target/linux/amazon/files/drivers/serial/amazon_asc.c

   1 /*
   2  *  Driver for AMAZONASC serial ports
   3  *
   4  *  Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
   5  *  Based on drivers/serial/serial_s3c2400.c
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  * Copyright (C) 2004 Infineon IFAP DC COM CPE
  22  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
  23  * Copyright (C) 2007 John Crispin <blogic@openwrt.org>
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/signal.h>
  29 #include <linux/sched.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/tty.h>
  32 #include <linux/tty_flip.h>
  33 #include <linux/major.h>
  34 #include <linux/string.h>
  35 #include <linux/fcntl.h>
  36 #include <linux/ptrace.h>
  37 #include <linux/ioport.h>
  38 #include <linux/mm.h>
  39 #include <linux/slab.h>
  40 #include <linux/init.h>
  41 #include <linux/circ_buf.h>
  42 #include <linux/serial.h>
  43 #include <linux/serial_core.h>
  44 #include <linux/console.h>
  45 #include <linux/sysrq.h>
  46 #include <linux/irq.h>
  47 #include <linux/platform_device.h>
  48
  49 #include <asm/system.h>
  50 #include <asm/io.h>
  51 #include <asm/uaccess.h>
  52 #include <asm/bitops.h>
  53 #include <asm/amazon/amazon.h>
  54 #include <asm/amazon/irq.h>
  55 #include <asm/amazon/serial.h>
  56
  57 #define PORT_AMAZONASC  111
  58
  59 #include <linux/serial_core.h>
  60
  61 #define UART_NR         1
  62
  63 #define UART_DUMMY_UER_RX 1
  64
  65 #define SERIAL_AMAZONASC_MAJOR  TTY_MAJOR
  66 #define CALLOUT_AMAZONASC_MAJOR TTYAUX_MAJOR
  67 #define SERIAL_AMAZONASC_MINOR  64
  68 #define SERIAL_AMAZONASC_NR     UART_NR
  69
  70 static void amazonasc_tx_chars(struct uart_port *port);
  71 extern void prom_printf(const char * fmt, ...);
  72 static struct uart_port amazonasc_ports[UART_NR];
  73 static struct uart_driver amazonasc_reg;
  74 static unsigned int uartclk = 0;
  75 extern unsigned int amazon_get_fpi_hz(void);
  76
  77 static void amazonasc_stop_tx(struct uart_port *port)
  78 {
  79         /* fifo underrun shuts up after firing once */
  80         return;
  81 }
  82
  83 static void amazonasc_start_tx(struct uart_port *port)
  84 {
  85         unsigned long flags;
  86
  87         local_irq_save(flags);
  88         amazonasc_tx_chars(port);
  89         local_irq_restore(flags);
  90
  91         return;
  92 }
  93
  94 static void amazonasc_stop_rx(struct uart_port *port)
  95 {
  96         /* clear the RX enable bit */
  97         amazon_writel(ASCWHBCON_CLRREN, AMAZON_ASC_WHBCON);
  98 }
  99
 100 static void amazonasc_enable_ms(struct uart_port *port)
 101 {
 102         /* no modem signals */
 103         return;
 104 }
 105
 106 #include <linux/version.h>
 107
 108 static void
 109 amazonasc_rx_chars(struct uart_port *port)
 110 {
 111 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 26))
 112         struct tty_struct *tty = port->info->port.tty;
 113 #else
 114         struct tty_struct *tty = port->info->tty;
 115 #endif
 116         unsigned int ch = 0, rsr = 0, fifocnt;
 117
 118         fifocnt = amazon_readl(AMAZON_ASC_FSTAT) & ASCFSTAT_RXFFLMASK;
 119         while (fifocnt--)
 120         {
 121                 u8 flag = TTY_NORMAL;
 122                 ch = amazon_readl(AMAZON_ASC_RBUF);
 123                 rsr = (amazon_readl(AMAZON_ASC_CON) & ASCCON_ANY) | UART_DUMMY_UER_RX;
 124                 tty_flip_buffer_push(tty);
 125                 port->icount.rx++;
 126
 127                 /*
 128                  * Note that the error handling code is
 129                  * out of the main execution path
 130                  */
 131                 if (rsr & ASCCON_ANY) {
 132                         if (rsr & ASCCON_PE) {
 133                                 port->icount.parity++;
 134                                 amazon_writel_masked(AMAZON_ASC_WHBCON, ASCWHBCON_CLRPE, ASCWHBCON_CLRPE);
 135                         } else if (rsr & ASCCON_FE) {
 136                                 port->icount.frame++;
 137                                 amazon_writel_masked(AMAZON_ASC_WHBCON, ASCWHBCON_CLRFE, ASCWHBCON_CLRFE);
 138                         }
 139                         if (rsr & ASCCON_OE) {
 140                                 port->icount.overrun++;
 141                                 amazon_writel_masked(AMAZON_ASC_WHBCON, ASCWHBCON_CLROE, ASCWHBCON_CLROE);
 142                         }
 143
 144                         rsr &= port->read_status_mask;
 145
 146                         if (rsr & ASCCON_PE)
 147                                 flag = TTY_PARITY;
 148                         else if (rsr & ASCCON_FE)
 149                                 flag = TTY_FRAME;
 150                 }
 151
 152                 if ((rsr & port->ignore_status_mask) == 0)
 153                         tty_insert_flip_char(tty, ch, flag);
 154
 155                 if (rsr & ASCCON_OE)
 156                         /*
 157                          * Overrun is special, since it's reported
 158                          * immediately, and doesn't affect the current
 159                          * character
 160                          */
 161                         tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 162         }
 163         if (ch != 0)
 164                 tty_flip_buffer_push(tty);
 165
 166         return;
 167 }
 168
 169
 170 static void amazonasc_tx_chars(struct uart_port *port)
 171 {
 172         struct circ_buf *xmit = &port->info->xmit;
 173
 174         if (uart_tx_stopped(port)) {
 175                 amazonasc_stop_tx(port);
 176                 return;
 177         }
 178
 179         while (((amazon_readl(AMAZON_ASC_FSTAT) & ASCFSTAT_TXFFLMASK)
 180                         >> ASCFSTAT_TXFFLOFF) != AMAZONASC_TXFIFO_FULL)
 181         {
 182                 if (port->x_char) {
 183                         amazon_writel(port->x_char, AMAZON_ASC_TBUF);
 184                         port->icount.tx++;
 185                         port->x_char = 0;
 186                         continue;
 187                 }
 188
 189                 if (uart_circ_empty(xmit))
 190                         break;
 191
 192                 amazon_writel(xmit->buf[xmit->tail], AMAZON_ASC_TBUF);
 193                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 194                 port->icount.tx++;
 195         }
 196
 197         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 198                 uart_write_wakeup(port);
 199 }
 200
 201 static irqreturn_t amazonasc_tx_int(int irq, void *port)
 202 {
 203         amazon_writel(ASC_IRNCR_TIR, AMAZON_ASC_IRNCR1);
 204         amazonasc_start_tx(port);
 205
 206         /* clear any pending interrupts */
 207         amazon_writel_masked(AMAZON_ASC_WHBCON,
 208                         (ASCWHBCON_CLRPE | ASCWHBCON_CLRFE | ASCWHBCON_CLROE),
 209                         (ASCWHBCON_CLRPE | ASCWHBCON_CLRFE | ASCWHBCON_CLROE));
 210
 211         return IRQ_HANDLED;
 212 }
 213
 214 static irqreturn_t amazonasc_er_int(int irq, void *port)
 215 {
 216         /* clear any pending interrupts */
 217         amazon_writel_masked(AMAZON_ASC_WHBCON,
 218                         (ASCWHBCON_CLRPE | ASCWHBCON_CLRFE | ASCWHBCON_CLROE),
 219                         (ASCWHBCON_CLRPE | ASCWHBCON_CLRFE | ASCWHBCON_CLROE));
 220
 221         return IRQ_HANDLED;
 222 }
 223
 224 static irqreturn_t amazonasc_rx_int(int irq, void *port)
 225 {
 226         amazon_writel(ASC_IRNCR_RIR, AMAZON_ASC_IRNCR1);
 227         amazonasc_rx_chars((struct uart_port *) port);
 228         return IRQ_HANDLED;
 229 }
 230
 231 static u_int amazonasc_tx_empty(struct uart_port *port)
 232 {
 233         int status;
 234
 235         /*
 236          * FSTAT tells exactly how many bytes are in the FIFO.
 237          * The question is whether we really need to wait for all
 238          * 16 bytes to be transmitted before reporting that the
 239          * transmitter is empty.
 240          */
 241         status = amazon_readl(AMAZON_ASC_FSTAT) & ASCFSTAT_TXFFLMASK;
 242         return status ? 0 : TIOCSER_TEMT;
 243 }
 244
 245 static u_int amazonasc_get_mctrl(struct uart_port *port)
 246 {
 247         /* no modem control signals - the readme says to pretend all are set */
 248         return TIOCM_CTS|TIOCM_CAR|TIOCM_DSR;
 249 }
 250
 251 static void amazonasc_set_mctrl(struct uart_port *port, u_int mctrl)
 252 {
 253         /* no modem control - just return */
 254         return;
 255 }
 256
 257 static void amazonasc_break_ctl(struct uart_port *port, int break_state)
 258 {
 259         /* no way to send a break */
 260         return;
 261 }
 262
 263 static int amazonasc_startup(struct uart_port *port)
 264 {
 265         unsigned int con = 0;
 266         unsigned long flags;
 267         int retval;
 268
 269         /* this assumes: CON.BRS = CON.FDE = 0 */
 270         if (uartclk == 0)
 271                 uartclk = amazon_get_fpi_hz();
 272
 273         amazonasc_ports[0].uartclk = uartclk;
 274
 275         local_irq_save(flags);
 276
 277         /* this setup was probably already done in u-boot */
 278         /* ASC and GPIO Port 1 bits 3 and 4 share the same pins
 279          * P1.3 (RX) in, Alternate 10
 280          * P1.4 (TX) in, Alternate 10
 281          */
 282          amazon_writel_masked(AMAZON_GPIO_P1_DIR, 0x18, 0x10);  //P1.4 output, P1.3 input
 283          amazon_writel_masked(AMAZON_GPIO_P1_ALTSEL0, 0x18, 0x18);              //ALTSETL0 11
 284          amazon_writel_masked(AMAZON_GPIO_P1_ALTSEL1, 0x18, 0);         //ALTSETL1 00
 285          amazon_writel_masked(AMAZON_GPIO_P1_OD, 0x18, 0x10);
 286
 287         /* set up the CLC */
 288         amazon_writel_masked(AMAZON_ASC_CLC, AMAZON_ASC_CLC_DISS, 0);
 289         amazon_writel_masked(AMAZON_ASC_CLC, ASCCLC_RMCMASK, 1 << ASCCLC_RMCOFFSET);
 290
 291         /* asynchronous mode */
 292         con = ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_OEN | ASCCON_PEN;
 293
 294         /* choose the line - there's only one */
 295         amazon_writel(0, AMAZON_ASC_PISEL);
 296         amazon_writel(((AMAZONASC_TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) | ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU,
 297                 AMAZON_ASC_TXFCON);
 298         amazon_writel(((AMAZONASC_RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK) | ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU,
 299                 AMAZON_ASC_RXFCON);
 300         wmb();
 301
 302         amazon_writel_masked(AMAZON_ASC_CON, con, con);
 303
 304         retval = request_irq(AMAZONASC_RIR, amazonasc_rx_int, 0, "asc_rx", port);
 305         if (retval){
 306                 printk("failed to request amazonasc_rx_int\n");
 307                 return retval;
 308         }
 309         retval = request_irq(AMAZONASC_TIR, amazonasc_tx_int, 0, "asc_tx", port);
 310         if (retval){
 311                 printk("failed to request amazonasc_tx_int\n");
 312                 goto err1;
 313         }
 314
 315         retval = request_irq(AMAZONASC_EIR, amazonasc_er_int, 0, "asc_er", port);
 316         if (retval){
 317                 printk("failed to request amazonasc_er_int\n");
 318                 goto err2;
 319         }
 320
 321         local_irq_restore(flags);
 322         return 0;
 323
 324 err2:
 325         free_irq(AMAZONASC_TIR, port);
 326
 327 err1:
 328         free_irq(AMAZONASC_RIR, port);
 329         local_irq_restore(flags);
 330         return retval;
 331 }
 332
 333 static void amazonasc_shutdown(struct uart_port *port)
 334 {
 335         free_irq(AMAZONASC_RIR, port);
 336         free_irq(AMAZONASC_TIR, port);
 337         free_irq(AMAZONASC_EIR, port);
 338         /*
 339          * disable the baudrate generator to disable the ASC
 340          */
 341         amazon_writel(0, AMAZON_ASC_CON);
 342
 343         /* flush and then disable the fifos */
 344         amazon_writel_masked(AMAZON_ASC_RXFCON, ASCRXFCON_RXFFLU, ASCRXFCON_RXFFLU);
 345         amazon_writel_masked(AMAZON_ASC_RXFCON, ASCRXFCON_RXFEN, 0);
 346         amazon_writel_masked(AMAZON_ASC_TXFCON, ASCTXFCON_TXFFLU, ASCTXFCON_TXFFLU);
 347         amazon_writel_masked(AMAZON_ASC_TXFCON, ASCTXFCON_TXFEN, 0);
 348 }
 349
 350 static void amazonasc_set_termios(struct uart_port *port, struct ktermios *new, struct ktermios *old)
 351 {
 352         unsigned int cflag;
 353         unsigned int iflag;
 354         unsigned int baud, quot;
 355         unsigned int con = 0;
 356         unsigned long flags;
 357
 358         cflag = new->c_cflag;
 359         iflag = new->c_iflag;
 360
 361         /* byte size and parity */
 362         switch (cflag & CSIZE) {
 363         /* 7 bits are always with parity */
 364         case CS7: con = ASCCON_M_7ASYNCPAR; break;
 365         /* the ASC only suports 7 and 8 bits */
 366         case CS5:
 367         case CS6:
 368         default:
 369                 if (cflag & PARENB)
 370                         con = ASCCON_M_8ASYNCPAR;
 371                 else
 372                         con = ASCCON_M_8ASYNC;
 373                 break;
 374         }
 375         if (cflag & CSTOPB)
 376                 con |= ASCCON_STP;
 377         if (cflag & PARENB) {
 378                 if (!(cflag & PARODD))
 379                         con &= ~ASCCON_ODD;
 380                 else
 381                         con |= ASCCON_ODD;
 382         }
 383
 384         port->read_status_mask = ASCCON_OE;
 385         if (iflag & INPCK)
 386                 port->read_status_mask |= ASCCON_FE | ASCCON_PE;
 387
 388         port->ignore_status_mask = 0;
 389         if (iflag & IGNPAR)
 390                 port->ignore_status_mask |= ASCCON_FE | ASCCON_PE;
 391
 392         if (iflag & IGNBRK) {
 393                 /*
 394                  * If we're ignoring parity and break indicators,
 395                  * ignore overruns too (for real raw support).
 396                  */
 397                 if (iflag & IGNPAR)
 398                         port->ignore_status_mask |= ASCCON_OE;
 399         }
 400
 401         /*
 402          * Ignore all characters if CREAD is not set.
 403          */
 404         if ((cflag & CREAD) == 0)
 405                 port->ignore_status_mask |= UART_DUMMY_UER_RX;
 406
 407         /* set error signals  - framing, parity  and overrun */
 408         con |= ASCCON_FEN;
 409         con |= ASCCON_OEN;
 410         con |= ASCCON_PEN;
 411         /* enable the receiver */
 412         con |= ASCCON_REN;
 413
 414         /* block the IRQs */
 415         local_irq_save(flags);
 416
 417         /* set up CON */
 418         amazon_writel(con, AMAZON_ASC_CON);
 419
 420         /* Set baud rate - take a divider of 2 into account */
 421     baud = uart_get_baud_rate(port, new, old, 0, port->uartclk/16);
 422         quot = uart_get_divisor(port, baud);
 423         quot = quot/2 - 1;
 424
 425         /* the next 3 probably already happened when we set CON above */
 426         /* disable the baudrate generator */
 427         amazon_writel_masked(AMAZON_ASC_CON, ASCCON_R, 0);
 428         /* make sure the fractional divider is off */
 429         amazon_writel_masked(AMAZON_ASC_CON, ASCCON_FDE, 0);
 430         /* set up to use divisor of 2 */
 431         amazon_writel_masked(AMAZON_ASC_CON, ASCCON_BRS, 0);
 432         /* now we can write the new baudrate into the register */
 433         amazon_writel(quot, AMAZON_ASC_BTR);
 434         /* turn the baudrate generator back on */
 435         amazon_writel_masked(AMAZON_ASC_CON, ASCCON_R, ASCCON_R);
 436
 437         local_irq_restore(flags);
 438 }
 439
 440 static const char *amazonasc_type(struct uart_port *port)
 441 {
 442         return port->type == PORT_AMAZONASC ? "AMAZONASC" : NULL;
 443 }
 444
 445 /*
 446  * Release the memory region(s) being used by 'port'
 447  */
 448 static void amazonasc_release_port(struct uart_port *port)
 449 {
 450         return;
 451 }
 452
 453 /*
 454  * Request the memory region(s) being used by 'port'
 455  */
 456 static int amazonasc_request_port(struct uart_port *port)
 457 {
 458         return 0;
 459 }
 460
 461 /*
 462  * Configure/autoconfigure the port.
 463  */
 464 static void amazonasc_config_port(struct uart_port *port, int flags)
 465 {
 466         if (flags & UART_CONFIG_TYPE) {
 467                 port->type = PORT_AMAZONASC;
 468                 amazonasc_request_port(port);
 469         }
 470 }
 471
 472 /*
 473  * verify the new serial_struct (for TIOCSSERIAL).
 474  */
 475 static int amazonasc_verify_port(struct uart_port *port, struct serial_struct *ser)
 476 {
 477         int ret = 0;
 478         if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMAZONASC)
 479                 ret = -EINVAL;
 480         if (ser->irq < 0 || ser->irq >= NR_IRQS)
 481                 ret = -EINVAL;
 482         if (ser->baud_base < 9600)
 483                 ret = -EINVAL;
 484         return ret;
 485 }
 486
 487 static struct uart_ops amazonasc_pops = {
 488         .tx_empty =             amazonasc_tx_empty,
 489         .set_mctrl =    amazonasc_set_mctrl,
 490         .get_mctrl =    amazonasc_get_mctrl,
 491         .stop_tx =              amazonasc_stop_tx,
 492         .start_tx =             amazonasc_start_tx,
 493         .stop_rx =              amazonasc_stop_rx,
 494         .enable_ms =    amazonasc_enable_ms,
 495         .break_ctl =    amazonasc_break_ctl,
 496         .startup =              amazonasc_startup,
 497         .shutdown =             amazonasc_shutdown,
 498         .set_termios =  amazonasc_set_termios,
 499         .type =                 amazonasc_type,
 500         .release_port = amazonasc_release_port,
 501         .request_port = amazonasc_request_port,
 502         .config_port =  amazonasc_config_port,
 503         .verify_port =  amazonasc_verify_port,
 504 };
 505
 506 static struct uart_port amazonasc_ports[UART_NR] = {
 507         {
 508                 membase:        (void *)AMAZON_ASC,
 509                 mapbase:        AMAZON_ASC,
 510                 iotype:         SERIAL_IO_MEM,
 511                 irq:            AMAZONASC_RIR, /* RIR */
 512                 uartclk:        0, /* filled in dynamically */
 513                 fifosize:       16,
 514                 unused:         { AMAZONASC_TIR, AMAZONASC_EIR}, /* xmit/error/xmit-buffer-empty IRQ */
 515                 type:           PORT_AMAZONASC,
 516                 ops:            &amazonasc_pops,
 517                 flags:          ASYNC_BOOT_AUTOCONF,
 518         },
 519 };
 520
 521 static void amazonasc_console_write(struct console *co, const char *s, u_int count)
 522 {
 523         int i, fifocnt;
 524         unsigned long flags;
 525         local_irq_save(flags);
 526         for (i = 0; i < count;)
 527         {
 528                 /* wait until the FIFO is not full */
 529                 do
 530                 {
 531                         fifocnt = (amazon_readl(AMAZON_ASC_FSTAT) & ASCFSTAT_TXFFLMASK)
 532                                         >> ASCFSTAT_TXFFLOFF;
 533                 } while (fifocnt == AMAZONASC_TXFIFO_FULL);
 534                 if (s[i] == '\0')
 535                 {
 536                         break;
 537                 }
 538                 if (s[i] == '\n')
 539                 {
 540                         amazon_writel('\r', AMAZON_ASC_TBUF);
 541                         do
 542                         {
 543                                 fifocnt = (amazon_readl(AMAZON_ASC_FSTAT) &
 544                                 ASCFSTAT_TXFFLMASK) >> ASCFSTAT_TXFFLOFF;
 545                         } while (fifocnt == AMAZONASC_TXFIFO_FULL);
 546                 }
 547                 amazon_writel(s[i], AMAZON_ASC_TBUF);
 548                 i++;
 549         }
 550
 551         local_irq_restore(flags);
 552 }
 553
 554 static void __init
 555 amazonasc_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits)
 556 {
 557         u_int lcr_h;
 558
 559         lcr_h = amazon_readl(AMAZON_ASC_CON);
 560         /* do this only if the ASC is turned on */
 561         if (lcr_h & ASCCON_R) {
 562                 u_int quot, div, fdiv, frac;
 563
 564                 *parity = 'n';
 565                 if ((lcr_h & ASCCON_MODEMASK) == ASCCON_M_7ASYNCPAR ||
 566                             (lcr_h & ASCCON_MODEMASK) == ASCCON_M_8ASYNCPAR) {
 567                         if (lcr_h & ASCCON_ODD)
 568                                 *parity = 'o';
 569                         else
 570                                 *parity = 'e';
 571                 }
 572
 573                 if ((lcr_h & ASCCON_MODEMASK) == ASCCON_M_7ASYNCPAR)
 574                         *bits = 7;
 575                 else
 576                         *bits = 8;
 577
 578                 quot = amazon_readl(AMAZON_ASC_BTR) + 1;
 579
 580                 /* this gets hairy if the fractional divider is used */
 581                 if (lcr_h & ASCCON_FDE)
 582                 {
 583                         div = 1;
 584                         fdiv = amazon_readl(AMAZON_ASC_FDV);
 585                         if (fdiv == 0)
 586                                 fdiv = 512;
 587                         frac = 512;
 588                 }
 589                 else
 590                 {
 591                         div = lcr_h & ASCCON_BRS ? 3 : 2;
 592                         fdiv = frac = 1;
 593                 }
 594                 /*
 595                  * This doesn't work exactly because we use integer
 596                  * math to calculate baud which results in rounding
 597                  * errors when we try to go from quot -> baud !!
 598                  * Try to make this work for both the fractional divider
 599                  * and the simple divider. Also try to avoid rounding
 600                  * errors using integer math.
 601                  */
 602
 603                 *baud = frac * (port->uartclk / (div * 512 * 16 * quot));
 604                 if (*baud > 1100 && *baud < 2400)
 605                         *baud = 1200;
 606                 if (*baud > 2300 && *baud < 4800)
 607                         *baud = 2400;
 608                 if (*baud > 4700 && *baud < 9600)
 609                         *baud = 4800;
 610                 if (*baud > 9500 && *baud < 19200)
 611                         *baud = 9600;
 612                 if (*baud > 19000 && *baud < 38400)
 613                         *baud = 19200;
 614                 if (*baud > 38400 && *baud < 57600)
 615                         *baud = 38400;
 616                 if (*baud > 57600 && *baud < 115200)
 617                         *baud = 57600;
 618                 if (*baud > 115200 && *baud < 230400)
 619                         *baud = 115200;
 620         }
 621 }
 622
 623 static int __init amazonasc_console_setup(struct console *co, char *options)
 624 {
 625         struct uart_port *port;
 626         int baud = 115200;
 627         int bits = 8;
 628         int parity = 'n';
 629         int flow = 'n';
 630
 631         /* this assumes: CON.BRS = CON.FDE = 0 */
 632         if (uartclk == 0)
 633                 uartclk = amazon_get_fpi_hz();
 634         co->index = 0;
 635         port = &amazonasc_ports[0];
 636         amazonasc_ports[0].uartclk = uartclk;
 637         amazonasc_ports[0].type = PORT_AMAZONASC;
 638
 639         if (options){
 640                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 641         }
 642
 643         return uart_set_options(port, co, baud, parity, bits, flow);
 644 }
 645
 646 static struct uart_driver amazonasc_reg;
 647 static struct console amazonasc_console = {
 648         name:           "ttyS",
 649         write:          amazonasc_console_write,
 650         device:         uart_console_device,
 651         setup:          amazonasc_console_setup,
 652         flags:          CON_PRINTBUFFER,
 653         index:          -1,
 654         data:           &amazonasc_reg,
 655 };
 656
 657 static int __init amazonasc_console_init(void)
 658 {
 659         register_console(&amazonasc_console);
 660         return 0;
 661 }
 662 console_initcall(amazonasc_console_init);
 663
 664 static struct uart_driver amazonasc_reg = {
 665         .owner =                        THIS_MODULE,
 666         .driver_name =          "serial",
 667         .dev_name =                     "ttyS",
 668         .major =                        TTY_MAJOR,
 669         .minor =                        64,
 670         .nr =                           UART_NR,
 671         .cons =                         &amazonasc_console,
 672 };
 673
 674 static int __init amazon_asc_probe(struct platform_device *dev)
 675 {
 676         unsigned char res;
 677         uart_register_driver(&amazonasc_reg);
 678         res = uart_add_one_port(&amazonasc_reg, &amazonasc_ports[0]);
 679         return res;
 680 }
 681
 682 static int __exit amazon_asc_remove(struct platform_device *dev)
 683 {
 684         uart_unregister_driver(&amazonasc_reg);
 685         return 0;
 686 }
 687
 688 static struct platform_driver amazon_asc_driver = {
 689         .probe = amazon_asc_probe,
 690         .remove = amazon_asc_remove,
 691         .driver = {
 692                 .name = "amazon_asc",
 693                 .owner = THIS_MODULE,
 694         },
 695 };
 696
 697 static int __init amazon_asc_init(void)
 698 {
 699         int ret = platform_driver_register(&amazon_asc_driver);
 700         if (ret)
 701                 printk(KERN_WARNING "amazon_asc: error registering platfom driver!\n");
 702         return ret;
 703 }
 704
 705 static void __exit amazon_asc_cleanup(void)
 706 {
 707         platform_driver_unregister(&amazon_asc_driver);
 708 }
 709
 710 module_init(amazon_asc_init);
 711 module_exit(amazon_asc_cleanup);
 712
 713 MODULE_AUTHOR("Gary Jennejohn, Felix Fietkau, John Crispin");
 714 MODULE_DESCRIPTION("MIPS AMAZONASC serial port driver");
 715 MODULE_LICENSE("GPL");
 716