drivers/tty/serial/max3100.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *
   4  *  Copyright (C) 2008 Christian Pellegrin <chripell@evolware.org>
   5  *
   6  * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have
   7  * to use polling for flow control. TX empty IRQ is unusable, since
   8  * writing conf clears FIFO buffer and we cannot have this interrupt
   9  * always asking us for attention.
  10  *
  11  * Example platform data:
  12
  13  static struct plat_max3100 max3100_plat_data = {
  14  .loopback = 0,
  15  .crystal = 0,
  16  .poll_time = 100,
  17  };
  18
  19  static struct spi_board_info spi_board_info[] = {
  20  {
  21  .modalias      = "max3100",
  22  .platform_data = &max3100_plat_data,
  23  .irq           = IRQ_EINT12,
  24  .max_speed_hz  = 5*1000*1000,
  25  .chip_select   = 0,
  26  },
  27  };
  28
  29  * The initial minor number is 209 in the low-density serial port:
  30  * mknod /dev/ttyMAX0 c 204 209
  31  */
  32
  33 #define MAX3100_MAJOR 204
  34 #define MAX3100_MINOR 209
  35 /* 4 MAX3100s should be enough for everyone */
  36 #define MAX_MAX3100 4
  37
  38 #include <linux/delay.h>
  39 #include <linux/slab.h>
  40 #include <linux/device.h>
  41 #include <linux/module.h>
  42 #include <linux/serial_core.h>
  43 #include <linux/serial.h>
  44 #include <linux/spi/spi.h>
  45 #include <linux/freezer.h>
  46 #include <linux/tty.h>
  47 #include <linux/tty_flip.h>
  48
  49 #include <linux/serial_max3100.h>
  50
  51 #define MAX3100_C    (1<<14)
  52 #define MAX3100_D    (0<<14)
  53 #define MAX3100_W    (1<<15)
  54 #define MAX3100_RX   (0<<15)
  55
  56 #define MAX3100_WC   (MAX3100_W  | MAX3100_C)
  57 #define MAX3100_RC   (MAX3100_RX | MAX3100_C)
  58 #define MAX3100_WD   (MAX3100_W  | MAX3100_D)
  59 #define MAX3100_RD   (MAX3100_RX | MAX3100_D)
  60 #define MAX3100_CMD  (3 << 14)
  61
  62 #define MAX3100_T    (1<<14)
  63 #define MAX3100_R    (1<<15)
  64
  65 #define MAX3100_FEN  (1<<13)
  66 #define MAX3100_SHDN (1<<12)
  67 #define MAX3100_TM   (1<<11)
  68 #define MAX3100_RM   (1<<10)
  69 #define MAX3100_PM   (1<<9)
  70 #define MAX3100_RAM  (1<<8)
  71 #define MAX3100_IR   (1<<7)
  72 #define MAX3100_ST   (1<<6)
  73 #define MAX3100_PE   (1<<5)
  74 #define MAX3100_L    (1<<4)
  75 #define MAX3100_BAUD (0xf)
  76
  77 #define MAX3100_TE   (1<<10)
  78 #define MAX3100_RAFE (1<<10)
  79 #define MAX3100_RTS  (1<<9)
  80 #define MAX3100_CTS  (1<<9)
  81 #define MAX3100_PT   (1<<8)
  82 #define MAX3100_DATA (0xff)
  83
  84 #define MAX3100_RT   (MAX3100_R | MAX3100_T)
  85 #define MAX3100_RTC  (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
  86
  87 /* the following simulate a status reg for ignore_status_mask */
  88 #define MAX3100_STATUS_PE 1
  89 #define MAX3100_STATUS_FE 2
  90 #define MAX3100_STATUS_OE 4
  91
  92 struct max3100_port {
  93         struct uart_port port;
  94         struct spi_device *spi;
  95
  96         int cts;                /* last CTS received for flow ctrl */
  97         int tx_empty;           /* last TX empty bit */
  98
  99         spinlock_t conf_lock;   /* shared data */
 100         int conf_commit;        /* need to make changes */
 101         int conf;               /* configuration for the MAX31000
 102                                  * (bits 0-7, bits 8-11 are irqs) */
 103         int rts_commit;         /* need to change rts */
 104         int rts;                /* rts status */
 105         int baud;               /* current baud rate */
 106
 107         int parity;             /* keeps track if we should send parity */
 108 #define MAX3100_PARITY_ON 1
 109 #define MAX3100_PARITY_ODD 2
 110 #define MAX3100_7BIT 4
 111         int rx_enabled;         /* if we should rx chars */
 112
 113         int irq;                /* irq assigned to the max3100 */
 114
 115         int minor;              /* minor number */
 116         int crystal;            /* 1 if 3.6864Mhz crystal 0 for 1.8432 */
 117         int loopback;           /* 1 if we are in loopback mode */
 118
 119         /* for handling irqs: need workqueue since we do spi_sync */
 120         struct workqueue_struct *workqueue;
 121         struct work_struct work;
 122         /* set to 1 to make the workhandler exit as soon as possible */
 123         int  force_end_work;
 124         /* need to know we are suspending to avoid deadlock on workqueue */
 125         int suspending;
 126
 127         /* hook for suspending MAX3100 via dedicated pin */
 128         void (*max3100_hw_suspend) (int suspend);
 129
 130         /* poll time (in ms) for ctrl lines */
 131         int poll_time;
 132         /* and its timer */
 133         struct timer_list       timer;
 134 };
 135
 136 static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
 137 static DEFINE_MUTEX(max3100s_lock);                /* race on probe */
 138
 139 static int max3100_do_parity(struct max3100_port *s, u16 c)
 140 {
 141         int parity;
 142
 143         if (s->parity & MAX3100_PARITY_ODD)
 144                 parity = 1;
 145         else
 146                 parity = 0;
 147
 148         if (s->parity & MAX3100_7BIT)
 149                 c &= 0x7f;
 150         else
 151                 c &= 0xff;
 152
 153         parity = parity ^ (hweight8(c) & 1);
 154         return parity;
 155 }
 156
 157 static int max3100_check_parity(struct max3100_port *s, u16 c)
 158 {
 159         return max3100_do_parity(s, c) == ((c >> 8) & 1);
 160 }
 161
 162 static void max3100_calc_parity(struct max3100_port *s, u16 *c)
 163 {
 164         if (s->parity & MAX3100_7BIT)
 165                 *c &= 0x7f;
 166         else
 167                 *c &= 0xff;
 168
 169         if (s->parity & MAX3100_PARITY_ON)
 170                 *c |= max3100_do_parity(s, *c) << 8;
 171 }
 172
 173 static void max3100_work(struct work_struct *w);
 174
 175 static void max3100_dowork(struct max3100_port *s)
 176 {
 177         if (!s->force_end_work && !freezing(current) && !s->suspending)
 178                 queue_work(s->workqueue, &s->work);
 179 }
 180
 181 static void max3100_timeout(struct timer_list *t)
 182 {
 183         struct max3100_port *s = from_timer(s, t, timer);
 184
 185         if (s->port.state) {
 186                 max3100_dowork(s);
 187                 mod_timer(&s->timer, jiffies + s->poll_time);
 188         }
 189 }
 190
 191 static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx)
 192 {
 193         struct spi_message message;
 194         u16 etx, erx;
 195         int status;
 196         struct spi_transfer tran = {
 197                 .tx_buf = &etx,
 198                 .rx_buf = &erx,
 199                 .len = 2,
 200         };
 201
 202         etx = cpu_to_be16(tx);
 203         spi_message_init(&message);
 204         spi_message_add_tail(&tran, &message);
 205         status = spi_sync(s->spi, &message);
 206         if (status) {
 207                 dev_warn(&s->spi->dev, "error while calling spi_sync\n");
 208                 return -EIO;
 209         }
 210         *rx = be16_to_cpu(erx);
 211         s->tx_empty = (*rx & MAX3100_T) > 0;
 212         dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
 213         return 0;
 214 }
 215
 216 static int max3100_handlerx(struct max3100_port *s, u16 rx)
 217 {
 218         unsigned int ch, flg, status = 0;
 219         int ret = 0, cts;
 220
 221         if (rx & MAX3100_R && s->rx_enabled) {
 222                 dev_dbg(&s->spi->dev, "%s\n", __func__);
 223                 ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
 224                 if (rx & MAX3100_RAFE) {
 225                         s->port.icount.frame++;
 226                         flg = TTY_FRAME;
 227                         status |= MAX3100_STATUS_FE;
 228                 } else {
 229                         if (s->parity & MAX3100_PARITY_ON) {
 230                                 if (max3100_check_parity(s, rx)) {
 231                                         s->port.icount.rx++;
 232                                         flg = TTY_NORMAL;
 233                                 } else {
 234                                         s->port.icount.parity++;
 235                                         flg = TTY_PARITY;
 236                                         status |= MAX3100_STATUS_PE;
 237                                 }
 238                         } else {
 239                                 s->port.icount.rx++;
 240                                 flg = TTY_NORMAL;
 241                         }
 242                 }
 243                 uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
 244                 ret = 1;
 245         }
 246
 247         cts = (rx & MAX3100_CTS) > 0;
 248         if (s->cts != cts) {
 249                 s->cts = cts;
 250                 uart_handle_cts_change(&s->port, cts ? TIOCM_CTS : 0);
 251         }
 252
 253         return ret;
 254 }
 255
 256 static void max3100_work(struct work_struct *w)
 257 {
 258         struct max3100_port *s = container_of(w, struct max3100_port, work);
 259         int rxchars;
 260         u16 tx, rx;
 261         int conf, cconf, crts;
 262         struct circ_buf *xmit = &s->port.state->xmit;
 263
 264         dev_dbg(&s->spi->dev, "%s\n", __func__);
 265
 266         rxchars = 0;
 267         do {
 268                 spin_lock(&s->conf_lock);
 269                 conf = s->conf;
 270                 cconf = s->conf_commit;
 271                 s->conf_commit = 0;
 272                 crts = s->rts_commit;
 273                 s->rts_commit = 0;
 274                 spin_unlock(&s->conf_lock);
 275                 if (cconf)
 276                         max3100_sr(s, MAX3100_WC | conf, &rx);
 277                 if (crts) {
 278                         max3100_sr(s, MAX3100_WD | MAX3100_TE |
 279                                    (s->rts ? MAX3100_RTS : 0), &rx);
 280                         rxchars += max3100_handlerx(s, rx);
 281                 }
 282
 283                 max3100_sr(s, MAX3100_RD, &rx);
 284                 rxchars += max3100_handlerx(s, rx);
 285
 286                 if (rx & MAX3100_T) {
 287                         tx = 0xffff;
 288                         if (s->port.x_char) {
 289                                 tx = s->port.x_char;
 290                                 s->port.icount.tx++;
 291                                 s->port.x_char = 0;
 292                         } else if (!uart_circ_empty(xmit) &&
 293                                    !uart_tx_stopped(&s->port)) {
 294                                 tx = xmit->buf[xmit->tail];
 295                                 xmit->tail = (xmit->tail + 1) &
 296                                         (UART_XMIT_SIZE - 1);
 297                                 s->port.icount.tx++;
 298                         }
 299                         if (tx != 0xffff) {
 300                                 max3100_calc_parity(s, &tx);
 301                                 tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0);
 302                                 max3100_sr(s, tx, &rx);
 303                                 rxchars += max3100_handlerx(s, rx);
 304                         }
 305                 }
 306
 307                 if (rxchars > 16) {
 308                         tty_flip_buffer_push(&s->port.state->port);
 309                         rxchars = 0;
 310                 }
 311                 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 312                         uart_write_wakeup(&s->port);
 313
 314         } while (!s->force_end_work &&
 315                  !freezing(current) &&
 316                  ((rx & MAX3100_R) ||
 317                   (!uart_circ_empty(xmit) &&
 318                    !uart_tx_stopped(&s->port))));
 319
 320         if (rxchars > 0)
 321                 tty_flip_buffer_push(&s->port.state->port);
 322 }
 323
 324 static irqreturn_t max3100_irq(int irqno, void *dev_id)
 325 {
 326         struct max3100_port *s = dev_id;
 327
 328         dev_dbg(&s->spi->dev, "%s\n", __func__);
 329
 330         max3100_dowork(s);
 331         return IRQ_HANDLED;
 332 }
 333
 334 static void max3100_enable_ms(struct uart_port *port)
 335 {
 336         struct max3100_port *s = container_of(port,
 337                                               struct max3100_port,
 338                                               port);
 339
 340         if (s->poll_time > 0)
 341                 mod_timer(&s->timer, jiffies);
 342         dev_dbg(&s->spi->dev, "%s\n", __func__);
 343 }
 344
 345 static void max3100_start_tx(struct uart_port *port)
 346 {
 347         struct max3100_port *s = container_of(port,
 348                                               struct max3100_port,
 349                                               port);
 350
 351         dev_dbg(&s->spi->dev, "%s\n", __func__);
 352
 353         max3100_dowork(s);
 354 }
 355
 356 static void max3100_stop_rx(struct uart_port *port)
 357 {
 358         struct max3100_port *s = container_of(port,
 359                                               struct max3100_port,
 360                                               port);
 361
 362         dev_dbg(&s->spi->dev, "%s\n", __func__);
 363
 364         s->rx_enabled = 0;
 365         spin_lock(&s->conf_lock);
 366         s->conf &= ~MAX3100_RM;
 367         s->conf_commit = 1;
 368         spin_unlock(&s->conf_lock);
 369         max3100_dowork(s);
 370 }
 371
 372 static unsigned int max3100_tx_empty(struct uart_port *port)
 373 {
 374         struct max3100_port *s = container_of(port,
 375                                               struct max3100_port,
 376                                               port);
 377
 378         dev_dbg(&s->spi->dev, "%s\n", __func__);
 379
 380         /* may not be truly up-to-date */
 381         max3100_dowork(s);
 382         return s->tx_empty;
 383 }
 384
 385 static unsigned int max3100_get_mctrl(struct uart_port *port)
 386 {
 387         struct max3100_port *s = container_of(port,
 388                                               struct max3100_port,
 389                                               port);
 390
 391         dev_dbg(&s->spi->dev, "%s\n", __func__);
 392
 393         /* may not be truly up-to-date */
 394         max3100_dowork(s);
 395         /* always assert DCD and DSR since these lines are not wired */
 396         return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR;
 397 }
 398
 399 static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
 400 {
 401         struct max3100_port *s = container_of(port,
 402                                               struct max3100_port,
 403                                               port);
 404         int rts;
 405
 406         dev_dbg(&s->spi->dev, "%s\n", __func__);
 407
 408         rts = (mctrl & TIOCM_RTS) > 0;
 409
 410         spin_lock(&s->conf_lock);
 411         if (s->rts != rts) {
 412                 s->rts = rts;
 413                 s->rts_commit = 1;
 414                 max3100_dowork(s);
 415         }
 416         spin_unlock(&s->conf_lock);
 417 }
 418
 419 static void
 420 max3100_set_termios(struct uart_port *port, struct ktermios *termios,
 421                     struct ktermios *old)
 422 {
 423         struct max3100_port *s = container_of(port,
 424                                               struct max3100_port,
 425                                               port);
 426         int baud = 0;
 427         unsigned cflag;
 428         u32 param_new, param_mask, parity = 0;
 429
 430         dev_dbg(&s->spi->dev, "%s\n", __func__);
 431
 432         cflag = termios->c_cflag;
 433         param_mask = 0;
 434
 435         baud = tty_termios_baud_rate(termios);
 436         param_new = s->conf & MAX3100_BAUD;
 437         switch (baud) {
 438         case 300:
 439                 if (s->crystal)
 440                         baud = s->baud;
 441                 else
 442                         param_new = 15;
 443                 break;
 444         case 600:
 445                 param_new = 14 + s->crystal;
 446                 break;
 447         case 1200:
 448                 param_new = 13 + s->crystal;
 449                 break;
 450         case 2400:
 451                 param_new = 12 + s->crystal;
 452                 break;
 453         case 4800:
 454                 param_new = 11 + s->crystal;
 455                 break;
 456         case 9600:
 457                 param_new = 10 + s->crystal;
 458                 break;
 459         case 19200:
 460                 param_new = 9 + s->crystal;
 461                 break;
 462         case 38400:
 463                 param_new = 8 + s->crystal;
 464                 break;
 465         case 57600:
 466                 param_new = 1 + s->crystal;
 467                 break;
 468         case 115200:
 469                 param_new = 0 + s->crystal;
 470                 break;
 471         case 230400:
 472                 if (s->crystal)
 473                         param_new = 0;
 474                 else
 475                         baud = s->baud;
 476                 break;
 477         default:
 478                 baud = s->baud;
 479         }
 480         tty_termios_encode_baud_rate(termios, baud, baud);
 481         s->baud = baud;
 482         param_mask |= MAX3100_BAUD;
 483
 484         if ((cflag & CSIZE) == CS8) {
 485                 param_new &= ~MAX3100_L;
 486                 parity &= ~MAX3100_7BIT;
 487         } else {
 488                 param_new |= MAX3100_L;
 489                 parity |= MAX3100_7BIT;
 490                 cflag = (cflag & ~CSIZE) | CS7;
 491         }
 492         param_mask |= MAX3100_L;
 493
 494         if (cflag & CSTOPB)
 495                 param_new |= MAX3100_ST;
 496         else
 497                 param_new &= ~MAX3100_ST;
 498         param_mask |= MAX3100_ST;
 499
 500         if (cflag & PARENB) {
 501                 param_new |= MAX3100_PE;
 502                 parity |= MAX3100_PARITY_ON;
 503         } else {
 504                 param_new &= ~MAX3100_PE;
 505                 parity &= ~MAX3100_PARITY_ON;
 506         }
 507         param_mask |= MAX3100_PE;
 508
 509         if (cflag & PARODD)
 510                 parity |= MAX3100_PARITY_ODD;
 511         else
 512                 parity &= ~MAX3100_PARITY_ODD;
 513
 514         /* mask termios capabilities we don't support */
 515         cflag &= ~CMSPAR;
 516         termios->c_cflag = cflag;
 517
 518         s->port.ignore_status_mask = 0;
 519         if (termios->c_iflag & IGNPAR)
 520                 s->port.ignore_status_mask |=
 521                         MAX3100_STATUS_PE | MAX3100_STATUS_FE |
 522                         MAX3100_STATUS_OE;
 523
 524         /* we are sending char from a workqueue so enable */
 525         s->port.state->port.low_latency = 1;
 526
 527         if (s->poll_time > 0)
 528                 del_timer_sync(&s->timer);
 529
 530         uart_update_timeout(port, termios->c_cflag, baud);
 531
 532         spin_lock(&s->conf_lock);
 533         s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
 534         s->conf_commit = 1;
 535         s->parity = parity;
 536         spin_unlock(&s->conf_lock);
 537         max3100_dowork(s);
 538
 539         if (UART_ENABLE_MS(&s->port, termios->c_cflag))
 540                 max3100_enable_ms(&s->port);
 541 }
 542
 543 static void max3100_shutdown(struct uart_port *port)
 544 {
 545         struct max3100_port *s = container_of(port,
 546                                               struct max3100_port,
 547                                               port);
 548
 549         dev_dbg(&s->spi->dev, "%s\n", __func__);
 550
 551         if (s->suspending)
 552                 return;
 553
 554         s->force_end_work = 1;
 555
 556         if (s->poll_time > 0)
 557                 del_timer_sync(&s->timer);
 558
 559         if (s->workqueue) {
 560                 flush_workqueue(s->workqueue);
 561                 destroy_workqueue(s->workqueue);
 562                 s->workqueue = NULL;
 563         }
 564         if (s->irq)
 565                 free_irq(s->irq, s);
 566
 567         /* set shutdown mode to save power */
 568         if (s->max3100_hw_suspend)
 569                 s->max3100_hw_suspend(1);
 570         else  {
 571                 u16 tx, rx;
 572
 573                 tx = MAX3100_WC | MAX3100_SHDN;
 574                 max3100_sr(s, tx, &rx);
 575         }
 576 }
 577
 578 static int max3100_startup(struct uart_port *port)
 579 {
 580         struct max3100_port *s = container_of(port,
 581                                               struct max3100_port,
 582                                               port);
 583         char b[12];
 584
 585         dev_dbg(&s->spi->dev, "%s\n", __func__);
 586
 587         s->conf = MAX3100_RM;
 588         s->baud = s->crystal ? 230400 : 115200;
 589         s->rx_enabled = 1;
 590
 591         if (s->suspending)
 592                 return 0;
 593
 594         s->force_end_work = 0;
 595         s->parity = 0;
 596         s->rts = 0;
 597
 598         sprintf(b, "max3100-%d", s->minor);
 599         s->workqueue = create_freezable_workqueue(b);
 600         if (!s->workqueue) {
 601                 dev_warn(&s->spi->dev, "cannot create workqueue\n");
 602                 return -EBUSY;
 603         }
 604         INIT_WORK(&s->work, max3100_work);
 605
 606         if (request_irq(s->irq, max3100_irq,
 607                         IRQF_TRIGGER_FALLING, "max3100", s) < 0) {
 608                 dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
 609                 s->irq = 0;
 610                 destroy_workqueue(s->workqueue);
 611                 s->workqueue = NULL;
 612                 return -EBUSY;
 613         }
 614
 615         if (s->loopback) {
 616                 u16 tx, rx;
 617                 tx = 0x4001;
 618                 max3100_sr(s, tx, &rx);
 619         }
 620
 621         if (s->max3100_hw_suspend)
 622                 s->max3100_hw_suspend(0);
 623         s->conf_commit = 1;
 624         max3100_dowork(s);
 625         /* wait for clock to settle */
 626         msleep(50);
 627
 628         max3100_enable_ms(&s->port);
 629
 630         return 0;
 631 }
 632
 633 static const char *max3100_type(struct uart_port *port)
 634 {
 635         struct max3100_port *s = container_of(port,
 636                                               struct max3100_port,
 637                                               port);
 638
 639         dev_dbg(&s->spi->dev, "%s\n", __func__);
 640
 641         return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
 642 }
 643
 644 static void max3100_release_port(struct uart_port *port)
 645 {
 646         struct max3100_port *s = container_of(port,
 647                                               struct max3100_port,
 648                                               port);
 649
 650         dev_dbg(&s->spi->dev, "%s\n", __func__);
 651 }
 652
 653 static void max3100_config_port(struct uart_port *port, int flags)
 654 {
 655         struct max3100_port *s = container_of(port,
 656                                               struct max3100_port,
 657                                               port);
 658
 659         dev_dbg(&s->spi->dev, "%s\n", __func__);
 660
 661         if (flags & UART_CONFIG_TYPE)
 662                 s->port.type = PORT_MAX3100;
 663 }
 664
 665 static int max3100_verify_port(struct uart_port *port,
 666                                struct serial_struct *ser)
 667 {
 668         struct max3100_port *s = container_of(port,
 669                                               struct max3100_port,
 670                                               port);
 671         int ret = -EINVAL;
 672
 673         dev_dbg(&s->spi->dev, "%s\n", __func__);
 674
 675         if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
 676                 ret = 0;
 677         return ret;
 678 }
 679
 680 static void max3100_stop_tx(struct uart_port *port)
 681 {
 682         struct max3100_port *s = container_of(port,
 683                                               struct max3100_port,
 684                                               port);
 685
 686         dev_dbg(&s->spi->dev, "%s\n", __func__);
 687 }
 688
 689 static int max3100_request_port(struct uart_port *port)
 690 {
 691         struct max3100_port *s = container_of(port,
 692                                               struct max3100_port,
 693                                               port);
 694
 695         dev_dbg(&s->spi->dev, "%s\n", __func__);
 696         return 0;
 697 }
 698
 699 static void max3100_break_ctl(struct uart_port *port, int break_state)
 700 {
 701         struct max3100_port *s = container_of(port,
 702                                               struct max3100_port,
 703                                               port);
 704
 705         dev_dbg(&s->spi->dev, "%s\n", __func__);
 706 }
 707
 708 static const struct uart_ops max3100_ops = {
 709         .tx_empty       = max3100_tx_empty,
 710         .set_mctrl      = max3100_set_mctrl,
 711         .get_mctrl      = max3100_get_mctrl,
 712         .stop_tx        = max3100_stop_tx,
 713         .start_tx       = max3100_start_tx,
 714         .stop_rx        = max3100_stop_rx,
 715         .enable_ms      = max3100_enable_ms,
 716         .break_ctl      = max3100_break_ctl,
 717         .startup        = max3100_startup,
 718         .shutdown       = max3100_shutdown,
 719         .set_termios    = max3100_set_termios,
 720         .type           = max3100_type,
 721         .release_port   = max3100_release_port,
 722         .request_port   = max3100_request_port,
 723         .config_port    = max3100_config_port,
 724         .verify_port    = max3100_verify_port,
 725 };
 726
 727 static struct uart_driver max3100_uart_driver = {
 728         .owner          = THIS_MODULE,
 729         .driver_name    = "ttyMAX",
 730         .dev_name       = "ttyMAX",
 731         .major          = MAX3100_MAJOR,
 732         .minor          = MAX3100_MINOR,
 733         .nr             = MAX_MAX3100,
 734 };
 735 static int uart_driver_registered;
 736
 737 static int max3100_probe(struct spi_device *spi)
 738 {
 739         int i, retval;
 740         struct plat_max3100 *pdata;
 741         u16 tx, rx;
 742
 743         mutex_lock(&max3100s_lock);
 744
 745         if (!uart_driver_registered) {
 746                 uart_driver_registered = 1;
 747                 retval = uart_register_driver(&max3100_uart_driver);
 748                 if (retval) {
 749                         printk(KERN_ERR "Couldn't register max3100 uart driver\n");
 750                         mutex_unlock(&max3100s_lock);
 751                         return retval;
 752                 }
 753         }
 754
 755         for (i = 0; i < MAX_MAX3100; i++)
 756                 if (!max3100s[i])
 757                         break;
 758         if (i == MAX_MAX3100) {
 759                 dev_warn(&spi->dev, "too many MAX3100 chips\n");
 760                 mutex_unlock(&max3100s_lock);
 761                 return -ENOMEM;
 762         }
 763
 764         max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL);
 765         if (!max3100s[i]) {
 766                 dev_warn(&spi->dev,
 767                          "kmalloc for max3100 structure %d failed!\n", i);
 768                 mutex_unlock(&max3100s_lock);
 769                 return -ENOMEM;
 770         }
 771         max3100s[i]->spi = spi;
 772         max3100s[i]->irq = spi->irq;
 773         spin_lock_init(&max3100s[i]->conf_lock);
 774         spi_set_drvdata(spi, max3100s[i]);
 775         pdata = dev_get_platdata(&spi->dev);
 776         max3100s[i]->crystal = pdata->crystal;
 777         max3100s[i]->loopback = pdata->loopback;
 778         max3100s[i]->poll_time = msecs_to_jiffies(pdata->poll_time);
 779         if (pdata->poll_time > 0 && max3100s[i]->poll_time == 0)
 780                 max3100s[i]->poll_time = 1;
 781         max3100s[i]->max3100_hw_suspend = pdata->max3100_hw_suspend;
 782         max3100s[i]->minor = i;
 783         timer_setup(&max3100s[i]->timer, max3100_timeout, 0);
 784
 785         dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i);
 786         max3100s[i]->port.irq = max3100s[i]->irq;
 787         max3100s[i]->port.uartclk = max3100s[i]->crystal ? 3686400 : 1843200;
 788         max3100s[i]->port.fifosize = 16;
 789         max3100s[i]->port.ops = &max3100_ops;
 790         max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
 791         max3100s[i]->port.line = i;
 792         max3100s[i]->port.type = PORT_MAX3100;
 793         max3100s[i]->port.dev = &spi->dev;
 794         retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
 795         if (retval < 0)
 796                 dev_warn(&spi->dev,
 797                          "uart_add_one_port failed for line %d with error %d\n",
 798                          i, retval);
 799
 800         /* set shutdown mode to save power. Will be woken-up on open */
 801         if (max3100s[i]->max3100_hw_suspend)
 802                 max3100s[i]->max3100_hw_suspend(1);
 803         else {
 804                 tx = MAX3100_WC | MAX3100_SHDN;
 805                 max3100_sr(max3100s[i], tx, &rx);
 806         }
 807         mutex_unlock(&max3100s_lock);
 808         return 0;
 809 }
 810
 811 static int max3100_remove(struct spi_device *spi)
 812 {
 813         struct max3100_port *s = spi_get_drvdata(spi);
 814         int i;
 815
 816         mutex_lock(&max3100s_lock);
 817
 818         /* find out the index for the chip we are removing */
 819         for (i = 0; i < MAX_MAX3100; i++)
 820                 if (max3100s[i] == s) {
 821                         dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
 822                         uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
 823                         kfree(max3100s[i]);
 824                         max3100s[i] = NULL;
 825                         break;
 826                 }
 827
 828         WARN_ON(i == MAX_MAX3100);
 829
 830         /* check if this is the last chip we have */
 831         for (i = 0; i < MAX_MAX3100; i++)
 832                 if (max3100s[i]) {
 833                         mutex_unlock(&max3100s_lock);
 834                         return 0;
 835                 }
 836         pr_debug("removing max3100 driver\n");
 837         uart_unregister_driver(&max3100_uart_driver);
 838
 839         mutex_unlock(&max3100s_lock);
 840         return 0;
 841 }
 842
 843 #ifdef CONFIG_PM_SLEEP
 844
 845 static int max3100_suspend(struct device *dev)
 846 {
 847         struct max3100_port *s = dev_get_drvdata(dev);
 848
 849         dev_dbg(&s->spi->dev, "%s\n", __func__);
 850
 851         disable_irq(s->irq);
 852
 853         s->suspending = 1;
 854         uart_suspend_port(&max3100_uart_driver, &s->port);
 855
 856         if (s->max3100_hw_suspend)
 857                 s->max3100_hw_suspend(1);
 858         else {
 859                 /* no HW suspend, so do SW one */
 860                 u16 tx, rx;
 861
 862                 tx = MAX3100_WC | MAX3100_SHDN;
 863                 max3100_sr(s, tx, &rx);
 864         }
 865         return 0;
 866 }
 867
 868 static int max3100_resume(struct device *dev)
 869 {
 870         struct max3100_port *s = dev_get_drvdata(dev);
 871
 872         dev_dbg(&s->spi->dev, "%s\n", __func__);
 873
 874         if (s->max3100_hw_suspend)
 875                 s->max3100_hw_suspend(0);
 876         uart_resume_port(&max3100_uart_driver, &s->port);
 877         s->suspending = 0;
 878
 879         enable_irq(s->irq);
 880
 881         s->conf_commit = 1;
 882         if (s->workqueue)
 883                 max3100_dowork(s);
 884
 885         return 0;
 886 }
 887
 888 static SIMPLE_DEV_PM_OPS(max3100_pm_ops, max3100_suspend, max3100_resume);
 889 #define MAX3100_PM_OPS (&max3100_pm_ops)
 890
 891 #else
 892 #define MAX3100_PM_OPS NULL
 893 #endif
 894
 895 static struct spi_driver max3100_driver = {
 896         .driver = {
 897                 .name           = "max3100",
 898                 .pm             = MAX3100_PM_OPS,
 899         },
 900         .probe          = max3100_probe,
 901         .remove         = max3100_remove,
 902 };
 903
 904 module_spi_driver(max3100_driver);
 905
 906 MODULE_DESCRIPTION("MAX3100 driver");
 907 MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
 908 MODULE_LICENSE("GPL");
 909 MODULE_ALIAS("spi:max3100");