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