drivers/tty/serial/altera_uart.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * altera_uart.c -- Altera UART driver
   4  *
   5  * Based on mcf.c -- Freescale ColdFire UART driver
   6  *
   7  * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
   8  * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw>
   9  * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch>
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/timer.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/module.h>
  17 #include <linux/console.h>
  18 #include <linux/tty.h>
  19 #include <linux/tty_flip.h>
  20 #include <linux/serial.h>
  21 #include <linux/serial_core.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/of.h>
  24 #include <linux/io.h>
  25 #include <linux/altera_uart.h>
  26
  27 #define DRV_NAME "altera_uart"
  28 #define SERIAL_ALTERA_MAJOR 204
  29 #define SERIAL_ALTERA_MINOR 213
  30
  31 /*
  32  * Altera UART register definitions according to the Nios UART datasheet:
  33  * http://www.altera.com/literature/ds/ds_nios_uart.pdf
  34  */
  35
  36 #define ALTERA_UART_SIZE                32
  37
  38 #define ALTERA_UART_RXDATA_REG          0
  39 #define ALTERA_UART_TXDATA_REG          4
  40 #define ALTERA_UART_STATUS_REG          8
  41 #define ALTERA_UART_CONTROL_REG         12
  42 #define ALTERA_UART_DIVISOR_REG         16
  43 #define ALTERA_UART_EOP_REG             20
  44
  45 #define ALTERA_UART_STATUS_PE_MSK       0x0001  /* parity error */
  46 #define ALTERA_UART_STATUS_FE_MSK       0x0002  /* framing error */
  47 #define ALTERA_UART_STATUS_BRK_MSK      0x0004  /* break */
  48 #define ALTERA_UART_STATUS_ROE_MSK      0x0008  /* RX overrun error */
  49 #define ALTERA_UART_STATUS_TOE_MSK      0x0010  /* TX overrun error */
  50 #define ALTERA_UART_STATUS_TMT_MSK      0x0020  /* TX shift register state */
  51 #define ALTERA_UART_STATUS_TRDY_MSK     0x0040  /* TX ready */
  52 #define ALTERA_UART_STATUS_RRDY_MSK     0x0080  /* RX ready */
  53 #define ALTERA_UART_STATUS_E_MSK        0x0100  /* exception condition */
  54 #define ALTERA_UART_STATUS_DCTS_MSK     0x0400  /* CTS logic-level change */
  55 #define ALTERA_UART_STATUS_CTS_MSK      0x0800  /* CTS logic state */
  56 #define ALTERA_UART_STATUS_EOP_MSK      0x1000  /* EOP written/read */
  57
  58                                                 /* Enable interrupt on... */
  59 #define ALTERA_UART_CONTROL_PE_MSK      0x0001  /* ...parity error */
  60 #define ALTERA_UART_CONTROL_FE_MSK      0x0002  /* ...framing error */
  61 #define ALTERA_UART_CONTROL_BRK_MSK     0x0004  /* ...break */
  62 #define ALTERA_UART_CONTROL_ROE_MSK     0x0008  /* ...RX overrun */
  63 #define ALTERA_UART_CONTROL_TOE_MSK     0x0010  /* ...TX overrun */
  64 #define ALTERA_UART_CONTROL_TMT_MSK     0x0020  /* ...TX shift register empty */
  65 #define ALTERA_UART_CONTROL_TRDY_MSK    0x0040  /* ...TX ready */
  66 #define ALTERA_UART_CONTROL_RRDY_MSK    0x0080  /* ...RX ready */
  67 #define ALTERA_UART_CONTROL_E_MSK       0x0100  /* ...exception*/
  68
  69 #define ALTERA_UART_CONTROL_TRBK_MSK    0x0200  /* TX break */
  70 #define ALTERA_UART_CONTROL_DCTS_MSK    0x0400  /* Interrupt on CTS change */
  71 #define ALTERA_UART_CONTROL_RTS_MSK     0x0800  /* RTS signal */
  72 #define ALTERA_UART_CONTROL_EOP_MSK     0x1000  /* Interrupt on EOP */
  73
  74 /*
  75  * Local per-uart structure.
  76  */
  77 struct altera_uart {
  78         struct uart_port port;
  79         struct timer_list tmr;
  80         unsigned int sigs;      /* Local copy of line sigs */
  81         unsigned short imr;     /* Local IMR mirror */
  82 };
  83
  84 static u32 altera_uart_readl(struct uart_port *port, int reg)
  85 {
  86         return readl(port->membase + (reg << port->regshift));
  87 }
  88
  89 static void altera_uart_writel(struct uart_port *port, u32 dat, int reg)
  90 {
  91         writel(dat, port->membase + (reg << port->regshift));
  92 }
  93
  94 static unsigned int altera_uart_tx_empty(struct uart_port *port)
  95 {
  96         return (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
  97                 ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0;
  98 }
  99
 100 static unsigned int altera_uart_get_mctrl(struct uart_port *port)
 101 {
 102         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 103         unsigned int sigs;
 104
 105         sigs = (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 106              ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0;
 107         sigs |= (pp->sigs & TIOCM_RTS);
 108
 109         return sigs;
 110 }
 111
 112 static void altera_uart_update_ctrl_reg(struct altera_uart *pp)
 113 {
 114         unsigned short imr = pp->imr;
 115
 116         /*
 117          * If the device doesn't have an irq, ensure that the irq bits are
 118          * masked out to keep the irq line inactive.
 119          */
 120         if (!pp->port.irq)
 121                 imr &= ALTERA_UART_CONTROL_TRBK_MSK | ALTERA_UART_CONTROL_RTS_MSK;
 122
 123         altera_uart_writel(&pp->port, imr, ALTERA_UART_CONTROL_REG);
 124 }
 125
 126 static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs)
 127 {
 128         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 129
 130         pp->sigs = sigs;
 131         if (sigs & TIOCM_RTS)
 132                 pp->imr |= ALTERA_UART_CONTROL_RTS_MSK;
 133         else
 134                 pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK;
 135         altera_uart_update_ctrl_reg(pp);
 136 }
 137
 138 static void altera_uart_start_tx(struct uart_port *port)
 139 {
 140         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 141
 142         pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK;
 143         altera_uart_update_ctrl_reg(pp);
 144 }
 145
 146 static void altera_uart_stop_tx(struct uart_port *port)
 147 {
 148         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 149
 150         pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
 151         altera_uart_update_ctrl_reg(pp);
 152 }
 153
 154 static void altera_uart_stop_rx(struct uart_port *port)
 155 {
 156         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 157
 158         pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK;
 159         altera_uart_update_ctrl_reg(pp);
 160 }
 161
 162 static void altera_uart_break_ctl(struct uart_port *port, int break_state)
 163 {
 164         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 165         unsigned long flags;
 166
 167         spin_lock_irqsave(&port->lock, flags);
 168         if (break_state == -1)
 169                 pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
 170         else
 171                 pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
 172         altera_uart_update_ctrl_reg(pp);
 173         spin_unlock_irqrestore(&port->lock, flags);
 174 }
 175
 176 static void altera_uart_set_termios(struct uart_port *port,
 177                                     struct ktermios *termios,
 178                                     struct ktermios *old)
 179 {
 180         unsigned long flags;
 181         unsigned int baud, baudclk;
 182
 183         baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 184         baudclk = port->uartclk / baud;
 185
 186         if (old)
 187                 tty_termios_copy_hw(termios, old);
 188         tty_termios_encode_baud_rate(termios, baud, baud);
 189
 190         spin_lock_irqsave(&port->lock, flags);
 191         uart_update_timeout(port, termios->c_cflag, baud);
 192         altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
 193         spin_unlock_irqrestore(&port->lock, flags);
 194
 195         /*
 196          * FIXME: port->read_status_mask and port->ignore_status_mask
 197          * need to be initialized based on termios settings for
 198          * INPCK, IGNBRK, IGNPAR, PARMRK, BRKINT
 199          */
 200 }
 201
 202 static void altera_uart_rx_chars(struct altera_uart *pp)
 203 {
 204         struct uart_port *port = &pp->port;
 205         unsigned char ch, flag;
 206         unsigned short status;
 207
 208         while ((status = altera_uart_readl(port, ALTERA_UART_STATUS_REG)) &
 209                ALTERA_UART_STATUS_RRDY_MSK) {
 210                 ch = altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
 211                 flag = TTY_NORMAL;
 212                 port->icount.rx++;
 213
 214                 if (status & ALTERA_UART_STATUS_E_MSK) {
 215                         altera_uart_writel(port, status,
 216                                            ALTERA_UART_STATUS_REG);
 217
 218                         if (status & ALTERA_UART_STATUS_BRK_MSK) {
 219                                 port->icount.brk++;
 220                                 if (uart_handle_break(port))
 221                                         continue;
 222                         } else if (status & ALTERA_UART_STATUS_PE_MSK) {
 223                                 port->icount.parity++;
 224                         } else if (status & ALTERA_UART_STATUS_ROE_MSK) {
 225                                 port->icount.overrun++;
 226                         } else if (status & ALTERA_UART_STATUS_FE_MSK) {
 227                                 port->icount.frame++;
 228                         }
 229
 230                         status &= port->read_status_mask;
 231
 232                         if (status & ALTERA_UART_STATUS_BRK_MSK)
 233                                 flag = TTY_BREAK;
 234                         else if (status & ALTERA_UART_STATUS_PE_MSK)
 235                                 flag = TTY_PARITY;
 236                         else if (status & ALTERA_UART_STATUS_FE_MSK)
 237                                 flag = TTY_FRAME;
 238                 }
 239
 240                 if (uart_handle_sysrq_char(port, ch))
 241                         continue;
 242                 uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch,
 243                                  flag);
 244         }
 245
 246         spin_unlock(&port->lock);
 247         tty_flip_buffer_push(&port->state->port);
 248         spin_lock(&port->lock);
 249 }
 250
 251 static void altera_uart_tx_chars(struct altera_uart *pp)
 252 {
 253         struct uart_port *port = &pp->port;
 254         struct circ_buf *xmit = &port->state->xmit;
 255
 256         if (port->x_char) {
 257                 /* Send special char - probably flow control */
 258                 altera_uart_writel(port, port->x_char, ALTERA_UART_TXDATA_REG);
 259                 port->x_char = 0;
 260                 port->icount.tx++;
 261                 return;
 262         }
 263
 264         while (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 265                ALTERA_UART_STATUS_TRDY_MSK) {
 266                 if (xmit->head == xmit->tail)
 267                         break;
 268                 altera_uart_writel(port, xmit->buf[xmit->tail],
 269                        ALTERA_UART_TXDATA_REG);
 270                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 271                 port->icount.tx++;
 272         }
 273
 274         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 275                 uart_write_wakeup(port);
 276
 277         if (xmit->head == xmit->tail) {
 278                 pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
 279                 altera_uart_update_ctrl_reg(pp);
 280         }
 281 }
 282
 283 static irqreturn_t altera_uart_interrupt(int irq, void *data)
 284 {
 285         struct uart_port *port = data;
 286         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 287         unsigned int isr;
 288
 289         isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
 290
 291         spin_lock(&port->lock);
 292         if (isr & ALTERA_UART_STATUS_RRDY_MSK)
 293                 altera_uart_rx_chars(pp);
 294         if (isr & ALTERA_UART_STATUS_TRDY_MSK)
 295                 altera_uart_tx_chars(pp);
 296         spin_unlock(&port->lock);
 297
 298         return IRQ_RETVAL(isr);
 299 }
 300
 301 static void altera_uart_timer(struct timer_list *t)
 302 {
 303         struct altera_uart *pp = from_timer(pp, t, tmr);
 304         struct uart_port *port = &pp->port;
 305
 306         altera_uart_interrupt(0, port);
 307         mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
 308 }
 309
 310 static void altera_uart_config_port(struct uart_port *port, int flags)
 311 {
 312         port->type = PORT_ALTERA_UART;
 313
 314         /* Clear mask, so no surprise interrupts. */
 315         altera_uart_writel(port, 0, ALTERA_UART_CONTROL_REG);
 316         /* Clear status register */
 317         altera_uart_writel(port, 0, ALTERA_UART_STATUS_REG);
 318 }
 319
 320 static int altera_uart_startup(struct uart_port *port)
 321 {
 322         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 323         unsigned long flags;
 324
 325         if (!port->irq) {
 326                 timer_setup(&pp->tmr, altera_uart_timer, 0);
 327                 mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
 328         } else {
 329                 int ret;
 330
 331                 ret = request_irq(port->irq, altera_uart_interrupt, 0,
 332                                 DRV_NAME, port);
 333                 if (ret) {
 334                         pr_err(DRV_NAME ": unable to attach Altera UART %d "
 335                                "interrupt vector=%d\n", port->line, port->irq);
 336                         return ret;
 337                 }
 338         }
 339
 340         spin_lock_irqsave(&port->lock, flags);
 341
 342         /* Enable RX interrupts now */
 343         pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
 344         altera_uart_update_ctrl_reg(pp);
 345
 346         spin_unlock_irqrestore(&port->lock, flags);
 347
 348         return 0;
 349 }
 350
 351 static void altera_uart_shutdown(struct uart_port *port)
 352 {
 353         struct altera_uart *pp = container_of(port, struct altera_uart, port);
 354         unsigned long flags;
 355
 356         spin_lock_irqsave(&port->lock, flags);
 357
 358         /* Disable all interrupts now */
 359         pp->imr = 0;
 360         altera_uart_update_ctrl_reg(pp);
 361
 362         spin_unlock_irqrestore(&port->lock, flags);
 363
 364         if (port->irq)
 365                 free_irq(port->irq, port);
 366         else
 367                 del_timer_sync(&pp->tmr);
 368 }
 369
 370 static const char *altera_uart_type(struct uart_port *port)
 371 {
 372         return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL;
 373 }
 374
 375 static int altera_uart_request_port(struct uart_port *port)
 376 {
 377         /* UARTs always present */
 378         return 0;
 379 }
 380
 381 static void altera_uart_release_port(struct uart_port *port)
 382 {
 383         /* Nothing to release... */
 384 }
 385
 386 static int altera_uart_verify_port(struct uart_port *port,
 387                                    struct serial_struct *ser)
 388 {
 389         if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART))
 390                 return -EINVAL;
 391         return 0;
 392 }
 393
 394 #ifdef CONFIG_CONSOLE_POLL
 395 static int altera_uart_poll_get_char(struct uart_port *port)
 396 {
 397         while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 398                  ALTERA_UART_STATUS_RRDY_MSK))
 399                 cpu_relax();
 400
 401         return altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
 402 }
 403
 404 static void altera_uart_poll_put_char(struct uart_port *port, unsigned char c)
 405 {
 406         while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 407                  ALTERA_UART_STATUS_TRDY_MSK))
 408                 cpu_relax();
 409
 410         altera_uart_writel(port, c, ALTERA_UART_TXDATA_REG);
 411 }
 412 #endif
 413
 414 /*
 415  *      Define the basic serial functions we support.
 416  */
 417 static const struct uart_ops altera_uart_ops = {
 418         .tx_empty       = altera_uart_tx_empty,
 419         .get_mctrl      = altera_uart_get_mctrl,
 420         .set_mctrl      = altera_uart_set_mctrl,
 421         .start_tx       = altera_uart_start_tx,
 422         .stop_tx        = altera_uart_stop_tx,
 423         .stop_rx        = altera_uart_stop_rx,
 424         .break_ctl      = altera_uart_break_ctl,
 425         .startup        = altera_uart_startup,
 426         .shutdown       = altera_uart_shutdown,
 427         .set_termios    = altera_uart_set_termios,
 428         .type           = altera_uart_type,
 429         .request_port   = altera_uart_request_port,
 430         .release_port   = altera_uart_release_port,
 431         .config_port    = altera_uart_config_port,
 432         .verify_port    = altera_uart_verify_port,
 433 #ifdef CONFIG_CONSOLE_POLL
 434         .poll_get_char  = altera_uart_poll_get_char,
 435         .poll_put_char  = altera_uart_poll_put_char,
 436 #endif
 437 };
 438
 439 static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
 440
 441 #if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
 442
 443 static void altera_uart_console_putc(struct uart_port *port, int c)
 444 {
 445         while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 446                  ALTERA_UART_STATUS_TRDY_MSK))
 447                 cpu_relax();
 448
 449         altera_uart_writel(port, c, ALTERA_UART_TXDATA_REG);
 450 }
 451
 452 static void altera_uart_console_write(struct console *co, const char *s,
 453                                       unsigned int count)
 454 {
 455         struct uart_port *port = &(altera_uart_ports + co->index)->port;
 456
 457         uart_console_write(port, s, count, altera_uart_console_putc);
 458 }
 459
 460 static int __init altera_uart_console_setup(struct console *co, char *options)
 461 {
 462         struct uart_port *port;
 463         int baud = CONFIG_SERIAL_ALTERA_UART_BAUDRATE;
 464         int bits = 8;
 465         int parity = 'n';
 466         int flow = 'n';
 467
 468         if (co->index < 0 || co->index >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
 469                 return -EINVAL;
 470         port = &altera_uart_ports[co->index].port;
 471         if (!port->membase)
 472                 return -ENODEV;
 473
 474         if (options)
 475                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 476
 477         return uart_set_options(port, co, baud, parity, bits, flow);
 478 }
 479
 480 static struct uart_driver altera_uart_driver;
 481
 482 static struct console altera_uart_console = {
 483         .name   = "ttyAL",
 484         .write  = altera_uart_console_write,
 485         .device = uart_console_device,
 486         .setup  = altera_uart_console_setup,
 487         .flags  = CON_PRINTBUFFER,
 488         .index  = -1,
 489         .data   = &altera_uart_driver,
 490 };
 491
 492 static int __init altera_uart_console_init(void)
 493 {
 494         register_console(&altera_uart_console);
 495         return 0;
 496 }
 497
 498 console_initcall(altera_uart_console_init);
 499
 500 #define ALTERA_UART_CONSOLE     (&altera_uart_console)
 501
 502 static void altera_uart_earlycon_write(struct console *co, const char *s,
 503                                        unsigned int count)
 504 {
 505         struct earlycon_device *dev = co->data;
 506
 507         uart_console_write(&dev->port, s, count, altera_uart_console_putc);
 508 }
 509
 510 static int __init altera_uart_earlycon_setup(struct earlycon_device *dev,
 511                                              const char *options)
 512 {
 513         struct uart_port *port = &dev->port;
 514
 515         if (!port->membase)
 516                 return -ENODEV;
 517
 518         /* Enable RX interrupts now */
 519         altera_uart_writel(port, ALTERA_UART_CONTROL_RRDY_MSK,
 520                            ALTERA_UART_CONTROL_REG);
 521
 522         if (dev->baud) {
 523                 unsigned int baudclk = port->uartclk / dev->baud;
 524
 525                 altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
 526         }
 527
 528         dev->con->write = altera_uart_earlycon_write;
 529         return 0;
 530 }
 531
 532 OF_EARLYCON_DECLARE(uart, "altr,uart-1.0", altera_uart_earlycon_setup);
 533
 534 #else
 535
 536 #define ALTERA_UART_CONSOLE     NULL
 537
 538 #endif /* CONFIG_SERIAL_ALTERA_UART_CONSOLE */
 539
 540 /*
 541  *      Define the altera_uart UART driver structure.
 542  */
 543 static struct uart_driver altera_uart_driver = {
 544         .owner          = THIS_MODULE,
 545         .driver_name    = DRV_NAME,
 546         .dev_name       = "ttyAL",
 547         .major          = SERIAL_ALTERA_MAJOR,
 548         .minor          = SERIAL_ALTERA_MINOR,
 549         .nr             = CONFIG_SERIAL_ALTERA_UART_MAXPORTS,
 550         .cons           = ALTERA_UART_CONSOLE,
 551 };
 552
 553 static int altera_uart_probe(struct platform_device *pdev)
 554 {
 555         struct altera_uart_platform_uart *platp = dev_get_platdata(&pdev->dev);
 556         struct uart_port *port;
 557         struct resource *res_mem;
 558         struct resource *res_irq;
 559         int i = pdev->id;
 560         int ret;
 561
 562         /* if id is -1 scan for a free id and use that one */
 563         if (i == -1) {
 564                 for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++)
 565                         if (altera_uart_ports[i].port.mapbase == 0)
 566                                 break;
 567         }
 568
 569         if (i < 0 || i >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
 570                 return -EINVAL;
 571
 572         port = &altera_uart_ports[i].port;
 573
 574         res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 575         if (res_mem)
 576                 port->mapbase = res_mem->start;
 577         else if (platp)
 578                 port->mapbase = platp->mapbase;
 579         else
 580                 return -EINVAL;
 581
 582         res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 583         if (res_irq)
 584                 port->irq = res_irq->start;
 585         else if (platp)
 586                 port->irq = platp->irq;
 587
 588         /* Check platform data first so we can override device node data */
 589         if (platp)
 590                 port->uartclk = platp->uartclk;
 591         else {
 592                 ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 593                                            &port->uartclk);
 594                 if (ret)
 595                         return ret;
 596         }
 597
 598         port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
 599         if (!port->membase)
 600                 return -ENOMEM;
 601
 602         if (platp)
 603                 port->regshift = platp->bus_shift;
 604         else
 605                 port->regshift = 0;
 606
 607         port->line = i;
 608         port->type = PORT_ALTERA_UART;
 609         port->iotype = SERIAL_IO_MEM;
 610         port->ops = &altera_uart_ops;
 611         port->flags = UPF_BOOT_AUTOCONF;
 612         port->dev = &pdev->dev;
 613
 614         platform_set_drvdata(pdev, port);
 615
 616         uart_add_one_port(&altera_uart_driver, port);
 617
 618         return 0;
 619 }
 620
 621 static int altera_uart_remove(struct platform_device *pdev)
 622 {
 623         struct uart_port *port = platform_get_drvdata(pdev);
 624
 625         if (port) {
 626                 uart_remove_one_port(&altera_uart_driver, port);
 627                 port->mapbase = 0;
 628                 iounmap(port->membase);
 629         }
 630
 631         return 0;
 632 }
 633
 634 #ifdef CONFIG_OF
 635 static const struct of_device_id altera_uart_match[] = {
 636         { .compatible = "ALTR,uart-1.0", },
 637         { .compatible = "altr,uart-1.0", },
 638         {},
 639 };
 640 MODULE_DEVICE_TABLE(of, altera_uart_match);
 641 #endif /* CONFIG_OF */
 642
 643 static struct platform_driver altera_uart_platform_driver = {
 644         .probe  = altera_uart_probe,
 645         .remove = altera_uart_remove,
 646         .driver = {
 647                 .name           = DRV_NAME,
 648                 .of_match_table = of_match_ptr(altera_uart_match),
 649         },
 650 };
 651
 652 static int __init altera_uart_init(void)
 653 {
 654         int rc;
 655
 656         rc = uart_register_driver(&altera_uart_driver);
 657         if (rc)
 658                 return rc;
 659         rc = platform_driver_register(&altera_uart_platform_driver);
 660         if (rc)
 661                 uart_unregister_driver(&altera_uart_driver);
 662         return rc;
 663 }
 664
 665 static void __exit altera_uart_exit(void)
 666 {
 667         platform_driver_unregister(&altera_uart_platform_driver);
 668         uart_unregister_driver(&altera_uart_driver);
 669 }
 670
 671 module_init(altera_uart_init);
 672 module_exit(altera_uart_exit);
 673
 674 MODULE_DESCRIPTION("Altera UART driver");
 675 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 676 MODULE_LICENSE("GPL");
 677 MODULE_ALIAS("platform:" DRV_NAME);
 678 MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_ALTERA_MAJOR);