arch/mn10300/kernel/mn10300-serial.c

   1 /* MN10300 On-chip serial port UART driver
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11
  12 static const char serial_name[] = "MN10300 Serial driver";
  13 static const char serial_version[] = "mn10300_serial-1.0";
  14 static const char serial_revdate[] = "2007-11-06";
  15
  16 #if defined(CONFIG_MN10300_TTYSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
  17 #define SUPPORT_SYSRQ
  18 #endif
  19
  20 #include <linux/module.h>
  21 #include <linux/serial.h>
  22 #include <linux/circ_buf.h>
  23 #include <linux/errno.h>
  24 #include <linux/signal.h>
  25 #include <linux/sched.h>
  26 #include <linux/timer.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/tty.h>
  29 #include <linux/tty_flip.h>
  30 #include <linux/major.h>
  31 #include <linux/string.h>
  32 #include <linux/ioport.h>
  33 #include <linux/mm.h>
  34 #include <linux/slab.h>
  35 #include <linux/init.h>
  36 #include <linux/console.h>
  37 #include <linux/sysrq.h>
  38
  39 #include <asm/system.h>
  40 #include <asm/io.h>
  41 #include <asm/irq.h>
  42 #include <asm/bitops.h>
  43 #include <asm/serial-regs.h>
  44 #include <unit/timex.h>
  45 #include "mn10300-serial.h"
  46
  47 #ifdef CONFIG_SMP
  48 #undef  GxICR
  49 #define GxICR(X) CROSS_GxICR(X, 0)
  50 #endif /* CONFIG_SMP */
  51
  52 #define kenter(FMT, ...) \
  53         printk(KERN_DEBUG "-->%s(" FMT ")\n", __func__, ##__VA_ARGS__)
  54 #define _enter(FMT, ...) \
  55         no_printk(KERN_DEBUG "-->%s(" FMT ")\n", __func__, ##__VA_ARGS__)
  56 #define kdebug(FMT, ...) \
  57         printk(KERN_DEBUG "--- " FMT "\n", ##__VA_ARGS__)
  58 #define _debug(FMT, ...) \
  59         no_printk(KERN_DEBUG "--- " FMT "\n", ##__VA_ARGS__)
  60 #define kproto(FMT, ...) \
  61         printk(KERN_DEBUG "### MNSERIAL " FMT " ###\n", ##__VA_ARGS__)
  62 #define _proto(FMT, ...) \
  63         no_printk(KERN_DEBUG "### MNSERIAL " FMT " ###\n", ##__VA_ARGS__)
  64
  65 #ifndef CODMSB
  66 /* c_cflag bit meaning */
  67 #define CODMSB  004000000000    /* change Transfer bit-order */
  68 #endif
  69
  70 #define NR_UARTS 3
  71
  72 #ifdef CONFIG_MN10300_TTYSM_CONSOLE
  73 static void mn10300_serial_console_write(struct console *co,
  74                                            const char *s, unsigned count);
  75 static int __init mn10300_serial_console_setup(struct console *co,
  76                                                  char *options);
  77
  78 static struct uart_driver mn10300_serial_driver;
  79 static struct console mn10300_serial_console = {
  80         .name           = "ttySM",
  81         .write          = mn10300_serial_console_write,
  82         .device         = uart_console_device,
  83         .setup          = mn10300_serial_console_setup,
  84         .flags          = CON_PRINTBUFFER,
  85         .index          = -1,
  86         .data           = &mn10300_serial_driver,
  87 };
  88 #endif
  89
  90 static struct uart_driver mn10300_serial_driver = {
  91         .owner          = NULL,
  92         .driver_name    = "mn10300-serial",
  93         .dev_name       = "ttySM",
  94         .major          = TTY_MAJOR,
  95         .minor          = 128,
  96         .nr             = NR_UARTS,
  97 #ifdef CONFIG_MN10300_TTYSM_CONSOLE
  98         .cons           = &mn10300_serial_console,
  99 #endif
 100 };
 101
 102 static unsigned int mn10300_serial_tx_empty(struct uart_port *);
 103 static void mn10300_serial_set_mctrl(struct uart_port *, unsigned int mctrl);
 104 static unsigned int mn10300_serial_get_mctrl(struct uart_port *);
 105 static void mn10300_serial_stop_tx(struct uart_port *);
 106 static void mn10300_serial_start_tx(struct uart_port *);
 107 static void mn10300_serial_send_xchar(struct uart_port *, char ch);
 108 static void mn10300_serial_stop_rx(struct uart_port *);
 109 static void mn10300_serial_enable_ms(struct uart_port *);
 110 static void mn10300_serial_break_ctl(struct uart_port *, int ctl);
 111 static int mn10300_serial_startup(struct uart_port *);
 112 static void mn10300_serial_shutdown(struct uart_port *);
 113 static void mn10300_serial_set_termios(struct uart_port *,
 114                                          struct ktermios *new,
 115                                          struct ktermios *old);
 116 static const char *mn10300_serial_type(struct uart_port *);
 117 static void mn10300_serial_release_port(struct uart_port *);
 118 static int mn10300_serial_request_port(struct uart_port *);
 119 static void mn10300_serial_config_port(struct uart_port *, int);
 120 static int mn10300_serial_verify_port(struct uart_port *,
 121                                         struct serial_struct *);
 122 #ifdef CONFIG_CONSOLE_POLL
 123 static void mn10300_serial_poll_put_char(struct uart_port *, unsigned char);
 124 static int mn10300_serial_poll_get_char(struct uart_port *);
 125 #endif
 126
 127 static const struct uart_ops mn10300_serial_ops = {
 128         .tx_empty       = mn10300_serial_tx_empty,
 129         .set_mctrl      = mn10300_serial_set_mctrl,
 130         .get_mctrl      = mn10300_serial_get_mctrl,
 131         .stop_tx        = mn10300_serial_stop_tx,
 132         .start_tx       = mn10300_serial_start_tx,
 133         .send_xchar     = mn10300_serial_send_xchar,
 134         .stop_rx        = mn10300_serial_stop_rx,
 135         .enable_ms      = mn10300_serial_enable_ms,
 136         .break_ctl      = mn10300_serial_break_ctl,
 137         .startup        = mn10300_serial_startup,
 138         .shutdown       = mn10300_serial_shutdown,
 139         .set_termios    = mn10300_serial_set_termios,
 140         .type           = mn10300_serial_type,
 141         .release_port   = mn10300_serial_release_port,
 142         .request_port   = mn10300_serial_request_port,
 143         .config_port    = mn10300_serial_config_port,
 144         .verify_port    = mn10300_serial_verify_port,
 145 #ifdef CONFIG_CONSOLE_POLL
 146         .poll_put_char  = mn10300_serial_poll_put_char,
 147         .poll_get_char  = mn10300_serial_poll_get_char,
 148 #endif
 149 };
 150
 151 static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id);
 152
 153 /*
 154  * the first on-chip serial port: ttySM0 (aka SIF0)
 155  */
 156 #ifdef CONFIG_MN10300_TTYSM0
 157 struct mn10300_serial_port mn10300_serial_port_sif0 = {
 158         .uart.ops       = &mn10300_serial_ops,
 159         .uart.membase   = (void __iomem *) &SC0CTR,
 160         .uart.mapbase   = (unsigned long) &SC0CTR,
 161         .uart.iotype    = UPIO_MEM,
 162         .uart.irq       = 0,
 163         .uart.uartclk   = 0, /* MN10300_IOCLK, */
 164         .uart.fifosize  = 1,
 165         .uart.flags     = UPF_BOOT_AUTOCONF,
 166         .uart.line      = 0,
 167         .uart.type      = PORT_MN10300,
 168         .uart.lock      =
 169         __SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif0.uart.lock),
 170         .name           = "ttySM0",
 171         ._iobase        = &SC0CTR,
 172         ._control       = &SC0CTR,
 173         ._status        = (volatile u8 *)&SC0STR,
 174         ._intr          = &SC0ICR,
 175         ._rxb           = &SC0RXB,
 176         ._txb           = &SC0TXB,
 177         .rx_name        = "ttySM0:Rx",
 178         .tx_name        = "ttySM0:Tx",
 179 #if defined(CONFIG_MN10300_TTYSM0_TIMER8)
 180         .tm_name        = "ttySM0:Timer8",
 181         ._tmxmd         = &TM8MD,
 182         ._tmxbr         = &TM8BR,
 183         ._tmicr         = &TM8ICR,
 184         .tm_irq         = TM8IRQ,
 185         .div_timer      = MNSCx_DIV_TIMER_16BIT,
 186 #elif defined(CONFIG_MN10300_TTYSM0_TIMER0)
 187         .tm_name        = "ttySM0:Timer0",
 188         ._tmxmd         = &TM0MD,
 189         ._tmxbr         = (volatile u16 *)&TM0BR,
 190         ._tmicr         = &TM0ICR,
 191         .tm_irq         = TM0IRQ,
 192         .div_timer      = MNSCx_DIV_TIMER_8BIT,
 193 #elif defined(CONFIG_MN10300_TTYSM0_TIMER2)
 194         .tm_name        = "ttySM0:Timer2",
 195         ._tmxmd         = &TM2MD,
 196         ._tmxbr         = (volatile u16 *)&TM2BR,
 197         ._tmicr         = &TM2ICR,
 198         .tm_irq         = TM2IRQ,
 199         .div_timer      = MNSCx_DIV_TIMER_8BIT,
 200 #else
 201 #error "Unknown config for ttySM0"
 202 #endif
 203         .rx_irq         = SC0RXIRQ,
 204         .tx_irq         = SC0TXIRQ,
 205         .rx_icr         = &GxICR(SC0RXIRQ),
 206         .tx_icr         = &GxICR(SC0TXIRQ),
 207         .clock_src      = MNSCx_CLOCK_SRC_IOCLK,
 208         .options        = 0,
 209 #ifdef CONFIG_GDBSTUB_ON_TTYSM0
 210         .gdbstub        = 1,
 211 #endif
 212 };
 213 #endif /* CONFIG_MN10300_TTYSM0 */
 214
 215 /*
 216  * the second on-chip serial port: ttySM1 (aka SIF1)
 217  */
 218 #ifdef CONFIG_MN10300_TTYSM1
 219 struct mn10300_serial_port mn10300_serial_port_sif1 = {
 220         .uart.ops       = &mn10300_serial_ops,
 221         .uart.membase   = (void __iomem *) &SC1CTR,
 222         .uart.mapbase   = (unsigned long) &SC1CTR,
 223         .uart.iotype    = UPIO_MEM,
 224         .uart.irq       = 0,
 225         .uart.uartclk   = 0, /* MN10300_IOCLK, */
 226         .uart.fifosize  = 1,
 227         .uart.flags     = UPF_BOOT_AUTOCONF,
 228         .uart.line      = 1,
 229         .uart.type      = PORT_MN10300,
 230         .uart.lock      =
 231         __SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif1.uart.lock),
 232         .name           = "ttySM1",
 233         ._iobase        = &SC1CTR,
 234         ._control       = &SC1CTR,
 235         ._status        = (volatile u8 *)&SC1STR,
 236         ._intr          = &SC1ICR,
 237         ._rxb           = &SC1RXB,
 238         ._txb           = &SC1TXB,
 239         .rx_name        = "ttySM1:Rx",
 240         .tx_name        = "ttySM1:Tx",
 241 #if defined(CONFIG_MN10300_TTYSM1_TIMER9)
 242         .tm_name        = "ttySM1:Timer9",
 243         ._tmxmd         = &TM9MD,
 244         ._tmxbr         = &TM9BR,
 245         ._tmicr         = &TM9ICR,
 246         .tm_irq         = TM9IRQ,
 247         .div_timer      = MNSCx_DIV_TIMER_16BIT,
 248 #elif defined(CONFIG_MN10300_TTYSM1_TIMER3)
 249         .tm_name        = "ttySM1:Timer3",
 250         ._tmxmd         = &TM3MD,
 251         ._tmxbr         = (volatile u16 *)&TM3BR,
 252         ._tmicr         = &TM3ICR,
 253         .tm_irq         = TM3IRQ,
 254         .div_timer      = MNSCx_DIV_TIMER_8BIT,
 255 #elif defined(CONFIG_MN10300_TTYSM1_TIMER12)
 256         .tm_name        = "ttySM1/Timer12",
 257         ._tmxmd         = &TM12MD,
 258         ._tmxbr         = &TM12BR,
 259         ._tmicr         = &TM12ICR,
 260         .tm_irq         = TM12IRQ,
 261         .div_timer      = MNSCx_DIV_TIMER_16BIT,
 262 #else
 263 #error "Unknown config for ttySM1"
 264 #endif
 265         .rx_irq         = SC1RXIRQ,
 266         .tx_irq         = SC1TXIRQ,
 267         .rx_icr         = &GxICR(SC1RXIRQ),
 268         .tx_icr         = &GxICR(SC1TXIRQ),
 269         .clock_src      = MNSCx_CLOCK_SRC_IOCLK,
 270         .options        = 0,
 271 #ifdef CONFIG_GDBSTUB_ON_TTYSM1
 272         .gdbstub        = 1,
 273 #endif
 274 };
 275 #endif /* CONFIG_MN10300_TTYSM1 */
 276
 277 /*
 278  * the third on-chip serial port: ttySM2 (aka SIF2)
 279  */
 280 #ifdef CONFIG_MN10300_TTYSM2
 281 struct mn10300_serial_port mn10300_serial_port_sif2 = {
 282         .uart.ops       = &mn10300_serial_ops,
 283         .uart.membase   = (void __iomem *) &SC2CTR,
 284         .uart.mapbase   = (unsigned long) &SC2CTR,
 285         .uart.iotype    = UPIO_MEM,
 286         .uart.irq       = 0,
 287         .uart.uartclk   = 0, /* MN10300_IOCLK, */
 288         .uart.fifosize  = 1,
 289         .uart.flags     = UPF_BOOT_AUTOCONF,
 290         .uart.line      = 2,
 291 #ifdef CONFIG_MN10300_TTYSM2_CTS
 292         .uart.type      = PORT_MN10300_CTS,
 293 #else
 294         .uart.type      = PORT_MN10300,
 295 #endif
 296         .uart.lock      =
 297         __SPIN_LOCK_UNLOCKED(mn10300_serial_port_sif2.uart.lock),
 298         .name           = "ttySM2",
 299         ._iobase        = &SC2CTR,
 300         ._control       = &SC2CTR,
 301         ._status        = (volatile u8 *)&SC2STR,
 302         ._intr          = &SC2ICR,
 303         ._rxb           = &SC2RXB,
 304         ._txb           = &SC2TXB,
 305         .rx_name        = "ttySM2:Rx",
 306         .tx_name        = "ttySM2:Tx",
 307 #if defined(CONFIG_MN10300_TTYSM2_TIMER10)
 308         .tm_name        = "ttySM2/Timer10",
 309         ._tmxmd         = &TM10MD,
 310         ._tmxbr         = &TM10BR,
 311         ._tmicr         = &TM10ICR,
 312         .tm_irq         = TM10IRQ,
 313         .div_timer      = MNSCx_DIV_TIMER_16BIT,
 314 #elif defined(CONFIG_MN10300_TTYSM2_TIMER9)
 315         .tm_name        = "ttySM2/Timer9",
 316         ._tmxmd         = &TM9MD,
 317         ._tmxbr         = &TM9BR,
 318         ._tmicr         = &TM9ICR,
 319         .tm_irq         = TM9IRQ,
 320         .div_timer      = MNSCx_DIV_TIMER_16BIT,
 321 #elif defined(CONFIG_MN10300_TTYSM2_TIMER1)
 322         .tm_name        = "ttySM2/Timer1",
 323         ._tmxmd         = &TM1MD,
 324         ._tmxbr         = (volatile u16 *)&TM1BR,
 325         ._tmicr         = &TM1ICR,
 326         .tm_irq         = TM1IRQ,
 327         .div_timer      = MNSCx_DIV_TIMER_8BIT,
 328 #elif defined(CONFIG_MN10300_TTYSM2_TIMER3)
 329         .tm_name        = "ttySM2/Timer3",
 330         ._tmxmd         = &TM3MD,
 331         ._tmxbr         = (volatile u16 *)&TM3BR,
 332         ._tmicr         = &TM3ICR,
 333         .tm_irq         = TM3IRQ,
 334         .div_timer      = MNSCx_DIV_TIMER_8BIT,
 335 #else
 336 #error "Unknown config for ttySM2"
 337 #endif
 338         .rx_irq         = SC2RXIRQ,
 339         .tx_irq         = SC2TXIRQ,
 340         .rx_icr         = &GxICR(SC2RXIRQ),
 341         .tx_icr         = &GxICR(SC2TXIRQ),
 342         .clock_src      = MNSCx_CLOCK_SRC_IOCLK,
 343 #ifdef CONFIG_MN10300_TTYSM2_CTS
 344         .options        = MNSCx_OPT_CTS,
 345 #else
 346         .options        = 0,
 347 #endif
 348 #ifdef CONFIG_GDBSTUB_ON_TTYSM2
 349         .gdbstub        = 1,
 350 #endif
 351 };
 352 #endif /* CONFIG_MN10300_TTYSM2 */
 353
 354
 355 /*
 356  * list of available serial ports
 357  */
 358 struct mn10300_serial_port *mn10300_serial_ports[NR_UARTS + 1] = {
 359 #ifdef CONFIG_MN10300_TTYSM0
 360         [0]     = &mn10300_serial_port_sif0,
 361 #endif
 362 #ifdef CONFIG_MN10300_TTYSM1
 363         [1]     = &mn10300_serial_port_sif1,
 364 #endif
 365 #ifdef CONFIG_MN10300_TTYSM2
 366         [2]     = &mn10300_serial_port_sif2,
 367 #endif
 368         [NR_UARTS] = NULL,
 369 };
 370
 371
 372 /*
 373  * we abuse the serial ports' baud timers' interrupt lines to get the ability
 374  * to deliver interrupts to userspace as we use the ports' interrupt lines to
 375  * do virtual DMA on account of the ports having no hardware FIFOs
 376  *
 377  * we can generate an interrupt manually in the assembly stubs by writing to
 378  * the enable and detect bits in the interrupt control register, so all we need
 379  * to do here is disable the interrupt line
 380  *
 381  * note that we can't just leave the line enabled as the baud rate timer *also*
 382  * generates interrupts
 383  */
 384 static void mn10300_serial_mask_ack(unsigned int irq)
 385 {
 386         unsigned long flags;
 387         u16 tmp;
 388
 389         flags = arch_local_cli_save();
 390         GxICR(irq) = GxICR_LEVEL_6;
 391         tmp = GxICR(irq); /* flush write buffer */
 392         arch_local_irq_restore(flags);
 393 }
 394
 395 static void mn10300_serial_chip_mask_ack(struct irq_data *d)
 396 {
 397         mn10300_serial_mask_ack(d->irq);
 398 }
 399
 400 static void mn10300_serial_nop(struct irq_data *d)
 401 {
 402 }
 403
 404 static struct irq_chip mn10300_serial_pic = {
 405         .name           = "mnserial",
 406         .irq_ack        = mn10300_serial_chip_mask_ack,
 407         .irq_mask       = mn10300_serial_chip_mask_ack,
 408         .irq_mask_ack   = mn10300_serial_chip_mask_ack,
 409         .irq_unmask     = mn10300_serial_nop,
 410 };
 411
 412
 413 /*
 414  * serial virtual DMA interrupt jump table
 415  */
 416 struct mn10300_serial_int mn10300_serial_int_tbl[NR_IRQS];
 417
 418 static void mn10300_serial_dis_tx_intr(struct mn10300_serial_port *port)
 419 {
 420         unsigned long flags;
 421         u16 x;
 422
 423         flags = arch_local_cli_save();
 424         *port->tx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
 425         x = *port->tx_icr;
 426         arch_local_irq_restore(flags);
 427 }
 428
 429 static void mn10300_serial_en_tx_intr(struct mn10300_serial_port *port)
 430 {
 431         unsigned long flags;
 432         u16 x;
 433
 434         flags = arch_local_cli_save();
 435         *port->tx_icr =
 436                 NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL) | GxICR_ENABLE;
 437         x = *port->tx_icr;
 438         arch_local_irq_restore(flags);
 439 }
 440
 441 static void mn10300_serial_dis_rx_intr(struct mn10300_serial_port *port)
 442 {
 443         unsigned long flags;
 444         u16 x;
 445
 446         flags = arch_local_cli_save();
 447         *port->rx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
 448         x = *port->rx_icr;
 449         arch_local_irq_restore(flags);
 450 }
 451
 452 /*
 453  * multi-bit equivalent of test_and_clear_bit()
 454  */
 455 static int mask_test_and_clear(volatile u8 *ptr, u8 mask)
 456 {
 457         u32 epsw;
 458         asm volatile("  bclr    %1,(%2)         \n"
 459                      "  mov     epsw,%0         \n"
 460                      : "=d"(epsw) : "d"(mask), "a"(ptr)
 461                      : "cc", "memory");
 462         return !(epsw & EPSW_FLAG_Z);
 463 }
 464
 465 /*
 466  * receive chars from the ring buffer for this serial port
 467  * - must do break detection here (not done in the UART)
 468  */
 469 static void mn10300_serial_receive_interrupt(struct mn10300_serial_port *port)
 470 {
 471         struct uart_icount *icount = &port->uart.icount;
 472         struct tty_struct *tty = port->uart.state->port.tty;
 473         unsigned ix;
 474         int count;
 475         u8 st, ch, push, status, overrun;
 476
 477         _enter("%s", port->name);
 478
 479         push = 0;
 480
 481         count = CIRC_CNT(port->rx_inp, port->rx_outp, MNSC_BUFFER_SIZE);
 482         count = tty_buffer_request_room(tty, count);
 483         if (count == 0) {
 484                 if (!tty->low_latency)
 485                         tty_flip_buffer_push(tty);
 486                 return;
 487         }
 488
 489 try_again:
 490         /* pull chars out of the hat */
 491         ix = port->rx_outp;
 492         if (ix == port->rx_inp) {
 493                 if (push && !tty->low_latency)
 494                         tty_flip_buffer_push(tty);
 495                 return;
 496         }
 497
 498         ch = port->rx_buffer[ix++];
 499         st = port->rx_buffer[ix++];
 500         smp_rmb();
 501         port->rx_outp = ix & (MNSC_BUFFER_SIZE - 1);
 502         port->uart.icount.rx++;
 503
 504         st &= SC01STR_FEF | SC01STR_PEF | SC01STR_OEF;
 505         status = 0;
 506         overrun = 0;
 507
 508         /* the UART doesn't detect BREAK, so we have to do that ourselves
 509          * - it starts as a framing error on a NUL character
 510          * - then we count another two NUL characters before issuing TTY_BREAK
 511          * - then we end on a normal char or one that has all the bottom bits
 512          *   zero and the top bits set
 513          */
 514         switch (port->rx_brk) {
 515         case 0:
 516                 /* not breaking at the moment */
 517                 break;
 518
 519         case 1:
 520                 if (st & SC01STR_FEF && ch == 0) {
 521                         port->rx_brk = 2;
 522                         goto try_again;
 523                 }
 524                 goto not_break;
 525
 526         case 2:
 527                 if (st & SC01STR_FEF && ch == 0) {
 528                         port->rx_brk = 3;
 529                         _proto("Rx Break Detected");
 530                         icount->brk++;
 531                         if (uart_handle_break(&port->uart))
 532                                 goto ignore_char;
 533                         status |= 1 << TTY_BREAK;
 534                         goto insert;
 535                 }
 536                 goto not_break;
 537
 538         default:
 539                 if (st & (SC01STR_FEF | SC01STR_PEF | SC01STR_OEF))
 540                         goto try_again; /* still breaking */
 541
 542                 port->rx_brk = 0; /* end of the break */
 543
 544                 switch (ch) {
 545                 case 0xFF:
 546                 case 0xFE:
 547                 case 0xFC:
 548                 case 0xF8:
 549                 case 0xF0:
 550                 case 0xE0:
 551                 case 0xC0:
 552                 case 0x80:
 553                 case 0x00:
 554                         /* discard char at probable break end */
 555                         goto try_again;
 556                 }
 557                 break;
 558         }
 559
 560 process_errors:
 561         /* handle framing error */
 562         if (st & SC01STR_FEF) {
 563                 if (ch == 0) {
 564                         /* framing error with NUL char is probably a BREAK */
 565                         port->rx_brk = 1;
 566                         goto try_again;
 567                 }
 568
 569                 _proto("Rx Framing Error");
 570                 icount->frame++;
 571                 status |= 1 << TTY_FRAME;
 572         }
 573
 574         /* handle parity error */
 575         if (st & SC01STR_PEF) {
 576                 _proto("Rx Parity Error");
 577                 icount->parity++;
 578                 status = TTY_PARITY;
 579         }
 580
 581         /* handle normal char */
 582         if (status == 0) {
 583                 if (uart_handle_sysrq_char(&port->uart, ch))
 584                         goto ignore_char;
 585                 status = (1 << TTY_NORMAL);
 586         }
 587
 588         /* handle overrun error */
 589         if (st & SC01STR_OEF) {
 590                 if (port->rx_brk)
 591                         goto try_again;
 592
 593                 _proto("Rx Overrun Error");
 594                 icount->overrun++;
 595                 overrun = 1;
 596         }
 597
 598 insert:
 599         status &= port->uart.read_status_mask;
 600
 601         if (!overrun && !(status & port->uart.ignore_status_mask)) {
 602                 int flag;
 603
 604                 if (status & (1 << TTY_BREAK))
 605                         flag = TTY_BREAK;
 606                 else if (status & (1 << TTY_PARITY))
 607                         flag = TTY_PARITY;
 608                 else if (status & (1 << TTY_FRAME))
 609                         flag = TTY_FRAME;
 610                 else
 611                         flag = TTY_NORMAL;
 612
 613                 tty_insert_flip_char(tty, ch, flag);
 614         }
 615
 616         /* overrun is special, since it's reported immediately, and doesn't
 617          * affect the current character
 618          */
 619         if (overrun)
 620                 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
 621
 622         count--;
 623         if (count <= 0) {
 624                 if (!tty->low_latency)
 625                         tty_flip_buffer_push(tty);
 626                 return;
 627         }
 628
 629 ignore_char:
 630         push = 1;
 631         goto try_again;
 632
 633 not_break:
 634         port->rx_brk = 0;
 635         goto process_errors;
 636 }
 637
 638 /*
 639  * handle an interrupt from the serial transmission "virtual DMA" driver
 640  * - note: the interrupt routine will disable its own interrupts when the Tx
 641  *   buffer is empty
 642  */
 643 static void mn10300_serial_transmit_interrupt(struct mn10300_serial_port *port)
 644 {
 645         _enter("%s", port->name);
 646
 647         if (!port->uart.state || !port->uart.state->port.tty) {
 648                 mn10300_serial_dis_tx_intr(port);
 649                 return;
 650         }
 651
 652         if (uart_tx_stopped(&port->uart) ||
 653             uart_circ_empty(&port->uart.state->xmit))
 654                 mn10300_serial_dis_tx_intr(port);
 655
 656         if (uart_circ_chars_pending(&port->uart.state->xmit) < WAKEUP_CHARS)
 657                 uart_write_wakeup(&port->uart);
 658 }
 659
 660 /*
 661  * deal with a change in the status of the CTS line
 662  */
 663 static void mn10300_serial_cts_changed(struct mn10300_serial_port *port, u8 st)
 664 {
 665         u16 ctr;
 666
 667         port->tx_cts = st;
 668         port->uart.icount.cts++;
 669
 670         /* flip the CTS state selector flag to interrupt when it changes
 671          * back */
 672         ctr = *port->_control;
 673         ctr ^= SC2CTR_TWS;
 674         *port->_control = ctr;
 675
 676         uart_handle_cts_change(&port->uart, st & SC2STR_CTS);
 677         wake_up_interruptible(&port->uart.state->port.delta_msr_wait);
 678 }
 679
 680 /*
 681  * handle a virtual interrupt generated by the lower level "virtual DMA"
 682  * routines (irq is the baud timer interrupt)
 683  */
 684 static irqreturn_t mn10300_serial_interrupt(int irq, void *dev_id)
 685 {
 686         struct mn10300_serial_port *port = dev_id;
 687         u8 st;
 688
 689         spin_lock(&port->uart.lock);
 690
 691         if (port->intr_flags) {
 692                 _debug("INT %s: %x", port->name, port->intr_flags);
 693
 694                 if (mask_test_and_clear(&port->intr_flags, MNSCx_RX_AVAIL))
 695                         mn10300_serial_receive_interrupt(port);
 696
 697                 if (mask_test_and_clear(&port->intr_flags,
 698                                         MNSCx_TX_SPACE | MNSCx_TX_EMPTY))
 699                         mn10300_serial_transmit_interrupt(port);
 700         }
 701
 702         /* the only modem control line amongst the whole lot is CTS on
 703          * serial port 2 */
 704         if (port->type == PORT_MN10300_CTS) {
 705                 st = *port->_status;
 706                 if ((port->tx_cts ^ st) & SC2STR_CTS)
 707                         mn10300_serial_cts_changed(port, st);
 708         }
 709
 710         spin_unlock(&port->uart.lock);
 711
 712         return IRQ_HANDLED;
 713 }
 714
 715 /*
 716  * return indication of whether the hardware transmit buffer is empty
 717  */
 718 static unsigned int mn10300_serial_tx_empty(struct uart_port *_port)
 719 {
 720         struct mn10300_serial_port *port =
 721                 container_of(_port, struct mn10300_serial_port, uart);
 722
 723         _enter("%s", port->name);
 724
 725         return (*port->_status & (SC01STR_TXF | SC01STR_TBF)) ?
 726                 0 : TIOCSER_TEMT;
 727 }
 728
 729 /*
 730  * set the modem control lines (we don't have any)
 731  */
 732 static void mn10300_serial_set_mctrl(struct uart_port *_port,
 733                                      unsigned int mctrl)
 734 {
 735         struct mn10300_serial_port *port __attribute__ ((unused)) =
 736                 container_of(_port, struct mn10300_serial_port, uart);
 737
 738         _enter("%s,%x", port->name, mctrl);
 739 }
 740
 741 /*
 742  * get the modem control line statuses
 743  */
 744 static unsigned int mn10300_serial_get_mctrl(struct uart_port *_port)
 745 {
 746         struct mn10300_serial_port *port =
 747                 container_of(_port, struct mn10300_serial_port, uart);
 748
 749         _enter("%s", port->name);
 750
 751         if (port->type == PORT_MN10300_CTS && !(*port->_status & SC2STR_CTS))
 752                 return TIOCM_CAR | TIOCM_DSR;
 753
 754         return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
 755 }
 756
 757 /*
 758  * stop transmitting characters
 759  */
 760 static void mn10300_serial_stop_tx(struct uart_port *_port)
 761 {
 762         struct mn10300_serial_port *port =
 763                 container_of(_port, struct mn10300_serial_port, uart);
 764
 765         _enter("%s", port->name);
 766
 767         /* disable the virtual DMA */
 768         mn10300_serial_dis_tx_intr(port);
 769 }
 770
 771 /*
 772  * start transmitting characters
 773  * - jump-start transmission if it has stalled
 774  *   - enable the serial Tx interrupt (used by the virtual DMA controller)
 775  *   - force an interrupt to happen if necessary
 776  */
 777 static void mn10300_serial_start_tx(struct uart_port *_port)
 778 {
 779         struct mn10300_serial_port *port =
 780                 container_of(_port, struct mn10300_serial_port, uart);
 781
 782         u16 x;
 783
 784         _enter("%s{%lu}",
 785                port->name,
 786                CIRC_CNT(&port->uart.state->xmit.head,
 787                         &port->uart.state->xmit.tail,
 788                         UART_XMIT_SIZE));
 789
 790         /* kick the virtual DMA controller */
 791         arch_local_cli();
 792         x = *port->tx_icr;
 793         x |= GxICR_ENABLE;
 794
 795         if (*port->_status & SC01STR_TBF)
 796                 x &= ~(GxICR_REQUEST | GxICR_DETECT);
 797         else
 798                 x |= GxICR_REQUEST | GxICR_DETECT;
 799
 800         _debug("CTR=%04hx ICR=%02hx STR=%04x TMD=%02hx TBR=%04hx ICR=%04hx",
 801                *port->_control, *port->_intr, *port->_status,
 802                *port->_tmxmd,
 803                (port->div_timer == MNSCx_DIV_TIMER_8BIT) ?
 804                    *(volatile u8 *)port->_tmxbr : *port->_tmxbr,
 805                *port->tx_icr);
 806
 807         *port->tx_icr = x;
 808         x = *port->tx_icr;
 809         arch_local_sti();
 810 }
 811
 812 /*
 813  * transmit a high-priority XON/XOFF character
 814  */
 815 static void mn10300_serial_send_xchar(struct uart_port *_port, char ch)
 816 {
 817         struct mn10300_serial_port *port =
 818                 container_of(_port, struct mn10300_serial_port, uart);
 819
 820         _enter("%s,%02x", port->name, ch);
 821
 822         if (likely(port->gdbstub)) {
 823                 port->tx_xchar = ch;
 824                 if (ch)
 825                         mn10300_serial_en_tx_intr(port);
 826         }
 827 }
 828
 829 /*
 830  * stop receiving characters
 831  * - called whilst the port is being closed
 832  */
 833 static void mn10300_serial_stop_rx(struct uart_port *_port)
 834 {
 835         struct mn10300_serial_port *port =
 836                 container_of(_port, struct mn10300_serial_port, uart);
 837
 838         u16 ctr;
 839
 840         _enter("%s", port->name);
 841
 842         ctr = *port->_control;
 843         ctr &= ~SC01CTR_RXE;
 844         *port->_control = ctr;
 845
 846         mn10300_serial_dis_rx_intr(port);
 847 }
 848
 849 /*
 850  * enable modem status interrupts
 851  */
 852 static void mn10300_serial_enable_ms(struct uart_port *_port)
 853 {
 854         struct mn10300_serial_port *port =
 855                 container_of(_port, struct mn10300_serial_port, uart);
 856
 857         u16 ctr, cts;
 858
 859         _enter("%s", port->name);
 860
 861         if (port->type == PORT_MN10300_CTS) {
 862                 /* want to interrupt when CTS goes low if CTS is now high and
 863                  * vice versa
 864                  */
 865                 port->tx_cts = *port->_status;
 866
 867                 cts = (port->tx_cts & SC2STR_CTS) ?
 868                         SC2CTR_TWE : SC2CTR_TWE | SC2CTR_TWS;
 869
 870                 ctr = *port->_control;
 871                 ctr &= ~SC2CTR_TWS;
 872                 ctr |= cts;
 873                 *port->_control = ctr;
 874
 875                 mn10300_serial_en_tx_intr(port);
 876         }
 877 }
 878
 879 /*
 880  * transmit or cease transmitting a break signal
 881  */
 882 static void mn10300_serial_break_ctl(struct uart_port *_port, int ctl)
 883 {
 884         struct mn10300_serial_port *port =
 885                 container_of(_port, struct mn10300_serial_port, uart);
 886
 887         _enter("%s,%d", port->name, ctl);
 888
 889         if (ctl) {
 890                 /* tell the virtual DMA handler to assert BREAK */
 891                 port->tx_break = 1;
 892                 mn10300_serial_en_tx_intr(port);
 893         } else {
 894                 port->tx_break = 0;
 895                 *port->_control &= ~SC01CTR_BKE;
 896                 mn10300_serial_en_tx_intr(port);
 897         }
 898 }
 899
 900 /*
 901  * grab the interrupts and enable the port for reception
 902  */
 903 static int mn10300_serial_startup(struct uart_port *_port)
 904 {
 905         struct mn10300_serial_port *port =
 906                 container_of(_port, struct mn10300_serial_port, uart);
 907         struct mn10300_serial_int *pint;
 908
 909         _enter("%s{%d}", port->name, port->gdbstub);
 910
 911         if (unlikely(port->gdbstub))
 912                 return -EBUSY;
 913
 914         /* allocate an Rx buffer for the virtual DMA handler */
 915         port->rx_buffer = kmalloc(MNSC_BUFFER_SIZE, GFP_KERNEL);
 916         if (!port->rx_buffer)
 917                 return -ENOMEM;
 918
 919         port->rx_inp = port->rx_outp = 0;
 920
 921         /* finally, enable the device */
 922         *port->_intr = SC01ICR_TI;
 923         *port->_control |= SC01CTR_TXE | SC01CTR_RXE;
 924
 925         pint = &mn10300_serial_int_tbl[port->rx_irq];
 926         pint->port = port;
 927         pint->vdma = mn10300_serial_vdma_rx_handler;
 928         pint = &mn10300_serial_int_tbl[port->tx_irq];
 929         pint->port = port;
 930         pint->vdma = mn10300_serial_vdma_tx_handler;
 931
 932         set_intr_level(port->rx_irq,
 933                 NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL));
 934         set_intr_level(port->tx_irq,
 935                 NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL));
 936         irq_set_chip(port->tm_irq, &mn10300_serial_pic);
 937
 938         if (request_irq(port->rx_irq, mn10300_serial_interrupt,
 939                         IRQF_DISABLED, port->rx_name, port) < 0)
 940                 goto error;
 941
 942         if (request_irq(port->tx_irq, mn10300_serial_interrupt,
 943                         IRQF_DISABLED, port->tx_name, port) < 0)
 944                 goto error2;
 945
 946         if (request_irq(port->tm_irq, mn10300_serial_interrupt,
 947                         IRQF_DISABLED, port->tm_name, port) < 0)
 948                 goto error3;
 949         mn10300_serial_mask_ack(port->tm_irq);
 950
 951         return 0;
 952
 953 error3:
 954         free_irq(port->tx_irq, port);
 955 error2:
 956         free_irq(port->rx_irq, port);
 957 error:
 958         kfree(port->rx_buffer);
 959         port->rx_buffer = NULL;
 960         return -EBUSY;
 961 }
 962
 963 /*
 964  * shutdown the port and release interrupts
 965  */
 966 static void mn10300_serial_shutdown(struct uart_port *_port)
 967 {
 968         u16 x;
 969         struct mn10300_serial_port *port =
 970                 container_of(_port, struct mn10300_serial_port, uart);
 971
 972         _enter("%s", port->name);
 973
 974         /* disable the serial port and its baud rate timer */
 975         port->tx_break = 0;
 976         *port->_control &= ~(SC01CTR_TXE | SC01CTR_RXE | SC01CTR_BKE);
 977         *port->_tmxmd = 0;
 978
 979         if (port->rx_buffer) {
 980                 void *buf = port->rx_buffer;
 981                 port->rx_buffer = NULL;
 982                 kfree(buf);
 983         }
 984
 985         /* disable all intrs */
 986         free_irq(port->tm_irq, port);
 987         free_irq(port->rx_irq, port);
 988         free_irq(port->tx_irq, port);
 989
 990         arch_local_cli();
 991         *port->rx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
 992         x = *port->rx_icr;
 993         *port->tx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
 994         x = *port->tx_icr;
 995         arch_local_sti();
 996 }
 997
 998 /*
 999  * this routine is called to set the UART divisor registers to match the
1000  * specified baud rate for a serial port.
1001  */
1002 static void mn10300_serial_change_speed(struct mn10300_serial_port *port,
1003                                           struct ktermios *new,
1004                                           struct ktermios *old)
1005 {
1006         unsigned long flags;
1007         unsigned long ioclk = port->ioclk;
1008         unsigned cflag;
1009         int baud, bits, xdiv, tmp;
1010         u16 tmxbr, scxctr;
1011         u8 tmxmd, battempt;
1012         u8 div_timer = port->div_timer;
1013
1014         _enter("%s{%lu}", port->name, ioclk);
1015
1016         /* byte size and parity */
1017         cflag = new->c_cflag;
1018         switch (cflag & CSIZE) {
1019         case CS7: scxctr = SC01CTR_CLN_7BIT; bits = 9;  break;
1020         case CS8: scxctr = SC01CTR_CLN_8BIT; bits = 10; break;
1021         default:  scxctr = SC01CTR_CLN_8BIT; bits = 10; break;
1022         }
1023
1024         if (cflag & CSTOPB) {
1025                 scxctr |= SC01CTR_STB_2BIT;
1026                 bits++;
1027         }
1028
1029         if (cflag & PARENB) {
1030                 bits++;
1031                 if (cflag & PARODD)
1032                         scxctr |= SC01CTR_PB_ODD;
1033 #ifdef CMSPAR
1034                 else if (cflag & CMSPAR)
1035                         scxctr |= SC01CTR_PB_FIXED0;
1036 #endif
1037                 else
1038                         scxctr |= SC01CTR_PB_EVEN;
1039         }
1040
1041         /* Determine divisor based on baud rate */
1042         battempt = 0;
1043
1044         switch (port->uart.line) {
1045 #ifdef CONFIG_MN10300_TTYSM0
1046         case 0: /* ttySM0 */
1047 #if   defined(CONFIG_MN10300_TTYSM0_TIMER8)
1048                 scxctr |= SC0CTR_CK_TM8UFLOW_8;
1049 #elif defined(CONFIG_MN10300_TTYSM0_TIMER0)
1050                 scxctr |= SC0CTR_CK_TM0UFLOW_8;
1051 #elif defined(CONFIG_MN10300_TTYSM0_TIMER2)
1052                 scxctr |= SC0CTR_CK_TM2UFLOW_8;
1053 #else
1054 #error "Unknown config for ttySM0"
1055 #endif
1056                 break;
1057 #endif /* CONFIG_MN10300_TTYSM0 */
1058
1059 #ifdef CONFIG_MN10300_TTYSM1
1060         case 1: /* ttySM1 */
1061 #if defined(CONFIG_AM33_2) || defined(CONFIG_AM33_3)
1062 #if   defined(CONFIG_MN10300_TTYSM1_TIMER9)
1063                 scxctr |= SC1CTR_CK_TM9UFLOW_8;
1064 #elif defined(CONFIG_MN10300_TTYSM1_TIMER3)
1065                 scxctr |= SC1CTR_CK_TM3UFLOW_8;
1066 #else
1067 #error "Unknown config for ttySM1"
1068 #endif
1069 #else /* CONFIG_AM33_2 || CONFIG_AM33_3 */
1070 #if defined(CONFIG_MN10300_TTYSM1_TIMER12)
1071                 scxctr |= SC1CTR_CK_TM12UFLOW_8;
1072 #else
1073 #error "Unknown config for ttySM1"
1074 #endif
1075 #endif /* CONFIG_AM33_2 || CONFIG_AM33_3 */
1076                 break;
1077 #endif /* CONFIG_MN10300_TTYSM1 */
1078
1079 #ifdef CONFIG_MN10300_TTYSM2
1080         case 2: /* ttySM2 */
1081 #if defined(CONFIG_AM33_2)
1082 #if   defined(CONFIG_MN10300_TTYSM2_TIMER10)
1083                 scxctr |= SC2CTR_CK_TM10UFLOW;
1084 #else
1085 #error "Unknown config for ttySM2"
1086 #endif
1087 #else /* CONFIG_AM33_2 */
1088 #if   defined(CONFIG_MN10300_TTYSM2_TIMER9)
1089                 scxctr |= SC2CTR_CK_TM9UFLOW_8;
1090 #elif defined(CONFIG_MN10300_TTYSM2_TIMER1)
1091                 scxctr |= SC2CTR_CK_TM1UFLOW_8;
1092 #elif defined(CONFIG_MN10300_TTYSM2_TIMER3)
1093                 scxctr |= SC2CTR_CK_TM3UFLOW_8;
1094 #else
1095 #error "Unknown config for ttySM2"
1096 #endif
1097 #endif /* CONFIG_AM33_2 */
1098                 break;
1099 #endif /* CONFIG_MN10300_TTYSM2 */
1100
1101         default:
1102                 break;
1103         }
1104
1105 try_alternative:
1106         baud = uart_get_baud_rate(&port->uart, new, old, 0,
1107                                   port->ioclk / 8);
1108
1109         _debug("ALT %d [baud %d]", battempt, baud);
1110
1111         if (!baud)
1112                 baud = 9600;    /* B0 transition handled in rs_set_termios */
1113         xdiv = 1;
1114         if (baud == 134) {
1115                 baud = 269;     /* 134 is really 134.5 */
1116                 xdiv = 2;
1117         }
1118
1119         if (baud == 38400 &&
1120             (port->uart.flags & UPF_SPD_MASK) == UPF_SPD_CUST
1121             ) {
1122                 _debug("CUSTOM %u", port->uart.custom_divisor);
1123
1124                 if (div_timer == MNSCx_DIV_TIMER_16BIT) {
1125                         if (port->uart.custom_divisor <= 65535) {
1126                                 tmxmd = TM8MD_SRC_IOCLK;
1127                                 tmxbr = port->uart.custom_divisor;
1128                                 port->uart.uartclk = ioclk;
1129                                 goto timer_okay;
1130                         }
1131                         if (port->uart.custom_divisor / 8 <= 65535) {
1132                                 tmxmd = TM8MD_SRC_IOCLK_8;
1133                                 tmxbr = port->uart.custom_divisor / 8;
1134                                 port->uart.custom_divisor = tmxbr * 8;
1135                                 port->uart.uartclk = ioclk / 8;
1136                                 goto timer_okay;
1137                         }
1138                         if (port->uart.custom_divisor / 32 <= 65535) {
1139                                 tmxmd = TM8MD_SRC_IOCLK_32;
1140                                 tmxbr = port->uart.custom_divisor / 32;
1141                                 port->uart.custom_divisor = tmxbr * 32;
1142                                 port->uart.uartclk = ioclk / 32;
1143                                 goto timer_okay;
1144                         }
1145
1146                 } else if (div_timer == MNSCx_DIV_TIMER_8BIT) {
1147                         if (port->uart.custom_divisor <= 255) {
1148                                 tmxmd = TM2MD_SRC_IOCLK;
1149                                 tmxbr = port->uart.custom_divisor;
1150                                 port->uart.uartclk = ioclk;
1151                                 goto timer_okay;
1152                         }
1153                         if (port->uart.custom_divisor / 8 <= 255) {
1154                                 tmxmd = TM2MD_SRC_IOCLK_8;
1155                                 tmxbr = port->uart.custom_divisor / 8;
1156                                 port->uart.custom_divisor = tmxbr * 8;
1157                                 port->uart.uartclk = ioclk / 8;
1158                                 goto timer_okay;
1159                         }
1160                         if (port->uart.custom_divisor / 32 <= 255) {
1161                                 tmxmd = TM2MD_SRC_IOCLK_32;
1162                                 tmxbr = port->uart.custom_divisor / 32;
1163                                 port->uart.custom_divisor = tmxbr * 32;
1164                                 port->uart.uartclk = ioclk / 32;
1165                                 goto timer_okay;
1166                         }
1167                 }
1168         }
1169
1170         switch (div_timer) {
1171         case MNSCx_DIV_TIMER_16BIT:
1172                 port->uart.uartclk = ioclk;
1173                 tmxmd = TM8MD_SRC_IOCLK;
1174                 tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
1175                 if (tmp > 0 && tmp <= 65535)
1176                         goto timer_okay;
1177
1178                 port->uart.uartclk = ioclk / 8;
1179                 tmxmd = TM8MD_SRC_IOCLK_8;
1180                 tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
1181                 if (tmp > 0 && tmp <= 65535)
1182                         goto timer_okay;
1183
1184                 port->uart.uartclk = ioclk / 32;
1185                 tmxmd = TM8MD_SRC_IOCLK_32;
1186                 tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
1187                 if (tmp > 0 && tmp <= 65535)
1188                         goto timer_okay;
1189                 break;
1190
1191         case MNSCx_DIV_TIMER_8BIT:
1192                 port->uart.uartclk = ioclk;
1193                 tmxmd = TM2MD_SRC_IOCLK;
1194                 tmxbr = tmp = (ioclk / (baud * xdiv) + 4) / 8 - 1;
1195                 if (tmp > 0 && tmp <= 255)
1196                         goto timer_okay;
1197
1198                 port->uart.uartclk = ioclk / 8;
1199                 tmxmd = TM2MD_SRC_IOCLK_8;
1200                 tmxbr = tmp = (ioclk / (baud * 8 * xdiv) + 4) / 8 - 1;
1201                 if (tmp > 0 && tmp <= 255)
1202                         goto timer_okay;
1203
1204                 port->uart.uartclk = ioclk / 32;
1205                 tmxmd = TM2MD_SRC_IOCLK_32;
1206                 tmxbr = tmp = (ioclk / (baud * 32 * xdiv) + 4) / 8 - 1;
1207                 if (tmp > 0 && tmp <= 255)
1208                         goto timer_okay;
1209                 break;
1210
1211         default:
1212                 BUG();
1213                 return;
1214         }
1215
1216         /* refuse to change to a baud rate we can't support */
1217         _debug("CAN'T SUPPORT");
1218
1219         switch (battempt) {
1220         case 0:
1221                 if (old) {
1222                         new->c_cflag &= ~CBAUD;
1223                         new->c_cflag |= (old->c_cflag & CBAUD);
1224                         battempt = 1;
1225                         goto try_alternative;
1226                 }
1227
1228         case 1:
1229                 /* as a last resort, if the quotient is zero, default to 9600
1230                  * bps */
1231                 new->c_cflag &= ~CBAUD;
1232                 new->c_cflag |= B9600;
1233                 battempt = 2;
1234                 goto try_alternative;
1235
1236         default:
1237                 /* hmmm... can't seem to support 9600 either
1238                  * - we could try iterating through the speeds we know about to
1239                  *   find the lowest
1240                  */
1241                 new->c_cflag &= ~CBAUD;
1242                 new->c_cflag |= B0;
1243
1244                 if (div_timer == MNSCx_DIV_TIMER_16BIT)
1245                         tmxmd = TM8MD_SRC_IOCLK_32;
1246                 else if (div_timer == MNSCx_DIV_TIMER_8BIT)
1247                         tmxmd = TM2MD_SRC_IOCLK_32;
1248                 tmxbr = 1;
1249
1250                 port->uart.uartclk = ioclk / 32;
1251                 break;
1252         }
1253 timer_okay:
1254
1255         _debug("UARTCLK: %u / %hu", port->uart.uartclk, tmxbr);
1256
1257         /* make the changes */
1258         spin_lock_irqsave(&port->uart.lock, flags);
1259
1260         uart_update_timeout(&port->uart, new->c_cflag, baud);
1261
1262         /* set the timer to produce the required baud rate */
1263         switch (div_timer) {
1264         case MNSCx_DIV_TIMER_16BIT:
1265                 *port->_tmxmd = 0;
1266                 *port->_tmxbr = tmxbr;
1267                 *port->_tmxmd = TM8MD_INIT_COUNTER;
1268                 *port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
1269                 break;
1270
1271         case MNSCx_DIV_TIMER_8BIT:
1272                 *port->_tmxmd = 0;
1273                 *(volatile u8 *) port->_tmxbr = (u8) tmxbr;
1274                 *port->_tmxmd = TM2MD_INIT_COUNTER;
1275                 *port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
1276                 break;
1277         }
1278
1279         /* CTS flow control flag and modem status interrupts */
1280         scxctr &= ~(SC2CTR_TWE | SC2CTR_TWS);
1281
1282         if (port->type == PORT_MN10300_CTS && cflag & CRTSCTS) {
1283                 /* want to interrupt when CTS goes low if CTS is now
1284                  * high and vice versa
1285                  */
1286                 port->tx_cts = *port->_status;
1287
1288                 if (port->tx_cts & SC2STR_CTS)
1289                         scxctr |= SC2CTR_TWE;
1290                 else
1291                         scxctr |= SC2CTR_TWE | SC2CTR_TWS;
1292         }
1293
1294         /* set up parity check flag */
1295         port->uart.read_status_mask = (1 << TTY_NORMAL) | (1 << TTY_OVERRUN);
1296         if (new->c_iflag & INPCK)
1297                 port->uart.read_status_mask |=
1298                         (1 << TTY_PARITY) | (1 << TTY_FRAME);
1299         if (new->c_iflag & (BRKINT | PARMRK))
1300                 port->uart.read_status_mask |= (1 << TTY_BREAK);
1301
1302         /* characters to ignore */
1303         port->uart.ignore_status_mask = 0;
1304         if (new->c_iflag & IGNPAR)
1305                 port->uart.ignore_status_mask |=
1306                         (1 << TTY_PARITY) | (1 << TTY_FRAME);
1307         if (new->c_iflag & IGNBRK) {
1308                 port->uart.ignore_status_mask |= (1 << TTY_BREAK);
1309                 /*
1310                  * If we're ignoring parity and break indicators,
1311                  * ignore overruns to (for real raw support).
1312                  */
1313                 if (new->c_iflag & IGNPAR)
1314                         port->uart.ignore_status_mask |= (1 << TTY_OVERRUN);
1315         }
1316
1317         /* Ignore all characters if CREAD is not set */
1318         if ((new->c_cflag & CREAD) == 0)
1319                 port->uart.ignore_status_mask |= (1 << TTY_NORMAL);
1320
1321         scxctr |= *port->_control & (SC01CTR_TXE | SC01CTR_RXE | SC01CTR_BKE);
1322         *port->_control = scxctr;
1323
1324         spin_unlock_irqrestore(&port->uart.lock, flags);
1325 }
1326
1327 /*
1328  * set the terminal I/O parameters
1329  */
1330 static void mn10300_serial_set_termios(struct uart_port *_port,
1331                                          struct ktermios *new,
1332                                          struct ktermios *old)
1333 {
1334         struct mn10300_serial_port *port =
1335                 container_of(_port, struct mn10300_serial_port, uart);
1336
1337         _enter("%s,%p,%p", port->name, new, old);
1338
1339         mn10300_serial_change_speed(port, new, old);
1340
1341         /* handle turning off CRTSCTS */
1342         if (!(new->c_cflag & CRTSCTS)) {
1343                 u16 ctr = *port->_control;
1344                 ctr &= ~SC2CTR_TWE;
1345                 *port->_control = ctr;
1346         }
1347
1348         /* change Transfer bit-order (LSB/MSB) */
1349         if (new->c_cflag & CODMSB)
1350                 *port->_control |= SC01CTR_OD_MSBFIRST; /* MSB MODE */
1351         else
1352                 *port->_control &= ~SC01CTR_OD_MSBFIRST; /* LSB MODE */
1353 }
1354
1355 /*
1356  * return description of port type
1357  */
1358 static const char *mn10300_serial_type(struct uart_port *_port)
1359 {
1360         struct mn10300_serial_port *port =
1361                 container_of(_port, struct mn10300_serial_port, uart);
1362
1363         if (port->uart.type == PORT_MN10300_CTS)
1364                 return "MN10300 SIF_CTS";
1365
1366         return "MN10300 SIF";
1367 }
1368
1369 /*
1370  * release I/O and memory regions in use by port
1371  */
1372 static void mn10300_serial_release_port(struct uart_port *_port)
1373 {
1374         struct mn10300_serial_port *port =
1375                 container_of(_port, struct mn10300_serial_port, uart);
1376
1377         _enter("%s", port->name);
1378
1379         release_mem_region((unsigned long) port->_iobase, 16);
1380 }
1381
1382 /*
1383  * request I/O and memory regions for port
1384  */
1385 static int mn10300_serial_request_port(struct uart_port *_port)
1386 {
1387         struct mn10300_serial_port *port =
1388                 container_of(_port, struct mn10300_serial_port, uart);
1389
1390         _enter("%s", port->name);
1391
1392         request_mem_region((unsigned long) port->_iobase, 16, port->name);
1393         return 0;
1394 }
1395
1396 /*
1397  * configure the type and reserve the ports
1398  */
1399 static void mn10300_serial_config_port(struct uart_port *_port, int type)
1400 {
1401         struct mn10300_serial_port *port =
1402                 container_of(_port, struct mn10300_serial_port, uart);
1403
1404         _enter("%s", port->name);
1405
1406         port->uart.type = PORT_MN10300;
1407
1408         if (port->options & MNSCx_OPT_CTS)
1409                 port->uart.type = PORT_MN10300_CTS;
1410
1411         mn10300_serial_request_port(_port);
1412 }
1413
1414 /*
1415  * verify serial parameters are suitable for this port type
1416  */
1417 static int mn10300_serial_verify_port(struct uart_port *_port,
1418                                         struct serial_struct *ss)
1419 {
1420         struct mn10300_serial_port *port =
1421                 container_of(_port, struct mn10300_serial_port, uart);
1422         void *mapbase = (void *) (unsigned long) port->uart.mapbase;
1423
1424         _enter("%s", port->name);
1425
1426         /* these things may not be changed */
1427         if (ss->irq             != port->uart.irq       ||
1428             ss->port            != port->uart.iobase    ||
1429             ss->io_type         != port->uart.iotype    ||
1430             ss->iomem_base      != mapbase ||
1431             ss->iomem_reg_shift != port->uart.regshift  ||
1432             ss->hub6            != port->uart.hub6      ||
1433             ss->xmit_fifo_size  != port->uart.fifosize)
1434                 return -EINVAL;
1435
1436         /* type may be changed on a port that supports CTS */
1437         if (ss->type != port->uart.type) {
1438                 if (!(port->options & MNSCx_OPT_CTS))
1439                         return -EINVAL;
1440
1441                 if (ss->type != PORT_MN10300 &&
1442                     ss->type != PORT_MN10300_CTS)
1443                         return -EINVAL;
1444         }
1445
1446         return 0;
1447 }
1448
1449 /*
1450  * initialise the MN10300 on-chip UARTs
1451  */
1452 static int __init mn10300_serial_init(void)
1453 {
1454         struct mn10300_serial_port *port;
1455         int ret, i;
1456
1457         printk(KERN_INFO "%s version %s (%s)\n",
1458                serial_name, serial_version, serial_revdate);
1459
1460 #if defined(CONFIG_MN10300_TTYSM2) && defined(CONFIG_AM33_2)
1461         {
1462                 int tmp;
1463                 SC2TIM = 8; /* make the baud base of timer 2 IOCLK/8 */
1464                 tmp = SC2TIM;
1465         }
1466 #endif
1467
1468         set_intr_stub(NUM2EXCEP_IRQ_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL),
1469                 mn10300_serial_vdma_interrupt);
1470
1471         ret = uart_register_driver(&mn10300_serial_driver);
1472         if (!ret) {
1473                 for (i = 0 ; i < NR_PORTS ; i++) {
1474                         port = mn10300_serial_ports[i];
1475                         if (!port || port->gdbstub)
1476                                 continue;
1477
1478                         switch (port->clock_src) {
1479                         case MNSCx_CLOCK_SRC_IOCLK:
1480                                 port->ioclk = MN10300_IOCLK;
1481                                 break;
1482
1483 #ifdef MN10300_IOBCLK
1484                         case MNSCx_CLOCK_SRC_IOBCLK:
1485                                 port->ioclk = MN10300_IOBCLK;
1486                                 break;
1487 #endif
1488                         default:
1489                                 BUG();
1490                         }
1491
1492                         ret = uart_add_one_port(&mn10300_serial_driver,
1493                                                 &port->uart);
1494
1495                         if (ret < 0) {
1496                                 _debug("ERROR %d", -ret);
1497                                 break;
1498                         }
1499                 }
1500
1501                 if (ret)
1502                         uart_unregister_driver(&mn10300_serial_driver);
1503         }
1504
1505         return ret;
1506 }
1507
1508 __initcall(mn10300_serial_init);
1509
1510
1511 #ifdef CONFIG_MN10300_TTYSM_CONSOLE
1512
1513 /*
1514  * print a string to the serial port without disturbing the real user of the
1515  * port too much
1516  * - the console must be locked by the caller
1517  */
1518 static void mn10300_serial_console_write(struct console *co,
1519                                            const char *s, unsigned count)
1520 {
1521         struct mn10300_serial_port *port;
1522         unsigned i;
1523         u16 scxctr, txicr, tmp;
1524         u8 tmxmd;
1525
1526         port = mn10300_serial_ports[co->index];
1527
1528         /* firstly hijack the serial port from the "virtual DMA" controller */
1529         arch_local_cli();
1530         txicr = *port->tx_icr;
1531         *port->tx_icr = NUM2GxICR_LEVEL(CONFIG_MN10300_SERIAL_IRQ_LEVEL);
1532         tmp = *port->tx_icr;
1533         arch_local_sti();
1534
1535         /* the transmitter may be disabled */
1536         scxctr = *port->_control;
1537         if (!(scxctr & SC01CTR_TXE)) {
1538                 /* restart the UART clock */
1539                 tmxmd = *port->_tmxmd;
1540
1541                 switch (port->div_timer) {
1542                 case MNSCx_DIV_TIMER_16BIT:
1543                         *port->_tmxmd = 0;
1544                         *port->_tmxmd = TM8MD_INIT_COUNTER;
1545                         *port->_tmxmd = tmxmd | TM8MD_COUNT_ENABLE;
1546                         break;
1547
1548                 case MNSCx_DIV_TIMER_8BIT:
1549                         *port->_tmxmd = 0;
1550                         *port->_tmxmd = TM2MD_INIT_COUNTER;
1551                         *port->_tmxmd = tmxmd | TM2MD_COUNT_ENABLE;
1552                         break;
1553                 }
1554
1555                 /* enable the transmitter */
1556                 *port->_control = (scxctr & ~SC01CTR_BKE) | SC01CTR_TXE;
1557
1558         } else if (scxctr & SC01CTR_BKE) {
1559                 /* stop transmitting BREAK */
1560                 *port->_control = (scxctr & ~SC01CTR_BKE);
1561         }
1562
1563         /* send the chars into the serial port (with LF -> LFCR conversion) */
1564         for (i = 0; i < count; i++) {
1565                 char ch = *s++;
1566
1567                 while (*port->_status & SC01STR_TBF)
1568                         continue;
1569                 *(u8 *) port->_txb = ch;
1570
1571                 if (ch == 0x0a) {
1572                         while (*port->_status & SC01STR_TBF)
1573                                 continue;
1574                         *(u8 *) port->_txb = 0xd;
1575                 }
1576         }
1577
1578         /* can't let the transmitter be turned off if it's actually
1579          * transmitting */
1580         while (*port->_status & (SC01STR_TXF | SC01STR_TBF))
1581                 continue;
1582
1583         /* disable the transmitter if we re-enabled it */
1584         if (!(scxctr & SC01CTR_TXE))
1585                 *port->_control = scxctr;
1586
1587         arch_local_cli();
1588         *port->tx_icr = txicr;
1589         tmp = *port->tx_icr;
1590         arch_local_sti();
1591 }
1592
1593 /*
1594  * set up a serial port as a console
1595  * - construct a cflag setting for the first rs_open()
1596  * - initialize the serial port
1597  * - return non-zero if we didn't find a serial port.
1598  */
1599 static int __init mn10300_serial_console_setup(struct console *co,
1600                                                  char *options)
1601 {
1602         struct mn10300_serial_port *port;
1603         int i, parity = 'n', baud = 9600, bits = 8, flow = 0;
1604
1605         for (i = 0 ; i < NR_PORTS ; i++) {
1606                 port = mn10300_serial_ports[i];
1607                 if (port && !port->gdbstub && port->uart.line == co->index)
1608                         goto found_device;
1609         }
1610
1611         return -ENODEV;
1612
1613 found_device:
1614         switch (port->clock_src) {
1615         case MNSCx_CLOCK_SRC_IOCLK:
1616                 port->ioclk = MN10300_IOCLK;
1617                 break;
1618
1619 #ifdef MN10300_IOBCLK
1620         case MNSCx_CLOCK_SRC_IOBCLK:
1621                 port->ioclk = MN10300_IOBCLK;
1622                 break;
1623 #endif
1624         default:
1625                 BUG();
1626         }
1627
1628         if (options)
1629                 uart_parse_options(options, &baud, &parity, &bits, &flow);
1630
1631         return uart_set_options(&port->uart, co, baud, parity, bits, flow);
1632 }
1633
1634 /*
1635  * register console
1636  */
1637 static int __init mn10300_serial_console_init(void)
1638 {
1639         register_console(&mn10300_serial_console);
1640         return 0;
1641 }
1642
1643 console_initcall(mn10300_serial_console_init);
1644 #endif
1645
1646 #ifdef CONFIG_CONSOLE_POLL
1647 /*
1648  * Polled character reception for the kernel debugger
1649  */
1650 static int mn10300_serial_poll_get_char(struct uart_port *_port)
1651 {
1652         struct mn10300_serial_port *port =
1653                 container_of(_port, struct mn10300_serial_port, uart);
1654         unsigned ix;
1655         u8 st, ch;
1656
1657         _enter("%s", port->name);
1658
1659         do {
1660                 /* pull chars out of the hat */
1661                 ix = port->rx_outp;
1662                 if (ix == port->rx_inp)
1663                         return NO_POLL_CHAR;
1664
1665                 ch = port->rx_buffer[ix++];
1666                 st = port->rx_buffer[ix++];
1667                 smp_rmb();
1668                 port->rx_outp = ix & (MNSC_BUFFER_SIZE - 1);
1669
1670         } while (st & (SC01STR_FEF | SC01STR_PEF | SC01STR_OEF));
1671
1672         return ch;
1673 }
1674
1675
1676 /*
1677  * Polled character transmission for the kernel debugger
1678  */
1679 static void mn10300_serial_poll_put_char(struct uart_port *_port,
1680                                          unsigned char ch)
1681 {
1682         struct mn10300_serial_port *port =
1683                 container_of(_port, struct mn10300_serial_port, uart);
1684         u8 intr, tmp;
1685
1686         /* wait for the transmitter to finish anything it might be doing (and
1687          * this includes the virtual DMA handler, so it might take a while) */
1688         while (*port->_status & (SC01STR_TBF | SC01STR_TXF))
1689                 continue;
1690
1691         /* disable the Tx ready interrupt */
1692         intr = *port->_intr;
1693         *port->_intr = intr & ~SC01ICR_TI;
1694         tmp = *port->_intr;
1695
1696         if (ch == 0x0a) {
1697                 *(u8 *) port->_txb = 0x0d;
1698                 while (*port->_status & SC01STR_TBF)
1699                         continue;
1700         }
1701
1702         *(u8 *) port->_txb = ch;
1703         while (*port->_status & SC01STR_TBF)
1704                 continue;
1705
1706         /* restore the Tx interrupt flag */
1707         *port->_intr = intr;
1708         tmp = *port->_intr;
1709 }
1710
1711 #endif /* CONFIG_CONSOLE_POLL */