drivers/serial/max3100.c

   1 /*
   2  *
   3  *  Copyright (C) 2008 Christian Pellegrin <chripell@evolware.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  *
  11  * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have
  12  * to use polling for flow control. TX empty IRQ is unusable, since
  13  * writing conf clears FIFO buffer and we cannot have this interrupt
  14  * always asking us for attention.
  15  *
  16  * Example platform data:
  17
  18  static struct plat_max3100 max3100_plat_data = {
  19  .loopback = 0,
  20  .crystal = 0,
  21  .poll_time = 100,
  22  };
  23
  24  static struct spi_board_info spi_board_info[] = {
  25  {
  26  .modalias      = "max3100",
  27  .platform_data = &max3100_plat_data,
  28  .irq           = IRQ_EINT12,
  29  .max_speed_hz  = 5*1000*1000,
  30  .chip_select   = 0,
  31  },
  32  };
  33
  34  * The initial minor number is 209 in the low-density serial port:
  35  * mknod /dev/ttyMAX0 c 204 209
  36  */
  37
  38 #define MAX3100_MAJOR 204
  39 #define MAX3100_MINOR 209
  40 /* 4 MAX3100s should be enough for everyone */
  41 #define MAX_MAX3100 4
  42
  43 #include <linux/delay.h>
  44 #include <linux/device.h>
  45 #include <linux/serial_core.h>
  46 #include <linux/serial.h>
  47 #include <linux/spi/spi.h>
  48 #include <linux/freezer.h>
  49
  50 #include <linux/serial_max3100.h>
  51
  52 #define MAX3100_C    (1<<14)
  53 #define MAX3100_D    (0<<14)
  54 #define MAX3100_W    (1<<15)
  55 #define MAX3100_RX   (0<<15)
  56
  57 #define MAX3100_WC   (MAX3100_W  | MAX3100_C)
  58 #define MAX3100_RC   (MAX3100_RX | MAX3100_C)
  59 #define MAX3100_WD   (MAX3100_W  | MAX3100_D)
  60 #define MAX3100_RD   (MAX3100_RX | MAX3100_D)
  61 #define MAX3100_CMD  (3 << 14)
  62
  63 #define MAX3100_T    (1<<14)
  64 #define MAX3100_R    (1<<15)
  65
  66 #define MAX3100_FEN  (1<<13)
  67 #define MAX3100_SHDN (1<<12)
  68 #define MAX3100_TM   (1<<11)
  69 #define MAX3100_RM   (1<<10)
  70 #define MAX3100_PM   (1<<9)
  71 #define MAX3100_RAM  (1<<8)
  72 #define MAX3100_IR   (1<<7)
  73 #define MAX3100_ST   (1<<6)
  74 #define MAX3100_PE   (1<<5)
  75 #define MAX3100_L    (1<<4)
  76 #define MAX3100_BAUD (0xf)
  77
  78 #define MAX3100_TE   (1<<10)
  79 #define MAX3100_RAFE (1<<10)
  80 #define MAX3100_RTS  (1<<9)
  81 #define MAX3100_CTS  (1<<9)
  82 #define MAX3100_PT   (1<<8)
  83 #define MAX3100_DATA (0xff)
  84
  85 #define MAX3100_RT   (MAX3100_R | MAX3100_T)
  86 #define MAX3100_RTC  (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
  87
  88 /* the following simulate a status reg for ignore_status_mask */
  89 #define MAX3100_STATUS_PE 1
  90 #define MAX3100_STATUS_FE 2
  91 #define MAX3100_STATUS_OE 4
  92
  93 struct max3100_port {
  94         struct uart_port port;
  95         struct spi_device *spi;
  96
  97         int cts;                /* last CTS received for flow ctrl */
  98         int tx_empty;           /* last TX empty bit */
  99
 100         spinlock_t conf_lock;   /* shared data */
 101         int conf_commit;        /* need to make changes */
 102         int conf;               /* configuration for the MAX31000
 103                                  * (bits 0-7, bits 8-11 are irqs) */
 104         int rts_commit;         /* need to change rts */
 105         int rts;                /* rts status */
 106         int baud;               /* current baud rate */
 107
 108         int parity;             /* keeps track if we should send parity */
 109 #define MAX3100_PARITY_ON 1
 110 #define MAX3100_PARITY_ODD 2
 111 #define MAX3100_7BIT 4
 112         int rx_enabled;         /* if we should rx chars */
 113
 114         int irq;                /* irq assigned to the max3100 */
 115
 116         int minor;              /* minor number */
 117         int crystal;            /* 1 if 3.6864Mhz crystal 0 for 1.8432 */
 118         int loopback;           /* 1 if we are in loopback mode */
 119
 120         /* for handling irqs: need workqueue since we do spi_sync */
 121         struct workqueue_struct *workqueue;
 122         struct work_struct work;
 123         /* set to 1 to make the workhandler exit as soon as possible */
 124         int  force_end_work;
 125         /* need to know we are suspending to avoid deadlock on workqueue */
 126         int suspending;
 127
 128         /* hook for suspending MAX3100 via dedicated pin */
 129         void (*max3100_hw_suspend) (int suspend);
 130
 131         /* poll time (in ms) for ctrl lines */
 132         int poll_time;
 133         /* and its timer */
 134         struct timer_list       timer;
 135 };
 136
 137 static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
 138 static DEFINE_MUTEX(max3100s_lock);                /* race on probe */
 139
 140 static int max3100_do_parity(struct max3100_port *s, u16 c)
 141 {
 142         int parity;
 143
 144         if (s->parity & MAX3100_PARITY_ODD)
 145                 parity = 1;
 146         else
 147                 parity = 0;
 148
 149         if (s->parity & MAX3100_7BIT)
 150                 c &= 0x7f;
 151         else
 152                 c &= 0xff;
 153
 154         parity = parity ^ (hweight8(c) & 1);
 155         return parity;
 156 }
 157
 158 static int max3100_check_parity(struct max3100_port *s, u16 c)
 159 {
 160         return max3100_do_parity(s, c) == ((c >> 8) & 1);
 161 }
 162
 163 static void max3100_calc_parity(struct max3100_port *s, u16 *c)
 164 {
 165         if (s->parity & MAX3100_7BIT)
 166                 *c &= 0x7f;
 167         else
 168                 *c &= 0xff;
 169
 170         if (s->parity & MAX3100_PARITY_ON)
 171                 *c |= max3100_do_parity(s, *c) << 8;
 172 }
 173
 174 static void max3100_work(struct work_struct *w);
 175
 176 static void max3100_dowork(struct max3100_port *s)
 177 {
 178         if (!s->force_end_work && !work_pending(&s->work) &&
 179             !freezing(current) && !s->suspending)
 180                 queue_work(s->workqueue, &s->work);
 181 }
 182
 183 static void max3100_timeout(unsigned long data)
 184 {
 185         struct max3100_port *s = (struct max3100_port *)data;
 186
 187         if (s->port.state) {
 188                 max3100_dowork(s);
 189                 mod_timer(&s->timer, jiffies + s->poll_time);
 190         }
 191 }
 192
 193 static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
 194 {
 195         struct spi_message message;
 196         u16 etx, erx;
 197         int status;
 198         struct spi_transfer tran = {
 199                 .tx_buf = &etx,
 200                 .rx_buf = &erx,
 201                 .len = 2,
 202         };
 203
 204         etx = cpu_to_be16(tx);
 205         spi_message_init(&message);
 206         spi_message_add_tail(&tran, &message);
 207         status = spi_sync(s->spi, &message);
 208         if (status) {
 209                 dev_warn(&s->spi->dev, "error while calling spi_sync\n");
 210                 return -EIO;
 211         }
 212         *rx = be16_to_cpu(erx);
 213         s->tx_empty = (*rx & MAX3100_T) > 0;
 214         dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
 215         return 0;
 216 }
 217
 218 static int max3100_handlerx(struct max3100_port *s, u16 rx)
 219 {
 220         unsigned int ch, flg, status = 0;
 221         int ret = 0, cts;
 222
 223         if (rx & MAX3100_R && s->rx_enabled) {
 224                 dev_dbg(&s->spi->dev, "%s\n", __func__);
 225                 ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
 226                 if (rx & MAX3100_RAFE) {
 227                         s->port.icount.frame++;
 228                         flg = TTY_FRAME;
 229                         status |= MAX3100_STATUS_FE;
 230                 } else {
 231                         if (s->parity & MAX3100_PARITY_ON) {
 232                                 if (max3100_check_parity(s, rx)) {
 233                                         s->port.icount.rx++;
 234                                         flg = TTY_NORMAL;
 235                                 } else {
 236                                         s->port.icount.parity++;
 237                                         flg = TTY_PARITY;
 238                                         status |= MAX3100_STATUS_PE;
 239                                 }
 240                         } else {
 241                                 s->port.icount.rx++;
 242                                 flg = TTY_NORMAL;
 243                         }
 244                 }
 245                 uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
 246                 ret = 1;
 247         }
 248
 249         cts = (rx & MAX3100_CTS) > 0;
 250         if (s->cts != cts) {
 251                 s->cts = cts;
 252                 uart_handle_cts_change(&s->port, cts ? TIOCM_CTS : 0);
 253         }
 254
 255         return ret;
 256 }
 257
 258 static void max3100_work(struct work_struct *w)
 259 {
 260         struct max3100_port *s = container_of(w, struct max3100_port, work);
 261         int rxchars;
 262         u16 tx, rx;
 263         int conf, cconf, rts, crts;
 264         struct circ_buf *xmit = &s->port.state->xmit;
 265
 266         dev_dbg(&s->spi->dev, "%s\n", __func__);
 267
 268         rxchars = 0;
 269         do {
 270                 spin_lock(&s->conf_lock);
 271                 conf = s->conf;
 272                 cconf = s->conf_commit;
 273                 s->conf_commit = 0;
 274                 rts = s->rts;
 275                 crts = s->rts_commit;
 276                 s->rts_commit = 0;
 277                 spin_unlock(&s->conf_lock);
 278                 if (cconf)
 279                         max3100_sr(s, MAX3100_WC | conf, &rx);
 280                 if (crts) {
 281                         max3100_sr(s, MAX3100_WD | MAX3100_TE |
 282                                    (s->rts ? MAX3100_RTS : 0), &rx);
 283                         rxchars += max3100_handlerx(s, rx);
 284                 }
 285
 286                 max3100_sr(s, MAX3100_RD, &rx);
 287                 rxchars += max3100_handlerx(s, rx);
 288
 289                 if (rx & MAX3100_T) {
 290                         tx = 0xffff;
 291                         if (s->port.x_char) {
 292                                 tx = s->port.x_char;
 293                                 s->port.icount.tx++;
 294                                 s->port.x_char = 0;
 295                         } else if (!uart_circ_empty(xmit) &&
 296                                    !uart_tx_stopped(&s->port)) {
 297                                 tx = xmit->buf[xmit->tail];
 298                                 xmit->tail = (xmit->tail + 1) &
 299                                         (UART_XMIT_SIZE - 1);
 300                                 s->port.icount.tx++;
 301                         }
 302                         if (tx != 0xffff) {
 303                                 max3100_calc_parity(s, &tx);
 304                                 tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0);
 305                                 max3100_sr(s, tx, &rx);
 306                                 rxchars += max3100_handlerx(s, rx);
 307                         }
 308                 }
 309
 310                 if (rxchars > 16 && s->port.state->port.tty != NULL) {
 311                         tty_flip_buffer_push(s->port.state->port.tty);
 312                         rxchars = 0;
 313                 }
 314                 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 315                         uart_write_wakeup(&s->port);
 316
 317         } while (!s->force_end_work &&
 318                  !freezing(current) &&
 319                  ((rx & MAX3100_R) ||
 320                   (!uart_circ_empty(xmit) &&
 321                    !uart_tx_stopped(&s->port))));
 322
 323         if (rxchars > 0 && s->port.state->port.tty != NULL)
 324                 tty_flip_buffer_push(s->port.state->port.tty);
 325 }
 326
 327 static irqreturn_t max3100_irq(int irqno, void *dev_id)
 328 {
 329         struct max3100_port *s = dev_id;
 330
 331         dev_dbg(&s->spi->dev, "%s\n", __func__);
 332
 333         max3100_dowork(s);
 334         return IRQ_HANDLED;
 335 }
 336
 337 static void max3100_enable_ms(struct uart_port *port)
 338 {
 339         struct max3100_port *s = container_of(port,
 340                                               struct max3100_port,
 341                                               port);
 342
 343         if (s->poll_time > 0)
 344                 mod_timer(&s->timer, jiffies);
 345         dev_dbg(&s->spi->dev, "%s\n", __func__);
 346 }
 347
 348 static void max3100_start_tx(struct uart_port *port)
 349 {
 350         struct max3100_port *s = container_of(port,
 351                                               struct max3100_port,
 352                                               port);
 353
 354         dev_dbg(&s->spi->dev, "%s\n", __func__);
 355
 356         max3100_dowork(s);
 357 }
 358
 359 static void max3100_stop_rx(struct uart_port *port)
 360 {
 361         struct max3100_port *s = container_of(port,
 362                                               struct max3100_port,
 363                                               port);
 364
 365         dev_dbg(&s->spi->dev, "%s\n", __func__);
 366
 367         s->rx_enabled = 0;
 368         spin_lock(&s->conf_lock);
 369         s->conf &= ~MAX3100_RM;
 370         s->conf_commit = 1;
 371         spin_unlock(&s->conf_lock);
 372         max3100_dowork(s);
 373 }
 374
 375 static unsigned int max3100_tx_empty(struct uart_port *port)
 376 {
 377         struct max3100_port *s = container_of(port,
 378                                               struct max3100_port,
 379                                               port);
 380
 381         dev_dbg(&s->spi->dev, "%s\n", __func__);
 382
 383         /* may not be truly up-to-date */
 384         max3100_dowork(s);
 385         return s->tx_empty;
 386 }
 387
 388 static unsigned int max3100_get_mctrl(struct uart_port *port)
 389 {
 390         struct max3100_port *s = container_of(port,
 391                                               struct max3100_port,
 392                                               port);
 393
 394         dev_dbg(&s->spi->dev, "%s\n", __func__);
 395
 396         /* may not be truly up-to-date */
 397         max3100_dowork(s);
 398         /* always assert DCD and DSR since these lines are not wired */
 399         return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR;
 400 }
 401
 402 static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
 403 {
 404         struct max3100_port *s = container_of(port,
 405                                               struct max3100_port,
 406                                               port);
 407         int rts;
 408
 409         dev_dbg(&s->spi->dev, "%s\n", __func__);
 410
 411         rts = (mctrl & TIOCM_RTS) > 0;
 412
 413         spin_lock(&s->conf_lock);
 414         if (s->rts != rts) {
 415                 s->rts = rts;
 416                 s->rts_commit = 1;
 417                 max3100_dowork(s);
 418         }
 419         spin_unlock(&s->conf_lock);
 420 }
 421
 422 static void
 423 max3100_set_termios(struct uart_port *port, struct ktermios *termios,
 424                     struct ktermios *old)
 425 {
 426         struct max3100_port *s = container_of(port,
 427                                               struct max3100_port,
 428                                               port);
 429         int baud = 0;
 430         unsigned cflag;
 431         u32 param_new, param_mask, parity = 0;
 432         struct tty_struct *tty = s->port.state->port.tty;
 433
 434         dev_dbg(&s->spi->dev, "%s\n", __func__);
 435         if (!tty)
 436                 return;
 437
 438         cflag = termios->c_cflag;
 439         param_new = 0;
 440         param_mask = 0;
 441
 442         baud = tty_get_baud_rate(tty);
 443         param_new = s->conf & MAX3100_BAUD;
 444         switch (baud) {
 445         case 300:
 446                 if (s->crystal)
 447                         baud = s->baud;
 448                 else
 449                         param_new = 15;
 450                 break;
 451         case 600:
 452                 param_new = 14 + s->crystal;
 453                 break;
 454         case 1200:
 455                 param_new = 13 + s->crystal;
 456                 break;
 457         case 2400:
 458                 param_new = 12 + s->crystal;
 459                 break;
 460         case 4800:
 461                 param_new = 11 + s->crystal;
 462                 break;
 463         case 9600:
 464                 param_new = 10 + s->crystal;
 465                 break;
 466         case 19200:
 467                 param_new = 9 + s->crystal;
 468                 break;
 469         case 38400:
 470                 param_new = 8 + s->crystal;
 471                 break;
 472         case 57600:
 473                 param_new = 1 + s->crystal;
 474                 break;
 475         case 115200:
 476                 param_new = 0 + s->crystal;
 477                 break;
 478         case 230400:
 479                 if (s->crystal)
 480                         param_new = 0;
 481                 else
 482                         baud = s->baud;
 483                 break;
 484         default:
 485                 baud = s->baud;
 486         }
 487         tty_encode_baud_rate(tty, baud, baud);
 488         s->baud = baud;
 489         param_mask |= MAX3100_BAUD;
 490
 491         if ((cflag & CSIZE) == CS8) {
 492                 param_new &= ~MAX3100_L;
 493                 parity &= ~MAX3100_7BIT;
 494         } else {
 495                 param_new |= MAX3100_L;
 496                 parity |= MAX3100_7BIT;
 497                 cflag = (cflag & ~CSIZE) | CS7;
 498         }
 499         param_mask |= MAX3100_L;
 500
 501         if (cflag & CSTOPB)
 502                 param_new |= MAX3100_ST;
 503         else
 504                 param_new &= ~MAX3100_ST;
 505         param_mask |= MAX3100_ST;
 506
 507         if (cflag & PARENB) {
 508                 param_new |= MAX3100_PE;
 509                 parity |= MAX3100_PARITY_ON;
 510         } else {
 511                 param_new &= ~MAX3100_PE;
 512                 parity &= ~MAX3100_PARITY_ON;
 513         }
 514         param_mask |= MAX3100_PE;
 515
 516         if (cflag & PARODD)
 517                 parity |= MAX3100_PARITY_ODD;
 518         else
 519                 parity &= ~MAX3100_PARITY_ODD;
 520
 521         /* mask termios capabilities we don't support */
 522         cflag &= ~CMSPAR;
 523         termios->c_cflag = cflag;
 524
 525         s->port.ignore_status_mask = 0;
 526         if (termios->c_iflag & IGNPAR)
 527                 s->port.ignore_status_mask |=
 528                         MAX3100_STATUS_PE | MAX3100_STATUS_FE |
 529                         MAX3100_STATUS_OE;
 530
 531         /* we are sending char from a workqueue so enable */
 532         s->port.state->port.tty->low_latency = 1;
 533
 534         if (s->poll_time > 0)
 535                 del_timer_sync(&s->timer);
 536
 537         uart_update_timeout(port, termios->c_cflag, baud);
 538
 539         spin_lock(&s->conf_lock);
 540         s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
 541         s->conf_commit = 1;
 542         s->parity = parity;
 543         spin_unlock(&s->conf_lock);
 544         max3100_dowork(s);
 545
 546         if (UART_ENABLE_MS(&s->port, termios->c_cflag))
 547                 max3100_enable_ms(&s->port);
 548 }
 549
 550 static void max3100_shutdown(struct uart_port *port)
 551 {
 552         struct max3100_port *s = container_of(port,
 553                                               struct max3100_port,
 554                                               port);
 555
 556         dev_dbg(&s->spi->dev, "%s\n", __func__);
 557
 558         if (s->suspending)
 559                 return;
 560
 561         s->force_end_work = 1;
 562
 563         if (s->poll_time > 0)
 564                 del_timer_sync(&s->timer);
 565
 566         if (s->workqueue) {
 567                 flush_workqueue(s->workqueue);
 568                 destroy_workqueue(s->workqueue);
 569                 s->workqueue = NULL;
 570         }
 571         if (s->irq)
 572                 free_irq(s->irq, s);
 573
 574         /* set shutdown mode to save power */
 575         if (s->max3100_hw_suspend)
 576                 s->max3100_hw_suspend(1);
 577         else  {
 578                 u16 tx, rx;
 579
 580                 tx = MAX3100_WC | MAX3100_SHDN;
 581                 max3100_sr(s, tx, &rx);
 582         }
 583 }
 584
 585 static int max3100_startup(struct uart_port *port)
 586 {
 587         struct max3100_port *s = container_of(port,
 588                                               struct max3100_port,
 589                                               port);
 590         char b[12];
 591
 592         dev_dbg(&s->spi->dev, "%s\n", __func__);
 593
 594         s->conf = MAX3100_RM;
 595         s->baud = s->crystal ? 230400 : 115200;
 596         s->rx_enabled = 1;
 597
 598         if (s->suspending)
 599                 return 0;
 600
 601         s->force_end_work = 0;
 602         s->parity = 0;
 603         s->rts = 0;
 604
 605         sprintf(b, "max3100-%d", s->minor);
 606         s->workqueue = create_freezeable_workqueue(b);
 607         if (!s->workqueue) {
 608                 dev_warn(&s->spi->dev, "cannot create workqueue\n");
 609                 return -EBUSY;
 610         }
 611         INIT_WORK(&s->work, max3100_work);
 612
 613         if (request_irq(s->irq, max3100_irq,
 614                         IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
 615                 dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
 616                 s->irq = 0;
 617                 destroy_workqueue(s->workqueue);
 618                 s->workqueue = NULL;
 619                 return -EBUSY;
 620         }
 621
 622         if (s->loopback) {
 623                 u16 tx, rx;
 624                 tx = 0x4001;
 625                 max3100_sr(s, tx, &rx);
 626         }
 627
 628         if (s->max3100_hw_suspend)
 629                 s->max3100_hw_suspend(0);
 630         s->conf_commit = 1;
 631         max3100_dowork(s);
 632         /* wait for clock to settle */
 633         msleep(50);
 634
 635         max3100_enable_ms(&s->port);
 636
 637         return 0;
 638 }
 639
 640 static const char *max3100_type(struct uart_port *port)
 641 {
 642         struct max3100_port *s = container_of(port,
 643                                               struct max3100_port,
 644                                               port);
 645
 646         dev_dbg(&s->spi->dev, "%s\n", __func__);
 647
 648         return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
 649 }
 650
 651 static void max3100_release_port(struct uart_port *port)
 652 {
 653         struct max3100_port *s = container_of(port,
 654                                               struct max3100_port,
 655                                               port);
 656
 657         dev_dbg(&s->spi->dev, "%s\n", __func__);
 658 }
 659
 660 static void max3100_config_port(struct uart_port *port, int flags)
 661 {
 662         struct max3100_port *s = container_of(port,
 663                                               struct max3100_port,
 664                                               port);
 665
 666         dev_dbg(&s->spi->dev, "%s\n", __func__);
 667
 668         if (flags & UART_CONFIG_TYPE)
 669                 s->port.type = PORT_MAX3100;
 670 }
 671
 672 static int max3100_verify_port(struct uart_port *port,
 673                                struct serial_struct *ser)
 674 {
 675         struct max3100_port *s = container_of(port,
 676                                               struct max3100_port,
 677                                               port);
 678         int ret = -EINVAL;
 679
 680         dev_dbg(&s->spi->dev, "%s\n", __func__);
 681
 682         if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
 683                 ret = 0;
 684         return ret;
 685 }
 686
 687 static void max3100_stop_tx(struct uart_port *port)
 688 {
 689         struct max3100_port *s = container_of(port,
 690                                               struct max3100_port,
 691                                               port);
 692
 693         dev_dbg(&s->spi->dev, "%s\n", __func__);
 694 }
 695
 696 static int max3100_request_port(struct uart_port *port)
 697 {
 698         struct max3100_port *s = container_of(port,
 699                                               struct max3100_port,
 700                                               port);
 701
 702         dev_dbg(&s->spi->dev, "%s\n", __func__);
 703         return 0;
 704 }
 705
 706 static void max3100_break_ctl(struct uart_port *port, int break_state)
 707 {
 708         struct max3100_port *s = container_of(port,
 709                                               struct max3100_port,
 710                                               port);
 711
 712         dev_dbg(&s->spi->dev, "%s\n", __func__);
 713 }
 714
 715 static struct uart_ops max3100_ops = {
 716         .tx_empty       = max3100_tx_empty,
 717         .set_mctrl      = max3100_set_mctrl,
 718         .get_mctrl      = max3100_get_mctrl,
 719         .stop_tx        = max3100_stop_tx,
 720         .start_tx       = max3100_start_tx,
 721         .stop_rx        = max3100_stop_rx,
 722         .enable_ms      = max3100_enable_ms,
 723         .break_ctl      = max3100_break_ctl,
 724         .startup        = max3100_startup,
 725         .shutdown       = max3100_shutdown,
 726         .set_termios    = max3100_set_termios,
 727         .type           = max3100_type,
 728         .release_port   = max3100_release_port,
 729         .request_port   = max3100_request_port,
 730         .config_port    = max3100_config_port,
 731         .verify_port    = max3100_verify_port,
 732 };
 733
 734 static struct uart_driver max3100_uart_driver = {
 735         .owner          = THIS_MODULE,
 736         .driver_name    = "ttyMAX",
 737         .dev_name       = "ttyMAX",
 738         .major          = MAX3100_MAJOR,
 739         .minor          = MAX3100_MINOR,
 740         .nr             = MAX_MAX3100,
 741 };
 742 static int uart_driver_registered;
 743
 744 static int __devinit max3100_probe(struct spi_device *spi)
 745 {
 746         int i, retval;
 747         struct plat_max3100 *pdata;
 748         u16 tx, rx;
 749
 750         mutex_lock(&max3100s_lock);
 751
 752         if (!uart_driver_registered) {
 753                 uart_driver_registered = 1;
 754                 retval = uart_register_driver(&max3100_uart_driver);
 755                 if (retval) {
 756                         printk(KERN_ERR "Couldn't register max3100 uart driver\n");
 757                         mutex_unlock(&max3100s_lock);
 758                         return retval;
 759                 }
 760         }
 761
 762         for (i = 0; i < MAX_MAX3100; i++)
 763                 if (!max3100s[i])
 764                         break;
 765         if (i == MAX_MAX3100) {
 766                 dev_warn(&spi->dev, "too many MAX3100 chips\n");
 767                 mutex_unlock(&max3100s_lock);
 768                 return -ENOMEM;
 769         }
 770
 771         max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL);
 772         if (!max3100s[i]) {
 773                 dev_warn(&spi->dev,
 774                          "kmalloc for max3100 structure %d failed!\n", i);
 775                 mutex_unlock(&max3100s_lock);
 776                 return -ENOMEM;
 777         }
 778         max3100s[i]->spi = spi;
 779         max3100s[i]->irq = spi->irq;
 780         spin_lock_init(&max3100s[i]->conf_lock);
 781         dev_set_drvdata(&spi->dev, max3100s[i]);
 782         pdata = spi->dev.platform_data;
 783         max3100s[i]->crystal = pdata->crystal;
 784         max3100s[i]->loopback = pdata->loopback;
 785         max3100s[i]->poll_time = pdata->poll_time * HZ / 1000;
 786         if (pdata->poll_time > 0 && max3100s[i]->poll_time == 0)
 787                 max3100s[i]->poll_time = 1;
 788         max3100s[i]->max3100_hw_suspend = pdata->max3100_hw_suspend;
 789         max3100s[i]->minor = i;
 790         init_timer(&max3100s[i]->timer);
 791         max3100s[i]->timer.function = max3100_timeout;
 792         max3100s[i]->timer.data = (unsigned long) max3100s[i];
 793
 794         dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i);
 795         max3100s[i]->port.irq = max3100s[i]->irq;
 796         max3100s[i]->port.uartclk = max3100s[i]->crystal ? 3686400 : 1843200;
 797         max3100s[i]->port.fifosize = 16;
 798         max3100s[i]->port.ops = &max3100_ops;
 799         max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
 800         max3100s[i]->port.line = i;
 801         max3100s[i]->port.type = PORT_MAX3100;
 802         max3100s[i]->port.dev = &spi->dev;
 803         retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
 804         if (retval < 0)
 805                 dev_warn(&spi->dev,
 806                          "uart_add_one_port failed for line %d with error %d\n",
 807                          i, retval);
 808
 809         /* set shutdown mode to save power. Will be woken-up on open */
 810         if (max3100s[i]->max3100_hw_suspend)
 811                 max3100s[i]->max3100_hw_suspend(1);
 812         else {
 813                 tx = MAX3100_WC | MAX3100_SHDN;
 814                 max3100_sr(max3100s[i], tx, &rx);
 815         }
 816         mutex_unlock(&max3100s_lock);
 817         return 0;
 818 }
 819
 820 static int __devexit max3100_remove(struct spi_device *spi)
 821 {
 822         struct max3100_port *s = dev_get_drvdata(&spi->dev);
 823         int i;
 824
 825         mutex_lock(&max3100s_lock);
 826
 827         /* find out the index for the chip we are removing */
 828         for (i = 0; i < MAX_MAX3100; i++)
 829                 if (max3100s[i] == s)
 830                         break;
 831
 832         dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
 833         uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
 834         kfree(max3100s[i]);
 835         max3100s[i] = NULL;
 836
 837         /* check if this is the last chip we have */
 838         for (i = 0; i < MAX_MAX3100; i++)
 839                 if (max3100s[i]) {
 840                         mutex_unlock(&max3100s_lock);
 841                         return 0;
 842                 }
 843         pr_debug("removing max3100 driver\n");
 844         uart_unregister_driver(&max3100_uart_driver);
 845
 846         mutex_unlock(&max3100s_lock);
 847         return 0;
 848 }
 849
 850 #ifdef CONFIG_PM
 851
 852 static int max3100_suspend(struct spi_device *spi, pm_message_t state)
 853 {
 854         struct max3100_port *s = dev_get_drvdata(&spi->dev);
 855
 856         dev_dbg(&s->spi->dev, "%s\n", __func__);
 857
 858         disable_irq(s->irq);
 859
 860         s->suspending = 1;
 861         uart_suspend_port(&max3100_uart_driver, &s->port);
 862
 863         if (s->max3100_hw_suspend)
 864                 s->max3100_hw_suspend(1);
 865         else {
 866                 /* no HW suspend, so do SW one */
 867                 u16 tx, rx;
 868
 869                 tx = MAX3100_WC | MAX3100_SHDN;
 870                 max3100_sr(s, tx, &rx);
 871         }
 872         return 0;
 873 }
 874
 875 static int max3100_resume(struct spi_device *spi)
 876 {
 877         struct max3100_port *s = dev_get_drvdata(&spi->dev);
 878
 879         dev_dbg(&s->spi->dev, "%s\n", __func__);
 880
 881         if (s->max3100_hw_suspend)
 882                 s->max3100_hw_suspend(0);
 883         uart_resume_port(&max3100_uart_driver, &s->port);
 884         s->suspending = 0;
 885
 886         enable_irq(s->irq);
 887
 888         s->conf_commit = 1;
 889         if (s->workqueue)
 890                 max3100_dowork(s);
 891
 892         return 0;
 893 }
 894
 895 #else
 896 #define max3100_suspend NULL
 897 #define max3100_resume  NULL
 898 #endif
 899
 900 static struct spi_driver max3100_driver = {
 901         .driver = {
 902                 .name           = "max3100",
 903                 .bus            = &spi_bus_type,
 904                 .owner          = THIS_MODULE,
 905         },
 906
 907         .probe          = max3100_probe,
 908         .remove         = __devexit_p(max3100_remove),
 909         .suspend        = max3100_suspend,
 910         .resume         = max3100_resume,
 911 };
 912
 913 static int __init max3100_init(void)
 914 {
 915         return spi_register_driver(&max3100_driver);
 916 }
 917 module_init(max3100_init);
 918
 919 static void __exit max3100_exit(void)
 920 {
 921         spi_unregister_driver(&max3100_driver);
 922 }
 923 module_exit(max3100_exit);
 924
 925 MODULE_DESCRIPTION("MAX3100 driver");
 926 MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
 927 MODULE_LICENSE("GPL");
 928 MODULE_ALIAS("spi:max3100");