drivers/tty/serial/uartlite.c

   1 /*
   2  * uartlite.c: Serial driver for Xilinx uartlite serial controller
   3  *
   4  * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk>
   5  * Copyright (C) 2007 Secret Lab Technologies Ltd.
   6  *
   7  * This file is licensed under the terms of the GNU General Public License
   8  * version 2.  This program is licensed "as is" without any warranty of any
   9  * kind, whether express or implied.
  10  */
  11
  12 #include <linux/platform_device.h>
  13 #include <linux/module.h>
  14 #include <linux/console.h>
  15 #include <linux/serial.h>
  16 #include <linux/serial_core.h>
  17 #include <linux/tty.h>
  18 #include <linux/tty_flip.h>
  19 #include <linux/delay.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/init.h>
  22 #include <linux/io.h>
  23 #include <linux/of.h>
  24 #include <linux/of_address.h>
  25 #include <linux/of_device.h>
  26 #include <linux/of_platform.h>
  27
  28 #define ULITE_NAME              "ttyUL"
  29 #define ULITE_MAJOR             204
  30 #define ULITE_MINOR             187
  31 #define ULITE_NR_UARTS          16
  32
  33 /* ---------------------------------------------------------------------
  34  * Register definitions
  35  *
  36  * For register details see datasheet:
  37  * http://www.xilinx.com/support/documentation/ip_documentation/opb_uartlite.pdf
  38  */
  39
  40 #define ULITE_RX                0x00
  41 #define ULITE_TX                0x04
  42 #define ULITE_STATUS            0x08
  43 #define ULITE_CONTROL           0x0c
  44
  45 #define ULITE_REGION            16
  46
  47 #define ULITE_STATUS_RXVALID    0x01
  48 #define ULITE_STATUS_RXFULL     0x02
  49 #define ULITE_STATUS_TXEMPTY    0x04
  50 #define ULITE_STATUS_TXFULL     0x08
  51 #define ULITE_STATUS_IE         0x10
  52 #define ULITE_STATUS_OVERRUN    0x20
  53 #define ULITE_STATUS_FRAME      0x40
  54 #define ULITE_STATUS_PARITY     0x80
  55
  56 #define ULITE_CONTROL_RST_TX    0x01
  57 #define ULITE_CONTROL_RST_RX    0x02
  58 #define ULITE_CONTROL_IE        0x10
  59
  60 struct uartlite_reg_ops {
  61         u32 (*in)(void __iomem *addr);
  62         void (*out)(u32 val, void __iomem *addr);
  63 };
  64
  65 static u32 uartlite_inbe32(void __iomem *addr)
  66 {
  67         return ioread32be(addr);
  68 }
  69
  70 static void uartlite_outbe32(u32 val, void __iomem *addr)
  71 {
  72         iowrite32be(val, addr);
  73 }
  74
  75 static const struct uartlite_reg_ops uartlite_be = {
  76         .in = uartlite_inbe32,
  77         .out = uartlite_outbe32,
  78 };
  79
  80 static u32 uartlite_inle32(void __iomem *addr)
  81 {
  82         return ioread32(addr);
  83 }
  84
  85 static void uartlite_outle32(u32 val, void __iomem *addr)
  86 {
  87         iowrite32(val, addr);
  88 }
  89
  90 static const struct uartlite_reg_ops uartlite_le = {
  91         .in = uartlite_inle32,
  92         .out = uartlite_outle32,
  93 };
  94
  95 static inline u32 uart_in32(u32 offset, struct uart_port *port)
  96 {
  97         const struct uartlite_reg_ops *reg_ops = port->private_data;
  98
  99         return reg_ops->in(port->membase + offset);
 100 }
 101
 102 static inline void uart_out32(u32 val, u32 offset, struct uart_port *port)
 103 {
 104         const struct uartlite_reg_ops *reg_ops = port->private_data;
 105
 106         reg_ops->out(val, port->membase + offset);
 107 }
 108
 109 static struct uart_port ulite_ports[ULITE_NR_UARTS];
 110
 111 /* ---------------------------------------------------------------------
 112  * Core UART driver operations
 113  */
 114
 115 static int ulite_receive(struct uart_port *port, int stat)
 116 {
 117         struct tty_port *tport = &port->state->port;
 118         unsigned char ch = 0;
 119         char flag = TTY_NORMAL;
 120
 121         if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
 122                      | ULITE_STATUS_FRAME)) == 0)
 123                 return 0;
 124
 125         /* stats */
 126         if (stat & ULITE_STATUS_RXVALID) {
 127                 port->icount.rx++;
 128                 ch = uart_in32(ULITE_RX, port);
 129
 130                 if (stat & ULITE_STATUS_PARITY)
 131                         port->icount.parity++;
 132         }
 133
 134         if (stat & ULITE_STATUS_OVERRUN)
 135                 port->icount.overrun++;
 136
 137         if (stat & ULITE_STATUS_FRAME)
 138                 port->icount.frame++;
 139
 140
 141         /* drop byte with parity error if IGNPAR specificed */
 142         if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
 143                 stat &= ~ULITE_STATUS_RXVALID;
 144
 145         stat &= port->read_status_mask;
 146
 147         if (stat & ULITE_STATUS_PARITY)
 148                 flag = TTY_PARITY;
 149
 150
 151         stat &= ~port->ignore_status_mask;
 152
 153         if (stat & ULITE_STATUS_RXVALID)
 154                 tty_insert_flip_char(tport, ch, flag);
 155
 156         if (stat & ULITE_STATUS_FRAME)
 157                 tty_insert_flip_char(tport, 0, TTY_FRAME);
 158
 159         if (stat & ULITE_STATUS_OVERRUN)
 160                 tty_insert_flip_char(tport, 0, TTY_OVERRUN);
 161
 162         return 1;
 163 }
 164
 165 static int ulite_transmit(struct uart_port *port, int stat)
 166 {
 167         struct circ_buf *xmit  = &port->state->xmit;
 168
 169         if (stat & ULITE_STATUS_TXFULL)
 170                 return 0;
 171
 172         if (port->x_char) {
 173                 uart_out32(port->x_char, ULITE_TX, port);
 174                 port->x_char = 0;
 175                 port->icount.tx++;
 176                 return 1;
 177         }
 178
 179         if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 180                 return 0;
 181
 182         uart_out32(xmit->buf[xmit->tail], ULITE_TX, port);
 183         xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
 184         port->icount.tx++;
 185
 186         /* wake up */
 187         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 188                 uart_write_wakeup(port);
 189
 190         return 1;
 191 }
 192
 193 static irqreturn_t ulite_isr(int irq, void *dev_id)
 194 {
 195         struct uart_port *port = dev_id;
 196         int stat, busy, n = 0;
 197         unsigned long flags;
 198
 199         do {
 200                 spin_lock_irqsave(&port->lock, flags);
 201                 stat = uart_in32(ULITE_STATUS, port);
 202                 busy  = ulite_receive(port, stat);
 203                 busy |= ulite_transmit(port, stat);
 204                 spin_unlock_irqrestore(&port->lock, flags);
 205                 n++;
 206         } while (busy);
 207
 208         /* work done? */
 209         if (n > 1) {
 210                 tty_flip_buffer_push(&port->state->port);
 211                 return IRQ_HANDLED;
 212         } else {
 213                 return IRQ_NONE;
 214         }
 215 }
 216
 217 static unsigned int ulite_tx_empty(struct uart_port *port)
 218 {
 219         unsigned long flags;
 220         unsigned int ret;
 221
 222         spin_lock_irqsave(&port->lock, flags);
 223         ret = uart_in32(ULITE_STATUS, port);
 224         spin_unlock_irqrestore(&port->lock, flags);
 225
 226         return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
 227 }
 228
 229 static unsigned int ulite_get_mctrl(struct uart_port *port)
 230 {
 231         return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 232 }
 233
 234 static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
 235 {
 236         /* N/A */
 237 }
 238
 239 static void ulite_stop_tx(struct uart_port *port)
 240 {
 241         /* N/A */
 242 }
 243
 244 static void ulite_start_tx(struct uart_port *port)
 245 {
 246         ulite_transmit(port, uart_in32(ULITE_STATUS, port));
 247 }
 248
 249 static void ulite_stop_rx(struct uart_port *port)
 250 {
 251         /* don't forward any more data (like !CREAD) */
 252         port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
 253                 | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
 254 }
 255
 256 static void ulite_break_ctl(struct uart_port *port, int ctl)
 257 {
 258         /* N/A */
 259 }
 260
 261 static int ulite_startup(struct uart_port *port)
 262 {
 263         int ret;
 264
 265         ret = request_irq(port->irq, ulite_isr, IRQF_SHARED | IRQF_TRIGGER_RISING,
 266                           "uartlite", port);
 267         if (ret)
 268                 return ret;
 269
 270         uart_out32(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX,
 271                 ULITE_CONTROL, port);
 272         uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
 273
 274         return 0;
 275 }
 276
 277 static void ulite_shutdown(struct uart_port *port)
 278 {
 279         uart_out32(0, ULITE_CONTROL, port);
 280         uart_in32(ULITE_CONTROL, port); /* dummy */
 281         free_irq(port->irq, port);
 282 }
 283
 284 static void ulite_set_termios(struct uart_port *port, struct ktermios *termios,
 285                               struct ktermios *old)
 286 {
 287         unsigned long flags;
 288         unsigned int baud;
 289
 290         spin_lock_irqsave(&port->lock, flags);
 291
 292         port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
 293                 | ULITE_STATUS_TXFULL;
 294
 295         if (termios->c_iflag & INPCK)
 296                 port->read_status_mask |=
 297                         ULITE_STATUS_PARITY | ULITE_STATUS_FRAME;
 298
 299         port->ignore_status_mask = 0;
 300         if (termios->c_iflag & IGNPAR)
 301                 port->ignore_status_mask |= ULITE_STATUS_PARITY
 302                         | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
 303
 304         /* ignore all characters if CREAD is not set */
 305         if ((termios->c_cflag & CREAD) == 0)
 306                 port->ignore_status_mask |=
 307                         ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY
 308                         | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN;
 309
 310         /* update timeout */
 311         baud = uart_get_baud_rate(port, termios, old, 0, 460800);
 312         uart_update_timeout(port, termios->c_cflag, baud);
 313
 314         spin_unlock_irqrestore(&port->lock, flags);
 315 }
 316
 317 static const char *ulite_type(struct uart_port *port)
 318 {
 319         return port->type == PORT_UARTLITE ? "uartlite" : NULL;
 320 }
 321
 322 static void ulite_release_port(struct uart_port *port)
 323 {
 324         release_mem_region(port->mapbase, ULITE_REGION);
 325         iounmap(port->membase);
 326         port->membase = NULL;
 327 }
 328
 329 static int ulite_request_port(struct uart_port *port)
 330 {
 331         int ret;
 332
 333         pr_debug("ulite console: port=%p; port->mapbase=%llx\n",
 334                  port, (unsigned long long) port->mapbase);
 335
 336         if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
 337                 dev_err(port->dev, "Memory region busy\n");
 338                 return -EBUSY;
 339         }
 340
 341         port->membase = ioremap(port->mapbase, ULITE_REGION);
 342         if (!port->membase) {
 343                 dev_err(port->dev, "Unable to map registers\n");
 344                 release_mem_region(port->mapbase, ULITE_REGION);
 345                 return -EBUSY;
 346         }
 347
 348         port->private_data = &uartlite_be;
 349         ret = uart_in32(ULITE_CONTROL, port);
 350         uart_out32(ULITE_CONTROL_RST_TX, ULITE_CONTROL, port);
 351         ret = uart_in32(ULITE_STATUS, port);
 352         /* Endianess detection */
 353         if ((ret & ULITE_STATUS_TXEMPTY) != ULITE_STATUS_TXEMPTY)
 354                 port->private_data = &uartlite_le;
 355
 356         return 0;
 357 }
 358
 359 static void ulite_config_port(struct uart_port *port, int flags)
 360 {
 361         if (!ulite_request_port(port))
 362                 port->type = PORT_UARTLITE;
 363 }
 364
 365 static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
 366 {
 367         /* we don't want the core code to modify any port params */
 368         return -EINVAL;
 369 }
 370
 371 #ifdef CONFIG_CONSOLE_POLL
 372 static int ulite_get_poll_char(struct uart_port *port)
 373 {
 374         if (!(uart_in32(ULITE_STATUS, port) & ULITE_STATUS_RXVALID))
 375                 return NO_POLL_CHAR;
 376
 377         return uart_in32(ULITE_RX, port);
 378 }
 379
 380 static void ulite_put_poll_char(struct uart_port *port, unsigned char ch)
 381 {
 382         while (uart_in32(ULITE_STATUS, port) & ULITE_STATUS_TXFULL)
 383                 cpu_relax();
 384
 385         /* write char to device */
 386         uart_out32(ch, ULITE_TX, port);
 387 }
 388 #endif
 389
 390 static struct uart_ops ulite_ops = {
 391         .tx_empty       = ulite_tx_empty,
 392         .set_mctrl      = ulite_set_mctrl,
 393         .get_mctrl      = ulite_get_mctrl,
 394         .stop_tx        = ulite_stop_tx,
 395         .start_tx       = ulite_start_tx,
 396         .stop_rx        = ulite_stop_rx,
 397         .break_ctl      = ulite_break_ctl,
 398         .startup        = ulite_startup,
 399         .shutdown       = ulite_shutdown,
 400         .set_termios    = ulite_set_termios,
 401         .type           = ulite_type,
 402         .release_port   = ulite_release_port,
 403         .request_port   = ulite_request_port,
 404         .config_port    = ulite_config_port,
 405         .verify_port    = ulite_verify_port,
 406 #ifdef CONFIG_CONSOLE_POLL
 407         .poll_get_char  = ulite_get_poll_char,
 408         .poll_put_char  = ulite_put_poll_char,
 409 #endif
 410 };
 411
 412 /* ---------------------------------------------------------------------
 413  * Console driver operations
 414  */
 415
 416 #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
 417 static void ulite_console_wait_tx(struct uart_port *port)
 418 {
 419         u8 val;
 420         unsigned long timeout;
 421
 422         /*
 423          * Spin waiting for TX fifo to have space available.
 424          * When using the Microblaze Debug Module this can take up to 1s
 425          */
 426         timeout = jiffies + msecs_to_jiffies(1000);
 427         while (1) {
 428                 val = uart_in32(ULITE_STATUS, port);
 429                 if ((val & ULITE_STATUS_TXFULL) == 0)
 430                         break;
 431                 if (time_after(jiffies, timeout)) {
 432                         dev_warn(port->dev,
 433                                  "timeout waiting for TX buffer empty\n");
 434                         break;
 435                 }
 436                 cpu_relax();
 437         }
 438 }
 439
 440 static void ulite_console_putchar(struct uart_port *port, int ch)
 441 {
 442         ulite_console_wait_tx(port);
 443         uart_out32(ch, ULITE_TX, port);
 444 }
 445
 446 static void ulite_console_write(struct console *co, const char *s,
 447                                 unsigned int count)
 448 {
 449         struct uart_port *port = &ulite_ports[co->index];
 450         unsigned long flags;
 451         unsigned int ier;
 452         int locked = 1;
 453
 454         if (oops_in_progress) {
 455                 locked = spin_trylock_irqsave(&port->lock, flags);
 456         } else
 457                 spin_lock_irqsave(&port->lock, flags);
 458
 459         /* save and disable interrupt */
 460         ier = uart_in32(ULITE_STATUS, port) & ULITE_STATUS_IE;
 461         uart_out32(0, ULITE_CONTROL, port);
 462
 463         uart_console_write(port, s, count, ulite_console_putchar);
 464
 465         ulite_console_wait_tx(port);
 466
 467         /* restore interrupt state */
 468         if (ier)
 469                 uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
 470
 471         if (locked)
 472                 spin_unlock_irqrestore(&port->lock, flags);
 473 }
 474
 475 static int ulite_console_setup(struct console *co, char *options)
 476 {
 477         struct uart_port *port;
 478         int baud = 9600;
 479         int bits = 8;
 480         int parity = 'n';
 481         int flow = 'n';
 482
 483         if (co->index < 0 || co->index >= ULITE_NR_UARTS)
 484                 return -EINVAL;
 485
 486         port = &ulite_ports[co->index];
 487
 488         /* Has the device been initialized yet? */
 489         if (!port->mapbase) {
 490                 pr_debug("console on ttyUL%i not present\n", co->index);
 491                 return -ENODEV;
 492         }
 493
 494         /* not initialized yet? */
 495         if (!port->membase) {
 496                 if (ulite_request_port(port))
 497                         return -ENODEV;
 498         }
 499
 500         if (options)
 501                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 502
 503         return uart_set_options(port, co, baud, parity, bits, flow);
 504 }
 505
 506 static struct uart_driver ulite_uart_driver;
 507
 508 static struct console ulite_console = {
 509         .name   = ULITE_NAME,
 510         .write  = ulite_console_write,
 511         .device = uart_console_device,
 512         .setup  = ulite_console_setup,
 513         .flags  = CON_PRINTBUFFER,
 514         .index  = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
 515         .data   = &ulite_uart_driver,
 516 };
 517
 518 static int __init ulite_console_init(void)
 519 {
 520         register_console(&ulite_console);
 521         return 0;
 522 }
 523
 524 console_initcall(ulite_console_init);
 525
 526 static void early_uartlite_putc(struct uart_port *port, int c)
 527 {
 528         /*
 529          * Limit how many times we'll spin waiting for TX FIFO status.
 530          * This will prevent lockups if the base address is incorrectly
 531          * set, or any other issue on the UARTLITE.
 532          * This limit is pretty arbitrary, unless we are at about 10 baud
 533          * we'll never timeout on a working UART.
 534          */
 535
 536         unsigned retries = 1000000;
 537         /* read status bit - 0x8 offset */
 538         while (--retries && (readl(port->membase + 8) & (1 << 3)))
 539                 ;
 540
 541         /* Only attempt the iowrite if we didn't timeout */
 542         /* write to TX_FIFO - 0x4 offset */
 543         if (retries)
 544                 writel(c & 0xff, port->membase + 4);
 545 }
 546
 547 static void early_uartlite_write(struct console *console,
 548                                  const char *s, unsigned n)
 549 {
 550         struct earlycon_device *device = console->data;
 551         uart_console_write(&device->port, s, n, early_uartlite_putc);
 552 }
 553
 554 static int __init early_uartlite_setup(struct earlycon_device *device,
 555                                        const char *options)
 556 {
 557         if (!device->port.membase)
 558                 return -ENODEV;
 559
 560         device->con->write = early_uartlite_write;
 561         return 0;
 562 }
 563 EARLYCON_DECLARE(uartlite, early_uartlite_setup);
 564 OF_EARLYCON_DECLARE(uartlite_b, "xlnx,opb-uartlite-1.00.b", early_uartlite_setup);
 565 OF_EARLYCON_DECLARE(uartlite_a, "xlnx,xps-uartlite-1.00.a", early_uartlite_setup);
 566
 567 #endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */
 568
 569 static struct uart_driver ulite_uart_driver = {
 570         .owner          = THIS_MODULE,
 571         .driver_name    = "uartlite",
 572         .dev_name       = ULITE_NAME,
 573         .major          = ULITE_MAJOR,
 574         .minor          = ULITE_MINOR,
 575         .nr             = ULITE_NR_UARTS,
 576 #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
 577         .cons           = &ulite_console,
 578 #endif
 579 };
 580
 581 /* ---------------------------------------------------------------------
 582  * Port assignment functions (mapping devices to uart_port structures)
 583  */
 584
 585 /** ulite_assign: register a uartlite device with the driver
 586  *
 587  * @dev: pointer to device structure
 588  * @id: requested id number.  Pass -1 for automatic port assignment
 589  * @base: base address of uartlite registers
 590  * @irq: irq number for uartlite
 591  *
 592  * Returns: 0 on success, <0 otherwise
 593  */
 594 static int ulite_assign(struct device *dev, int id, u32 base, int irq)
 595 {
 596         struct uart_port *port;
 597         int rc;
 598
 599         /* if id = -1; then scan for a free id and use that */
 600         if (id < 0) {
 601                 for (id = 0; id < ULITE_NR_UARTS; id++)
 602                         if (ulite_ports[id].mapbase == 0)
 603                                 break;
 604         }
 605         if (id < 0 || id >= ULITE_NR_UARTS) {
 606                 dev_err(dev, "%s%i too large\n", ULITE_NAME, id);
 607                 return -EINVAL;
 608         }
 609
 610         if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) {
 611                 dev_err(dev, "cannot assign to %s%i; it is already in use\n",
 612                         ULITE_NAME, id);
 613                 return -EBUSY;
 614         }
 615
 616         port = &ulite_ports[id];
 617
 618         spin_lock_init(&port->lock);
 619         port->fifosize = 16;
 620         port->regshift = 2;
 621         port->iotype = UPIO_MEM;
 622         port->iobase = 1; /* mark port in use */
 623         port->mapbase = base;
 624         port->membase = NULL;
 625         port->ops = &ulite_ops;
 626         port->irq = irq;
 627         port->flags = UPF_BOOT_AUTOCONF;
 628         port->dev = dev;
 629         port->type = PORT_UNKNOWN;
 630         port->line = id;
 631
 632         dev_set_drvdata(dev, port);
 633
 634         /* Register the port */
 635         rc = uart_add_one_port(&ulite_uart_driver, port);
 636         if (rc) {
 637                 dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc);
 638                 port->mapbase = 0;
 639                 dev_set_drvdata(dev, NULL);
 640                 return rc;
 641         }
 642
 643         return 0;
 644 }
 645
 646 /** ulite_release: register a uartlite device with the driver
 647  *
 648  * @dev: pointer to device structure
 649  */
 650 static int ulite_release(struct device *dev)
 651 {
 652         struct uart_port *port = dev_get_drvdata(dev);
 653         int rc = 0;
 654
 655         if (port) {
 656                 rc = uart_remove_one_port(&ulite_uart_driver, port);
 657                 dev_set_drvdata(dev, NULL);
 658                 port->mapbase = 0;
 659         }
 660
 661         return rc;
 662 }
 663
 664 /* ---------------------------------------------------------------------
 665  * Platform bus binding
 666  */
 667
 668 #if defined(CONFIG_OF)
 669 /* Match table for of_platform binding */
 670 static const struct of_device_id ulite_of_match[] = {
 671         { .compatible = "xlnx,opb-uartlite-1.00.b", },
 672         { .compatible = "xlnx,xps-uartlite-1.00.a", },
 673         {}
 674 };
 675 MODULE_DEVICE_TABLE(of, ulite_of_match);
 676 #endif /* CONFIG_OF */
 677
 678 static int ulite_probe(struct platform_device *pdev)
 679 {
 680         struct resource *res;
 681         int irq;
 682         int id = pdev->id;
 683 #ifdef CONFIG_OF
 684         const __be32 *prop;
 685
 686         prop = of_get_property(pdev->dev.of_node, "port-number", NULL);
 687         if (prop)
 688                 id = be32_to_cpup(prop);
 689 #endif
 690
 691         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 692         if (!res)
 693                 return -ENODEV;
 694
 695         irq = platform_get_irq(pdev, 0);
 696         if (irq <= 0)
 697                 return -ENXIO;
 698
 699         return ulite_assign(&pdev->dev, id, res->start, irq);
 700 }
 701
 702 static int ulite_remove(struct platform_device *pdev)
 703 {
 704         return ulite_release(&pdev->dev);
 705 }
 706
 707 /* work with hotplug and coldplug */
 708 MODULE_ALIAS("platform:uartlite");
 709
 710 static struct platform_driver ulite_platform_driver = {
 711         .probe = ulite_probe,
 712         .remove = ulite_remove,
 713         .driver = {
 714                 .name  = "uartlite",
 715                 .of_match_table = of_match_ptr(ulite_of_match),
 716         },
 717 };
 718
 719 /* ---------------------------------------------------------------------
 720  * Module setup/teardown
 721  */
 722
 723 static int __init ulite_init(void)
 724 {
 725         int ret;
 726
 727         pr_debug("uartlite: calling uart_register_driver()\n");
 728         ret = uart_register_driver(&ulite_uart_driver);
 729         if (ret)
 730                 goto err_uart;
 731
 732         pr_debug("uartlite: calling platform_driver_register()\n");
 733         ret = platform_driver_register(&ulite_platform_driver);
 734         if (ret)
 735                 goto err_plat;
 736
 737         return 0;
 738
 739 err_plat:
 740         uart_unregister_driver(&ulite_uart_driver);
 741 err_uart:
 742         pr_err("registering uartlite driver failed: err=%i", ret);
 743         return ret;
 744 }
 745
 746 static void __exit ulite_exit(void)
 747 {
 748         platform_driver_unregister(&ulite_platform_driver);
 749         uart_unregister_driver(&ulite_uart_driver);
 750 }
 751
 752 module_init(ulite_init);
 753 module_exit(ulite_exit);
 754
 755 MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
 756 MODULE_DESCRIPTION("Xilinx uartlite serial driver");
 757 MODULE_LICENSE("GPL");