drivers/serial/apbuart.c

   1 /*
   2  *  Driver for GRLIB serial ports (APBUART)
   3  *
   4  *  Based on linux/drivers/serial/amba.c
   5  *
   6  *  Copyright (C) 2000 Deep Blue Solutions Ltd.
   7  *  Copyright (C) 2003 Konrad Eisele <eiselekd@web.de>
   8  *  Copyright (C) 2006 Daniel Hellstrom <daniel@gaisler.com>, Aeroflex Gaisler AB
   9  *  Copyright (C) 2008 Gilead Kutnick <kutnickg@zin-tech.com>
  10  *  Copyright (C) 2009 Kristoffer Glembo <kristoffer@gaisler.com>, Aeroflex Gaisler AB
  11  */
  12
  13 #if defined(CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  14 #define SUPPORT_SYSRQ
  15 #endif
  16
  17 #include <linux/module.h>
  18 #include <linux/tty.h>
  19 #include <linux/ioport.h>
  20 #include <linux/init.h>
  21 #include <linux/serial.h>
  22 #include <linux/console.h>
  23 #include <linux/sysrq.h>
  24 #include <linux/kthread.h>
  25 #include <linux/device.h>
  26 #include <linux/of.h>
  27 #include <linux/of_device.h>
  28 #include <linux/of_platform.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/io.h>
  31 #include <linux/serial_core.h>
  32 #include <asm/irq.h>
  33
  34 #include "apbuart.h"
  35
  36 #define SERIAL_APBUART_MAJOR    TTY_MAJOR
  37 #define SERIAL_APBUART_MINOR    64
  38 #define UART_DUMMY_RSR_RX       0x8000  /* for ignore all read */
  39
  40 static void apbuart_tx_chars(struct uart_port *port);
  41
  42 static void apbuart_stop_tx(struct uart_port *port)
  43 {
  44         unsigned int cr;
  45
  46         cr = UART_GET_CTRL(port);
  47         cr &= ~UART_CTRL_TI;
  48         UART_PUT_CTRL(port, cr);
  49 }
  50
  51 static void apbuart_start_tx(struct uart_port *port)
  52 {
  53         unsigned int cr;
  54
  55         cr = UART_GET_CTRL(port);
  56         cr |= UART_CTRL_TI;
  57         UART_PUT_CTRL(port, cr);
  58
  59         if (UART_GET_STATUS(port) & UART_STATUS_THE)
  60                 apbuart_tx_chars(port);
  61 }
  62
  63 static void apbuart_stop_rx(struct uart_port *port)
  64 {
  65         unsigned int cr;
  66
  67         cr = UART_GET_CTRL(port);
  68         cr &= ~(UART_CTRL_RI);
  69         UART_PUT_CTRL(port, cr);
  70 }
  71
  72 static void apbuart_enable_ms(struct uart_port *port)
  73 {
  74         /* No modem status change interrupts for APBUART */
  75 }
  76
  77 static void apbuart_rx_chars(struct uart_port *port)
  78 {
  79         struct tty_struct *tty = port->state->port.tty;
  80         unsigned int status, ch, rsr, flag;
  81         unsigned int max_chars = port->fifosize;
  82
  83         status = UART_GET_STATUS(port);
  84
  85         while (UART_RX_DATA(status) && (max_chars--)) {
  86
  87                 ch = UART_GET_CHAR(port);
  88                 flag = TTY_NORMAL;
  89
  90                 port->icount.rx++;
  91
  92                 rsr = UART_GET_STATUS(port) | UART_DUMMY_RSR_RX;
  93                 UART_PUT_STATUS(port, 0);
  94                 if (rsr & UART_STATUS_ERR) {
  95
  96                         if (rsr & UART_STATUS_BR) {
  97                                 rsr &= ~(UART_STATUS_FE | UART_STATUS_PE);
  98                                 port->icount.brk++;
  99                                 if (uart_handle_break(port))
 100                                         goto ignore_char;
 101                         } else if (rsr & UART_STATUS_PE) {
 102                                 port->icount.parity++;
 103                         } else if (rsr & UART_STATUS_FE) {
 104                                 port->icount.frame++;
 105                         }
 106                         if (rsr & UART_STATUS_OE)
 107                                 port->icount.overrun++;
 108
 109                         rsr &= port->read_status_mask;
 110
 111                         if (rsr & UART_STATUS_PE)
 112                                 flag = TTY_PARITY;
 113                         else if (rsr & UART_STATUS_FE)
 114                                 flag = TTY_FRAME;
 115                 }
 116
 117                 if (uart_handle_sysrq_char(port, ch))
 118                         goto ignore_char;
 119
 120                 uart_insert_char(port, rsr, UART_STATUS_OE, ch, flag);
 121
 122
 123               ignore_char:
 124                 status = UART_GET_STATUS(port);
 125         }
 126
 127         tty_flip_buffer_push(tty);
 128 }
 129
 130 static void apbuart_tx_chars(struct uart_port *port)
 131 {
 132         struct circ_buf *xmit = &port->state->xmit;
 133         int count;
 134
 135         if (port->x_char) {
 136                 UART_PUT_CHAR(port, port->x_char);
 137                 port->icount.tx++;
 138                 port->x_char = 0;
 139                 return;
 140         }
 141
 142         if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
 143                 apbuart_stop_tx(port);
 144                 return;
 145         }
 146
 147         /* amba: fill FIFO */
 148         count = port->fifosize >> 1;
 149         do {
 150                 UART_PUT_CHAR(port, xmit->buf[xmit->tail]);
 151                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 152                 port->icount.tx++;
 153                 if (uart_circ_empty(xmit))
 154                         break;
 155         } while (--count > 0);
 156
 157         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 158                 uart_write_wakeup(port);
 159
 160         if (uart_circ_empty(xmit))
 161                 apbuart_stop_tx(port);
 162 }
 163
 164 static irqreturn_t apbuart_int(int irq, void *dev_id)
 165 {
 166         struct uart_port *port = dev_id;
 167         unsigned int status;
 168
 169         spin_lock(&port->lock);
 170
 171         status = UART_GET_STATUS(port);
 172         if (status & UART_STATUS_DR)
 173                 apbuart_rx_chars(port);
 174         if (status & UART_STATUS_THE)
 175                 apbuart_tx_chars(port);
 176
 177         spin_unlock(&port->lock);
 178
 179         return IRQ_HANDLED;
 180 }
 181
 182 static unsigned int apbuart_tx_empty(struct uart_port *port)
 183 {
 184         unsigned int status = UART_GET_STATUS(port);
 185         return status & UART_STATUS_THE ? TIOCSER_TEMT : 0;
 186 }
 187
 188 static unsigned int apbuart_get_mctrl(struct uart_port *port)
 189 {
 190         /* The GRLIB APBUART handles flow control in hardware */
 191         return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
 192 }
 193
 194 static void apbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 195 {
 196         /* The GRLIB APBUART handles flow control in hardware */
 197 }
 198
 199 static void apbuart_break_ctl(struct uart_port *port, int break_state)
 200 {
 201         /* We don't support sending break */
 202 }
 203
 204 static int apbuart_startup(struct uart_port *port)
 205 {
 206         int retval;
 207         unsigned int cr;
 208
 209         /* Allocate the IRQ */
 210         retval = request_irq(port->irq, apbuart_int, 0, "apbuart", port);
 211         if (retval)
 212                 return retval;
 213
 214         /* Finally, enable interrupts */
 215         cr = UART_GET_CTRL(port);
 216         UART_PUT_CTRL(port,
 217                       cr | UART_CTRL_RE | UART_CTRL_TE |
 218                       UART_CTRL_RI | UART_CTRL_TI);
 219
 220         return 0;
 221 }
 222
 223 static void apbuart_shutdown(struct uart_port *port)
 224 {
 225         unsigned int cr;
 226
 227         /* disable all interrupts, disable the port */
 228         cr = UART_GET_CTRL(port);
 229         UART_PUT_CTRL(port,
 230                       cr & ~(UART_CTRL_RE | UART_CTRL_TE |
 231                              UART_CTRL_RI | UART_CTRL_TI));
 232
 233         /* Free the interrupt */
 234         free_irq(port->irq, port);
 235 }
 236
 237 static void apbuart_set_termios(struct uart_port *port,
 238                                 struct ktermios *termios, struct ktermios *old)
 239 {
 240         unsigned int cr;
 241         unsigned long flags;
 242         unsigned int baud, quot;
 243
 244         /* Ask the core to calculate the divisor for us. */
 245         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
 246         if (baud == 0)
 247                 panic("invalid baudrate %i\n", port->uartclk / 16);
 248
 249         /* uart_get_divisor calc a *16 uart freq, apbuart is *8 */
 250         quot = (uart_get_divisor(port, baud)) * 2;
 251         cr = UART_GET_CTRL(port);
 252         cr &= ~(UART_CTRL_PE | UART_CTRL_PS);
 253
 254         if (termios->c_cflag & PARENB) {
 255                 cr |= UART_CTRL_PE;
 256                 if ((termios->c_cflag & PARODD))
 257                         cr |= UART_CTRL_PS;
 258         }
 259
 260         /* Enable flow control. */
 261         if (termios->c_cflag & CRTSCTS)
 262                 cr |= UART_CTRL_FL;
 263
 264         spin_lock_irqsave(&port->lock, flags);
 265
 266         /* Update the per-port timeout. */
 267         uart_update_timeout(port, termios->c_cflag, baud);
 268
 269         port->read_status_mask = UART_STATUS_OE;
 270         if (termios->c_iflag & INPCK)
 271                 port->read_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
 272
 273         /* Characters to ignore */
 274         port->ignore_status_mask = 0;
 275         if (termios->c_iflag & IGNPAR)
 276                 port->ignore_status_mask |= UART_STATUS_FE | UART_STATUS_PE;
 277
 278         /* Ignore all characters if CREAD is not set. */
 279         if ((termios->c_cflag & CREAD) == 0)
 280                 port->ignore_status_mask |= UART_DUMMY_RSR_RX;
 281
 282         /* Set baud rate */
 283         quot -= 1;
 284         UART_PUT_SCAL(port, quot);
 285         UART_PUT_CTRL(port, cr);
 286
 287         spin_unlock_irqrestore(&port->lock, flags);
 288 }
 289
 290 static const char *apbuart_type(struct uart_port *port)
 291 {
 292         return port->type == PORT_APBUART ? "GRLIB/APBUART" : NULL;
 293 }
 294
 295 static void apbuart_release_port(struct uart_port *port)
 296 {
 297         release_mem_region(port->mapbase, 0x100);
 298 }
 299
 300 static int apbuart_request_port(struct uart_port *port)
 301 {
 302         return request_mem_region(port->mapbase, 0x100, "grlib-apbuart")
 303             != NULL ? 0 : -EBUSY;
 304         return 0;
 305 }
 306
 307 /* Configure/autoconfigure the port */
 308 static void apbuart_config_port(struct uart_port *port, int flags)
 309 {
 310         if (flags & UART_CONFIG_TYPE) {
 311                 port->type = PORT_APBUART;
 312                 apbuart_request_port(port);
 313         }
 314 }
 315
 316 /* Verify the new serial_struct (for TIOCSSERIAL) */
 317 static int apbuart_verify_port(struct uart_port *port,
 318                                struct serial_struct *ser)
 319 {
 320         int ret = 0;
 321         if (ser->type != PORT_UNKNOWN && ser->type != PORT_APBUART)
 322                 ret = -EINVAL;
 323         if (ser->irq < 0 || ser->irq >= NR_IRQS)
 324                 ret = -EINVAL;
 325         if (ser->baud_base < 9600)
 326                 ret = -EINVAL;
 327         return ret;
 328 }
 329
 330 static struct uart_ops grlib_apbuart_ops = {
 331         .tx_empty = apbuart_tx_empty,
 332         .set_mctrl = apbuart_set_mctrl,
 333         .get_mctrl = apbuart_get_mctrl,
 334         .stop_tx = apbuart_stop_tx,
 335         .start_tx = apbuart_start_tx,
 336         .stop_rx = apbuart_stop_rx,
 337         .enable_ms = apbuart_enable_ms,
 338         .break_ctl = apbuart_break_ctl,
 339         .startup = apbuart_startup,
 340         .shutdown = apbuart_shutdown,
 341         .set_termios = apbuart_set_termios,
 342         .type = apbuart_type,
 343         .release_port = apbuart_release_port,
 344         .request_port = apbuart_request_port,
 345         .config_port = apbuart_config_port,
 346         .verify_port = apbuart_verify_port,
 347 };
 348
 349 static struct uart_port grlib_apbuart_ports[UART_NR];
 350 static struct device_node *grlib_apbuart_nodes[UART_NR];
 351
 352 static int apbuart_scan_fifo_size(struct uart_port *port, int portnumber)
 353 {
 354         int ctrl, loop = 0;
 355         int status;
 356         int fifosize;
 357         unsigned long flags;
 358
 359         ctrl = UART_GET_CTRL(port);
 360
 361         /*
 362          * Enable the transceiver and wait for it to be ready to send data.
 363          * Clear interrupts so that this process will not be externally
 364          * interrupted in the middle (which can cause the transceiver to
 365          * drain prematurely).
 366          */
 367
 368         local_irq_save(flags);
 369
 370         UART_PUT_CTRL(port, ctrl | UART_CTRL_TE);
 371
 372         while (!UART_TX_READY(UART_GET_STATUS(port)))
 373                 loop++;
 374
 375         /*
 376          * Disable the transceiver so data isn't actually sent during the
 377          * actual test.
 378          */
 379
 380         UART_PUT_CTRL(port, ctrl & ~(UART_CTRL_TE));
 381
 382         fifosize = 1;
 383         UART_PUT_CHAR(port, 0);
 384
 385         /*
 386          * So long as transmitting a character increments the tranceivier FIFO
 387          * length the FIFO must be at least that big. These bytes will
 388          * automatically drain off of the FIFO.
 389          */
 390
 391         status = UART_GET_STATUS(port);
 392         while (((status >> 20) & 0x3F) == fifosize) {
 393                 fifosize++;
 394                 UART_PUT_CHAR(port, 0);
 395                 status = UART_GET_STATUS(port);
 396         }
 397
 398         fifosize--;
 399
 400         UART_PUT_CTRL(port, ctrl);
 401         local_irq_restore(flags);
 402
 403         if (fifosize == 0)
 404                 fifosize = 1;
 405
 406         return fifosize;
 407 }
 408
 409 static void apbuart_flush_fifo(struct uart_port *port)
 410 {
 411         int i;
 412
 413         for (i = 0; i < port->fifosize; i++)
 414                 UART_GET_CHAR(port);
 415 }
 416
 417
 418 /* ======================================================================== */
 419 /* Console driver, if enabled                                               */
 420 /* ======================================================================== */
 421
 422 #ifdef CONFIG_SERIAL_GRLIB_GAISLER_APBUART_CONSOLE
 423
 424 static void apbuart_console_putchar(struct uart_port *port, int ch)
 425 {
 426         unsigned int status;
 427         do {
 428                 status = UART_GET_STATUS(port);
 429         } while (!UART_TX_READY(status));
 430         UART_PUT_CHAR(port, ch);
 431 }
 432
 433 static void
 434 apbuart_console_write(struct console *co, const char *s, unsigned int count)
 435 {
 436         struct uart_port *port = &grlib_apbuart_ports[co->index];
 437         unsigned int status, old_cr, new_cr;
 438
 439         /* First save the CR then disable the interrupts */
 440         old_cr = UART_GET_CTRL(port);
 441         new_cr = old_cr & ~(UART_CTRL_RI | UART_CTRL_TI);
 442         UART_PUT_CTRL(port, new_cr);
 443
 444         uart_console_write(port, s, count, apbuart_console_putchar);
 445
 446         /*
 447          *      Finally, wait for transmitter to become empty
 448          *      and restore the TCR
 449          */
 450         do {
 451                 status = UART_GET_STATUS(port);
 452         } while (!UART_TX_READY(status));
 453         UART_PUT_CTRL(port, old_cr);
 454 }
 455
 456 static void __init
 457 apbuart_console_get_options(struct uart_port *port, int *baud,
 458                             int *parity, int *bits)
 459 {
 460         if (UART_GET_CTRL(port) & (UART_CTRL_RE | UART_CTRL_TE)) {
 461
 462                 unsigned int quot, status;
 463                 status = UART_GET_STATUS(port);
 464
 465                 *parity = 'n';
 466                 if (status & UART_CTRL_PE) {
 467                         if ((status & UART_CTRL_PS) == 0)
 468                                 *parity = 'e';
 469                         else
 470                                 *parity = 'o';
 471                 }
 472
 473                 *bits = 8;
 474                 quot = UART_GET_SCAL(port) / 8;
 475                 *baud = port->uartclk / (16 * (quot + 1));
 476         }
 477 }
 478
 479 static int __init apbuart_console_setup(struct console *co, char *options)
 480 {
 481         struct uart_port *port;
 482         int baud = 38400;
 483         int bits = 8;
 484         int parity = 'n';
 485         int flow = 'n';
 486
 487         pr_debug("apbuart_console_setup co=%p, co->index=%i, options=%s\n",
 488                  co, co->index, options);
 489
 490         /*
 491          * Check whether an invalid uart number has been specified, and
 492          * if so, search for the first available port that does have
 493          * console support.
 494          */
 495         if (co->index >= grlib_apbuart_port_nr)
 496                 co->index = 0;
 497
 498         port = &grlib_apbuart_ports[co->index];
 499
 500         spin_lock_init(&port->lock);
 501
 502         if (options)
 503                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 504         else
 505                 apbuart_console_get_options(port, &baud, &parity, &bits);
 506
 507         return uart_set_options(port, co, baud, parity, bits, flow);
 508 }
 509
 510 static struct uart_driver grlib_apbuart_driver;
 511
 512 static struct console grlib_apbuart_console = {
 513         .name = "ttyS",
 514         .write = apbuart_console_write,
 515         .device = uart_console_device,
 516         .setup = apbuart_console_setup,
 517         .flags = CON_PRINTBUFFER,
 518         .index = -1,
 519         .data = &grlib_apbuart_driver,
 520 };
 521
 522
 523 static void grlib_apbuart_configure(void);
 524
 525 static int __init apbuart_console_init(void)
 526 {
 527         grlib_apbuart_configure();
 528         register_console(&grlib_apbuart_console);
 529         return 0;
 530 }
 531
 532 console_initcall(apbuart_console_init);
 533
 534 #define APBUART_CONSOLE (&grlib_apbuart_console)
 535 #else
 536 #define APBUART_CONSOLE NULL
 537 #endif
 538
 539 static struct uart_driver grlib_apbuart_driver = {
 540         .owner = THIS_MODULE,
 541         .driver_name = "serial",
 542         .dev_name = "ttyS",
 543         .major = SERIAL_APBUART_MAJOR,
 544         .minor = SERIAL_APBUART_MINOR,
 545         .nr = UART_NR,
 546         .cons = APBUART_CONSOLE,
 547 };
 548
 549
 550 /* ======================================================================== */
 551 /* OF Platform Driver                                                       */
 552 /* ======================================================================== */
 553
 554 static int __devinit apbuart_probe(struct platform_device *op,
 555                                    const struct of_device_id *match)
 556 {
 557         int i = -1;
 558         struct uart_port *port = NULL;
 559
 560         i = 0;
 561         for (i = 0; i < grlib_apbuart_port_nr; i++) {
 562                 if (op->dev.of_node == grlib_apbuart_nodes[i])
 563                         break;
 564         }
 565
 566         port = &grlib_apbuart_ports[i];
 567         port->dev = &op->dev;
 568
 569         uart_add_one_port(&grlib_apbuart_driver, (struct uart_port *) port);
 570
 571         apbuart_flush_fifo((struct uart_port *) port);
 572
 573         printk(KERN_INFO "grlib-apbuart at 0x%llx, irq %d\n",
 574                (unsigned long long) port->mapbase, port->irq);
 575         return 0;
 576
 577 }
 578
 579 static struct of_device_id __initdata apbuart_match[] = {
 580         {
 581          .name = "GAISLER_APBUART",
 582          },
 583         {},
 584 };
 585
 586 static struct of_platform_driver grlib_apbuart_of_driver = {
 587         .probe = apbuart_probe,
 588         .driver = {
 589                 .owner = THIS_MODULE,
 590                 .name = "grlib-apbuart",
 591                 .of_match_table = apbuart_match,
 592         },
 593 };
 594
 595
 596 static void grlib_apbuart_configure(void)
 597 {
 598         static int enum_done;
 599         struct device_node *np, *rp;
 600         struct uart_port *port = NULL;
 601         const u32 *prop;
 602         int freq_khz;
 603         int v = 0, d = 0;
 604         unsigned int addr;
 605         int irq, line;
 606         struct amba_prom_registers *regs;
 607
 608         if (enum_done)
 609                 return;
 610
 611         /* Get bus frequency */
 612         rp = of_find_node_by_path("/");
 613         rp = of_get_next_child(rp, NULL);
 614         prop = of_get_property(rp, "clock-frequency", NULL);
 615         freq_khz = *prop;
 616
 617         line = 0;
 618         for_each_matching_node(np, apbuart_match) {
 619
 620                 int *vendor = (int *) of_get_property(np, "vendor", NULL);
 621                 int *device = (int *) of_get_property(np, "device", NULL);
 622                 int *irqs = (int *) of_get_property(np, "interrupts", NULL);
 623                 regs = (struct amba_prom_registers *)
 624                     of_get_property(np, "reg", NULL);
 625
 626                 if (vendor)
 627                         v = *vendor;
 628                 if (device)
 629                         d = *device;
 630
 631                 if (!irqs || !regs)
 632                         return;
 633
 634                 grlib_apbuart_nodes[line] = np;
 635
 636                 addr = regs->phys_addr;
 637                 irq = *irqs;
 638
 639                 port = &grlib_apbuart_ports[line];
 640
 641                 port->mapbase = addr;
 642                 port->membase = ioremap(addr, sizeof(struct grlib_apbuart_regs_map));
 643                 port->irq = irq;
 644                 port->iotype = UPIO_MEM;
 645                 port->ops = &grlib_apbuart_ops;
 646                 port->flags = UPF_BOOT_AUTOCONF;
 647                 port->line = line;
 648                 port->uartclk = freq_khz * 1000;
 649                 port->fifosize = apbuart_scan_fifo_size((struct uart_port *) port, line);
 650                 line++;
 651
 652                 /* We support maximum UART_NR uarts ... */
 653                 if (line == UART_NR)
 654                         break;
 655
 656         }
 657
 658         enum_done = 1;
 659
 660         grlib_apbuart_driver.nr = grlib_apbuart_port_nr = line;
 661 }
 662
 663 static int __init grlib_apbuart_init(void)
 664 {
 665         int ret;
 666
 667         /* Find all APBUARTS in device the tree and initialize their ports */
 668         grlib_apbuart_configure();
 669
 670         printk(KERN_INFO "Serial: GRLIB APBUART driver\n");
 671
 672         ret = uart_register_driver(&grlib_apbuart_driver);
 673
 674         if (ret) {
 675                 printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
 676                        __FILE__, ret);
 677                 return ret;
 678         }
 679
 680         ret = of_register_platform_driver(&grlib_apbuart_of_driver);
 681         if (ret) {
 682                 printk(KERN_ERR
 683                        "%s: of_register_platform_driver failed (%i)\n",
 684                        __FILE__, ret);
 685                 uart_unregister_driver(&grlib_apbuart_driver);
 686                 return ret;
 687         }
 688
 689         return ret;
 690 }
 691
 692 static void __exit grlib_apbuart_exit(void)
 693 {
 694         int i;
 695
 696         for (i = 0; i < grlib_apbuart_port_nr; i++)
 697                 uart_remove_one_port(&grlib_apbuart_driver,
 698                                      &grlib_apbuart_ports[i]);
 699
 700         uart_unregister_driver(&grlib_apbuart_driver);
 701         of_unregister_platform_driver(&grlib_apbuart_of_driver);
 702 }
 703
 704 module_init(grlib_apbuart_init);
 705 module_exit(grlib_apbuart_exit);
 706
 707 MODULE_AUTHOR("Aeroflex Gaisler AB");
 708 MODULE_DESCRIPTION("GRLIB APBUART serial driver");
 709 MODULE_VERSION("2.1");
 710 MODULE_LICENSE("GPL");