spin_lock_irqsave(&port->lock, flags);
 185         uart_update_timeout(port, termios->c_cflag, baud);
 186         altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
 187         spin_unlock_irqrestore(&port->lock, flags);
 188 }
 189
 190 static void altera_uart_rx_chars(struct altera_uart *pp)
 191 {
 192         struct uart_port *port = &pp->port;
 193         unsigned char ch, flag;
 194         unsigned short status;
 195
 196         while ((status = altera_uart_readl(port, ALTERA_UART_STATUS_REG)) &
 197                ALTERA_UART_STATUS_RRDY_MSK) {
 198                 ch = altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
 199                 flag = TTY_NORMAL;
 200                 port->icount.rx++;
 201
 202                 if (status & ALTERA_UART_STATUS_E_MSK) {
 203                         altera_uart_writel(port, status,
 204                                            ALTERA_UART_STATUS_REG);
 205
 206                         if (status & ALTERA_UART_STATUS_BRK_MSK) {
 207                                 port->icount.brk++;
 208                                 if (uart_handle_break(port))
 209                                         continue;
 210                         } else if (status & ALTERA_UART_STATUS_PE_MSK) {
 211                                 port->icount.parity++;
 212                         } else if (status & ALTERA_UART_STATUS_ROE_MSK) {
 213                                 port->icount.overrun++;
 214                         } else if (status & ALTERA_UART_STATUS_FE_MSK) {
 215                                 port->icount.frame++;
 216                         }
 217
 218                         status &= port->read_status_mask;
 219
 220                         if (status & ALTERA_UART_STATUS_BRK_MSK)
 221                                 flag = TTY_BREAK;
 222                         else if (status & ALTERA_UART_STATUS_PE_MSK)
 223                                 flag = TTY_PARITY;
 224                         else if (status & ALTERA_UART_STATUS_FE_MSK)
 225                                 flag = TTY_FRAME;
 226                 }
 227
 228                 if (uart_handle_sysrq_char(port, ch))
 229                         continue;
 230                 uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch,
 231                                  flag);
 232         }
 233
 234         tty_flip_buffer_push(port->state->port.tty);
 235 }
 236
 237 static void altera_uart_tx_chars(struct altera_uart *pp)
 238 {
 239         struct uart_port *port = &pp->port;
 240         struct circ_buf *xmit = &port->state->xmit;
 241
 242         if (port->x_char) {
 243                 /* Send special char - probably flow control */
 244                 altera_uart_writel(port, port->x_char, ALTERA_UART_TXDATA_REG);
 245                 port->x_char = 0;
 246                 port->icount.tx++;
 247                 return;
 248         }
 249
 250         while (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 251                ALTERA_UART_STATUS_TRDY_MSK) {
 252                 if (xmit->head == xmit->tail)
 253                         break;
 254                 altera_uart_writel(port, xmit->buf[xmit->tail],
 255                        ALTERA_UART_TXDATA_REG);
 256                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 257                 port->icount.tx++;
 258         }
 259
 260         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 261                 uart_write_wakeup(port);
 262
 263         if (xmit->head == xmit->tail) {
 264                 pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
 265                 altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 266         }
 267 }
 268
 269 static irqreturn_t altera_uart_interrupt(int irq, void *data)
 270 {
 271         struct uart_port *port = data;
 272         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 273         unsigned int isr;
 274
 275         isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
 276
 277         spin_lock(&port->lock);
 278         if (isr & ALTERA_UART_STATUS_RRDY_MSK)
 279                 altera_uart_rx_chars(pp);
 280         if (isr & ALTERA_UART_STATUS_TRDY_MSK)
 281                 altera_uart_tx_chars(pp);
 282         spin_unlock(&port->lock);
 283
 284         return IRQ_RETVAL(isr);
 285 }
 286
 287 static void altera_uart_timer(unsigned long data)
 288 {
 289         struct uart_port *port = (void *)data;
 290         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 291
 292         altera_uart_interrupt(0, port);
 293         mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
 294 }
 295
 296 static void altera_uart_config_port(struct uart_port *port, int flags)
 297 {
 298         port->type = PORT_ALTERA_UART;
 299
 300         /* Clear mask, so no surprise interrupts. */
 301         altera_uart_writel(port, 0, ALTERA_UART_CONTROL_REG);
 302         /* Clear status register */
 303         altera_uart_writel(port, 0, ALTERA_UART_STATUS_REG);
 304 }
 305
 306 static int altera_uart_startup(struct uart_port *port)
 307 {
 308         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 309         unsigned long flags;
 310         int ret;
 311
 312         if (!port->irq) {
 313                 setup_timer(&pp->tmr, altera_uart_timer, (unsigned long)port);
 314                 mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
 315                 return 0;
 316         }
 317
 318         ret = request_irq(port->irq, altera_uart_interrupt, IRQF_DISABLED,
 319                         DRV_NAME, port);
 320         if (ret) {
 321                 pr_err(DRV_NAME ": unable to attach Altera UART %d "
 322                        "interrupt vector=%d\n", port->line, port->irq);
 323                 return ret;
 324         }
 325
 326         spin_lock_irqsave(&port->lock, flags);
 327
 328         /* Enable RX interrupts now */
 329         pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
 330         writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
 331
 332         spin_unlock_irqrestore(&port->lock, flags);
 333
 334         return 0;
 335 }
 336
 337 static void altera_uart_shutdown(struct uart_port *port)
 338 {
 339         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 340         unsigned long flags;
 341
 342         spin_lock_irqsave(&port->lock, flags);
 343
 344         /* Disable all interrupts now */
 345         pp->imr = 0;
 346         writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
 347
 348         spin_unlock_irqrestore(&port->lock, flags);
 349
 350         if (port->irq)
 351                 free_irq(port->irq, port);
 352         else
 353                 del_timer_sync(&pp->tmr);
 354 }
 355
 356 static const char *altera_uart_type(struct uart_port *port)
 357 {
 358         return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL;
 359 }
 360
 361 static int altera_uart_request_port(struct uart_port *port)
 362 {
 363         /* UARTs always present */
 364         return 0;
 365 }
 366
 367 static void altera_uart_release_port(struct uart_port *port)
 368 {
 369         /* Nothing to release... */
 370 }
 371
 372 static int altera_uart_verify_port(struct uart_port *port,
 373                                    struct serial_struct *ser)
 374 {
 375         if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART))
 376                 return -EINVAL;
 377         return 0;
 378 }
 379
 380 /*
 381  *      Define the basic serial functions we support.
 382  */
 383 static struct uart_ops altera_uart_ops = {
 384         .tx_empty       = altera_uart_tx_empty,
 385         .get_mctrl      = altera_uart_get_mctrl,
 386         .set_mctrl      = altera_uart_set_mctrl,
 387         .start_tx       = altera_uart_start_tx,
 388         .stop_tx        = altera_uart_stop_tx,
 389         .stop_rx        = altera_uart_stop_rx,
 390         .enable_ms      = altera_uart_enable_ms,
 391         .break_ctl      = altera_uart_break_ctl,
 392         .startup        = altera_uart_startup,
 393         .shutdown       = altera_uart_shutdown,
 394         .set_termios    = altera_uart_set_termios,
 395         .type           = altera_uart_type,
 396         .request_port   = altera_uart_request_port,
 397         .release_port   = altera_uart_release_port,
 398         .config_port    = altera_uart_config_port,
 399         .verify_port    = altera_uart_verify_port,
 400 };
 401
 402 static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
 403
 404 #if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
 405
 406 int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
 407 {
 408         struct uart_port *port;
 409         int i;
 410
 411         for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) {
 412                 port = &altera_uart_ports[i].port;
 413
 414                 port->line = i;
 415                 port->type = PORT_ALTERA_UART;
 416                 port->mapbase = platp[i].mapbase;
 417                 port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
 418                 port->iotype = SERIAL_IO_MEM;
 419                 port->irq = platp[i].irq;
 420                 port->uartclk = platp[i].uartclk;
 421                 port->flags = UPF_BOOT_AUTOCONF;
 422                 port->ops = &altera_uart_ops;
 423                 port->private_data = platp;
 424         }
 425
 426         return 0;
 427 }
 428
 429 static void altera_uart_console_putc(struct uart_port *port, const char c)
 430 {
 431         while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 432                  ALTERA_UART_STATUS_TRDY_MSK))
 433                 cpu_relax();
 434
 435         writel(c, port->membase + ALTERA_UART_TXDATA_REG);
 436 }
 437
 438 static void altera_uart_console_write(struct console *co, const char *s,
 439                                       unsigned int count)
 440 {
 441         struct uart_port *port = &(altera_uart_ports + co->index)->port;
 442
 443         for (; count; count--, s++) {
 444                 altera_uart_console_putc(port, *s);
 445                 if (*s == '\n')
 446                         altera_uart_console_putc(port, '\r');
 447         }
 448 }
 449
 450 static int __init altera_uart_console_setup(struct console *co, char *options)
 451 {
 452         struct uart_port *port;
 453         int baud = CONFIG_SERIAL_ALTERA_UART_BAUDRATE;
 454         int bits = 8;
 455         int parity = 'n';
 456         int flow = 'n';
 457
 458         if (co->index < 0 || co->index >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
 459                 return -EINVAL;
 460         port = &altera_uart_ports[co->index].port;
 461         if (!port->membase)
 462                 return -ENODEV;
 463
 464         if (options)
 465                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 466
 467         return uart_set_options(port, co, baud, parity, bits, flow);
 468 }
 469
 470 static struct uart_driver altera_uart_driver;
 471
 472 static struct console altera_uart_console = {
 473         .name   = "ttyAL",
 474         .write  = altera_uart_console_write,
 475         .device = uart_console_device,
 476         .setup  = altera_uart_console_setup,
 477         .flags  = CON_PRINTBUFFER,
 478         .index  = -1,
 479         .data   = &altera_uart_driver,
 480 };
 481
 482 static int __init altera_uart_console_init(void)
 483 {
 484         register_console(&altera_uart_console);
 485         return 0;
 486 }
 487
 488 console_initcall(altera_uart_console_init);
 489
 490 #define ALTERA_UART_CONSOLE     (&altera_uart_console)
 491
 492 #else
 493
 494 #define ALTERA_UART_CONSOLE     NULL
 495
 496 #endif /* CONFIG_ALTERA_UART_CONSOLE */
 497
 498 /*
 499  *      Define the altera_uart UART driver structure.
 500  */
 501 static struct uart_driver altera_uart_driver = {
 502         .owner          = THIS_MODULE,
 503         .driver_name    = DRV_NAME,
 504         .dev_name       = "ttyAL",
 505         .major          = SERIAL_ALTERA_MAJOR,
 506         .minor          = SERIAL_ALTERA_MINOR,
 507         .nr             = CONFIG_SERIAL_ALTERA_UART_MAXPORTS,
 508         .cons           = ALTERA_UART_CONSOLE,
 509 };
 510
 511 #ifdef CONFIG_OF
 512 static int altera_uart_get_of_uartclk(struct platform_device *pdev,
 513                                       struct uart_port *port)
 514 {
 515         int len;
 516         const __be32 *clk;
 517
 518         clk = of_get_property(pdev->dev.of_node, "clock-frequency", &len);
 519         if (!clk || len < sizeof(__be32))
 520                 return -ENODEV;
 521
 522         port->uartclk = be32_to_cpup(clk);
 523
 524         return 0;
 525 }
 526 #else
 527 static int altera_uart_get_of_uartclk(struct platform_device *pdev,
 528                                       struct uart_port *port)
 529 {
 530         return -ENODEV;
 531 }
 532 #endif /* CONFIG_OF */
 533
 534 static int __devinit altera_uart_probe(struct platform_device *pdev)
 535 {
 536         struct altera_uart_platform_uart *platp = pdev->dev.platform_data;
 537         struct uart_port *port;
 538         struct resource *res_mem;
 539         struct resource *res_irq;
 540         int i = pdev->id;
 541         int ret;
 542
 543         /* if id is -1 scan for a free id and use that one */
 544         if (i == -1) {
 545                 for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++)
 546                         if (altera_uart_ports[i].port.mapbase == 0)
 547                                 break;
 548         }
 549
 550         if (i < 0 || i >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
 551                 return -EINVAL;
 552
 553         port = &altera_uart_ports[i].port;
 554
 555         res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 556         if (res_mem)
 557                 port->mapbase = res_mem->start;
 558         else if (platp->mapbase)
 559                 port->mapbase = platp->mapbase;
 560         else
 561                 return -EINVAL;
 562
 563         res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 564         if (res_irq)
 565                 port->irq = res_irq->start;
 566         else if (platp->irq)
 567                 port->irq = platp->irq;
 568
 569         /* Check platform data first so we can override device node data */
 570         if (platp)
 571                 port->uartclk = platp->uartclk;
 572         else {
 573                 ret = altera_uart_get_of_uartclk(pdev, port);
 574                 if (ret)
 575                         return ret;
 576         }
 577
 578         port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
 579         if (!port->membase)
 580                 return -ENOMEM;
 581
 582         if (platp)
 583                 port->regshift = platp->bus_shift;
 584         else
 585                 port->regshift = 0;
 586
 587         port->line = i;
 588         port->type = PORT_ALTERA_UART;
 589         port->iotype = SERIAL_IO_MEM;
 590         port->ops = &altera_uart_ops;
 591         port->flags = UPF_BOOT_AUTOCONF;
 592
 593         dev_set_drvdata(&pdev->dev, port);
 594
 595         uart_add_one_port(&altera_uart_driver, port);
 596
 597         return 0;
 598 }
 599
 600 static int __devexit altera_uart_remove(struct platform_device *pdev)
 601 {
 602         struct uart_port *port = dev_get_drvdata(&pdev->dev);
 603
 604         if (port) {
 605                 uart_remove_one_port(&altera_uart_driver, port);
 606                 dev_set_drvdata(&pdev->dev, NULL);
 607                 port->mapbase = 0;
 608         }
 609
 610         return 0;
 611 }
 612
 613 #ifdef CONFIG_OF
 614 static struct of_device_id altera_uart_match[] = {
 615         { .compatible = "ALTR,uart-1.0", },
 616         {},
 617 };
 618 MODULE_DEVICE_TABLE(of, altera_uart_match);
 619 #else
 620 #define altera_uart_match NULL
 621 #endif /* CONFIG_OF */
 622
 623 static struct platform_driver altera_uart_platform_driver = {
 624         .probe  = altera_uart_probe,
 625         .remove = __devexit_p(altera_uart_remove),
 626         .driver = {
 627                 .name           = DRV_NAME,
 628                 .owner          = THIS_MODULE,
 629                 .of_match_table = altera_uart_match,
 630         },
 631 };
 632
 633 static int __init altera_uart_init(void)
 634 {
 635         int rc;
 636
 637         rc = uart_register_driver(&altera_uart_driver);
 638         if (rc)
 639                 return rc;
 640         rc = platform_driver_register(&altera_uart_platform_driver);
 641         if (rc) {
 642                 uart_unregister_driver(&altera_uart_driver);
 643                 return rc;
 644         }
 645         return 0;
 646 }
 647
 648 static void __exit altera_uart_exit(void)
 649 {
 650         platform_driver_unregister(&altera_uart_platform_driver);
 651         uart_unregister_driver(&altera_uart_driver);
 652 }
 653
 654 module_init(altera_uart_init);
 655 module_exit(altera_uart_exit);
 656
 657 MODULE_DESCRIPTION("Altera UART driver");
 658 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 659 MODULE_LICENSE("GPL");
 660 MODULE_ALIAS("platform:" DRV_NAME);
 661 MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_ALTERA_MAJOR);