target/linux/adm5120/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 #include <asm/mach-adm5120/adm5120_defs.h>
  28 #include <asm/mach-adm5120/adm5120_irq.h>
  29
  30 #define ADM5120_UART_REG(base, reg) \
  31         (*(volatile u32 *)KSEG1ADDR((base)+(reg)))
  32
  33 #define ADM5120_UARTCLK_FREQ            62500000
  34 #define ADM5120_UART_BAUDDIV(rate)      ((unsigned long)(ADM5120_UARTCLK_FREQ/(16*(rate)) - 1))
  35
  36 #define ADM5120_UART_BAUD115200         ADM5120_UART_BAUDDIV(115200)
  37
  38 #define ADM5120_UART_DATA               0x00
  39 #define ADM5120_UART_RS                 0x04
  40 #define ADM5120_UART_LCR_H              0x08
  41 #define ADM5120_UART_LCR_M              0x0c
  42 #define ADM5120_UART_LCR_L              0x10
  43 #define ADM5120_UART_CR                 0x14
  44 #define ADM5120_UART_FR                 0x18
  45 #define ADM5120_UART_IR                 0x1c
  46
  47 #define ADM5120_UART_FE                 0x01
  48 #define ADM5120_UART_PE                 0x02
  49 #define ADM5120_UART_BE                 0x04
  50 #define ADM5120_UART_OE                 0x08
  51 #define ADM5120_UART_ERR                0x0f
  52 #define ADM5120_UART_FIFO_EN            0x10
  53 #define ADM5120_UART_EN                 0x01
  54 #define ADM5120_UART_TIE                0x20
  55 #define ADM5120_UART_RIE                0x50
  56 #define ADM5120_UART_IE                 0x78
  57 #define ADM5120_UART_CTS                0x01
  58 #define ADM5120_UART_DSR                0x02
  59 #define ADM5120_UART_DCD                0x04
  60 #define ADM5120_UART_TXFF               0x20
  61 #define ADM5120_UART_TXFE               0x80
  62 #define ADM5120_UART_RXFE               0x10
  63 #define ADM5120_UART_BRK                0x01
  64 #define ADM5120_UART_PEN                0x02
  65 #define ADM5120_UART_EPS                0x04
  66 #define ADM5120_UART_STP2               0x08
  67 #define ADM5120_UART_W5                 0x00
  68 #define ADM5120_UART_W6                 0x20
  69 #define ADM5120_UART_W7                 0x40
  70 #define ADM5120_UART_W8                 0x60
  71 #define ADM5120_UART_MIS                0x01
  72 #define ADM5120_UART_RIS                0x02
  73 #define ADM5120_UART_TIS                0x04
  74 #define ADM5120_UART_RTIS               0x08
  75
  76 static void adm5120ser_stop_tx(struct uart_port *port)
  77 {
  78         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_TIE;
  79 }
  80
  81 static void adm5120ser_irq_rx(struct uart_port *port)
  82 {
  83         struct tty_struct *tty = port->info->tty;
  84         unsigned int status, ch, rds, flg, ignored = 0;
  85
  86         status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
  87         while (!(status & ADM5120_UART_RXFE)) {
  88                 /*
  89                  * We need to read rds before reading the
  90                  * character from the fifo
  91                  */
  92                 rds = ADM5120_UART_REG(port->iobase, ADM5120_UART_RS);
  93                 ch = ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA);
  94                 port->icount.rx++;
  95
  96                 if (tty->low_latency)
  97                         tty_flip_buffer_push(tty);
  98
  99                 flg = TTY_NORMAL;
 100
 101                 /*
 102                  * Note that the error handling code is
 103                  * out of the main execution path
 104                  */
 105                 if (rds & ADM5120_UART_ERR)
 106                         goto handle_error;
 107                 if (uart_handle_sysrq_char(port, ch))
 108                         goto ignore_char;
 109
 110         error_return:
 111                 tty_insert_flip_char(tty, ch, flg);
 112
 113         ignore_char:
 114                 status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
 115         }
 116  out:
 117         tty_flip_buffer_push(tty);
 118         return;
 119
 120  handle_error:
 121         ADM5120_UART_REG(port->iobase, ADM5120_UART_RS) = 0xff;
 122         if (rds & ADM5120_UART_BE) {
 123                 port->icount.brk++;
 124                 if (uart_handle_break(port))
 125                         goto ignore_char;
 126         } else if (rds & ADM5120_UART_PE)
 127                 port->icount.parity++;
 128         else if (rds & ADM5120_UART_FE)
 129                 port->icount.frame++;
 130         if (rds & ADM5120_UART_OE)
 131                 port->icount.overrun++;
 132
 133         if (rds & port->ignore_status_mask) {
 134                 if (++ignored > 100)
 135                         goto out;
 136                 goto ignore_char;
 137         }
 138         rds &= port->read_status_mask;
 139
 140         if (rds & ADM5120_UART_BE)
 141                 flg = TTY_BREAK;
 142         else if (rds & ADM5120_UART_PE)
 143                 flg = TTY_PARITY;
 144         else if (rds & ADM5120_UART_FE)
 145                 flg = TTY_FRAME;
 146
 147         if (rds & ADM5120_UART_OE) {
 148                 /*
 149                  * CHECK: does overrun affect the current character?
 150                  * ASSUMPTION: it does not.
 151                  */
 152                 tty_insert_flip_char(tty, ch, flg);
 153                 ch = 0;
 154                 flg = TTY_OVERRUN;
 155         }
 156 #ifdef CONFIG_MAGIC_SYSRQ
 157         port->sysrq = 0;
 158 #endif
 159         goto error_return;
 160 }
 161
 162 static void adm5120ser_irq_tx(struct uart_port *port)
 163 {
 164         struct circ_buf *xmit = &port->info->xmit;
 165         int count;
 166
 167         if (port->x_char) {
 168                 ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA) =
 169                     port->x_char;
 170                 port->icount.tx++;
 171                 port->x_char = 0;
 172                 return;
 173         }
 174         if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
 175                 adm5120ser_stop_tx(port);
 176                 return;
 177         }
 178
 179         count = port->fifosize >> 1;
 180         do {
 181                 ADM5120_UART_REG(port->iobase, ADM5120_UART_DATA) =
 182                     xmit->buf[xmit->tail];
 183                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 184                 port->icount.tx++;
 185                 if (uart_circ_empty(xmit))
 186                         break;
 187         } while (--count > 0);
 188
 189         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 190                 uart_write_wakeup(port);
 191
 192         if (uart_circ_empty(xmit))
 193                 adm5120ser_stop_tx(port);
 194 }
 195
 196 static void adm5120ser_irq_modem(struct uart_port *port)
 197 {
 198         unsigned int status;
 199
 200         status = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
 201
 202         if (status & ADM5120_UART_DCD)
 203                 uart_handle_dcd_change(port, status & ADM5120_UART_DCD);
 204
 205         if (status & ADM5120_UART_DSR)
 206                 port->icount.dsr++;
 207
 208         if (status & ADM5120_UART_CTS)
 209                 uart_handle_cts_change(port, status & ADM5120_UART_CTS);
 210
 211         wake_up_interruptible(&port->info->delta_msr_wait);
 212 }
 213
 214 static irqreturn_t adm5120ser_irq(int irq, void *dev_id)
 215 {
 216         struct uart_port *port = dev_id;
 217         unsigned long ir = ADM5120_UART_REG(port->iobase, ADM5120_UART_IR);
 218
 219         if (ir & (ADM5120_UART_RIS | ADM5120_UART_RTIS))
 220                 adm5120ser_irq_rx(port);
 221         if (ir & ADM5120_UART_TIS)
 222                 adm5120ser_irq_tx(port);
 223         if (ir & ADM5120_UART_MIS) {
 224                 adm5120ser_irq_modem(port);
 225                 ADM5120_UART_REG(port->iobase, ADM5120_UART_IR) = 0xff;
 226         }
 227
 228         return IRQ_HANDLED;
 229 }
 230
 231 static unsigned int adm5120ser_tx_empty(struct uart_port *port)
 232 {
 233         unsigned int fr = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
 234         return (fr & ADM5120_UART_TXFE) ? TIOCSER_TEMT : 0;
 235 }
 236
 237 static void adm5120ser_set_mctrl(struct uart_port *port, unsigned int mctrl)
 238 {
 239 }
 240
 241 static unsigned int adm5120ser_get_mctrl(struct uart_port *port)
 242 {
 243         unsigned int result = 0;
 244         unsigned int fr = ADM5120_UART_REG(port->iobase, ADM5120_UART_FR);
 245
 246         if (fr & ADM5120_UART_CTS)
 247                 result |= TIOCM_CTS;
 248         if (fr & ADM5120_UART_DSR)
 249                 result |= TIOCM_DSR;
 250         if (fr & ADM5120_UART_DCD)
 251                 result |= TIOCM_CAR;
 252         return result;
 253 }
 254
 255 static void adm5120ser_start_tx(struct uart_port *port)
 256 {
 257         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) |= ADM5120_UART_TIE;
 258 }
 259
 260 static void adm5120ser_stop_rx(struct uart_port *port)
 261 {
 262         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_RIE;
 263 }
 264
 265 static void adm5120ser_enable_ms(struct uart_port *port)
 266 {
 267 }
 268
 269 static void adm5120ser_break_ctl(struct uart_port *port, int break_state)
 270 {
 271         unsigned long flags;
 272         unsigned long lcrh;
 273
 274         spin_lock_irqsave(&port->lock, flags);
 275         lcrh = ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H);
 276         if (break_state == -1)
 277                 lcrh |= ADM5120_UART_BRK;
 278         else
 279                 lcrh &= ~ADM5120_UART_BRK;
 280         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) = lcrh;
 281         spin_unlock_irqrestore(&port->lock, flags);
 282 }
 283
 284 static int adm5120ser_startup(struct uart_port *port)
 285 {
 286         int ret;
 287
 288         ret = request_irq(port->irq, adm5120ser_irq, 0, "ADM5120 UART", port);
 289         if (ret) {
 290                 printk(KERN_ERR "Couldn't get irq %d\n", port->irq);
 291                 return ret;
 292         }
 293         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) |=
 294             ADM5120_UART_FIFO_EN;
 295         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) |=
 296             ADM5120_UART_EN | ADM5120_UART_IE;
 297         return 0;
 298 }
 299
 300 static void adm5120ser_shutdown(struct uart_port *port)
 301 {
 302         ADM5120_UART_REG(port->iobase, ADM5120_UART_CR) &= ~ADM5120_UART_IE;
 303         free_irq(port->irq, port);
 304 }
 305
 306 static void adm5120ser_set_termios(struct uart_port *port,
 307     struct ktermios *termios, struct ktermios *old)
 308 {
 309         unsigned int baud, quot, lcrh;
 310         unsigned long flags;
 311
 312         termios->c_cflag |= CREAD;
 313
 314         baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
 315         quot = uart_get_divisor(port, baud);
 316
 317         lcrh = ADM5120_UART_FIFO_EN;
 318         switch (termios->c_cflag & CSIZE) {
 319                 case CS5:
 320                         lcrh |= ADM5120_UART_W5;
 321                         break;
 322                 case CS6:
 323                         lcrh |= ADM5120_UART_W6;
 324                         break;
 325                 case CS7:
 326                         lcrh |= ADM5120_UART_W7;
 327                         break;
 328                 default:
 329                         lcrh |= ADM5120_UART_W8;
 330                         break;
 331         }
 332         if (termios->c_cflag & CSTOPB)
 333                 lcrh |= ADM5120_UART_STP2;
 334         if (termios->c_cflag & PARENB) {
 335                 lcrh |= ADM5120_UART_PEN;
 336                 if (!(termios->c_cflag & PARODD))
 337                         lcrh |= ADM5120_UART_EPS;
 338         }
 339
 340         spin_lock_irqsave(port->lock, flags);
 341
 342         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_H) = lcrh;
 343
 344         /*
 345          * Update the per-port timeout.
 346          */
 347         uart_update_timeout(port, termios->c_cflag, baud);
 348
 349         port->read_status_mask = ADM5120_UART_OE;
 350         if (termios->c_iflag & INPCK)
 351                 port->read_status_mask |= ADM5120_UART_FE | ADM5120_UART_PE;
 352         if (termios->c_iflag & (BRKINT | PARMRK))
 353                 port->read_status_mask |= ADM5120_UART_BE;
 354
 355         /*
 356          * Characters to ignore
 357          */
 358         port->ignore_status_mask = 0;
 359         if (termios->c_iflag & IGNPAR)
 360                 port->ignore_status_mask |= ADM5120_UART_FE | ADM5120_UART_PE;
 361         if (termios->c_iflag & IGNBRK) {
 362                 port->ignore_status_mask |= ADM5120_UART_BE;
 363                 /*
 364                  * If we're ignoring parity and break indicators,
 365                  * ignore overruns to (for real raw support).
 366                  */
 367                 if (termios->c_iflag & IGNPAR)
 368                         port->ignore_status_mask |= ADM5120_UART_OE;
 369         }
 370
 371         quot = ADM5120_UART_BAUD115200;
 372         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_L) = quot & 0xff;
 373         ADM5120_UART_REG(port->iobase, ADM5120_UART_LCR_M) = quot >> 8;
 374
 375         spin_unlock_irqrestore(&port->lock, flags);
 376 }
 377
 378 static const char *adm5120ser_type(struct uart_port *port)
 379 {
 380         return port->type == PORT_ADM5120 ? "ADM5120" : NULL;
 381 }
 382
 383 static void adm5120ser_config_port(struct uart_port *port, int flags)
 384 {
 385         if (flags & UART_CONFIG_TYPE)
 386                 port->type = PORT_ADM5120;
 387 }
 388
 389 static void adm5120ser_release_port(struct uart_port *port)
 390 {
 391         release_mem_region(port->iobase, ADM5120_UART_SIZE);
 392 }
 393
 394 static int adm5120ser_request_port(struct uart_port *port)
 395 {
 396         return request_mem_region(port->iobase, ADM5120_UART_SIZE,
 397             "adm5120-uart") != NULL ? 0 : -EBUSY;
 398 }
 399
 400 static struct uart_ops adm5120ser_ops = {
 401         .tx_empty =     adm5120ser_tx_empty,
 402         .set_mctrl =    adm5120ser_set_mctrl,
 403         .get_mctrl =    adm5120ser_get_mctrl,
 404         .stop_tx =      adm5120ser_stop_tx,
 405         .start_tx =     adm5120ser_start_tx,
 406         .stop_rx =      adm5120ser_stop_rx,
 407         .enable_ms =    adm5120ser_enable_ms,
 408         .break_ctl =    adm5120ser_break_ctl,
 409         .startup =      adm5120ser_startup,
 410         .shutdown =     adm5120ser_shutdown,
 411         .set_termios =  adm5120ser_set_termios,
 412         .type =         adm5120ser_type,
 413         .config_port =  adm5120ser_config_port,
 414         .release_port = adm5120ser_release_port,
 415         .request_port = adm5120ser_request_port,
 416 };
 417
 418 static void adm5120console_put(const char c)
 419 {
 420         while ((ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_FR) &
 421              ADM5120_UART_TXFF) != 0);
 422         ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_DATA) = c;
 423 }
 424
 425 static void adm5120console_write(struct console *con, const char *s,
 426     unsigned int count)
 427 {
 428         while (count--) {
 429                 if (*s == '\n')
 430                         adm5120console_put('\r');
 431                 adm5120console_put(*s);
 432                 s++;
 433         }
 434 }
 435
 436 static int adm5120console_setup(struct console *con, char *options)
 437 {
 438         /* Set to 115200 baud, 8N1 and enable FIFO */
 439         ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_LCR_L) =
 440             ADM5120_UART_BAUD115200 & 0xff;
 441         ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_LCR_M) =
 442             ADM5120_UART_BAUD115200 >> 8;
 443         ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_LCR_H) =
 444             ADM5120_UART_W8 | ADM5120_UART_FIFO_EN;
 445         /* Enable port */
 446         ADM5120_UART_REG(ADM5120_UART0_BASE, ADM5120_UART_CR) =
 447             ADM5120_UART_EN;
 448
 449         return 0;
 450 }
 451
 452 static struct uart_driver adm5120ser_reg;
 453
 454 static struct console adm5120_serconsole = {
 455         .name =         "ttyS",
 456         .write =        adm5120console_write,
 457         .device =       uart_console_device,
 458         .setup =        adm5120console_setup,
 459         .flags =        CON_PRINTBUFFER,
 460         .cflag =        B115200 | CS8 | CREAD,
 461         .index =        0,
 462         .data =         &adm5120ser_reg,
 463 };
 464
 465 static int __init adm5120console_init(void)
 466 {
 467         register_console(&adm5120_serconsole);
 468         return 0;
 469 }
 470
 471 console_initcall(adm5120console_init);
 472
 473
 474 static struct uart_port adm5120ser_ports[] = {
 475         {
 476                 .iobase =       ADM5120_UART0_BASE,
 477                 .irq =          ADM5120_IRQ_UART0,
 478                 .uartclk =      ADM5120_UARTCLK_FREQ,
 479                 .fifosize =     16,
 480                 .ops =          &adm5120ser_ops,
 481                 .line =         0,
 482                 .flags =        ASYNC_BOOT_AUTOCONF,
 483         },
 484 #if (CONFIG_ADM5120_NR_UARTS > 1)
 485         {
 486                 .iobase =       ADM5120_UART1_BASE,
 487                 .irq =          ADM5120_IRQ_UART1,
 488                 .uartclk =      ADM5120_UARTCLK_FREQ,
 489                 .fifosize =     16,
 490                 .ops =          &adm5120ser_ops,
 491                 .line =         1,
 492                 .flags =        ASYNC_BOOT_AUTOCONF,
 493         },
 494 #endif
 495 };
 496
 497 static struct uart_driver adm5120ser_reg = {
 498         .owner  =       THIS_MODULE,
 499         .driver_name =  "ttyS",
 500         .dev_name =     "ttyS",
 501         .major =        TTY_MAJOR,
 502         .minor =        64,
 503         .nr =           CONFIG_ADM5120_NR_UARTS,
 504         .cons =         &adm5120_serconsole,
 505 };
 506
 507 static int __init adm5120ser_init(void)
 508 {
 509         int ret, i;
 510
 511         ret = uart_register_driver(&adm5120ser_reg);
 512         if (!ret) {
 513                 for (i = 0; i < CONFIG_ADM5120_NR_UARTS; i++)
 514                         uart_add_one_port(&adm5120ser_reg, &adm5120ser_ports[i]);
 515         }
 516
 517         return ret;
 518 }
 519
 520 __initcall(adm5120ser_init);