target/linux/adm5120-2.6/files/drivers/serial/adm5120_uart.c

   1 /*
   2  *      Serial driver for ADM5120 SoC
   3  *
   4  *      Derived from drivers/serial/uart00.c
   5  *      Copyright 2001 Altera Corporation
   6  *
   7  *      Some pieces are derived from the ADMtek 2.4 serial driver.
   8  *      Copyright (C) ADMtek Incorporated, 2003
   9  *              daniell@admtek.com.tw
  10  *      Which again was derived from drivers/char/serial.c
  11  *      Copyright (C) Linus Torvalds et al.
  12  *
  13  *      Copyright Jeroen Vreeken (pe1rxq@amsat.org), 2005
  14  */
  15
  16 #include <linux/autoconf.h>
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/ioport.h>
  21 #include <linux/serial.h>
  22 #include <linux/serial_core.h>
  23 #include <linux/tty.h>
  24 #include <linux/tty_flip.h>
  25 #include <linux/console.h>
  26
  27 #define ADM5120_UART_BASE0              0x12600000
  28 #define ADM5120_UART_BASE1              0x12800000
  29 #define ADM5120_UART_SIZE               0x20
  30
  31 #define ADM5120_UART_IRQ0               1
  32 #define ADM5120_UART_IRQ1               2
  33
  34 #define ADM5120_UART_REG(base, reg) \
  35         (*(volatile u32 *)KSEG1ADDR((base)+(reg)))
  36
  37 #define ADM5120_UARTCLK_FREQ            62500000
  38 #define ADM5120_UART_BAUDDIV(rate)      ((unsigned long)(ADM5120_UARTCLK_FREQ/(16*(rate)) - 1))
  39
  40 #define ADM5120_UART_BAUD115200         ADM5120_UART_BAUDDIV(115200)
  41
  42 #define ADM5120_UART_DATA               0x00
  43 #define ADM5120_UART_RS                 0x04
  44 #define ADM5120_UART_LCR_H              0x08
  45 #define ADM5120_UART_LCR_M              0x0c
  46 #define ADM5120_UART_LCR_L              0x10
  47 #define ADM5120_UART_CR                 0x14
  48 #define ADM5120_UART_FR                 0x18
  49 #define ADM5120_UART_IR                 0x1c
  50
  51 #define ADM5120_UART_FE                 0x01
  52 #define ADM5120_UART_PE                 0x02
  53 #define ADM5120_UART_BE                 0x04
  54 #define ADM5120_UART_OE                 0x08
  55 #define ADM5120_UART_ERR                0x0f
  56 #define ADM5120_UART_FIFO_EN            0x10
  57 #define ADM5120_UART_EN                 0x01
  58 #define ADM5120_UART_TIE                0x20
  59 #define ADM5120_UART_RIE                0x50
  60 #define ADM5120_UART_IE                 0x78
  61 #define ADM5120_UART_CTS                0x01
  62 #define ADM5120_UART_DSR                0x02
  63 #define ADM5120_UART_DCD                0x04
  64 #define ADM5120_UART_TXFF               0x20
  65 #define ADM5120_UART_TXFE               0x80
  66 #define ADM5120_UART_RXFE               0x10
  67 #define ADM5120_UART_BRK                0x01
  68 #define ADM5120_UART_PEN                0x02
  69 #define ADM5120_UART_EPS                0x04
  70 #define ADM5120_UART_STP2               0x08
  71 #define ADM5120_UART_W5                 0x00
  72 #define ADM5120_UART_W6                 0x20
  73 #define ADM5120_UART_W7                 0x40
  74 #define ADM5120_UART_W8                 0x60
  75 #define ADM5120_UART_MIS                0x01
  76 #define ADM5120_UART_RIS                0x02
  77 #define ADM5120_UART_TIS                0x04
  78 #define ADM5120_UART_RTIS               0x08
  79
  80 static void adm5120ser_stop_tx(struct uart_port *port)
  81 {
  82         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_TIE;
  83 }
  84
  85 static void adm5120ser_irq_rx(struct uart_port *port)
  86 {
  87         struct tty_struct *tty = port->info->tty;
  88         unsigned int status, ch, rds, flg, ignored = 0;
  89
  90         status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
  91         while (!(status & ADM5120_UART_RXFE)) {
  92                 /*
  93                  * We need to read rds before reading the
  94                  * character from the fifo
  95                  */
  96                 rds = ADM5120_UART_REG(port->iobase, ADM5120_UART_RS);
  97                 ch = ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA);
  98                 port->icount.rx++;
  99
 100                 if (tty->low_latency)
 101                         tty_flip_buffer_push(tty);
 102
 103                 flg = TTY_NORMAL;
 104
 105                 /*
 106                  * Note that the error handling code is
 107                  * out of the main execution path
 108                  */
 109                 if (rds & ADM5120_UART_ERR)
 110                         goto handle_error;
 111                 if (uart_handle_sysrq_char(port, ch))
 112                         goto ignore_char;
 113
 114         error_return:
 115                 tty_insert_flip_char(tty, ch, flg);
 116
 117         ignore_char:
 118                 status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
 119         }
 120  out:
 121         tty_flip_buffer_push(tty);
 122         return;
 123
 124  handle_error:
 125         ADM5120_UART_REG(port->iobase, ADM5120_UART_RS) = 0xff;
 126         if (rds & ADM5120_UART_BE) {
 127                 port->icount.brk++;
 128                 if (uart_handle_break(port))
 129                         goto ignore_char;
 130         } else if (rds & ADM5120_UART_PE)
 131                 port->icount.parity++;
 132         else if (rds & ADM5120_UART_FE)
 133                 port->icount.frame++;
 134         if (rds & ADM5120_UART_OE)
 135                 port->icount.overrun++;
 136
 137         if (rds & port->ignore_status_mask) {
 138                 if (++ignored > 100)
 139                         goto out;
 140                 goto ignore_char;
 141         }
 142         rds &= port->read_status_mask;
 143
 144         if (rds & ADM5120_UART_BE)
 145                 flg = TTY_BREAK;
 146         else if (rds & ADM5120_UART_PE)
 147                 flg = TTY_PARITY;
 148         else if (rds & ADM5120_UART_FE)
 149                 flg = TTY_FRAME;
 150
 151         if (rds & ADM5120_UART_OE) {
 152                 /*
 153                  * CHECK: does overrun affect the current character?
 154                  * ASSUMPTION: it does not.
 155                  */
 156                 tty_insert_flip_char(tty, ch, flg);
 157                 ch = 0;
 158                 flg = TTY_OVERRUN;
 159         }
 160 #ifdef CONFIG_MAGIC_SYSRQ
 161         port->sysrq = 0;
 162 #endif
 163         goto error_return;
 164 }
 165
 166 static void adm5120ser_irq_tx(struct uart_port *port)
 167 {
 168         struct circ_buf *xmit = &port->info->xmit;
 169         int count;
 170
 171         if (port->x_char) {
 172                 ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA) =
 173                     port->x_char;
 174                 port->icount.tx++;
 175                 port->x_char = 0;
 176                 return;
 177         }
 178         if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
 179                 adm5120ser_stop_tx(port);
 180                 return;
 181         }
 182
 183         count = port->fifosize >> 1;
 184         do {
 185                 ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA) =
 186                     xmit->buf[xmit->tail];
 187                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 188                 port->icount.tx++;
 189                 if (uart_circ_empty(xmit))
 190                         break;
 191         } while (--count > 0);
 192
 193         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 194                 uart_write_wakeup(port);
 195
 196         if (uart_circ_empty(xmit))
 197                 adm5120ser_stop_tx(port);
 198 }
 199
 200 static void adm5120ser_irq_modem(struct uart_port *port)
 201 {
 202         unsigned int status;
 203
 204         status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
 205
 206         if (status & ADM5120_UART_DCD)
 207                 uart_handle_dcd_change(port, status & ADM5120_UART_DCD);
 208
 209         if (status & ADM5120_UART_DSR)
 210                 port->icount.dsr++;
 211
 212         if (status & ADM5120_UART_CTS)
 213                 uart_handle_cts_change(port, status & ADM5120_UART_CTS);
 214
 215         wake_up_interruptible(&port->info->delta_msr_wait);
 216 }
 217
 218 static irqreturn_t adm5120ser_irq(int irq, void *dev_id)
 219 {
 220         struct uart_port *port = dev_id;
 221         unsigned long ir = ADM5120_UART_REG(port->iobase, ADM5120_UART_IR);
 222
 223         if (ir & (ADM5120_UART_RIS | ADM5120_UART_RTIS))
 224                 adm5120ser_irq_rx(port);
 225         if (ir & ADM5120_UART_TIS)
 226                 adm5120ser_irq_tx(port);
 227         if (ir & ADM5120_UART_MIS) {
 228                 adm5120ser_irq_modem(port);
 229                 ADM5120_UART_REG(port->iobase, ADM5120_UART_IR) = 0xff;
 230         }
 231
 232         return IRQ_HANDLED;
 233 }
 234
 235 static unsigned int adm5120ser_tx_empty(struct uart_port *port)
 236 {
 237         unsigned int fr = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
 238         return (fr & ADM5120_UART_TXFE) ? TIOCSER_TEMT : 0;
 239 }
 240
 241 static void adm5120ser_set_mctrl(struct uart_port *port, unsigned int mctrl)
 242 {
 243 }
 244
 245 static unsigned int adm5120ser_get_mctrl(struct uart_port *port)
 246 {
 247         unsigned int result = 0;
 248         unsigned int fr = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
 249
 250         if (fr & ADM5120_UART_CTS)
 251                 result |= TIOCM_CTS;
 252         if (fr & ADM5120_UART_DSR)
 253                 result |= TIOCM_DSR;
 254         if (fr & ADM5120_UART_DCD)
 255                 result |= TIOCM_CAR;
 256         return result;
 257 }
 258
 259 static void adm5120ser_start_tx(struct uart_port *port)
 260 {
 261         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) |= ADM5120_UART_TIE;
 262 }
 263
 264 static void adm5120ser_stop_rx(struct uart_port *port)
 265 {
 266         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_RIE;
 267 }
 268
 269 static void adm5120ser_enable_ms(struct uart_port *port)
 270 {
 271 }
 272
 273 static void adm5120ser_break_ctl(struct uart_port *port, int break_state)
 274 {
 275         unsigned long flags;
 276         unsigned long lcrh;
 277
 278         spin_lock_irqsave(&port->lock, flags);
 279         lcrh = ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H);
 280         if (break_state == -1)
 281                 lcrh |= ADM5120_UART_BRK;
 282         else
 283                 lcrh &= ~ADM5120_UART_BRK;
 284         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) = lcrh;
 285         spin_unlock_irqrestore(&port->lock, flags);
 286 }
 287
 288 static int adm5120ser_startup(struct uart_port *port)
 289 {
 290         int ret;
 291
 292         ret = request_irq(port->irq, adm5120ser_irq, 0, "ADM5120 UART", port);
 293         if (ret) {
 294                 printk(KERN_ERR "Couldn't get irq %d\n", port->irq);
 295                 return ret;
 296         }
 297         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) |=
 298             ADM5120_UART_FIFO_EN;
 299         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) |=
 300             ADM5120_UART_EN | ADM5120_UART_IE;
 301         return 0;
 302 }
 303
 304 static void adm5120ser_shutdown(struct uart_port *port)
 305 {
 306         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_IE;
 307         free_irq(port->irq, port);
 308 }
 309
 310 static void adm5120ser_set_termios(struct uart_port *port,
 311     struct termios *termios, struct termios *old)
 312 {
 313         unsigned int baud, quot, lcrh;
 314         unsigned long flags;
 315
 316         termios->c_cflag |= CREAD;
 317
 318         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
 319         quot = uart_get_divisor(port, baud);
 320
 321         lcrh = ADM5120_UART_FIFO_EN;
 322         switch (termios->c_cflag & CSIZE) {
 323                 case CS5:
 324                         lcrh |= ADM5120_UART_W5;
 325                         break;
 326                 case CS6:
 327                         lcrh |= ADM5120_UART_W6;
 328                         break;
 329                 case CS7:
 330                         lcrh |= ADM5120_UART_W7;
 331                         break;
 332                 default:
 333                         lcrh |= ADM5120_UART_W8;
 334                         break;
 335         }
 336         if (termios->c_cflag & CSTOPB)
 337                 lcrh |= ADM5120_UART_STP2;
 338         if (termios->c_cflag & PARENB) {
 339                 lcrh |= ADM5120_UART_PEN;
 340                 if (!(termios->c_cflag & PARODD))
 341                         lcrh |= ADM5120_UART_EPS;
 342         }
 343
 344         spin_lock_irqsave(port->lock, flags);
 345
 346         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) = lcrh;
 347
 348         /*
 349          * Update the per-port timeout.
 350          */
 351         uart_update_timeout(port, termios->c_cflag, baud);
 352
 353         port->read_status_mask = ADM5120_UART_OE;
 354         if (termios->c_iflag & INPCK)
 355                 port->read_status_mask |= ADM5120_UART_FE | ADM5120_UART_PE;
 356         if (termios->c_iflag & (BRKINT | PARMRK))
 357                 port->read_status_mask |= ADM5120_UART_BE;
 358
 359         /*
 360          * Characters to ignore
 361          */
 362         port->ignore_status_mask = 0;
 363         if (termios->c_iflag & IGNPAR)
 364                 port->ignore_status_mask |= ADM5120_UART_FE | ADM5120_UART_PE;
 365         if (termios->c_iflag & IGNBRK) {
 366                 port->ignore_status_mask |= ADM5120_UART_BE;
 367                 /*
 368                  * If we're ignoring parity and break indicators,
 369                  * ignore overruns to (for real raw support).
 370                  */
 371                 if (termios->c_iflag & IGNPAR)
 372                         port->ignore_status_mask |= ADM5120_UART_OE;
 373         }
 374
 375         quot = ADM5120_UART_BAUD115200;
 376         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_L) = quot & 0xff;
 377         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_M) = quot >> 8;
 378
 379         spin_unlock_irqrestore(&port->lock, flags);
 380 }
 381
 382 static const char *adm5120ser_type(struct uart_port *port)
 383 {
 384         return port->type == PORT_ADM5120 ? "ADM5120" : NULL;
 385 }
 386
 387 static void adm5120ser_config_port(struct uart_port *port, int flags)
 388 {
 389         if (flags & UART_CONFIG_TYPE)
 390                 port->type = PORT_ADM5120;
 391 }
 392
 393 static void adm5120ser_release_port(struct uart_port *port)
 394 {
 395         release_mem_region(port->iobase, ADM5120_UART_SIZE);
 396 }
 397
 398 static int adm5120ser_request_port(struct uart_port *port)
 399 {
 400         return request_mem_region(port->iobase, ADM5120_UART_SIZE,
 401             "adm5120-uart") != NULL ? 0 : -EBUSY;
 402 }
 403
 404 static struct uart_ops adm5120ser_ops = {
 405         .tx_empty =     adm5120ser_tx_empty,
 406         .set_mctrl =    adm5120ser_set_mctrl,
 407         .get_mctrl =    adm5120ser_get_mctrl,
 408         .stop_tx =      adm5120ser_stop_tx,
 409         .start_tx =     adm5120ser_start_tx,
 410         .stop_rx =      adm5120ser_stop_rx,
 411         .enable_ms =    adm5120ser_enable_ms,
 412         .break_ctl =    adm5120ser_break_ctl,
 413         .startup =      adm5120ser_startup,
 414         .shutdown =     adm5120ser_shutdown,
 415         .set_termios =  adm5120ser_set_termios,
 416         .type =         adm5120ser_type,
 417         .config_port =  adm5120ser_config_port,
 418         .release_port = adm5120ser_release_port,
 419         .request_port = adm5120ser_request_port,
 420 };
 421
 422 static void adm5120console_put(const char c)
 423 {
 424         while ((ADM5120_UART_REG(ADM5120_UART_BASE0, ADM5120_UART_FR) &
 425              ADM5120_UART_TXFF) != 0);
 426         ADM5120_UART_REG(ADM5120_UART_BASE0, ADM5120_UART_DATA) = c;
 427 }
 428
 429 static void adm5120console_write(struct console *con, const char *s,
 430     unsigned int count)
 431 {
 432         while (count--) {
 433                 if (*s == '\n')
 434                         adm5120console_put('\r');
 435                 adm5120console_put(*s);
 436                 s++;
 437         }
 438 }
 439
 440 static int __init adm5120console_setup(struct console *con, char *options)
 441 {
 442         /* Set to 115200 baud, 8N1 and enable FIFO */
 443         ADM5120_UART_REG(ADM5120_UART_BASE0, ADM5120_UART_LCR_L) =
 444             ADM5120_UART_BAUD115200 & 0xff;
 445         ADM5120_UART_REG(ADM5120_UART_BASE0, ADM5120_UART_LCR_M) =
 446             ADM5120_UART_BAUD115200 >> 8;
 447         ADM5120_UART_REG(ADM5120_UART_BASE0, ADM5120_UART_LCR_H) =
 448             ADM5120_UART_W8 | ADM5120_UART_FIFO_EN;
 449         /* Enable port */
 450         ADM5120_UART_REG(ADM5120_UART_BASE0, ADM5120_UART_CR) =
 451             ADM5120_UART_EN;
 452
 453         return 0;
 454 }
 455
 456 static struct uart_driver adm5120ser_reg;
 457
 458 static struct console adm5120_serconsole = {
 459         .name =         "ttyS",
 460         .write =        adm5120console_write,
 461         .device =       uart_console_device,
 462         .setup =        adm5120console_setup,
 463         .flags =        CON_PRINTBUFFER,
 464         .cflag =        B115200 | CS8 | CREAD,
 465         .index =        0,
 466         .data =         &adm5120ser_reg,
 467 };
 468
 469 static int __init adm5120console_init(void)
 470 {
 471         register_console(&adm5120_serconsole);
 472         return 0;
 473 }
 474
 475 console_initcall(adm5120console_init);
 476
 477
 478 static struct uart_port adm5120ser_ports[] = {
 479         {
 480                 .iobase =       ADM5120_UART_BASE0,
 481                 .irq =          ADM5120_UART_IRQ0,
 482                 .uartclk =      ADM5120_UARTCLK_FREQ,
 483                 .fifosize =     16,
 484                 .ops =          &adm5120ser_ops,
 485                 .line =         0,
 486                 .flags =        ASYNC_BOOT_AUTOCONF,
 487         },
 488 #if (CONFIG_ADM5120_NR_UARTS > 1)
 489         {
 490                 .iobase =       ADM5120_UART_BASE1,
 491                 .irq =          ADM5120_UART_IRQ1,
 492                 .uartclk =      ADM5120_UARTCLK_FREQ,
 493                 .fifosize =     16,
 494                 .ops =          &adm5120ser_ops,
 495                 .line =         1,
 496                 .flags =        ASYNC_BOOT_AUTOCONF,
 497         },
 498 #endif
 499 };
 500
 501 static struct uart_driver adm5120ser_reg = {
 502         .owner  =       THIS_MODULE,
 503         .driver_name =  "ttyS",
 504         .dev_name =     "ttyS",
 505         .major =        TTY_MAJOR,
 506         .minor =        64,
 507         .nr =           CONFIG_ADM5120_NR_UARTS,
 508         .cons =         &adm5120_serconsole,
 509 };
 510
 511 static int __init adm5120ser_init(void)
 512 {
 513         int ret, i;
 514
 515         ret = uart_register_driver(&adm5120ser_reg);
 516         if (!ret) {
 517                 for (i = 0; i < CONFIG_ADM5120_NR_UARTS; i++)
 518                         uart_add_one_port(&adm5120ser_reg, &adm5120ser_ports[i]);
 519         }
 520
 521         return ret;
 522 }
 523
 524 __initcall(adm5120ser_init);