drivers/serial/mpc52xx_uart.c

   1 /*
   2  * drivers/serial/mpc52xx_uart.c
   3  *
   4  * Driver for the PSC of the Freescale MPC52xx PSCs configured as UARTs.
   5  *
   6  * FIXME According to the usermanual the status bits in the status register
   7  * are only updated when the peripherals access the FIFO and not when the
   8  * CPU access them. So since we use this bits to know when we stop writing
   9  * and reading, they may not be updated in-time and a race condition may
  10  * exists. But I haven't be able to prove this and I don't care. But if
  11  * any problem arises, it might worth checking. The TX/RX FIFO Stats
  12  * registers should be used in addition.
  13  * Update: Actually, they seem updated ... At least the bits we use.
  14  *
  15  *
  16  * Maintainer : Sylvain Munaut <tnt@246tNt.com>
  17  *
  18  * Some of the code has been inspired/copied from the 2.4 code written
  19  * by Dale Farnsworth <dfarnsworth@mvista.com>.
  20  *
  21  * Copyright (C) 2004-2005 Sylvain Munaut <tnt@246tNt.com>
  22  * Copyright (C) 2003 MontaVista, Software, Inc.
  23  *
  24  * This file is licensed under the terms of the GNU General Public License
  25  * version 2. This program is licensed "as is" without any warranty of any
  26  * kind, whether express or implied.
  27  */
  28
  29 /* Platform device Usage :
  30  *
  31  * Since PSCs can have multiple function, the correct driver for each one
  32  * is selected by calling mpc52xx_match_psc_function(...). The function
  33  * handled by this driver is "uart".
  34  *
  35  * The driver init all necessary registers to place the PSC in uart mode without
  36  * DCD. However, the pin multiplexing aren't changed and should be set either
  37  * by the bootloader or in the platform init code.
  38  *
  39  * The idx field must be equal to the PSC index ( e.g. 0 for PSC1, 1 for PSC2,
  40  * and so on). So the PSC1 is mapped to /dev/ttyS0, PSC2 to /dev/ttyS1 and so
  41  * on. But be warned, it's an ABSOLUTE REQUIREMENT ! This is needed mainly for
  42  * the console code : without this 1:1 mapping, at early boot time, when we are
  43  * parsing the kernel args console=ttyS?, we wouldn't know wich PSC it will be
  44  * mapped to.
  45  */
  46
  47 #include <linux/config.h>
  48 #include <linux/device.h>
  49 #include <linux/module.h>
  50 #include <linux/tty.h>
  51 #include <linux/serial.h>
  52 #include <linux/sysrq.h>
  53 #include <linux/console.h>
  54
  55 #include <asm/delay.h>
  56 #include <asm/io.h>
  57
  58 #include <asm/mpc52xx.h>
  59 #include <asm/mpc52xx_psc.h>
  60
  61 #if defined(CONFIG_SERIAL_MPC52xx_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  62 #define SUPPORT_SYSRQ
  63 #endif
  64
  65 #include <linux/serial_core.h>
  66
  67
  68
  69 #define ISR_PASS_LIMIT 256      /* Max number of iteration in the interrupt */
  70
  71
  72 static struct uart_port mpc52xx_uart_ports[MPC52xx_PSC_MAXNUM];
  73         /* Rem: - We use the read_status_mask as a shadow of
  74          *        psc->mpc52xx_psc_imr
  75          *      - It's important that is array is all zero on start as we
  76          *        use it to know if it's initialized or not ! If it's not sure
  77          *        it's cleared, then a memset(...,0,...) should be added to
  78          *        the console_init
  79          */
  80
  81 #define PSC(port) ((struct mpc52xx_psc __iomem *)((port)->membase))
  82
  83
  84 /* Forward declaration of the interruption handling routine */
  85 static irqreturn_t mpc52xx_uart_int(int irq,void *dev_id,struct pt_regs *regs);
  86
  87
  88 /* Simple macro to test if a port is console or not. This one is taken
  89  * for serial_core.c and maybe should be moved to serial_core.h ? */
  90 #ifdef CONFIG_SERIAL_CORE_CONSOLE
  91 #define uart_console(port)      ((port)->cons && (port)->cons->index == (port)->line)
  92 #else
  93 #define uart_console(port)      (0)
  94 #endif
  95
  96
  97 /* ======================================================================== */
  98 /* UART operations                                                          */
  99 /* ======================================================================== */
 100
 101 static unsigned int
 102 mpc52xx_uart_tx_empty(struct uart_port *port)
 103 {
 104         int status = in_be16(&PSC(port)->mpc52xx_psc_status);
 105         return (status & MPC52xx_PSC_SR_TXEMP) ? TIOCSER_TEMT : 0;
 106 }
 107
 108 static void
 109 mpc52xx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 110 {
 111         /* Not implemented */
 112 }
 113
 114 static unsigned int
 115 mpc52xx_uart_get_mctrl(struct uart_port *port)
 116 {
 117         /* Not implemented */
 118         return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
 119 }
 120
 121 static void
 122 mpc52xx_uart_stop_tx(struct uart_port *port)
 123 {
 124         /* port->lock taken by caller */
 125         port->read_status_mask &= ~MPC52xx_PSC_IMR_TXRDY;
 126         out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
 127 }
 128
 129 static void
 130 mpc52xx_uart_start_tx(struct uart_port *port)
 131 {
 132         /* port->lock taken by caller */
 133         port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY;
 134         out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
 135 }
 136
 137 static void
 138 mpc52xx_uart_send_xchar(struct uart_port *port, char ch)
 139 {
 140         unsigned long flags;
 141         spin_lock_irqsave(&port->lock, flags);
 142
 143         port->x_char = ch;
 144         if (ch) {
 145                 /* Make sure tx interrupts are on */
 146                 /* Truly necessary ??? They should be anyway */
 147                 port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY;
 148                 out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
 149         }
 150
 151         spin_unlock_irqrestore(&port->lock, flags);
 152 }
 153
 154 static void
 155 mpc52xx_uart_stop_rx(struct uart_port *port)
 156 {
 157         /* port->lock taken by caller */
 158         port->read_status_mask &= ~MPC52xx_PSC_IMR_RXRDY;
 159         out_be16(&PSC(port)->mpc52xx_psc_imr,port->read_status_mask);
 160 }
 161
 162 static void
 163 mpc52xx_uart_enable_ms(struct uart_port *port)
 164 {
 165         /* Not implemented */
 166 }
 167
 168 static void
 169 mpc52xx_uart_break_ctl(struct uart_port *port, int ctl)
 170 {
 171         unsigned long flags;
 172         spin_lock_irqsave(&port->lock, flags);
 173
 174         if ( ctl == -1 )
 175                 out_8(&PSC(port)->command,MPC52xx_PSC_START_BRK);
 176         else
 177                 out_8(&PSC(port)->command,MPC52xx_PSC_STOP_BRK);
 178
 179         spin_unlock_irqrestore(&port->lock, flags);
 180 }
 181
 182 static int
 183 mpc52xx_uart_startup(struct uart_port *port)
 184 {
 185         struct mpc52xx_psc __iomem *psc = PSC(port);
 186         int ret;
 187
 188         /* Request IRQ */
 189         ret = request_irq(port->irq, mpc52xx_uart_int,
 190                 SA_INTERRUPT | SA_SAMPLE_RANDOM, "mpc52xx_psc_uart", port);
 191         if (ret)
 192                 return ret;
 193
 194         /* Reset/activate the port, clear and enable interrupts */
 195         out_8(&psc->command,MPC52xx_PSC_RST_RX);
 196         out_8(&psc->command,MPC52xx_PSC_RST_TX);
 197
 198         out_be32(&psc->sicr,0); /* UART mode DCD ignored */
 199
 200         out_be16(&psc->mpc52xx_psc_clock_select, 0xdd00); /* /16 prescaler on */
 201
 202         out_8(&psc->rfcntl, 0x00);
 203         out_be16(&psc->rfalarm, 0x1ff);
 204         out_8(&psc->tfcntl, 0x07);
 205         out_be16(&psc->tfalarm, 0x80);
 206
 207         port->read_status_mask |= MPC52xx_PSC_IMR_RXRDY | MPC52xx_PSC_IMR_TXRDY;
 208         out_be16(&psc->mpc52xx_psc_imr,port->read_status_mask);
 209
 210         out_8(&psc->command,MPC52xx_PSC_TX_ENABLE);
 211         out_8(&psc->command,MPC52xx_PSC_RX_ENABLE);
 212
 213         return 0;
 214 }
 215
 216 static void
 217 mpc52xx_uart_shutdown(struct uart_port *port)
 218 {
 219         struct mpc52xx_psc __iomem *psc = PSC(port);
 220
 221         /* Shut down the port, interrupt and all */
 222         out_8(&psc->command,MPC52xx_PSC_RST_RX);
 223         out_8(&psc->command,MPC52xx_PSC_RST_TX);
 224
 225         port->read_status_mask = 0;
 226         out_be16(&psc->mpc52xx_psc_imr,port->read_status_mask);
 227
 228         /* Release interrupt */
 229         free_irq(port->irq, port);
 230 }
 231
 232 static void
 233 mpc52xx_uart_set_termios(struct uart_port *port, struct termios *new,
 234                          struct termios *old)
 235 {
 236         struct mpc52xx_psc __iomem *psc = PSC(port);
 237         unsigned long flags;
 238         unsigned char mr1, mr2;
 239         unsigned short ctr;
 240         unsigned int j, baud, quot;
 241
 242         /* Prepare what we're gonna write */
 243         mr1 = 0;
 244
 245         switch (new->c_cflag & CSIZE) {
 246                 case CS5:       mr1 |= MPC52xx_PSC_MODE_5_BITS;
 247                                 break;
 248                 case CS6:       mr1 |= MPC52xx_PSC_MODE_6_BITS;
 249                                 break;
 250                 case CS7:       mr1 |= MPC52xx_PSC_MODE_7_BITS;
 251                                 break;
 252                 case CS8:
 253                 default:        mr1 |= MPC52xx_PSC_MODE_8_BITS;
 254         }
 255
 256         if (new->c_cflag & PARENB) {
 257                 mr1 |= (new->c_cflag & PARODD) ?
 258                         MPC52xx_PSC_MODE_PARODD : MPC52xx_PSC_MODE_PAREVEN;
 259         } else
 260                 mr1 |= MPC52xx_PSC_MODE_PARNONE;
 261
 262
 263         mr2 = 0;
 264
 265         if (new->c_cflag & CSTOPB)
 266                 mr2 |= MPC52xx_PSC_MODE_TWO_STOP;
 267         else
 268                 mr2 |= ((new->c_cflag & CSIZE) == CS5) ?
 269                         MPC52xx_PSC_MODE_ONE_STOP_5_BITS :
 270                         MPC52xx_PSC_MODE_ONE_STOP;
 271
 272
 273         baud = uart_get_baud_rate(port, new, old, 0, port->uartclk/16);
 274         quot = uart_get_divisor(port, baud);
 275         ctr = quot & 0xffff;
 276
 277         /* Get the lock */
 278         spin_lock_irqsave(&port->lock, flags);
 279
 280         /* Update the per-port timeout */
 281         uart_update_timeout(port, new->c_cflag, baud);
 282
 283         /* Do our best to flush TX & RX, so we don't loose anything */
 284         /* But we don't wait indefinitly ! */
 285         j = 5000000;    /* Maximum wait */
 286         /* FIXME Can't receive chars since set_termios might be called at early
 287          * boot for the console, all stuff is not yet ready to receive at that
 288          * time and that just makes the kernel oops */
 289         /* while (j-- && mpc52xx_uart_int_rx_chars(port)); */
 290         while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP) &&
 291                --j)
 292                 udelay(1);
 293
 294         if (!j)
 295                 printk( KERN_ERR "mpc52xx_uart.c: "
 296                         "Unable to flush RX & TX fifos in-time in set_termios."
 297                         "Some chars may have been lost.\n" );
 298
 299         /* Reset the TX & RX */
 300         out_8(&psc->command,MPC52xx_PSC_RST_RX);
 301         out_8(&psc->command,MPC52xx_PSC_RST_TX);
 302
 303         /* Send new mode settings */
 304         out_8(&psc->command,MPC52xx_PSC_SEL_MODE_REG_1);
 305         out_8(&psc->mode,mr1);
 306         out_8(&psc->mode,mr2);
 307         out_8(&psc->ctur,ctr >> 8);
 308         out_8(&psc->ctlr,ctr & 0xff);
 309
 310         /* Reenable TX & RX */
 311         out_8(&psc->command,MPC52xx_PSC_TX_ENABLE);
 312         out_8(&psc->command,MPC52xx_PSC_RX_ENABLE);
 313
 314         /* We're all set, release the lock */
 315         spin_unlock_irqrestore(&port->lock, flags);
 316 }
 317
 318 static const char *
 319 mpc52xx_uart_type(struct uart_port *port)
 320 {
 321         return port->type == PORT_MPC52xx ? "MPC52xx PSC" : NULL;
 322 }
 323
 324 static void
 325 mpc52xx_uart_release_port(struct uart_port *port)
 326 {
 327         if (port->flags & UPF_IOREMAP) { /* remapped by us ? */
 328                 iounmap(port->membase);
 329                 port->membase = NULL;
 330         }
 331
 332         release_mem_region(port->mapbase, MPC52xx_PSC_SIZE);
 333 }
 334
 335 static int
 336 mpc52xx_uart_request_port(struct uart_port *port)
 337 {
 338         if (port->flags & UPF_IOREMAP) /* Need to remap ? */
 339                 port->membase = ioremap(port->mapbase, MPC52xx_PSC_SIZE);
 340
 341         if (!port->membase)
 342                 return -EINVAL;
 343
 344         return request_mem_region(port->mapbase, MPC52xx_PSC_SIZE,
 345                         "mpc52xx_psc_uart") != NULL ? 0 : -EBUSY;
 346 }
 347
 348 static void
 349 mpc52xx_uart_config_port(struct uart_port *port, int flags)
 350 {
 351         if ( (flags & UART_CONFIG_TYPE) &&
 352              (mpc52xx_uart_request_port(port) == 0) )
 353                 port->type = PORT_MPC52xx;
 354 }
 355
 356 static int
 357 mpc52xx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
 358 {
 359         if ( ser->type != PORT_UNKNOWN && ser->type != PORT_MPC52xx )
 360                 return -EINVAL;
 361
 362         if ( (ser->irq != port->irq) ||
 363              (ser->io_type != SERIAL_IO_MEM) ||
 364              (ser->baud_base != port->uartclk)  ||
 365              (ser->iomem_base != (void*)port->mapbase) ||
 366              (ser->hub6 != 0 ) )
 367                 return -EINVAL;
 368
 369         return 0;
 370 }
 371
 372
 373 static struct uart_ops mpc52xx_uart_ops = {
 374         .tx_empty       = mpc52xx_uart_tx_empty,
 375         .set_mctrl      = mpc52xx_uart_set_mctrl,
 376         .get_mctrl      = mpc52xx_uart_get_mctrl,
 377         .stop_tx        = mpc52xx_uart_stop_tx,
 378         .start_tx       = mpc52xx_uart_start_tx,
 379         .send_xchar     = mpc52xx_uart_send_xchar,
 380         .stop_rx        = mpc52xx_uart_stop_rx,
 381         .enable_ms      = mpc52xx_uart_enable_ms,
 382         .break_ctl      = mpc52xx_uart_break_ctl,
 383         .startup        = mpc52xx_uart_startup,
 384         .shutdown       = mpc52xx_uart_shutdown,
 385         .set_termios    = mpc52xx_uart_set_termios,
 386 /*      .pm             = mpc52xx_uart_pm,              Not supported yet */
 387 /*      .set_wake       = mpc52xx_uart_set_wake,        Not supported yet */
 388         .type           = mpc52xx_uart_type,
 389         .release_port   = mpc52xx_uart_release_port,
 390         .request_port   = mpc52xx_uart_request_port,
 391         .config_port    = mpc52xx_uart_config_port,
 392         .verify_port    = mpc52xx_uart_verify_port
 393 };
 394
 395
 396 /* ======================================================================== */
 397 /* Interrupt handling                                                       */
 398 /* ======================================================================== */
 399
 400 static inline int
 401 mpc52xx_uart_int_rx_chars(struct uart_port *port, struct pt_regs *regs)
 402 {
 403         struct tty_struct *tty = port->info->tty;
 404         unsigned char ch;
 405         unsigned short status;
 406
 407         /* While we can read, do so ! */
 408         while ( (status = in_be16(&PSC(port)->mpc52xx_psc_status)) &
 409                 MPC52xx_PSC_SR_RXRDY) {
 410
 411                 /* If we are full, just stop reading */
 412                 if (tty->flip.count >= TTY_FLIPBUF_SIZE)
 413                         break;
 414
 415                 /* Get the char */
 416                 ch = in_8(&PSC(port)->mpc52xx_psc_buffer_8);
 417
 418                 /* Handle sysreq char */
 419 #ifdef SUPPORT_SYSRQ
 420                 if (uart_handle_sysrq_char(port, ch, regs)) {
 421                         port->sysrq = 0;
 422                         continue;
 423                 }
 424 #endif
 425
 426                 /* Store it */
 427                 *tty->flip.char_buf_ptr = ch;
 428                 *tty->flip.flag_buf_ptr = 0;
 429                 port->icount.rx++;
 430
 431                 if ( status & (MPC52xx_PSC_SR_PE |
 432                                MPC52xx_PSC_SR_FE |
 433                                MPC52xx_PSC_SR_RB |
 434                                MPC52xx_PSC_SR_OE) ) {
 435
 436                         if (status & MPC52xx_PSC_SR_RB) {
 437                                 *tty->flip.flag_buf_ptr = TTY_BREAK;
 438                                 uart_handle_break(port);
 439                         } else if (status & MPC52xx_PSC_SR_PE)
 440                                 *tty->flip.flag_buf_ptr = TTY_PARITY;
 441                         else if (status & MPC52xx_PSC_SR_FE)
 442                                 *tty->flip.flag_buf_ptr = TTY_FRAME;
 443                         if (status & MPC52xx_PSC_SR_OE) {
 444                                 /*
 445                                  * Overrun is special, since it's
 446                                  * reported immediately, and doesn't
 447                                  * affect the current character
 448                                  */
 449                                 if (tty->flip.count < (TTY_FLIPBUF_SIZE-1)) {
 450                                         tty->flip.flag_buf_ptr++;
 451                                         tty->flip.char_buf_ptr++;
 452                                         tty->flip.count++;
 453                                 }
 454                                 *tty->flip.flag_buf_ptr = TTY_OVERRUN;
 455                         }
 456
 457                         /* Clear error condition */
 458                         out_8(&PSC(port)->command,MPC52xx_PSC_RST_ERR_STAT);
 459
 460                 }
 461
 462                 tty->flip.char_buf_ptr++;
 463                 tty->flip.flag_buf_ptr++;
 464                 tty->flip.count++;
 465
 466         }
 467
 468         tty_flip_buffer_push(tty);
 469
 470         return in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_RXRDY;
 471 }
 472
 473 static inline int
 474 mpc52xx_uart_int_tx_chars(struct uart_port *port)
 475 {
 476         struct circ_buf *xmit = &port->info->xmit;
 477
 478         /* Process out of band chars */
 479         if (port->x_char) {
 480                 out_8(&PSC(port)->mpc52xx_psc_buffer_8, port->x_char);
 481                 port->icount.tx++;
 482                 port->x_char = 0;
 483                 return 1;
 484         }
 485
 486         /* Nothing to do ? */
 487         if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
 488                 mpc52xx_uart_stop_tx(port);
 489                 return 0;
 490         }
 491
 492         /* Send chars */
 493         while (in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXRDY) {
 494                 out_8(&PSC(port)->mpc52xx_psc_buffer_8, xmit->buf[xmit->tail]);
 495                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 496                 port->icount.tx++;
 497                 if (uart_circ_empty(xmit))
 498                         break;
 499         }
 500
 501         /* Wake up */
 502         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 503                 uart_write_wakeup(port);
 504
 505         /* Maybe we're done after all */
 506         if (uart_circ_empty(xmit)) {
 507                 mpc52xx_uart_stop_tx(port);
 508                 return 0;
 509         }
 510
 511         return 1;
 512 }
 513
 514 static irqreturn_t
 515 mpc52xx_uart_int(int irq, void *dev_id, struct pt_regs *regs)
 516 {
 517         struct uart_port *port = (struct uart_port *) dev_id;
 518         unsigned long pass = ISR_PASS_LIMIT;
 519         unsigned int keepgoing;
 520         unsigned short status;
 521
 522         if ( irq != port->irq ) {
 523                 printk( KERN_WARNING
 524                         "mpc52xx_uart_int : " \
 525                         "Received wrong int %d. Waiting for %d\n",
 526                        irq, port->irq);
 527                 return IRQ_NONE;
 528         }
 529
 530         spin_lock(&port->lock);
 531
 532         /* While we have stuff to do, we continue */
 533         do {
 534                 /* If we don't find anything to do, we stop */
 535                 keepgoing = 0;
 536
 537                 /* Read status */
 538                 status = in_be16(&PSC(port)->mpc52xx_psc_isr);
 539                 status &= port->read_status_mask;
 540
 541                 /* Do we need to receive chars ? */
 542                 /* For this RX interrupts must be on and some chars waiting */
 543                 if ( status & MPC52xx_PSC_IMR_RXRDY )
 544                         keepgoing |= mpc52xx_uart_int_rx_chars(port, regs);
 545
 546                 /* Do we need to send chars ? */
 547                 /* For this, TX must be ready and TX interrupt enabled */
 548                 if ( status & MPC52xx_PSC_IMR_TXRDY )
 549                         keepgoing |= mpc52xx_uart_int_tx_chars(port);
 550
 551                 /* Limit number of iteration */
 552                 if ( !(--pass) )
 553                         keepgoing = 0;
 554
 555         } while (keepgoing);
 556
 557         spin_unlock(&port->lock);
 558
 559         return IRQ_HANDLED;
 560 }
 561
 562
 563 /* ======================================================================== */
 564 /* Console ( if applicable )                                                */
 565 /* ======================================================================== */
 566
 567 #ifdef CONFIG_SERIAL_MPC52xx_CONSOLE
 568
 569 static void __init
 570 mpc52xx_console_get_options(struct uart_port *port,
 571                             int *baud, int *parity, int *bits, int *flow)
 572 {
 573         struct mpc52xx_psc __iomem *psc = PSC(port);
 574         unsigned char mr1;
 575
 576         /* Read the mode registers */
 577         out_8(&psc->command,MPC52xx_PSC_SEL_MODE_REG_1);
 578         mr1 = in_8(&psc->mode);
 579
 580         /* CT{U,L}R are write-only ! */
 581         *baud = __res.bi_baudrate ?
 582                 __res.bi_baudrate : CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;
 583
 584         /* Parse them */
 585         switch (mr1 & MPC52xx_PSC_MODE_BITS_MASK) {
 586                 case MPC52xx_PSC_MODE_5_BITS:   *bits = 5; break;
 587                 case MPC52xx_PSC_MODE_6_BITS:   *bits = 6; break;
 588                 case MPC52xx_PSC_MODE_7_BITS:   *bits = 7; break;
 589                 case MPC52xx_PSC_MODE_8_BITS:
 590                 default:                        *bits = 8;
 591         }
 592
 593         if (mr1 & MPC52xx_PSC_MODE_PARNONE)
 594                 *parity = 'n';
 595         else
 596                 *parity = mr1 & MPC52xx_PSC_MODE_PARODD ? 'o' : 'e';
 597 }
 598
 599 static void
 600 mpc52xx_console_write(struct console *co, const char *s, unsigned int count)
 601 {
 602         struct uart_port *port = &mpc52xx_uart_ports[co->index];
 603         struct mpc52xx_psc __iomem *psc = PSC(port);
 604         unsigned int i, j;
 605
 606         /* Disable interrupts */
 607         out_be16(&psc->mpc52xx_psc_imr, 0);
 608
 609         /* Wait the TX buffer to be empty */
 610         j = 5000000;    /* Maximum wait */
 611         while (!(in_be16(&psc->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP) &&
 612                --j)
 613                 udelay(1);
 614
 615         /* Write all the chars */
 616         for ( i=0 ; i<count ; i++ ) {
 617
 618                 /* Send the char */
 619                 out_8(&psc->mpc52xx_psc_buffer_8, *s);
 620
 621                 /* Line return handling */
 622                 if ( *s++ == '\n' )
 623                         out_8(&psc->mpc52xx_psc_buffer_8, '\r');
 624
 625                 /* Wait the TX buffer to be empty */
 626                 j = 20000;      /* Maximum wait */
 627                 while (!(in_be16(&psc->mpc52xx_psc_status) &
 628                          MPC52xx_PSC_SR_TXEMP) && --j)
 629                         udelay(1);
 630         }
 631
 632         /* Restore interrupt state */
 633         out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
 634 }
 635
 636 static int __init
 637 mpc52xx_console_setup(struct console *co, char *options)
 638 {
 639         struct uart_port *port = &mpc52xx_uart_ports[co->index];
 640
 641         int baud = CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;
 642         int bits = 8;
 643         int parity = 'n';
 644         int flow = 'n';
 645
 646         if (co->index < 0 || co->index >= MPC52xx_PSC_MAXNUM)
 647                 return -EINVAL;
 648
 649         /* Basic port init. Needed since we use some uart_??? func before
 650          * real init for early access */
 651         spin_lock_init(&port->lock);
 652         port->uartclk   = __res.bi_ipbfreq / 2; /* Look at CTLR doc */
 653         port->ops       = &mpc52xx_uart_ops;
 654         port->mapbase   = MPC52xx_PA(MPC52xx_PSCx_OFFSET(co->index+1));
 655
 656         /* We ioremap ourself */
 657         port->membase = ioremap(port->mapbase, MPC52xx_PSC_SIZE);
 658         if (port->membase == NULL)
 659                 return -EINVAL;
 660
 661         /* Setup the port parameters accoding to options */
 662         if (options)
 663                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 664         else
 665                 mpc52xx_console_get_options(port, &baud, &parity, &bits, &flow);
 666
 667         return uart_set_options(port, co, baud, parity, bits, flow);
 668 }
 669
 670
 671 extern struct uart_driver mpc52xx_uart_driver;
 672
 673 static struct console mpc52xx_console = {
 674         .name   = "ttyS",
 675         .write  = mpc52xx_console_write,
 676         .device = uart_console_device,
 677         .setup  = mpc52xx_console_setup,
 678         .flags  = CON_PRINTBUFFER,
 679         .index  = -1,   /* Specified on the cmdline (e.g. console=ttyS0 ) */
 680         .data   = &mpc52xx_uart_driver,
 681 };
 682
 683
 684 static int __init
 685 mpc52xx_console_init(void)
 686 {
 687         register_console(&mpc52xx_console);
 688         return 0;
 689 }
 690
 691 console_initcall(mpc52xx_console_init);
 692
 693 #define MPC52xx_PSC_CONSOLE &mpc52xx_console
 694 #else
 695 #define MPC52xx_PSC_CONSOLE NULL
 696 #endif
 697
 698
 699 /* ======================================================================== */
 700 /* UART Driver                                                              */
 701 /* ======================================================================== */
 702
 703 static struct uart_driver mpc52xx_uart_driver = {
 704         .owner          = THIS_MODULE,
 705         .driver_name    = "mpc52xx_psc_uart",
 706         .dev_name       = "ttyS",
 707         .devfs_name     = "ttyS",
 708         .major          = TTY_MAJOR,
 709         .minor          = 64,
 710         .nr             = MPC52xx_PSC_MAXNUM,
 711         .cons           = MPC52xx_PSC_CONSOLE,
 712 };
 713
 714
 715 /* ======================================================================== */
 716 /* Platform Driver                                                          */
 717 /* ======================================================================== */
 718
 719 static int __devinit
 720 mpc52xx_uart_probe(struct device *dev)
 721 {
 722         struct platform_device *pdev = to_platform_device(dev);
 723         struct resource *res = pdev->resource;
 724
 725         struct uart_port *port = NULL;
 726         int i, idx, ret;
 727
 728         /* Check validity & presence */
 729         idx = pdev->id;
 730         if (idx < 0 || idx >= MPC52xx_PSC_MAXNUM)
 731                 return -EINVAL;
 732
 733         if (!mpc52xx_match_psc_function(idx,"uart"))
 734                 return -ENODEV;
 735
 736         /* Init the port structure */
 737         port = &mpc52xx_uart_ports[idx];
 738
 739         memset(port, 0x00, sizeof(struct uart_port));
 740
 741         spin_lock_init(&port->lock);
 742         port->uartclk   = __res.bi_ipbfreq / 2; /* Look at CTLR doc */
 743         port->fifosize  = 255; /* Should be 512 ! But it can't be */
 744                                /* stored in a unsigned char       */
 745         port->iotype    = UPIO_MEM;
 746         port->flags     = UPF_BOOT_AUTOCONF |
 747                           ( uart_console(port) ? 0 : UPF_IOREMAP );
 748         port->line      = idx;
 749         port->ops       = &mpc52xx_uart_ops;
 750
 751         /* Search for IRQ and mapbase */
 752         for (i=0 ; i<pdev->num_resources ; i++, res++) {
 753                 if (res->flags & IORESOURCE_MEM)
 754                         port->mapbase = res->start;
 755                 else if (res->flags & IORESOURCE_IRQ)
 756                         port->irq = res->start;
 757         }
 758         if (!port->irq || !port->mapbase)
 759                 return -EINVAL;
 760
 761         /* Add the port to the uart sub-system */
 762         ret = uart_add_one_port(&mpc52xx_uart_driver, port);
 763         if (!ret)
 764                 dev_set_drvdata(dev, (void*)port);
 765
 766         return ret;
 767 }
 768
 769 static int
 770 mpc52xx_uart_remove(struct device *dev)
 771 {
 772         struct uart_port *port = (struct uart_port *) dev_get_drvdata(dev);
 773
 774         dev_set_drvdata(dev, NULL);
 775
 776         if (port)
 777                 uart_remove_one_port(&mpc52xx_uart_driver, port);
 778
 779         return 0;
 780 }
 781
 782 #ifdef CONFIG_PM
 783 static int
 784 mpc52xx_uart_suspend(struct device *dev, u32 state, u32 level)
 785 {
 786         struct uart_port *port = (struct uart_port *) dev_get_drvdata(dev);
 787
 788         if (sport && level == SUSPEND_DISABLE)
 789                 uart_suspend_port(&mpc52xx_uart_driver, port);
 790
 791         return 0;
 792 }
 793
 794 static int
 795 mpc52xx_uart_resume(struct device *dev, u32 level)
 796 {
 797         struct uart_port *port = (struct uart_port *) dev_get_drvdata(dev);
 798
 799         if (port && level == RESUME_ENABLE)
 800                 uart_resume_port(&mpc52xx_uart_driver, port);
 801
 802         return 0;
 803 }
 804 #endif
 805
 806 static struct device_driver mpc52xx_uart_platform_driver = {
 807         .name           = "mpc52xx-psc",
 808         .bus            = &platform_bus_type,
 809         .probe          = mpc52xx_uart_probe,
 810         .remove         = mpc52xx_uart_remove,
 811 #ifdef CONFIG_PM
 812         .suspend        = mpc52xx_uart_suspend,
 813         .resume         = mpc52xx_uart_resume,
 814 #endif
 815 };
 816
 817
 818 /* ======================================================================== */
 819 /* Module                                                                   */
 820 /* ======================================================================== */
 821
 822 static int __init
 823 mpc52xx_uart_init(void)
 824 {
 825         int ret;
 826
 827         printk(KERN_INFO "Serial: MPC52xx PSC driver\n");
 828
 829         ret = uart_register_driver(&mpc52xx_uart_driver);
 830         if (ret == 0) {
 831                 ret = driver_register(&mpc52xx_uart_platform_driver);
 832                 if (ret)
 833                         uart_unregister_driver(&mpc52xx_uart_driver);
 834         }
 835
 836         return ret;
 837 }
 838
 839 static void __exit
 840 mpc52xx_uart_exit(void)
 841 {
 842         driver_unregister(&mpc52xx_uart_platform_driver);
 843         uart_unregister_driver(&mpc52xx_uart_driver);
 844 }
 845
 846
 847 module_init(mpc52xx_uart_init);
 848 module_exit(mpc52xx_uart_exit);
 849
 850 MODULE_AUTHOR("Sylvain Munaut <tnt@246tNt.com>");
 851 MODULE_DESCRIPTION("Freescale MPC52xx PSC UART");
 852 MODULE_LICENSE("GPL");