drivers/tty/serial/vt8500_serial.c

   1 /*
   2  * Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
   3  *
   4  * Based on msm_serial.c, which is:
   5  * Copyright (C) 2007 Google, Inc.
   6  * Author: Robert Love <rlove@google.com>
   7  *
   8  * This software is licensed under the terms of the GNU General Public
   9  * License version 2, as published by the Free Software Foundation, and
  10  * may be copied, distributed, and modified under those terms.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #if defined(CONFIG_SERIAL_VT8500_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  19 # define SUPPORT_SYSRQ
  20 #endif
  21
  22 #include <linux/hrtimer.h>
  23 #include <linux/delay.h>
  24 #include <linux/module.h>
  25 #include <linux/io.h>
  26 #include <linux/ioport.h>
  27 #include <linux/irq.h>
  28 #include <linux/init.h>
  29 #include <linux/console.h>
  30 #include <linux/tty.h>
  31 #include <linux/tty_flip.h>
  32 #include <linux/serial_core.h>
  33 #include <linux/serial.h>
  34 #include <linux/slab.h>
  35 #include <linux/clk.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/of.h>
  38 #include <linux/err.h>
  39
  40 /*
  41  * UART Register offsets
  42  */
  43
  44 #define VT8500_URTDR            0x0000  /* Transmit data */
  45 #define VT8500_URRDR            0x0004  /* Receive data */
  46 #define VT8500_URDIV            0x0008  /* Clock/Baud rate divisor */
  47 #define VT8500_URLCR            0x000C  /* Line control */
  48 #define VT8500_URICR            0x0010  /* IrDA control */
  49 #define VT8500_URIER            0x0014  /* Interrupt enable */
  50 #define VT8500_URISR            0x0018  /* Interrupt status */
  51 #define VT8500_URUSR            0x001c  /* UART status */
  52 #define VT8500_URFCR            0x0020  /* FIFO control */
  53 #define VT8500_URFIDX           0x0024  /* FIFO index */
  54 #define VT8500_URBKR            0x0028  /* Break signal count */
  55 #define VT8500_URTOD            0x002c  /* Time out divisor */
  56 #define VT8500_TXFIFO           0x1000  /* Transmit FIFO (16x8) */
  57 #define VT8500_RXFIFO           0x1020  /* Receive FIFO (16x10) */
  58
  59 /*
  60  * Interrupt enable and status bits
  61  */
  62
  63 #define TXDE    (1 << 0)        /* Tx Data empty */
  64 #define RXDF    (1 << 1)        /* Rx Data full */
  65 #define TXFAE   (1 << 2)        /* Tx FIFO almost empty */
  66 #define TXFE    (1 << 3)        /* Tx FIFO empty */
  67 #define RXFAF   (1 << 4)        /* Rx FIFO almost full */
  68 #define RXFF    (1 << 5)        /* Rx FIFO full */
  69 #define TXUDR   (1 << 6)        /* Tx underrun */
  70 #define RXOVER  (1 << 7)        /* Rx overrun */
  71 #define PER     (1 << 8)        /* Parity error */
  72 #define FER     (1 << 9)        /* Frame error */
  73 #define TCTS    (1 << 10)       /* Toggle of CTS */
  74 #define RXTOUT  (1 << 11)       /* Rx timeout */
  75 #define BKDONE  (1 << 12)       /* Break signal done */
  76 #define ERR     (1 << 13)       /* AHB error response */
  77
  78 #define RX_FIFO_INTS    (RXFAF | RXFF | RXOVER | PER | FER | RXTOUT)
  79 #define TX_FIFO_INTS    (TXFAE | TXFE | TXUDR)
  80
  81 #define VT8500_MAX_PORTS        6
  82
  83 struct vt8500_port {
  84         struct uart_port        uart;
  85         char                    name[16];
  86         struct clk              *clk;
  87         unsigned int            ier;
  88 };
  89
  90 /*
  91  * we use this variable to keep track of which ports
  92  * have been allocated as we can't use pdev->id in
  93  * devicetree
  94  */
  95 static unsigned long vt8500_ports_in_use;
  96
  97 static inline void vt8500_write(struct uart_port *port, unsigned int val,
  98                              unsigned int off)
  99 {
 100         writel(val, port->membase + off);
 101 }
 102
 103 static inline unsigned int vt8500_read(struct uart_port *port, unsigned int off)
 104 {
 105         return readl(port->membase + off);
 106 }
 107
 108 static void vt8500_stop_tx(struct uart_port *port)
 109 {
 110         struct vt8500_port *vt8500_port = container_of(port,
 111                                                        struct vt8500_port,
 112                                                        uart);
 113
 114         vt8500_port->ier &= ~TX_FIFO_INTS;
 115         vt8500_write(port, vt8500_port->ier, VT8500_URIER);
 116 }
 117
 118 static void vt8500_stop_rx(struct uart_port *port)
 119 {
 120         struct vt8500_port *vt8500_port = container_of(port,
 121                                                        struct vt8500_port,
 122                                                        uart);
 123
 124         vt8500_port->ier &= ~RX_FIFO_INTS;
 125         vt8500_write(port, vt8500_port->ier, VT8500_URIER);
 126 }
 127
 128 static void vt8500_enable_ms(struct uart_port *port)
 129 {
 130         struct vt8500_port *vt8500_port = container_of(port,
 131                                                        struct vt8500_port,
 132                                                        uart);
 133
 134         vt8500_port->ier |= TCTS;
 135         vt8500_write(port, vt8500_port->ier, VT8500_URIER);
 136 }
 137
 138 static void handle_rx(struct uart_port *port)
 139 {
 140         struct tty_port *tport = &port->state->port;
 141
 142         /*
 143          * Handle overrun
 144          */
 145         if ((vt8500_read(port, VT8500_URISR) & RXOVER)) {
 146                 port->icount.overrun++;
 147                 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 148         }
 149
 150         /* and now the main RX loop */
 151         while (vt8500_read(port, VT8500_URFIDX) & 0x1f00) {
 152                 unsigned int c;
 153                 char flag = TTY_NORMAL;
 154
 155                 c = readw(port->membase + VT8500_RXFIFO) & 0x3ff;
 156
 157                 /* Mask conditions we're ignorning. */
 158                 c &= ~port->read_status_mask;
 159
 160                 if (c & FER) {
 161                         port->icount.frame++;
 162                         flag = TTY_FRAME;
 163                 } else if (c & PER) {
 164                         port->icount.parity++;
 165                         flag = TTY_PARITY;
 166                 }
 167                 port->icount.rx++;
 168
 169                 if (!uart_handle_sysrq_char(port, c))
 170                         tty_insert_flip_char(tport, c, flag);
 171         }
 172
 173         tty_flip_buffer_push(tport);
 174 }
 175
 176 static void handle_tx(struct uart_port *port)
 177 {
 178         struct circ_buf *xmit = &port->state->xmit;
 179
 180         if (port->x_char) {
 181                 writeb(port->x_char, port->membase + VT8500_TXFIFO);
 182                 port->icount.tx++;
 183                 port->x_char = 0;
 184         }
 185         if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
 186                 vt8500_stop_tx(port);
 187                 return;
 188         }
 189
 190         while ((vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16) {
 191                 if (uart_circ_empty(xmit))
 192                         break;
 193
 194                 writeb(xmit->buf[xmit->tail], port->membase + VT8500_TXFIFO);
 195
 196                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 197                 port->icount.tx++;
 198         }
 199
 200         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 201                 uart_write_wakeup(port);
 202
 203         if (uart_circ_empty(xmit))
 204                 vt8500_stop_tx(port);
 205 }
 206
 207 static void vt8500_start_tx(struct uart_port *port)
 208 {
 209         struct vt8500_port *vt8500_port = container_of(port,
 210                                                        struct vt8500_port,
 211                                                        uart);
 212
 213         vt8500_port->ier &= ~TX_FIFO_INTS;
 214         vt8500_write(port, vt8500_port->ier, VT8500_URIER);
 215         handle_tx(port);
 216         vt8500_port->ier |= TX_FIFO_INTS;
 217         vt8500_write(port, vt8500_port->ier, VT8500_URIER);
 218 }
 219
 220 static void handle_delta_cts(struct uart_port *port)
 221 {
 222         port->icount.cts++;
 223         wake_up_interruptible(&port->state->port.delta_msr_wait);
 224 }
 225
 226 static irqreturn_t vt8500_irq(int irq, void *dev_id)
 227 {
 228         struct uart_port *port = dev_id;
 229         unsigned long isr;
 230
 231         spin_lock(&port->lock);
 232         isr = vt8500_read(port, VT8500_URISR);
 233
 234         /* Acknowledge active status bits */
 235         vt8500_write(port, isr, VT8500_URISR);
 236
 237         if (isr & RX_FIFO_INTS)
 238                 handle_rx(port);
 239         if (isr & TX_FIFO_INTS)
 240                 handle_tx(port);
 241         if (isr & TCTS)
 242                 handle_delta_cts(port);
 243
 244         spin_unlock(&port->lock);
 245
 246         return IRQ_HANDLED;
 247 }
 248
 249 static unsigned int vt8500_tx_empty(struct uart_port *port)
 250 {
 251         return (vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16 ?
 252                                                 TIOCSER_TEMT : 0;
 253 }
 254
 255 static unsigned int vt8500_get_mctrl(struct uart_port *port)
 256 {
 257         unsigned int usr;
 258
 259         usr = vt8500_read(port, VT8500_URUSR);
 260         if (usr & (1 << 4))
 261                 return TIOCM_CTS;
 262         else
 263                 return 0;
 264 }
 265
 266 static void vt8500_set_mctrl(struct uart_port *port, unsigned int mctrl)
 267 {
 268 }
 269
 270 static void vt8500_break_ctl(struct uart_port *port, int break_ctl)
 271 {
 272         if (break_ctl)
 273                 vt8500_write(port, vt8500_read(port, VT8500_URLCR) | (1 << 9),
 274                              VT8500_URLCR);
 275 }
 276
 277 static int vt8500_set_baud_rate(struct uart_port *port, unsigned int baud)
 278 {
 279         unsigned long div;
 280         unsigned int loops = 1000;
 281
 282         div = vt8500_read(port, VT8500_URDIV) & ~(0x3ff);
 283
 284         if (unlikely((baud < 900) || (baud > 921600)))
 285                 div |= 7;
 286         else
 287                 div |= (921600 / baud) - 1;
 288
 289         while ((vt8500_read(port, VT8500_URUSR) & (1 << 5)) && --loops)
 290                 cpu_relax();
 291         vt8500_write(port, div, VT8500_URDIV);
 292
 293         return baud;
 294 }
 295
 296 static int vt8500_startup(struct uart_port *port)
 297 {
 298         struct vt8500_port *vt8500_port =
 299                         container_of(port, struct vt8500_port, uart);
 300         int ret;
 301
 302         snprintf(vt8500_port->name, sizeof(vt8500_port->name),
 303                  "vt8500_serial%d", port->line);
 304
 305         ret = request_irq(port->irq, vt8500_irq, IRQF_TRIGGER_HIGH,
 306                           vt8500_port->name, port);
 307         if (unlikely(ret))
 308                 return ret;
 309
 310         vt8500_write(port, 0x03, VT8500_URLCR); /* enable TX & RX */
 311
 312         return 0;
 313 }
 314
 315 static void vt8500_shutdown(struct uart_port *port)
 316 {
 317         struct vt8500_port *vt8500_port =
 318                         container_of(port, struct vt8500_port, uart);
 319
 320         vt8500_port->ier = 0;
 321
 322         /* disable interrupts and FIFOs */
 323         vt8500_write(&vt8500_port->uart, 0, VT8500_URIER);
 324         vt8500_write(&vt8500_port->uart, 0x880, VT8500_URFCR);
 325         free_irq(port->irq, port);
 326 }
 327
 328 static void vt8500_set_termios(struct uart_port *port,
 329                                struct ktermios *termios,
 330                                struct ktermios *old)
 331 {
 332         struct vt8500_port *vt8500_port =
 333                         container_of(port, struct vt8500_port, uart);
 334         unsigned long flags;
 335         unsigned int baud, lcr;
 336         unsigned int loops = 1000;
 337
 338         spin_lock_irqsave(&port->lock, flags);
 339
 340         /* calculate and set baud rate */
 341         baud = uart_get_baud_rate(port, termios, old, 900, 921600);
 342         baud = vt8500_set_baud_rate(port, baud);
 343         if (tty_termios_baud_rate(termios))
 344                 tty_termios_encode_baud_rate(termios, baud, baud);
 345
 346         /* calculate parity */
 347         lcr = vt8500_read(&vt8500_port->uart, VT8500_URLCR);
 348         lcr &= ~((1 << 5) | (1 << 4));
 349         if (termios->c_cflag & PARENB) {
 350                 lcr |= (1 << 4);
 351                 termios->c_cflag &= ~CMSPAR;
 352                 if (termios->c_cflag & PARODD)
 353                         lcr |= (1 << 5);
 354         }
 355
 356         /* calculate bits per char */
 357         lcr &= ~(1 << 2);
 358         switch (termios->c_cflag & CSIZE) {
 359         case CS7:
 360                 break;
 361         case CS8:
 362         default:
 363                 lcr |= (1 << 2);
 364                 termios->c_cflag &= ~CSIZE;
 365                 termios->c_cflag |= CS8;
 366                 break;
 367         }
 368
 369         /* calculate stop bits */
 370         lcr &= ~(1 << 3);
 371         if (termios->c_cflag & CSTOPB)
 372                 lcr |= (1 << 3);
 373
 374         /* set parity, bits per char, and stop bit */
 375         vt8500_write(&vt8500_port->uart, lcr, VT8500_URLCR);
 376
 377         /* Configure status bits to ignore based on termio flags. */
 378         port->read_status_mask = 0;
 379         if (termios->c_iflag & IGNPAR)
 380                 port->read_status_mask = FER | PER;
 381
 382         uart_update_timeout(port, termios->c_cflag, baud);
 383
 384         /* Reset FIFOs */
 385         vt8500_write(&vt8500_port->uart, 0x88c, VT8500_URFCR);
 386         while ((vt8500_read(&vt8500_port->uart, VT8500_URFCR) & 0xc)
 387                                                         && --loops)
 388                 cpu_relax();
 389
 390         /* Every possible FIFO-related interrupt */
 391         vt8500_port->ier = RX_FIFO_INTS | TX_FIFO_INTS;
 392
 393         /*
 394          * CTS flow control
 395          */
 396         if (UART_ENABLE_MS(&vt8500_port->uart, termios->c_cflag))
 397                 vt8500_port->ier |= TCTS;
 398
 399         vt8500_write(&vt8500_port->uart, 0x881, VT8500_URFCR);
 400         vt8500_write(&vt8500_port->uart, vt8500_port->ier, VT8500_URIER);
 401
 402         spin_unlock_irqrestore(&port->lock, flags);
 403 }
 404
 405 static const char *vt8500_type(struct uart_port *port)
 406 {
 407         struct vt8500_port *vt8500_port =
 408                         container_of(port, struct vt8500_port, uart);
 409         return vt8500_port->name;
 410 }
 411
 412 static void vt8500_release_port(struct uart_port *port)
 413 {
 414 }
 415
 416 static int vt8500_request_port(struct uart_port *port)
 417 {
 418         return 0;
 419 }
 420
 421 static void vt8500_config_port(struct uart_port *port, int flags)
 422 {
 423         port->type = PORT_VT8500;
 424 }
 425
 426 static int vt8500_verify_port(struct uart_port *port,
 427                               struct serial_struct *ser)
 428 {
 429         if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_VT8500))
 430                 return -EINVAL;
 431         if (unlikely(port->irq != ser->irq))
 432                 return -EINVAL;
 433         return 0;
 434 }
 435
 436 static struct vt8500_port *vt8500_uart_ports[VT8500_MAX_PORTS];
 437 static struct uart_driver vt8500_uart_driver;
 438
 439 #ifdef CONFIG_SERIAL_VT8500_CONSOLE
 440
 441 static inline void wait_for_xmitr(struct uart_port *port)
 442 {
 443         unsigned int status, tmout = 10000;
 444
 445         /* Wait up to 10ms for the character(s) to be sent. */
 446         do {
 447                 status = vt8500_read(port, VT8500_URFIDX);
 448
 449                 if (--tmout == 0)
 450                         break;
 451                 udelay(1);
 452         } while (status & 0x10);
 453 }
 454
 455 static void vt8500_console_putchar(struct uart_port *port, int c)
 456 {
 457         wait_for_xmitr(port);
 458         writeb(c, port->membase + VT8500_TXFIFO);
 459 }
 460
 461 static void vt8500_console_write(struct console *co, const char *s,
 462                               unsigned int count)
 463 {
 464         struct vt8500_port *vt8500_port = vt8500_uart_ports[co->index];
 465         unsigned long ier;
 466
 467         BUG_ON(co->index < 0 || co->index >= vt8500_uart_driver.nr);
 468
 469         ier = vt8500_read(&vt8500_port->uart, VT8500_URIER);
 470         vt8500_write(&vt8500_port->uart, VT8500_URIER, 0);
 471
 472         uart_console_write(&vt8500_port->uart, s, count,
 473                            vt8500_console_putchar);
 474
 475         /*
 476          *      Finally, wait for transmitter to become empty
 477          *      and switch back to FIFO
 478          */
 479         wait_for_xmitr(&vt8500_port->uart);
 480         vt8500_write(&vt8500_port->uart, VT8500_URIER, ier);
 481 }
 482
 483 static int __init vt8500_console_setup(struct console *co, char *options)
 484 {
 485         struct vt8500_port *vt8500_port;
 486         int baud = 9600;
 487         int bits = 8;
 488         int parity = 'n';
 489         int flow = 'n';
 490
 491         if (unlikely(co->index >= vt8500_uart_driver.nr || co->index < 0))
 492                 return -ENXIO;
 493
 494         vt8500_port = vt8500_uart_ports[co->index];
 495
 496         if (!vt8500_port)
 497                 return -ENODEV;
 498
 499         if (options)
 500                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 501
 502         return uart_set_options(&vt8500_port->uart,
 503                                  co, baud, parity, bits, flow);
 504 }
 505
 506 static struct console vt8500_console = {
 507         .name = "ttyWMT",
 508         .write = vt8500_console_write,
 509         .device = uart_console_device,
 510         .setup = vt8500_console_setup,
 511         .flags = CON_PRINTBUFFER,
 512         .index = -1,
 513         .data = &vt8500_uart_driver,
 514 };
 515
 516 #define VT8500_CONSOLE  (&vt8500_console)
 517
 518 #else
 519 #define VT8500_CONSOLE  NULL
 520 #endif
 521
 522 static struct uart_ops vt8500_uart_pops = {
 523         .tx_empty       = vt8500_tx_empty,
 524         .set_mctrl      = vt8500_set_mctrl,
 525         .get_mctrl      = vt8500_get_mctrl,
 526         .stop_tx        = vt8500_stop_tx,
 527         .start_tx       = vt8500_start_tx,
 528         .stop_rx        = vt8500_stop_rx,
 529         .enable_ms      = vt8500_enable_ms,
 530         .break_ctl      = vt8500_break_ctl,
 531         .startup        = vt8500_startup,
 532         .shutdown       = vt8500_shutdown,
 533         .set_termios    = vt8500_set_termios,
 534         .type           = vt8500_type,
 535         .release_port   = vt8500_release_port,
 536         .request_port   = vt8500_request_port,
 537         .config_port    = vt8500_config_port,
 538         .verify_port    = vt8500_verify_port,
 539 };
 540
 541 static struct uart_driver vt8500_uart_driver = {
 542         .owner          = THIS_MODULE,
 543         .driver_name    = "vt8500_serial",
 544         .dev_name       = "ttyWMT",
 545         .nr             = 6,
 546         .cons           = VT8500_CONSOLE,
 547 };
 548
 549 static int vt8500_serial_probe(struct platform_device *pdev)
 550 {
 551         struct vt8500_port *vt8500_port;
 552         struct resource *mmres, *irqres;
 553         struct device_node *np = pdev->dev.of_node;
 554         int ret;
 555         int port;
 556
 557         mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 558         irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 559         if (!mmres || !irqres)
 560                 return -ENODEV;
 561
 562         if (np)
 563                 port = of_alias_get_id(np, "serial");
 564                 if (port >= VT8500_MAX_PORTS)
 565                         port = -1;
 566         else
 567                 port = -1;
 568
 569         if (port < 0) {
 570                 /* calculate the port id */
 571                 port = find_first_zero_bit(&vt8500_ports_in_use,
 572                                         sizeof(vt8500_ports_in_use));
 573         }
 574
 575         if (port >= VT8500_MAX_PORTS)
 576                 return -ENODEV;
 577
 578         /* reserve the port id */
 579         if (test_and_set_bit(port, &vt8500_ports_in_use)) {
 580                 /* port already in use - shouldn't really happen */
 581                 return -EBUSY;
 582         }
 583
 584         vt8500_port = devm_kzalloc(&pdev->dev, sizeof(struct vt8500_port),
 585                                    GFP_KERNEL);
 586         if (!vt8500_port)
 587                 return -ENOMEM;
 588
 589         vt8500_port->uart.membase = devm_ioremap_resource(&pdev->dev, mmres);
 590         if (IS_ERR(vt8500_port->uart.membase))
 591                 return PTR_ERR(vt8500_port->uart.membase);
 592
 593         vt8500_port->clk = of_clk_get(pdev->dev.of_node, 0);
 594         if (IS_ERR(vt8500_port->clk)) {
 595                 dev_err(&pdev->dev, "failed to get clock\n");
 596                 return  -EINVAL;
 597         }
 598
 599         ret = clk_prepare_enable(vt8500_port->clk);
 600         if (ret) {
 601                 dev_err(&pdev->dev, "failed to enable clock\n");
 602                 return ret;
 603         }
 604
 605         vt8500_port->uart.type = PORT_VT8500;
 606         vt8500_port->uart.iotype = UPIO_MEM;
 607         vt8500_port->uart.mapbase = mmres->start;
 608         vt8500_port->uart.irq = irqres->start;
 609         vt8500_port->uart.fifosize = 16;
 610         vt8500_port->uart.ops = &vt8500_uart_pops;
 611         vt8500_port->uart.line = port;
 612         vt8500_port->uart.dev = &pdev->dev;
 613         vt8500_port->uart.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
 614
 615         vt8500_port->uart.uartclk = clk_get_rate(vt8500_port->clk);
 616
 617         snprintf(vt8500_port->name, sizeof(vt8500_port->name),
 618                  "VT8500 UART%d", pdev->id);
 619
 620         vt8500_uart_ports[port] = vt8500_port;
 621
 622         uart_add_one_port(&vt8500_uart_driver, &vt8500_port->uart);
 623
 624         platform_set_drvdata(pdev, vt8500_port);
 625
 626         return 0;
 627 }
 628
 629 static int vt8500_serial_remove(struct platform_device *pdev)
 630 {
 631         struct vt8500_port *vt8500_port = platform_get_drvdata(pdev);
 632
 633         platform_set_drvdata(pdev, NULL);
 634         clk_disable_unprepare(vt8500_port->clk);
 635         uart_remove_one_port(&vt8500_uart_driver, &vt8500_port->uart);
 636
 637         return 0;
 638 }
 639
 640 static const struct of_device_id wmt_dt_ids[] = {
 641         { .compatible = "via,vt8500-uart", },
 642         {}
 643 };
 644
 645 static struct platform_driver vt8500_platform_driver = {
 646         .probe  = vt8500_serial_probe,
 647         .remove = vt8500_serial_remove,
 648         .driver = {
 649                 .name = "vt8500_serial",
 650                 .owner = THIS_MODULE,
 651                 .of_match_table = wmt_dt_ids,
 652         },
 653 };
 654
 655 static int __init vt8500_serial_init(void)
 656 {
 657         int ret;
 658
 659         ret = uart_register_driver(&vt8500_uart_driver);
 660         if (unlikely(ret))
 661                 return ret;
 662
 663         ret = platform_driver_register(&vt8500_platform_driver);
 664
 665         if (unlikely(ret))
 666                 uart_unregister_driver(&vt8500_uart_driver);
 667
 668         return ret;
 669 }
 670
 671 static void __exit vt8500_serial_exit(void)
 672 {
 673 #ifdef CONFIG_SERIAL_VT8500_CONSOLE
 674         unregister_console(&vt8500_console);
 675 #endif
 676         platform_driver_unregister(&vt8500_platform_driver);
 677         uart_unregister_driver(&vt8500_uart_driver);
 678 }
 679
 680 module_init(vt8500_serial_init);
 681 module_exit(vt8500_serial_exit);
 682
 683 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
 684 MODULE_DESCRIPTION("Driver for vt8500 serial device");
 685 MODULE_LICENSE("GPL v2");