drivers/serial/serial_ks8695.c

   1 /*
   2  *  linux/drivers/char/serial_ks8695.c
   3  *
   4  *  Driver for KS8695 serial port
   5  *
   6  *  Based on drivers/serial/serial_ks8695uart.c, by Kam Lee.
   7  *
   8  *  Copyright 2002 Micrel Inc.
   9  *  (C) Copyrght 2006 Greg Ungerer <gerg@snapgear.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/signal.h>
  29 #include <linux/sched.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/tty.h>
  32 #include <linux/tty_flip.h>
  33 #include <linux/major.h>
  34 #include <linux/string.h>
  35 #include <linux/fcntl.h>
  36 #include <linux/ptrace.h>
  37 #include <linux/ioport.h>
  38 #include <linux/mm.h>
  39 #include <linux/slab.h>
  40 #include <linux/init.h>
  41 #include <linux/circ_buf.h>
  42 #include <linux/serial.h>
  43 #include <linux/console.h>
  44 #include <linux/sysrq.h>
  45 #include <linux/serial_core.h>
  46 #include <asm/system.h>
  47 #include <asm/io.h>
  48 #include <asm/irq.h>
  49 #include <asm/uaccess.h>
  50 #include <asm/bitops.h>
  51
  52 #define KS8695_UART_NR          1
  53
  54 #ifdef CONFIG_SERIAL_KS8695_COM
  55 #define KS8695_SERIAL_MAJOR     4
  56 #define KS8695_SERIAL_MINOR     64
  57 #define KS8695_SERIAL_DEV_NAME  "ttyS"
  58 #else
  59 #define KS8695_SERIAL_MAJOR     204
  60 #define KS8695_SERIAL_MINOR     16
  61 #define KS8695_SERIAL_DEV_NAME  "ttyAM"
  62 #endif
  63
  64 /*
  65  * Access macros for the KS8695 UART
  66  */
  67 #define UART_GET_INT_STATUS(p)    (*(volatile unsigned int *)((p)->membase + KS8695_INT_STATUS))
  68 #define UART_CLR_INT_STATUS(p, c) (*(unsigned int *)((p)->membase + KS8695_INT_STATUS) = (c))
  69 #define UART_GET_CHAR(p)          ((*(volatile unsigned int *)((p)->membase + KS8695_UART_RX_BUFFER)) & 0xFF)
  70 #define UART_PUT_CHAR(p, c)       (*(unsigned int *)((p)->membase + KS8695_UART_TX_HOLDING) = (c))
  71 #define UART_GET_IER(p)           (*(volatile unsigned int *)((p)->membase + KS8695_INT_ENABLE))
  72 #define UART_PUT_IER(p, c)        (*(unsigned int *)((p)->membase + KS8695_INT_ENABLE) = (c))
  73 #define UART_GET_FCR(p)           (*(volatile unsigned int *)((p)->membase + KS8695_UART_FIFO_CTRL))
  74 #define UART_PUT_FCR(p, c)        (*(unsigned int *)((p)->membase + KS8695_UART_FIFO_CTRL) = (c))
  75 #define UART_GET_MSR(p)           (*(volatile unsigned int *)((p)->membase + KS8695_UART_MODEM_STATUS))
  76 #define UART_GET_LSR(p)           (*(volatile unsigned int *)((p)->membase + KS8695_UART_LINE_STATUS))
  77 #define UART_GET_LCR(p)           (*(volatile unsigned int *)((p)->membase + KS8695_UART_LINE_CTRL))
  78 #define UART_PUT_LCR(p, c)        (*(unsigned int *)((p)->membase + KS8695_UART_LINE_CTRL) = (c))
  79 #define UART_GET_MCR(p)           (*(volatile unsigned int *)((p)->membase + KS8695_UART_MODEM_CTRL))
  80 #define UART_PUT_MCR(p, c)        (*(unsigned int *)((p)->membase + KS8695_UART_MODEM_CTRL) = (c))
  81 #define UART_GET_BRDR(p)          (*(volatile unsigned int *)((p)->membase + KS8695_UART_DIVISOR))
  82 #define UART_PUT_BRDR(p, c)       (*(unsigned int *)((p)->membase + KS8695_UART_DIVISOR) = (c))
  83 #define UART_RX_DATA(s)           (((s) & KS8695_UART_LINES_RXFE) != 0)
  84 #define UART_TX_READY(s)          (((s) & KS8695_UART_LINES_TXFE) != 0)
  85
  86 #define UART_DUMMY_LSR_RX       0x100
  87
  88 static void ks8695uart_stop_tx(struct uart_port *port)
  89 {
  90         unsigned int ier;
  91
  92         ier = UART_GET_IER(port);
  93         if (ier &  KS8695_INT_ENABLE_TX)
  94                 disable_irq(8);
  95 }
  96
  97 static void ks8695uart_start_tx(struct uart_port *port)
  98 {
  99         unsigned int ier;
 100
 101         ier = UART_GET_IER(port);
 102         if ((ier &  KS8695_INT_ENABLE_TX ) == 0)
 103                 enable_irq(8);
 104 }
 105
 106 static void ks8695uart_stop_rx(struct uart_port *port)
 107 {
 108         unsigned int ier;
 109
 110         ier = UART_GET_IER(port);
 111         ier &= ~KS8695_INT_ENABLE_RX;
 112         UART_PUT_IER(port, ier);
 113 }
 114
 115 static void ks8695uart_enable_ms(struct uart_port *port)
 116 {
 117        UART_PUT_IER(port, UART_GET_IER(port) | KS8695_INT_ENABLE_MODEM);
 118 }
 119
 120 static irqreturn_t ks8695uart_tx_chars(int irq, void *data)
 121 {
 122         struct uart_port *port = data;
 123         struct circ_buf *xmit = &port->info->xmit;
 124         int i;
 125
 126         if (port->x_char) {
 127                 UART_CLR_INT_STATUS(port, KS8695_INTMASK_UART_TX);
 128                 UART_PUT_CHAR(port, (unsigned int) port->x_char);
 129                 port->icount.tx++;
 130                 port->x_char = 0;
 131                 return IRQ_HANDLED;
 132         }
 133
 134         for (i = 0; (i < 16); i++) {
 135                 if (xmit->head == xmit->tail)
 136                         break;
 137                 UART_CLR_INT_STATUS(port, KS8695_INTMASK_UART_TX);
 138                 UART_PUT_CHAR(port, (unsigned int) (xmit->buf[xmit->tail]));
 139                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 140                 port->icount.tx++;
 141         }
 142
 143         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 144                 uart_write_wakeup(port);
 145
 146         if (xmit->head == xmit->tail)
 147                 disable_irq(irq);
 148
 149         return IRQ_HANDLED;
 150 }
 151
 152 static irqreturn_t ks8695uart_rx_chars(int irq, void *data)
 153 {
 154         struct uart_port *port = data;
 155         struct tty_struct *tty = port->info->tty;
 156         unsigned int status, ch, lsr, max_count = 256;
 157         char flag;
 158
 159         status = UART_GET_LSR(port);
 160         while (UART_RX_DATA(status) && max_count--) {
 161
 162                 ch = UART_GET_CHAR(port);
 163                 flag = TTY_NORMAL;
 164                 port->icount.rx++;
 165
 166                 /*
 167                  * Note that the error handling code is
 168                  * out of the main execution path
 169                  */
 170                 lsr = UART_GET_LSR(port) | UART_DUMMY_LSR_RX;
 171                 if (lsr & KS8695_UART_LINES_ANY) {
 172                         if (lsr & KS8695_UART_LINES_BE) {
 173                                 lsr &= ~(KS8695_UART_LINES_FE | KS8695_UART_LINES_FE);
 174                                 port->icount.brk++;
 175                                 if (uart_handle_break(port))
 176                                         goto ignore_char;
 177                         } else if (lsr & KS8695_UART_LINES_PE)
 178                                 port->icount.parity++;
 179                         else if (lsr & KS8695_UART_LINES_FE)
 180                                 port->icount.frame++;
 181                         if (lsr & KS8695_UART_LINES_OE)
 182                                 port->icount.overrun++;
 183
 184                         lsr &= port->read_status_mask;
 185
 186                         if (lsr & KS8695_UART_LINES_BE)
 187                                 flag = TTY_BREAK;
 188                         else if (lsr & KS8695_UART_LINES_PE)
 189                                 flag = TTY_PARITY;
 190                         else if (lsr & KS8695_UART_LINES_FE)
 191                                 flag = TTY_FRAME;
 192                 }
 193
 194                 if (uart_handle_sysrq_char(port, ch))
 195                         goto ignore_char;
 196
 197                 uart_insert_char(port, lsr, KS8695_UART_LINES_OE, ch, flag);
 198
 199 ignore_char:
 200                 status = UART_GET_LSR(port);
 201         }
 202
 203         tty_flip_buffer_push(tty);
 204         return IRQ_HANDLED;
 205 }
 206
 207
 208 static irqreturn_t ks8695uart_modem(int irq, void *data)
 209 {
 210         struct uart_port *port = data;
 211         unsigned int status, delta;
 212
 213         /* clear modem interrupt by reading MSR */
 214         status = UART_GET_MSR(port);
 215         delta = status & 0x0B;
 216
 217         if (!delta)
 218                 return IRQ_NONE;
 219
 220         if (delta & KS8695_UART_MODEM_DDCD)
 221                 uart_handle_dcd_change(port, status & KS8695_UART_MODEM_DDCD);
 222         if (delta & KS8695_UART_MODEM_DDSR)
 223                 port->icount.dsr++;
 224         if (delta & KS8695_UART_MODEM_DCTS)
 225                 uart_handle_cts_change(port, status & KS8695_UART_MODEM_DCTS);
 226         wake_up_interruptible(&port->info->delta_msr_wait);
 227
 228         return IRQ_HANDLED;
 229 }
 230
 231 static unsigned int ks8695uart_tx_empty(struct uart_port *port)
 232 {
 233         unsigned int status;
 234
 235         status = UART_GET_LSR(port);
 236         return UART_TX_READY(status) ? TIOCSER_TEMT : 0;
 237 }
 238
 239 static unsigned int ks8695uart_get_mctrl(struct uart_port *port)
 240 {
 241         unsigned int result = 0;
 242         unsigned int status;
 243
 244         status = UART_GET_MSR(port);
 245         if (status & KS8695_UART_MODEM_DCD)
 246                 result |= TIOCM_CAR;
 247         if (status & KS8695_UART_MODEM_DSR)
 248                 result |= TIOCM_DSR;
 249         if (status & KS8695_UART_MODEM_CTS)
 250                 result |= TIOCM_CTS;
 251
 252         return result;
 253 }
 254
 255 static void ks8695uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
 256 {
 257         unsigned int mcr;
 258
 259         mcr = UART_GET_MCR(port);
 260         if (mctrl & TIOCM_RTS)
 261                 mcr |= KS8695_UART_MODEMC_RTS;
 262         else
 263                 mcr &= ~KS8695_UART_MODEMC_RTS;
 264
 265         if (mctrl & TIOCM_DTR)
 266                 mcr |= KS8695_UART_MODEMC_DTR;
 267         else
 268                 mcr &= ~KS8695_UART_MODEMC_DTR;
 269
 270         UART_PUT_MCR(port, mcr);
 271 }
 272
 273 static void ks8695uart_break_ctl(struct uart_port *port, int break_state)
 274 {
 275         unsigned int lcr;
 276
 277         lcr = UART_GET_LCR(port);
 278         if (break_state == -1)
 279                 lcr |= KS8695_UART_LINEC_BRK;
 280         else
 281                 lcr &= ~KS8695_UART_LINEC_BRK;
 282         UART_PUT_LCR(port, lcr);
 283 }
 284
 285 static int ks8695uart_startup(struct uart_port *port)
 286 {
 287         int retval;
 288
 289         retval = request_irq(KS8695_INT_UART_TX, ks8695uart_tx_chars, SA_SHIRQ | SA_INTERRUPT, "KS8695 uart(TX)", port);
 290         if (retval)
 291                 return retval;
 292
 293         retval = request_irq(KS8695_INT_UART_RX, ks8695uart_rx_chars, SA_SHIRQ | SA_INTERRUPT, "KS8695 uart(RX)", port);
 294         if (retval)
 295                 return retval;
 296
 297         retval = request_irq(KS8695_INT_UART_LINE_ERR, ks8695uart_rx_chars, SA_SHIRQ | SA_INTERRUPT, "KS8695 uart(error)", port);
 298         if (retval)
 299                 return retval;
 300
 301         retval = request_irq(KS8695_INT_UART_MODEMS, ks8695uart_modem, SA_SHIRQ | SA_INTERRUPT, "KS8695 uart(modem)", port);
 302         if (retval)
 303                 return retval;
 304
 305         return 0;
 306 }
 307
 308 static void ks8695uart_shutdown(struct uart_port *port)
 309 {
 310         /* disable break condition and fifos */
 311         UART_PUT_LCR(port, UART_GET_LCR(port) & ~KS8695_UART_LINEC_BRK);
 312         UART_PUT_FCR(port, UART_GET_FCR(port) & ~KS8695_UART_FIFO_FEN);
 313
 314         free_irq(KS8695_INT_UART_RX, port);
 315         free_irq(KS8695_INT_UART_TX, port);
 316         free_irq(KS8695_INT_UART_LINE_ERR, port);
 317         free_irq(KS8695_INT_UART_MODEMS, port);
 318 }
 319
 320 static void ks8695uart_set_termios(struct uart_port *port, struct termios *termios, struct termios *old)
 321 {
 322         unsigned int baud, lcr, fcr = 0;
 323         unsigned long flags;
 324
 325         /* byte size and parity */
 326         switch (termios->c_cflag & CSIZE) {
 327         case CS5: lcr = KS8695_UART_LINEC_WLEN5; break;
 328         case CS6: lcr = KS8695_UART_LINEC_WLEN6; break;
 329         case CS7: lcr = KS8695_UART_LINEC_WLEN7; break;
 330         default:  lcr = KS8695_UART_LINEC_WLEN8; break; // CS8
 331         }
 332
 333         if (termios->c_cflag & CSTOPB)
 334                 lcr |= KS8695_UART_LINEC_STP2;
 335         if (termios->c_cflag & PARENB) {
 336                 lcr |= KS8695_UART_LINEC_PEN;
 337                 if (!(termios->c_cflag & PARODD))
 338                         lcr |= KS8695_UART_LINEC_EPS;
 339         }
 340
 341         if (port->fifosize > 1)
 342                 fcr = KS8695_UART_FIFO_TRIG04 | KS8695_UART_FIFO_TXRST | KS8695_UART_FIFO_RXRST | KS8695_UART_FIFO_FEN;
 343
 344         port->read_status_mask = KS8695_UART_LINES_OE;
 345         if (termios->c_iflag & INPCK)
 346                 port->read_status_mask |= (KS8695_UART_LINES_FE | KS8695_UART_LINES_PE);
 347         if (termios->c_iflag & (BRKINT | PARMRK))
 348                 port->read_status_mask |= KS8695_UART_LINES_BE;
 349
 350         /* Characters to ignore */
 351         port->ignore_status_mask = 0;
 352         if (termios->c_iflag & IGNPAR)
 353                 port->ignore_status_mask |= (KS8695_UART_LINES_FE | KS8695_UART_LINES_PE);
 354         if (termios->c_iflag & IGNBRK) {
 355                 port->ignore_status_mask |= KS8695_UART_LINES_BE;
 356                 /*
 357                  * If we're ignoring parity and break indicators,
 358                  * ignore overruns too (for real raw support).
 359                  */
 360                 if (termios->c_iflag & IGNPAR)
 361                         port->ignore_status_mask |= KS8695_UART_LINES_OE;
 362         }
 363
 364         /* Ignore all characters if CREAD is not set.  */
 365         if ((termios->c_cflag & CREAD) == 0)
 366                 port->ignore_status_mask |= UART_DUMMY_LSR_RX;
 367
 368         baud = uart_get_baud_rate(port, termios, old, 50, 230400);
 369
 370         /* first, disable everything */
 371         local_irq_save(flags);
 372
 373         if ((port->flags & ASYNC_HARDPPS_CD) ||
 374             (termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL))
 375                 ks8695uart_enable_ms(port);
 376
 377         UART_PUT_BRDR(port, port->uartclk / baud);
 378         UART_PUT_LCR(port, lcr);
 379         UART_PUT_FCR(port, fcr);
 380
 381         local_irq_restore(flags);
 382 }
 383
 384 static const char *ks8695uart_type(struct uart_port *port)
 385 {
 386         return port->type == PORT_KS8695 ? "KS8695" : NULL;
 387 }
 388
 389 /*
 390  * Release the memory region(s) being used by 'port'
 391  */
 392 static void ks8695uart_release_port(struct uart_port *port)
 393 {
 394         release_mem_region(port->mapbase, 0x24);
 395 }
 396
 397 /*
 398  * Request the memory region(s) being used by 'port'
 399  */
 400 static int ks8695uart_request_port(struct uart_port *port)
 401 {
 402         return request_mem_region(port->mapbase, 0x24, "KS8695 UART") != NULL ? 0 : -EBUSY;
 403 }
 404
 405 /*
 406  * Configure/autoconfigure the port.
 407  */
 408 static void ks8695uart_config_port(struct uart_port *port, int flags)
 409 {
 410         if (flags & UART_CONFIG_TYPE) {
 411                 port->type = PORT_KS8695;
 412                 ks8695uart_request_port(port);
 413         }
 414 }
 415
 416 /*
 417  * verify the new serial_struct (for TIOCSSERIAL).
 418  */
 419 static int ks8695uart_verify_port(struct uart_port *port, struct serial_struct *ser)
 420 {
 421         if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_KS8695))
 422                 return -EINVAL;
 423         if ((ser->irq < 0) || (ser->irq >= NR_IRQS))
 424                 return -EINVAL;
 425         if (ser->baud_base < 9600)
 426                 return -EINVAL;
 427         return 0;
 428 }
 429
 430 static struct uart_ops ks8695uart_ops = {
 431         .tx_empty       = ks8695uart_tx_empty,
 432         .set_mctrl      = ks8695uart_set_mctrl,
 433         .get_mctrl      = ks8695uart_get_mctrl,
 434         .stop_tx        = ks8695uart_stop_tx,
 435         .start_tx       = ks8695uart_start_tx,
 436         .stop_rx        = ks8695uart_stop_rx,
 437         .enable_ms      = ks8695uart_enable_ms,
 438         .break_ctl      = ks8695uart_break_ctl,
 439         .startup        = ks8695uart_startup,
 440         .shutdown       = ks8695uart_shutdown,
 441         .set_termios    = ks8695uart_set_termios,
 442         .type           = ks8695uart_type,
 443         .release_port   = ks8695uart_release_port,
 444         .request_port   = ks8695uart_request_port,
 445         .config_port    = ks8695uart_config_port,
 446         .verify_port    = ks8695uart_verify_port,
 447 };
 448
 449 static struct uart_port ks8695uart_ports[KS8695_UART_NR] = {
 450         {
 451                 .line           = 0,
 452                 .membase        = (void *) KS8695_IO_VIRT,
 453                 .mapbase        = KS8695_IO_BASE + KS8695_UART_RX_BUFFER,
 454                 .iotype         = SERIAL_IO_MEM,
 455                 .irq            = KS8695_INT_UART_RX,
 456                 .uartclk        = 25000000,
 457                 .fifosize       = 16,
 458                 .ops            = &ks8695uart_ops,
 459                 .flags          = ASYNC_BOOT_AUTOCONF,
 460         }
 461 };
 462
 463 #ifdef CONFIG_SERIAL_KS8695_CONSOLE
 464
 465 /*
 466  * Force a single char out the serial. It must go out, poll the ready
 467  * register until we can send it, and make sure it is sent.
 468  */
 469 static void ks8695uart_console_putc(struct console *co, const char c)
 470 {
 471         struct uart_port *port = ks8695uart_ports + co->index;
 472
 473         while (!UART_TX_READY(UART_GET_LSR(port)))
 474                 ;
 475
 476         UART_PUT_CHAR(port, (unsigned int) c);
 477
 478         while (!UART_TX_READY(UART_GET_LSR(port)))
 479                 ;
 480 }
 481
 482 static void ks8695uart_console_write(struct console *co, const char *s, unsigned int count)
 483 {
 484         int i;
 485
 486         for (i = 0; i < count; i++, s++) {
 487                 ks8695uart_console_putc(co, *s);
 488                 if (*s == '\n')
 489                         ks8695uart_console_putc(co, '\r');
 490         }
 491 }
 492
 493 static int __init ks8695uart_console_setup(struct console *co, char *options)
 494 {
 495         struct uart_port *port;
 496         int baud = 115200;
 497         int bits = 8;
 498         int parity = 'n';
 499         int flow = 'n';
 500
 501         port = uart_get_console(ks8695uart_ports, KS8695_UART_NR, co);
 502         if (options)
 503                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 504
 505         return uart_set_options(port, co, baud, parity, bits, flow);
 506 }
 507
 508 static struct uart_driver ks8695uart_reg;
 509 static struct console ks8695uart_console = {
 510         .name           = KS8695_SERIAL_DEV_NAME,
 511         .write          = ks8695uart_console_write,
 512         .device         = uart_console_device,
 513         .setup          = ks8695uart_console_setup,
 514         .flags          = CON_PRINTBUFFER,
 515         .index          = -1,
 516         .data           = &ks8695uart_reg,
 517 };
 518
 519 static int __init ks8695uart_console_init(void)
 520 {
 521         register_console(&ks8695uart_console);
 522         return 0;
 523 }
 524
 525 console_initcall(ks8695uart_console_init);
 526
 527 #define KS8695UART_CONSOLE      &ks8695uart_console
 528 #else
 529 #define KS8695UART_CONSOLE      NULL
 530 #endif
 531
 532 static struct uart_driver ks8695uart_reg = {
 533         .owner          = THIS_MODULE,
 534         .driver_name    = "serial_ks8695",
 535         .dev_name       = KS8695_SERIAL_DEV_NAME,
 536         .major          = KS8695_SERIAL_MAJOR,
 537         .minor          = KS8695_SERIAL_MINOR,
 538         .nr             = KS8695_UART_NR,
 539         .cons           = KS8695UART_CONSOLE,
 540 };
 541
 542 static int __init ks8695uart_init(void)
 543 {
 544         int i, rc;
 545
 546         rc = uart_register_driver(&ks8695uart_reg);
 547         if (rc == 0) {
 548                 for (i = 0; (i < KS8695_UART_NR); i++)
 549                         uart_add_one_port(&ks8695uart_reg, &ks8695uart_ports[i]);
 550         }
 551
 552         return rc;
 553 }
 554
 555 static void __exit ks8695uart_exit(void)
 556 {
 557         int i;
 558
 559         for (i = 0; (i < KS8695_UART_NR); i++)
 560                 uart_remove_one_port(&ks8695uart_reg, &ks8695uart_ports[i]);
 561         uart_unregister_driver(&ks8695uart_reg);
 562 }
 563
 564 module_init(ks8695uart_init);
 565 module_exit(ks8695uart_exit);
 566
 567 MODULE_AUTHOR("Micrel Semiconductor");
 568 MODULE_DESCRIPTION("KS8695 serial port driver");
 569 MODULE_LICENSE("GPL");