drivers/serial/mcf.c

   1 /****************************************************************************/
   2
   3 /*
   4  *      mcf.c -- Freescale ColdFire UART driver
   5  *
   6  *      (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 /****************************************************************************/
  15
  16 #include <linux/kernel.h>
  17 #include <linux/init.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/module.h>
  20 #include <linux/console.h>
  21 #include <linux/tty.h>
  22 #include <linux/tty_flip.h>
  23 #include <linux/serial.h>
  24 #include <linux/serial_core.h>
  25 #include <linux/io.h>
  26 #include <asm/coldfire.h>
  27 #include <asm/mcfsim.h>
  28 #include <asm/mcfuart.h>
  29 #include <asm/nettel.h>
  30
  31 /****************************************************************************/
  32
  33 /*
  34  *      Some boards implement the DTR/DCD lines using GPIO lines, most
  35  *      don't. Dummy out the access macros for those that don't. Those
  36  *      that do should define these macros somewhere in there board
  37  *      specific inlude files.
  38  */
  39 #if !defined(mcf_getppdcd)
  40 #define mcf_getppdcd(p)         (1)
  41 #endif
  42 #if !defined(mcf_getppdtr)
  43 #define mcf_getppdtr(p)         (1)
  44 #endif
  45 #if !defined(mcf_setppdtr)
  46 #define mcf_setppdtr(p, v)      do { } while (0)
  47 #endif
  48
  49 /****************************************************************************/
  50
  51 /*
  52  *      Local per-uart structure.
  53  */
  54 struct mcf_uart {
  55         struct uart_port        port;
  56         unsigned int            sigs;           /* Local copy of line sigs */
  57         unsigned char           imr;            /* Local IMR mirror */
  58 };
  59
  60 /****************************************************************************/
  61
  62 static unsigned int mcf_tx_empty(struct uart_port *port)
  63 {
  64         return (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXEMPTY) ?
  65                 TIOCSER_TEMT : 0;
  66 }
  67
  68 /****************************************************************************/
  69
  70 static unsigned int mcf_get_mctrl(struct uart_port *port)
  71 {
  72         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
  73         unsigned long flags;
  74         unsigned int sigs;
  75
  76         spin_lock_irqsave(&port->lock, flags);
  77         sigs = (readb(port->membase + MCFUART_UIPR) & MCFUART_UIPR_CTS) ?
  78                 0 : TIOCM_CTS;
  79         sigs |= (pp->sigs & TIOCM_RTS);
  80         sigs |= (mcf_getppdcd(port->line) ? TIOCM_CD : 0);
  81         sigs |= (mcf_getppdtr(port->line) ? TIOCM_DTR : 0);
  82         spin_unlock_irqrestore(&port->lock, flags);
  83         return sigs;
  84 }
  85
  86 /****************************************************************************/
  87
  88 static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs)
  89 {
  90         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
  91         unsigned long flags;
  92
  93         spin_lock_irqsave(&port->lock, flags);
  94         pp->sigs = sigs;
  95         mcf_setppdtr(port->line, (sigs & TIOCM_DTR));
  96         if (sigs & TIOCM_RTS)
  97                 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
  98         else
  99                 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP0);
 100         spin_unlock_irqrestore(&port->lock, flags);
 101 }
 102
 103 /****************************************************************************/
 104
 105 static void mcf_start_tx(struct uart_port *port)
 106 {
 107         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 108         unsigned long flags;
 109
 110         spin_lock_irqsave(&port->lock, flags);
 111         pp->imr |= MCFUART_UIR_TXREADY;
 112         writeb(pp->imr, port->membase + MCFUART_UIMR);
 113         spin_unlock_irqrestore(&port->lock, flags);
 114 }
 115
 116 /****************************************************************************/
 117
 118 static void mcf_stop_tx(struct uart_port *port)
 119 {
 120         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 121         unsigned long flags;
 122
 123         spin_lock_irqsave(&port->lock, flags);
 124         pp->imr &= ~MCFUART_UIR_TXREADY;
 125         writeb(pp->imr, port->membase + MCFUART_UIMR);
 126         spin_unlock_irqrestore(&port->lock, flags);
 127 }
 128
 129 /****************************************************************************/
 130
 131 static void mcf_stop_rx(struct uart_port *port)
 132 {
 133         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 134         unsigned long flags;
 135
 136         spin_lock_irqsave(&port->lock, flags);
 137         pp->imr &= ~MCFUART_UIR_RXREADY;
 138         writeb(pp->imr, port->membase + MCFUART_UIMR);
 139         spin_unlock_irqrestore(&port->lock, flags);
 140 }
 141
 142 /****************************************************************************/
 143
 144 static void mcf_break_ctl(struct uart_port *port, int break_state)
 145 {
 146         unsigned long flags;
 147
 148         spin_lock_irqsave(&port->lock, flags);
 149         if (break_state == -1)
 150                 writeb(MCFUART_UCR_CMDBREAKSTART, port->membase + MCFUART_UCR);
 151         else
 152                 writeb(MCFUART_UCR_CMDBREAKSTOP, port->membase + MCFUART_UCR);
 153         spin_unlock_irqrestore(&port->lock, flags);
 154 }
 155
 156 /****************************************************************************/
 157
 158 static void mcf_enable_ms(struct uart_port *port)
 159 {
 160 }
 161
 162 /****************************************************************************/
 163
 164 static int mcf_startup(struct uart_port *port)
 165 {
 166         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 167         unsigned long flags;
 168
 169         spin_lock_irqsave(&port->lock, flags);
 170
 171         /* Reset UART, get it into known state... */
 172         writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
 173         writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
 174
 175         /* Enable the UART transmitter and receiver */
 176         writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
 177                 port->membase + MCFUART_UCR);
 178
 179         /* Enable RX interrupts now */
 180         pp->imr = MCFUART_UIR_RXREADY;
 181         writeb(pp->imr, port->membase + MCFUART_UIMR);
 182
 183         spin_unlock_irqrestore(&port->lock, flags);
 184
 185         return 0;
 186 }
 187
 188 /****************************************************************************/
 189
 190 static void mcf_shutdown(struct uart_port *port)
 191 {
 192         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 193         unsigned long flags;
 194
 195         spin_lock_irqsave(&port->lock, flags);
 196
 197         /* Disable all interrupts now */
 198         pp->imr = 0;
 199         writeb(pp->imr, port->membase + MCFUART_UIMR);
 200
 201         /* Disable UART transmitter and receiver */
 202         writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
 203         writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
 204
 205         spin_unlock_irqrestore(&port->lock, flags);
 206 }
 207
 208 /****************************************************************************/
 209
 210 static void mcf_set_termios(struct uart_port *port, struct ktermios *termios,
 211         struct ktermios *old)
 212 {
 213         unsigned long flags;
 214         unsigned int baud, baudclk;
 215         unsigned char mr1, mr2;
 216
 217         baud = uart_get_baud_rate(port, termios, old, 0, 230400);
 218         baudclk = ((MCF_BUSCLK / baud) + 16) / 32;
 219
 220         mr1 = MCFUART_MR1_RXIRQRDY | MCFUART_MR1_RXERRCHAR;
 221         mr2 = 0;
 222
 223         switch (termios->c_cflag & CSIZE) {
 224         case CS5: mr1 |= MCFUART_MR1_CS5; break;
 225         case CS6: mr1 |= MCFUART_MR1_CS6; break;
 226         case CS7: mr1 |= MCFUART_MR1_CS7; break;
 227         case CS8:
 228         default:  mr1 |= MCFUART_MR1_CS8; break;
 229         }
 230
 231         if (termios->c_cflag & PARENB) {
 232                 if (termios->c_cflag & CMSPAR) {
 233                         if (termios->c_cflag & PARODD)
 234                                 mr1 |= MCFUART_MR1_PARITYMARK;
 235                         else
 236                                 mr1 |= MCFUART_MR1_PARITYSPACE;
 237                 } else {
 238                         if (termios->c_cflag & PARODD)
 239                                 mr1 |= MCFUART_MR1_PARITYODD;
 240                         else
 241                                 mr1 |= MCFUART_MR1_PARITYEVEN;
 242                 }
 243         } else {
 244                 mr1 |= MCFUART_MR1_PARITYNONE;
 245         }
 246
 247         if (termios->c_cflag & CSTOPB)
 248                 mr2 |= MCFUART_MR2_STOP2;
 249         else
 250                 mr2 |= MCFUART_MR2_STOP1;
 251
 252         if (termios->c_cflag & CRTSCTS) {
 253                 mr1 |= MCFUART_MR1_RXRTS;
 254                 mr2 |= MCFUART_MR2_TXCTS;
 255         }
 256
 257         spin_lock_irqsave(&port->lock, flags);
 258         writeb(MCFUART_UCR_CMDRESETRX, port->membase + MCFUART_UCR);
 259         writeb(MCFUART_UCR_CMDRESETTX, port->membase + MCFUART_UCR);
 260         writeb(MCFUART_UCR_CMDRESETMRPTR, port->membase + MCFUART_UCR);
 261         writeb(mr1, port->membase + MCFUART_UMR);
 262         writeb(mr2, port->membase + MCFUART_UMR);
 263         writeb((baudclk & 0xff00) >> 8, port->membase + MCFUART_UBG1);
 264         writeb((baudclk & 0xff), port->membase + MCFUART_UBG2);
 265         writeb(MCFUART_UCSR_RXCLKTIMER | MCFUART_UCSR_TXCLKTIMER,
 266                 port->membase + MCFUART_UCSR);
 267         writeb(MCFUART_UCR_RXENABLE | MCFUART_UCR_TXENABLE,
 268                 port->membase + MCFUART_UCR);
 269         spin_unlock_irqrestore(&port->lock, flags);
 270 }
 271
 272 /****************************************************************************/
 273
 274 static void mcf_rx_chars(struct mcf_uart *pp)
 275 {
 276         struct uart_port *port = &pp->port;
 277         unsigned char status, ch, flag;
 278
 279         while ((status = readb(port->membase + MCFUART_USR)) & MCFUART_USR_RXREADY) {
 280                 ch = readb(port->membase + MCFUART_URB);
 281                 flag = TTY_NORMAL;
 282                 port->icount.rx++;
 283
 284                 if (status & MCFUART_USR_RXERR) {
 285                         writeb(MCFUART_UCR_CMDRESETERR,
 286                                 port->membase + MCFUART_UCR);
 287
 288                         if (status & MCFUART_USR_RXBREAK) {
 289                                 port->icount.brk++;
 290                                 if (uart_handle_break(port))
 291                                         continue;
 292                         } else if (status & MCFUART_USR_RXPARITY) {
 293                                 port->icount.parity++;
 294                         } else if (status & MCFUART_USR_RXOVERRUN) {
 295                                 port->icount.overrun++;
 296                         } else if (status & MCFUART_USR_RXFRAMING) {
 297                                 port->icount.frame++;
 298                         }
 299
 300                         status &= port->read_status_mask;
 301
 302                         if (status & MCFUART_USR_RXBREAK)
 303                                 flag = TTY_BREAK;
 304                         else if (status & MCFUART_USR_RXPARITY)
 305                                 flag = TTY_PARITY;
 306                         else if (status & MCFUART_USR_RXFRAMING)
 307                                 flag = TTY_FRAME;
 308                 }
 309
 310                 if (uart_handle_sysrq_char(port, ch))
 311                         continue;
 312                 uart_insert_char(port, status, MCFUART_USR_RXOVERRUN, ch, flag);
 313         }
 314
 315         tty_flip_buffer_push(port->info->tty);
 316 }
 317
 318 /****************************************************************************/
 319
 320 static void mcf_tx_chars(struct mcf_uart *pp)
 321 {
 322         struct uart_port *port = &pp->port;
 323         struct circ_buf *xmit = &port->info->xmit;
 324
 325         if (port->x_char) {
 326                 /* Send special char - probably flow control */
 327                 writeb(port->x_char, port->membase + MCFUART_UTB);
 328                 port->x_char = 0;
 329                 port->icount.tx++;
 330                 return;
 331         }
 332
 333         while (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY) {
 334                 if (xmit->head == xmit->tail)
 335                         break;
 336                 writeb(xmit->buf[xmit->tail], port->membase + MCFUART_UTB);
 337                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE -1);
 338                 port->icount.tx++;
 339         }
 340
 341         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 342                 uart_write_wakeup(port);
 343
 344         if (xmit->head == xmit->tail) {
 345                 pp->imr &= ~MCFUART_UIR_TXREADY;
 346                 writeb(pp->imr, port->membase + MCFUART_UIMR);
 347         }
 348 }
 349
 350 /****************************************************************************/
 351
 352 static irqreturn_t mcf_interrupt(int irq, void *data)
 353 {
 354         struct uart_port *port = data;
 355         struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
 356         unsigned int isr;
 357
 358         isr = readb(port->membase + MCFUART_UISR) & pp->imr;
 359         if (isr & MCFUART_UIR_RXREADY)
 360                 mcf_rx_chars(pp);
 361         if (isr & MCFUART_UIR_TXREADY)
 362                 mcf_tx_chars(pp);
 363         return IRQ_HANDLED;
 364 }
 365
 366 /****************************************************************************/
 367
 368 static void mcf_config_port(struct uart_port *port, int flags)
 369 {
 370         port->type = PORT_MCF;
 371
 372         /* Clear mask, so no surprise interrupts. */
 373         writeb(0, port->membase + MCFUART_UIMR);
 374
 375         if (request_irq(port->irq, mcf_interrupt, IRQF_DISABLED, "UART", port))
 376                 printk(KERN_ERR "MCF: unable to attach ColdFire UART %d "
 377                         "interrupt vector=%d\n", port->line, port->irq);
 378 }
 379
 380 /****************************************************************************/
 381
 382 static const char *mcf_type(struct uart_port *port)
 383 {
 384         return (port->type == PORT_MCF) ? "ColdFire UART" : NULL;
 385 }
 386
 387 /****************************************************************************/
 388
 389 static int mcf_request_port(struct uart_port *port)
 390 {
 391         /* UARTs always present */
 392         return 0;
 393 }
 394
 395 /****************************************************************************/
 396
 397 static void mcf_release_port(struct uart_port *port)
 398 {
 399         /* Nothing to release... */
 400 }
 401
 402 /****************************************************************************/
 403
 404 static int mcf_verify_port(struct uart_port *port, struct serial_struct *ser)
 405 {
 406         if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_MCF))
 407                 return -EINVAL;
 408         return 0;
 409 }
 410
 411 /****************************************************************************/
 412
 413 /*
 414  *      Define the basic serial functions we support.
 415  */
 416 static struct uart_ops mcf_uart_ops = {
 417         .tx_empty       = mcf_tx_empty,
 418         .get_mctrl      = mcf_get_mctrl,
 419         .set_mctrl      = mcf_set_mctrl,
 420         .start_tx       = mcf_start_tx,
 421         .stop_tx        = mcf_stop_tx,
 422         .stop_rx        = mcf_stop_rx,
 423         .enable_ms      = mcf_enable_ms,
 424         .break_ctl      = mcf_break_ctl,
 425         .startup        = mcf_startup,
 426         .shutdown       = mcf_shutdown,
 427         .set_termios    = mcf_set_termios,
 428         .type           = mcf_type,
 429         .request_port   = mcf_request_port,
 430         .release_port   = mcf_release_port,
 431         .config_port    = mcf_config_port,
 432         .verify_port    = mcf_verify_port,
 433 };
 434
 435 static struct mcf_uart mcf_ports[3];
 436
 437 #define MCF_MAXPORTS    (sizeof(mcf_ports) / sizeof(struct mcf_uart))
 438
 439 /****************************************************************************/
 440 #if defined(CONFIG_SERIAL_MCF_CONSOLE)
 441 /****************************************************************************/
 442
 443 int __init early_mcf_setup(struct mcf_platform_uart *platp)
 444 {
 445         struct uart_port *port;
 446         int i;
 447
 448         for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
 449                 port = &mcf_ports[i].port;
 450
 451                 port->line = i;
 452                 port->type = PORT_MCF;
 453                 port->mapbase = platp[i].mapbase;
 454                 port->membase = (platp[i].membase) ? platp[i].membase :
 455                         (unsigned char __iomem *) port->mapbase;
 456                 port->iotype = SERIAL_IO_MEM;
 457                 port->irq = platp[i].irq;
 458                 port->uartclk = MCF_BUSCLK;
 459                 port->flags = ASYNC_BOOT_AUTOCONF;
 460                 port->ops = &mcf_uart_ops;
 461         }
 462
 463         return 0;
 464 }
 465
 466 /****************************************************************************/
 467
 468 static void mcf_console_putc(struct console *co, const char c)
 469 {
 470         struct uart_port *port = &(mcf_ports + co->index)->port;
 471         int i;
 472
 473         for (i = 0; (i < 0x10000); i++) {
 474                 if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
 475                         break;
 476         }
 477         writeb(c, port->membase + MCFUART_UTB);
 478         for (i = 0; (i < 0x10000); i++) {
 479                 if (readb(port->membase + MCFUART_USR) & MCFUART_USR_TXREADY)
 480                         break;
 481         }
 482 }
 483
 484 /****************************************************************************/
 485
 486 static void mcf_console_write(struct console *co, const char *s, unsigned int count)
 487 {
 488         for (; (count); count--, s++) {
 489                 mcf_console_putc(co, *s);
 490                 if (*s == '\n')
 491                         mcf_console_putc(co, '\r');
 492         }
 493 }
 494
 495 /****************************************************************************/
 496
 497 static int __init mcf_console_setup(struct console *co, char *options)
 498 {
 499         struct uart_port *port;
 500         int baud = CONFIG_SERIAL_MCF_BAUDRATE;
 501         int bits = 8;
 502         int parity = 'n';
 503         int flow = 'n';
 504
 505         if ((co->index >= 0) && (co->index <= MCF_MAXPORTS))
 506                 co->index = 0;
 507         port = &mcf_ports[co->index].port;
 508         if (port->membase == 0)
 509                 return -ENODEV;
 510
 511         if (options)
 512                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 513
 514         return uart_set_options(port, co, baud, parity, bits, flow);
 515 }
 516
 517 /****************************************************************************/
 518
 519 static struct uart_driver mcf_driver;
 520
 521 static struct console mcf_console = {
 522         .name           = "ttyS",
 523         .write          = mcf_console_write,
 524         .device         = uart_console_device,
 525         .setup          = mcf_console_setup,
 526         .flags          = CON_PRINTBUFFER,
 527         .index          = -1,
 528         .data           = &mcf_driver,
 529 };
 530
 531 static int __init mcf_console_init(void)
 532 {
 533         register_console(&mcf_console);
 534         return 0;
 535 }
 536
 537 console_initcall(mcf_console_init);
 538
 539 #define MCF_CONSOLE     &mcf_console
 540
 541 /****************************************************************************/
 542 #else
 543 /****************************************************************************/
 544
 545 #define MCF_CONSOLE     NULL
 546
 547 /****************************************************************************/
 548 #endif /* CONFIG_MCF_CONSOLE */
 549 /****************************************************************************/
 550
 551 /*
 552  *      Define the mcf UART driver structure.
 553  */
 554 static struct uart_driver mcf_driver = {
 555         .owner          = THIS_MODULE,
 556         .driver_name    = "mcf",
 557         .dev_name       = "ttyS",
 558         .major          = TTY_MAJOR,
 559         .minor          = 64,
 560         .nr             = MCF_MAXPORTS,
 561         .cons           = MCF_CONSOLE,
 562 };
 563
 564 /****************************************************************************/
 565
 566 static int __devinit mcf_probe(struct platform_device *pdev)
 567 {
 568         struct mcf_platform_uart *platp = pdev->dev.platform_data;
 569         struct uart_port *port;
 570         int i;
 571
 572         for (i = 0; ((i < MCF_MAXPORTS) && (platp[i].mapbase)); i++) {
 573                 port = &mcf_ports[i].port;
 574
 575                 port->line = i;
 576                 port->type = PORT_MCF;
 577                 port->mapbase = platp[i].mapbase;
 578                 port->membase = (platp[i].membase) ? platp[i].membase :
 579                         (unsigned char __iomem *) platp[i].mapbase;
 580                 port->iotype = SERIAL_IO_MEM;
 581                 port->irq = platp[i].irq;
 582                 port->uartclk = MCF_BUSCLK;
 583                 port->ops = &mcf_uart_ops;
 584                 port->flags = ASYNC_BOOT_AUTOCONF;
 585
 586                 uart_add_one_port(&mcf_driver, port);
 587         }
 588
 589         return 0;
 590 }
 591
 592 /****************************************************************************/
 593
 594 static int mcf_remove(struct platform_device *pdev)
 595 {
 596         struct uart_port *port;
 597         int i;
 598
 599         for (i = 0; (i < MCF_MAXPORTS); i++) {
 600                 port = &mcf_ports[i].port;
 601                 if (port)
 602                         uart_remove_one_port(&mcf_driver, port);
 603         }
 604
 605         return 0;
 606 }
 607
 608 /****************************************************************************/
 609
 610 static struct platform_driver mcf_platform_driver = {
 611         .probe          = mcf_probe,
 612         .remove         = __devexit_p(mcf_remove),
 613         .driver         = {
 614                 .name   = "mcfuart",
 615                 .owner  = THIS_MODULE,
 616         },
 617 };
 618
 619 /****************************************************************************/
 620
 621 static int __init mcf_init(void)
 622 {
 623         int rc;
 624
 625         printk("ColdFire internal UART serial driver\n");
 626
 627         rc = uart_register_driver(&mcf_driver);
 628         if (rc)
 629                 return rc;
 630         rc = platform_driver_register(&mcf_platform_driver);
 631         if (rc)
 632                 return rc;
 633         return 0;
 634 }
 635
 636 /****************************************************************************/
 637
 638 static void __exit mcf_exit(void)
 639 {
 640         platform_driver_unregister(&mcf_platform_driver);
 641         uart_unregister_driver(&mcf_driver);
 642 }
 643
 644 /****************************************************************************/
 645
 646 module_init(mcf_init);
 647 module_exit(mcf_exit);
 648
 649 MODULE_AUTHOR("Greg Ungerer <gerg@snapgear.com>");
 650 MODULE_DESCRIPTION("Freescale ColdFire UART driver");
 651 MODULE_LICENSE("GPL");
 652
 653 /****************************************************************************/