linux/drivers/tty/serial/max3100.c
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   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
  92struct 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
 136static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */
 137static DEFINE_MUTEX(max3100s_lock);                /* race on probe */
 138
 139static 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
 157static int max3100_check_parity(struct max3100_port *s, u16 c)
 158{
 159        return max3100_do_parity(s, c) == ((c >> 8) & 1);
 160}
 161
 162static 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
 173static void max3100_work(struct work_struct *w);
 174
 175static 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
 181static 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
 191static 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
 216static 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
 256static 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
 324static 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
 334static 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
 345static 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
 356static 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
 372static 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
 385static 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
 399static 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
 419static void
 420max3100_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
 543static 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
 578static 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
 633static 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
 644static 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
 653static 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
 665static 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
 680static 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
 689static 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
 699static 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
 708static 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
 727static 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};
 735static int uart_driver_registered;
 736
 737static 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
 811static 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
 845static 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
 868static 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
 888static 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
 895static 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
 904module_spi_driver(max3100_driver);
 905
 906MODULE_DESCRIPTION("MAX3100 driver");
 907MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
 908MODULE_LICENSE("GPL");
 909MODULE_ALIAS("spi:max3100");
 910