LXR linux/drivers/tty/serial/altera

   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 */
  81struct 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
  88static u32 altera_uart_readl(struct uart_port *port, int reg)
  89{
  90        return readl(port->membase + (reg << port->regshift));
  91}
  92
  93static void altera_uart_writel(struct uart_port *port, u32 dat, int reg)
  94{
  95        writel(dat, port->membase + (reg << port->regshift));
  96}
  97
  98static 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
 104static 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
 116static 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
 128static 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
 136static 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
 144static 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
 152static 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
 166static void altera_uart_set_termios(struct uart_port *port,
 167                                    struct ktermios *termios,
 168                                    struct ktermios *old)
 169{
 170        unsigned long flags;
 171        unsigned int baud, baudclk;
 172
 173        baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
 174        baudclk = port->uartclk / baud;
 175
 176        if (old)
 177                tty_termios_copy_hw(termios, old);
 178        tty_termios_encode_baud_rate(termios, baud, baud);
 179
 180        spin_lock_irqsave(&port->lock, flags);
 181        uart_update_timeout(port, termios->c_cflag, baud);
 182        altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
 183        spin_unlock_irqrestore(&port->lock, flags);
 184
 185        /*
 186         * FIXME: port->read_status_mask and port->ignore_status_mask
 187         * need to be initialized based on termios settings for
 188         * INPCK, IGNBRK, IGNPAR, PARMRK, BRKINT
 189         */
 190}
 191
 192static void altera_uart_rx_chars(struct altera_uart *pp)
 193{
 194        struct uart_port *port = &pp->port;
 195        unsigned char ch, flag;
 196        unsigned short status;
 197
 198        while ((status = altera_uart_readl(port, ALTERA_UART_STATUS_REG)) &
 199               ALTERA_UART_STATUS_RRDY_MSK) {
 200                ch = altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
 201                flag = TTY_NORMAL;
 202                port->icount.rx++;
 203
 204                if (status & ALTERA_UART_STATUS_E_MSK) {
 205                        altera_uart_writel(port, status,
 206                                           ALTERA_UART_STATUS_REG);
 207
 208                        if (status & ALTERA_UART_STATUS_BRK_MSK) {
 209                                port->icount.brk++;
 210                                if (uart_handle_break(port))
 211                                        continue;
 212                        } else if (status & ALTERA_UART_STATUS_PE_MSK) {
 213                                port->icount.parity++;
 214                        } else if (status & ALTERA_UART_STATUS_ROE_MSK) {
 215                                port->icount.overrun++;
 216                        } else if (status & ALTERA_UART_STATUS_FE_MSK) {
 217                                port->icount.frame++;
 218                        }
 219
 220                        status &= port->read_status_mask;
 221
 222                        if (status & ALTERA_UART_STATUS_BRK_MSK)
 223                                flag = TTY_BREAK;
 224                        else if (status & ALTERA_UART_STATUS_PE_MSK)
 225                                flag = TTY_PARITY;
 226                        else if (status & ALTERA_UART_STATUS_FE_MSK)
 227                                flag = TTY_FRAME;
 228                }
 229
 230                if (uart_handle_sysrq_char(port, ch))
 231                        continue;
 232                uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch,
 233                                 flag);
 234        }
 235
 236        spin_unlock(&port->lock);
 237        tty_flip_buffer_push(&port->state->port);
 238        spin_lock(&port->lock);
 239}
 240
 241static void altera_uart_tx_chars(struct altera_uart *pp)
 242{
 243        struct uart_port *port = &pp->port;
 244        struct circ_buf *xmit = &port->state->xmit;
 245
 246        if (port->x_char) {
 247                /* Send special char - probably flow control */
 248                altera_uart_writel(port, port->x_char, ALTERA_UART_TXDATA_REG);
 249                port->x_char = 0;
 250                port->icount.tx++;
 251                return;
 252        }
 253
 254        while (altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 255               ALTERA_UART_STATUS_TRDY_MSK) {
 256                if (xmit->head == xmit->tail)
 257                        break;
 258                altera_uart_writel(port, xmit->buf[xmit->tail],
 259                       ALTERA_UART_TXDATA_REG);
 260                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 261                port->icount.tx++;
 262        }
 263
 264        if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 265                uart_write_wakeup(port);
 266
 267        if (xmit->head == xmit->tail) {
 268                pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK;
 269                altera_uart_writel(port, pp->imr, ALTERA_UART_CONTROL_REG);
 270        }
 271}
 272
 273static irqreturn_t altera_uart_interrupt(int irq, void *data)
 274{
 275        struct uart_port *port = data;
 276        struct altera_uart *pp = container_of(port, struct altera_uart, port);
 277        unsigned int isr;
 278
 279        isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
 280
 281        spin_lock(&port->lock);
 282        if (isr & ALTERA_UART_STATUS_RRDY_MSK)
 283                altera_uart_rx_chars(pp);
 284        if (isr & ALTERA_UART_STATUS_TRDY_MSK)
 285                altera_uart_tx_chars(pp);
 286        spin_unlock(&port->lock);
 287
 288        return IRQ_RETVAL(isr);
 289}
 290
 291static void altera_uart_timer(unsigned long data)
 292{
 293        struct uart_port *port = (void *)data;
 294        struct altera_uart *pp = container_of(port, struct altera_uart, port);
 295
 296        altera_uart_interrupt(0, port);
 297        mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
 298}
 299
 300static void altera_uart_config_port(struct uart_port *port, int flags)
 301{
 302        port->type = PORT_ALTERA_UART;
 303
 304        /* Clear mask, so no surprise interrupts. */
 305        altera_uart_writel(port, 0, ALTERA_UART_CONTROL_REG);
 306        /* Clear status register */
 307        altera_uart_writel(port, 0, ALTERA_UART_STATUS_REG);
 308}
 309
 310static int altera_uart_startup(struct uart_port *port)
 311{
 312        struct altera_uart *pp = container_of(port, struct altera_uart, port);
 313        unsigned long flags;
 314        int ret;
 315
 316        if (!port->irq) {
 317                setup_timer(&pp->tmr, altera_uart_timer, (unsigned long)port);
 318                mod_timer(&pp->tmr, jiffies + uart_poll_timeout(port));
 319                return 0;
 320        }
 321
 322        ret = request_irq(port->irq, altera_uart_interrupt, 0,
 323                        DRV_NAME, port);
 324        if (ret) {
 325                pr_err(DRV_NAME ": unable to attach Altera UART %d "
 326                       "interrupt vector=%d\n", port->line, port->irq);
 327                return ret;
 328        }
 329
 330        spin_lock_irqsave(&port->lock, flags);
 331
 332        /* Enable RX interrupts now */
 333        pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
 334        writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
 335
 336        spin_unlock_irqrestore(&port->lock, flags);
 337
 338        return 0;
 339}
 340
 341static void altera_uart_shutdown(struct uart_port *port)
 342{
 343        struct altera_uart *pp = container_of(port, struct altera_uart, port);
 344        unsigned long flags;
 345
 346        spin_lock_irqsave(&port->lock, flags);
 347
 348        /* Disable all interrupts now */
 349        pp->imr = 0;
 350        writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG);
 351
 352        spin_unlock_irqrestore(&port->lock, flags);
 353
 354        if (port->irq)
 355                free_irq(port->irq, port);
 356        else
 357                del_timer_sync(&pp->tmr);
 358}
 359
 360static const char *altera_uart_type(struct uart_port *port)
 361{
 362        return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL;
 363}
 364
 365static int altera_uart_request_port(struct uart_port *port)
 366{
 367        /* UARTs always present */
 368        return 0;
 369}
 370
 371static void altera_uart_release_port(struct uart_port *port)
 372{
 373        /* Nothing to release... */
 374}
 375
 376static int altera_uart_verify_port(struct uart_port *port,
 377                                   struct serial_struct *ser)
 378{
 379        if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART))
 380                return -EINVAL;
 381        return 0;
 382}
 383
 384#ifdef CONFIG_CONSOLE_POLL
 385static int altera_uart_poll_get_char(struct uart_port *port)
 386{
 387        while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 388                 ALTERA_UART_STATUS_RRDY_MSK))
 389                cpu_relax();
 390
 391        return altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
 392}
 393
 394static void altera_uart_poll_put_char(struct uart_port *port, unsigned char c)
 395{
 396        while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 397                 ALTERA_UART_STATUS_TRDY_MSK))
 398                cpu_relax();
 399
 400        altera_uart_writel(port, c, ALTERA_UART_TXDATA_REG);
 401}
 402#endif
 403
 404/*
 405 *      Define the basic serial functions we support.
 406 */
 407static const struct uart_ops altera_uart_ops = {
 408        .tx_empty       = altera_uart_tx_empty,
 409        .get_mctrl      = altera_uart_get_mctrl,
 410        .set_mctrl      = altera_uart_set_mctrl,
 411        .start_tx       = altera_uart_start_tx,
 412        .stop_tx        = altera_uart_stop_tx,
 413        .stop_rx        = altera_uart_stop_rx,
 414        .break_ctl      = altera_uart_break_ctl,
 415        .startup        = altera_uart_startup,
 416        .shutdown       = altera_uart_shutdown,
 417        .set_termios    = altera_uart_set_termios,
 418        .type           = altera_uart_type,
 419        .request_port   = altera_uart_request_port,
 420        .release_port   = altera_uart_release_port,
 421        .config_port    = altera_uart_config_port,
 422        .verify_port    = altera_uart_verify_port,
 423#ifdef CONFIG_CONSOLE_POLL
 424        .poll_get_char  = altera_uart_poll_get_char,
 425        .poll_put_char  = altera_uart_poll_put_char,
 426#endif
 427};
 428
 429static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
 430
 431#if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
 432
 433static void altera_uart_console_putc(struct uart_port *port, int c)
 434{
 435        while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
 436                 ALTERA_UART_STATUS_TRDY_MSK))
 437                cpu_relax();
 438
 439        writel(c, port->membase + ALTERA_UART_TXDATA_REG);
 440}
 441
 442static void altera_uart_console_write(struct console *co, const char *s,
 443                                      unsigned int count)
 444{
 445        struct uart_port *port = &(altera_uart_ports + co->index)->port;
 446
 447        uart_console_write(port, s, count, altera_uart_console_putc);
 448}
 449
 450static 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
 470static struct uart_driver altera_uart_driver;
 471
 472static 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
 482static int __init altera_uart_console_init(void)
 483{
 484        register_console(&altera_uart_console);
 485        return 0;
 486}
 487
 488console_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_SERIAL_ALTERA_UART_CONSOLE */
 497
 498/*
 499 *      Define the altera_uart UART driver structure.
 500 */
 501static 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
 511static int altera_uart_probe(struct platform_device *pdev)
 512{
 513        struct altera_uart_platform_uart *platp = dev_get_platdata(&pdev->dev);
 514        struct uart_port *port;
 515        struct resource *res_mem;
 516        struct resource *res_irq;
 517        int i = pdev->id;
 518        int ret;
 519
 520        /* if id is -1 scan for a free id and use that one */
 521        if (i == -1) {
 522                for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++)
 523                        if (altera_uart_ports[i].port.mapbase == 0)
 524                                break;
 525        }
 526
 527        if (i < 0 || i >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS)
 528                return -EINVAL;
 529
 530        port = &altera_uart_ports[i].port;
 531
 532        res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 533        if (res_mem)
 534                port->mapbase = res_mem->start;
 535        else if (platp)
 536                port->mapbase = platp->mapbase;
 537        else
 538                return -EINVAL;
 539
 540        res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 541        if (res_irq)
 542                port->irq = res_irq->start;
 543        else if (platp)
 544                port->irq = platp->irq;
 545
 546        /* Check platform data first so we can override device node data */
 547        if (platp)
 548                port->uartclk = platp->uartclk;
 549        else {
 550                ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
 551                                           &port->uartclk);
 552                if (ret)
 553                        return ret;
 554        }
 555
 556        port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
 557        if (!port->membase)
 558                return -ENOMEM;
 559
 560        if (platp)
 561                port->regshift = platp->bus_shift;
 562        else
 563                port->regshift = 0;
 564
 565        port->line = i;
 566        port->type = PORT_ALTERA_UART;
 567        port->iotype = SERIAL_IO_MEM;
 568        port->ops = &altera_uart_ops;
 569        port->flags = UPF_BOOT_AUTOCONF;
 570        port->dev = &pdev->dev;
 571
 572        platform_set_drvdata(pdev, port);
 573
 574        uart_add_one_port(&altera_uart_driver, port);
 575
 576        return 0;
 577}
 578
 579static int altera_uart_remove(struct platform_device *pdev)
 580{
 581        struct uart_port *port = platform_get_drvdata(pdev);
 582
 583        if (port) {
 584                uart_remove_one_port(&altera_uart_driver, port);
 585                port->mapbase = 0;
 586        }
 587
 588        return 0;
 589}
 590
 591#ifdef CONFIG_OF
 592static const struct of_device_id altera_uart_match[] = {
 593        { .compatible = "ALTR,uart-1.0", },
 594        { .compatible = "altr,uart-1.0", },
 595        {},
 596};
 597MODULE_DEVICE_TABLE(of, altera_uart_match);
 598#endif /* CONFIG_OF */
 599
 600static struct platform_driver altera_uart_platform_driver = {
 601        .probe  = altera_uart_probe,
 602        .remove = altera_uart_remove,
 603        .driver = {
 604                .name           = DRV_NAME,
 605                .of_match_table = of_match_ptr(altera_uart_match),
 606        },
 607};
 608
 609static int __init altera_uart_init(void)
 610{
 611        int rc;
 612
 613        rc = uart_register_driver(&altera_uart_driver);
 614        if (rc)
 615                return rc;
 616        rc = platform_driver_register(&altera_uart_platform_driver);
 617        if (rc)
 618                uart_unregister_driver(&altera_uart_driver);
 619        return rc;
 620}
 621
 622static void __exit altera_uart_exit(void)
 623{
 624        platform_driver_unregister(&altera_uart_platform_driver);
 625        uart_unregister_driver(&altera_uart_driver);
 626}
 627
 628module_init(altera_uart_init);
 629module_exit(altera_uart_exit);
 630
 631MODULE_DESCRIPTION("Altera UART driver");
 632MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 633MODULE_LICENSE("GPL");
 634MODULE_ALIAS("platform:" DRV_NAME);
 635MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_ALTERA_MAJOR);
 636