drivers/tty/serial/mrst_max3110.c

   1 /*
   2  *  mrst_max3110.c - spi uart protocol driver for Maxim 3110
   3  *
   4  * Copyright (c) 2008-2010, Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 /*
  21  * Note:
  22  * 1. From Max3110 spec, the Rx FIFO has 8 words, while the Tx FIFO only has
  23  *    1 word. If SPI master controller doesn't support sclk frequency change,
  24  *    then the char need be sent out one by one with some delay
  25  *
  26  * 2. Currently only RX available interrupt is used, no need for waiting TXE
  27  *    interrupt for a low speed UART device
  28  */
  29
  30 #ifdef CONFIG_MAGIC_SYSRQ
  31 #define SUPPORT_SYSRQ
  32 #endif
  33
  34 #include <linux/module.h>
  35 #include <linux/ioport.h>
  36 #include <linux/irq.h>
  37 #include <linux/init.h>
  38 #include <linux/console.h>
  39 #include <linux/tty.h>
  40 #include <linux/tty_flip.h>
  41 #include <linux/serial_core.h>
  42 #include <linux/serial_reg.h>
  43
  44 #include <linux/kthread.h>
  45 #include <linux/spi/spi.h>
  46
  47 #include "mrst_max3110.h"
  48
  49 #define PR_FMT  "mrst_max3110: "
  50
  51 #define UART_TX_NEEDED 1
  52 #define CON_TX_NEEDED  2
  53 #define BIT_IRQ_PENDING    3
  54
  55 struct uart_max3110 {
  56         struct uart_port port;
  57         struct spi_device *spi;
  58         char name[SPI_NAME_SIZE];
  59
  60         wait_queue_head_t wq;
  61         struct task_struct *main_thread;
  62         struct task_struct *read_thread;
  63         struct mutex thread_mutex;
  64
  65         u32 baud;
  66         u16 cur_conf;
  67         u8 clock;
  68         u8 parity, word_7bits;
  69         u16 irq;
  70
  71         unsigned long uart_flags;
  72
  73         /* console related */
  74         struct circ_buf con_xmit;
  75 };
  76
  77 /* global data structure, may need be removed */
  78 static struct uart_max3110 *pmax;
  79
  80 static int receive_chars(struct uart_max3110 *max,
  81                                 unsigned short *str, int len);
  82 static int max3110_read_multi(struct uart_max3110 *max);
  83 static void max3110_con_receive(struct uart_max3110 *max);
  84
  85 static int max3110_write_then_read(struct uart_max3110 *max,
  86                 const void *txbuf, void *rxbuf, unsigned len, int always_fast)
  87 {
  88         struct spi_device *spi = max->spi;
  89         struct spi_message      message;
  90         struct spi_transfer     x;
  91         int ret;
  92
  93         spi_message_init(&message);
  94         memset(&x, 0, sizeof x);
  95         x.len = len;
  96         x.tx_buf = txbuf;
  97         x.rx_buf = rxbuf;
  98         spi_message_add_tail(&x, &message);
  99
 100         if (always_fast)
 101                 x.speed_hz = spi->max_speed_hz;
 102         else if (max->baud)
 103                 x.speed_hz = max->baud;
 104
 105         /* Do the i/o */
 106         ret = spi_sync(spi, &message);
 107         return ret;
 108 }
 109
 110 /* Write a 16b word to the device */
 111 static int max3110_out(struct uart_max3110 *max, const u16 out)
 112 {
 113         void *buf;
 114         u16 *obuf, *ibuf;
 115         int ret;
 116
 117         buf = kzalloc(8, GFP_KERNEL | GFP_DMA);
 118         if (!buf)
 119                 return -ENOMEM;
 120
 121         obuf = buf;
 122         ibuf = buf + 4;
 123         *obuf = out;
 124         ret = max3110_write_then_read(max, obuf, ibuf, 2, 1);
 125         if (ret) {
 126                 pr_warning(PR_FMT "%s(): get err msg %d when sending 0x%x\n",
 127                                 __func__, ret, out);
 128                 goto exit;
 129         }
 130
 131         receive_chars(max, ibuf, 1);
 132
 133 exit:
 134         kfree(buf);
 135         return ret;
 136 }
 137
 138 /*
 139  * This is usually used to read data from SPIC RX FIFO, which doesn't
 140  * need any delay like flushing character out.
 141  *
 142  * Return how many valide bytes are read back
 143  */
 144 static int max3110_read_multi(struct uart_max3110 *max)
 145 {
 146         void *buf;
 147         u16 *obuf, *ibuf;
 148         int ret, blen;
 149
 150         blen = M3110_RX_FIFO_DEPTH * sizeof(u16);
 151         buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA);
 152         if (!buf) {
 153                 pr_warning(PR_FMT "%s(): fail to alloc dma buffer\n", __func__);
 154                 return 0;
 155         }
 156
 157         /* tx/rx always have the same length */
 158         obuf = buf;
 159         ibuf = buf + blen;
 160
 161         if (max3110_write_then_read(max, obuf, ibuf, blen, 1)) {
 162                 kfree(buf);
 163                 return 0;
 164         }
 165
 166         ret = receive_chars(max, ibuf, M3110_RX_FIFO_DEPTH);
 167
 168         kfree(buf);
 169         return ret;
 170 }
 171
 172 static void serial_m3110_con_putchar(struct uart_port *port, int ch)
 173 {
 174         struct uart_max3110 *max =
 175                 container_of(port, struct uart_max3110, port);
 176         struct circ_buf *xmit = &max->con_xmit;
 177
 178         if (uart_circ_chars_free(xmit)) {
 179                 xmit->buf[xmit->head] = (char)ch;
 180                 xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
 181         }
 182 }
 183
 184 /*
 185  * Print a string to the serial port trying not to disturb
 186  * any possible real use of the port...
 187  *
 188  *      The console_lock must be held when we get here.
 189  */
 190 static void serial_m3110_con_write(struct console *co,
 191                                 const char *s, unsigned int count)
 192 {
 193         if (!pmax)
 194                 return;
 195
 196         uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
 197
 198         if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags))
 199                 wake_up(&pmax->wq);
 200 }
 201
 202 static int __init
 203 serial_m3110_con_setup(struct console *co, char *options)
 204 {
 205         struct uart_max3110 *max = pmax;
 206         int baud = 115200;
 207         int bits = 8;
 208         int parity = 'n';
 209         int flow = 'n';
 210
 211         pr_info(PR_FMT "setting up console\n");
 212
 213         if (co->index == -1)
 214                 co->index = 0;
 215
 216         if (!max) {
 217                 pr_err(PR_FMT "pmax is NULL, return");
 218                 return -ENODEV;
 219         }
 220
 221         if (options)
 222                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 223
 224         return uart_set_options(&max->port, co, baud, parity, bits, flow);
 225 }
 226
 227 static struct tty_driver *serial_m3110_con_device(struct console *co,
 228                                                         int *index)
 229 {
 230         struct uart_driver *p = co->data;
 231         *index = co->index;
 232         return p->tty_driver;
 233 }
 234
 235 static struct uart_driver serial_m3110_reg;
 236 static struct console serial_m3110_console = {
 237         .name           = "ttyS",
 238         .write          = serial_m3110_con_write,
 239         .device         = serial_m3110_con_device,
 240         .setup          = serial_m3110_con_setup,
 241         .flags          = CON_PRINTBUFFER,
 242         .index          = -1,
 243         .data           = &serial_m3110_reg,
 244 };
 245
 246 static unsigned int serial_m3110_tx_empty(struct uart_port *port)
 247 {
 248         return 1;
 249 }
 250
 251 static void serial_m3110_stop_tx(struct uart_port *port)
 252 {
 253         return;
 254 }
 255
 256 /* stop_rx will be called in spin_lock env */
 257 static void serial_m3110_stop_rx(struct uart_port *port)
 258 {
 259         return;
 260 }
 261
 262 #define WORDS_PER_XFER  128
 263 static void send_circ_buf(struct uart_max3110 *max,
 264                                 struct circ_buf *xmit)
 265 {
 266         void *buf;
 267         u16 *obuf, *ibuf;
 268         int i, len, blen, dma_size, left, ret = 0;
 269
 270
 271         dma_size = WORDS_PER_XFER * sizeof(u16) * 2;
 272         buf = kzalloc(dma_size, GFP_KERNEL | GFP_DMA);
 273         if (!buf)
 274                 return;
 275         obuf = buf;
 276         ibuf = buf + dma_size/2;
 277
 278         while (!uart_circ_empty(xmit)) {
 279                 left = uart_circ_chars_pending(xmit);
 280                 while (left) {
 281                         len = min(left, WORDS_PER_XFER);
 282                         blen = len * sizeof(u16);
 283                         memset(ibuf, 0, blen);
 284
 285                         for (i = 0; i < len; i++) {
 286                                 obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG;
 287                                 xmit->tail = (xmit->tail + 1) &
 288                                                 (UART_XMIT_SIZE - 1);
 289                         }
 290
 291                         /* Fail to send msg to console is not very critical */
 292
 293                         ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
 294                         if (ret)
 295                                 pr_warning(PR_FMT "%s(): get err msg %d\n",
 296                                                 __func__, ret);
 297
 298                         receive_chars(max, ibuf, len);
 299
 300                         max->port.icount.tx += len;
 301                         left -= len;
 302                 }
 303         }
 304
 305         kfree(buf);
 306 }
 307
 308 static void transmit_char(struct uart_max3110 *max)
 309 {
 310         struct uart_port *port = &max->port;
 311         struct circ_buf *xmit = &port->state->xmit;
 312
 313         if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 314                 return;
 315
 316         send_circ_buf(max, xmit);
 317
 318         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 319                 uart_write_wakeup(port);
 320
 321         if (uart_circ_empty(xmit))
 322                 serial_m3110_stop_tx(port);
 323 }
 324
 325 /*
 326  * This will be called by uart_write() and tty_write, can't
 327  * go to sleep
 328  */
 329 static void serial_m3110_start_tx(struct uart_port *port)
 330 {
 331         struct uart_max3110 *max =
 332                 container_of(port, struct uart_max3110, port);
 333
 334         if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
 335                 wake_up(&max->wq);
 336 }
 337
 338 static int
 339 receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
 340 {
 341         struct uart_port *port = &max->port;
 342         struct tty_struct *tty;
 343         char buf[M3110_RX_FIFO_DEPTH];
 344         int r, w, usable;
 345
 346         /* If uart is not opened, just return */
 347         if (!port->state)
 348                 return 0;
 349
 350         tty = tty_port_tty_get(&port->state->port);
 351         if (!tty)
 352                 return 0;
 353
 354         for (r = 0, w = 0; r < len; r++) {
 355                 if (str[r] & MAX3110_BREAK &&
 356                     uart_handle_break(port))
 357                         continue;
 358
 359                 if (str[r] & MAX3110_READ_DATA_AVAILABLE) {
 360                         if (uart_handle_sysrq_char(port, str[r] & 0xff))
 361                                 continue;
 362
 363                         buf[w++] = str[r] & 0xff;
 364                 }
 365         }
 366
 367         if (!w) {
 368                 tty_kref_put(tty);
 369                 return 0;
 370         }
 371
 372         for (r = 0; w; r += usable, w -= usable) {
 373                 usable = tty_buffer_request_room(tty, w);
 374                 if (usable) {
 375                         tty_insert_flip_string(tty, buf + r, usable);
 376                         port->icount.rx += usable;
 377                 }
 378         }
 379         tty_flip_buffer_push(tty);
 380         tty_kref_put(tty);
 381
 382         return r;
 383 }
 384
 385 /*
 386  * This routine will be used in read_thread or RX IRQ handling,
 387  * it will first do one round buffer read(8 words), if there is some
 388  * valid RX data, will try to read 5 more rounds till all data
 389  * is read out.
 390  *
 391  * Use stack space as data buffer to save some system load, and chose
 392  * 504 Btyes as a threadhold to do a bulk push to upper tty layer when
 393  * receiving bulk data, a much bigger buffer may cause stack overflow
 394  */
 395 static void max3110_con_receive(struct uart_max3110 *max)
 396 {
 397         int loop = 1, num;
 398
 399         do {
 400                 num = max3110_read_multi(max);
 401
 402                 if (num) {
 403                         loop = 5;
 404                 }
 405         } while (--loop);
 406 }
 407
 408 static int max3110_main_thread(void *_max)
 409 {
 410         struct uart_max3110 *max = _max;
 411         wait_queue_head_t *wq = &max->wq;
 412         int ret = 0;
 413         struct circ_buf *xmit = &max->con_xmit;
 414
 415         pr_info(PR_FMT "start main thread\n");
 416
 417         do {
 418                 wait_event_interruptible(*wq,
 419                                 max->uart_flags || kthread_should_stop());
 420
 421                 mutex_lock(&max->thread_mutex);
 422
 423                 if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
 424                         max3110_con_receive(max);
 425
 426                 /* first handle console output */
 427                 if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
 428                         send_circ_buf(max, xmit);
 429
 430                 /* handle uart output */
 431                 if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
 432                         transmit_char(max);
 433
 434                 mutex_unlock(&max->thread_mutex);
 435
 436         } while (!kthread_should_stop());
 437
 438         return ret;
 439 }
 440
 441 static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
 442 {
 443         struct uart_max3110 *max = dev_id;
 444
 445         /* max3110's irq is a falling edge, not level triggered,
 446          * so no need to disable the irq */
 447
 448         if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
 449                 wake_up(&max->wq);
 450
 451         return IRQ_HANDLED;
 452 }
 453
 454 /* if don't use RX IRQ, then need a thread to polling read */
 455 static int max3110_read_thread(void *_max)
 456 {
 457         struct uart_max3110 *max = _max;
 458
 459         pr_info(PR_FMT "start read thread\n");
 460         do {
 461                 /*
 462                  * If can't acquire the mutex, it means the main thread
 463                  * is running which will also perform the rx job
 464                  */
 465                 if (mutex_trylock(&max->thread_mutex)) {
 466                         max3110_con_receive(max);
 467                         mutex_unlock(&max->thread_mutex);
 468                 }
 469
 470                 set_current_state(TASK_INTERRUPTIBLE);
 471                 schedule_timeout(HZ / 20);
 472         } while (!kthread_should_stop());
 473
 474         return 0;
 475 }
 476
 477 static int serial_m3110_startup(struct uart_port *port)
 478 {
 479         struct uart_max3110 *max =
 480                 container_of(port, struct uart_max3110, port);
 481         u16 config = 0;
 482         int ret = 0;
 483
 484         if (port->line != 0) {
 485                 pr_err(PR_FMT "uart port startup failed\n");
 486                 return -1;
 487         }
 488
 489         /* Disable all IRQ and config it to 115200, 8n1 */
 490         config = WC_TAG | WC_FIFO_ENABLE
 491                         | WC_1_STOPBITS
 492                         | WC_8BIT_WORD
 493                         | WC_BAUD_DR2;
 494
 495         /* as we use thread to handle tx/rx, need set low latency */
 496         port->state->port.tty->low_latency = 1;
 497
 498         if (max->irq) {
 499                 max->read_thread = NULL;
 500                 ret = request_irq(max->irq, serial_m3110_irq,
 501                                 IRQ_TYPE_EDGE_FALLING, "max3110", max);
 502                 if (ret) {
 503                         max->irq = 0;
 504                         pr_err(PR_FMT "unable to allocate IRQ, polling\n");
 505                 }  else {
 506                         /* Enable RX IRQ only */
 507                         config |= WC_RXA_IRQ_ENABLE;
 508                 }
 509         }
 510
 511         if (max->irq == 0) {
 512                 /* If IRQ is disabled, start a read thread for input data */
 513                 max->read_thread =
 514                         kthread_run(max3110_read_thread, max, "max3110_read");
 515                 if (IS_ERR(max->read_thread)) {
 516                         ret = PTR_ERR(max->read_thread);
 517                         max->read_thread = NULL;
 518                         pr_err(PR_FMT "Can't create read thread!\n");
 519                         return ret;
 520                 }
 521         }
 522
 523         ret = max3110_out(max, config);
 524         if (ret) {
 525                 if (max->irq)
 526                         free_irq(max->irq, max);
 527                 if (max->read_thread)
 528                         kthread_stop(max->read_thread);
 529                 max->read_thread = NULL;
 530                 return ret;
 531         }
 532
 533         max->cur_conf = config;
 534         return 0;
 535 }
 536
 537 static void serial_m3110_shutdown(struct uart_port *port)
 538 {
 539         struct uart_max3110 *max =
 540                 container_of(port, struct uart_max3110, port);
 541         u16 config;
 542
 543         if (max->read_thread) {
 544                 kthread_stop(max->read_thread);
 545                 max->read_thread = NULL;
 546         }
 547
 548         if (max->irq)
 549                 free_irq(max->irq, max);
 550
 551         /* Disable interrupts from this port */
 552         config = WC_TAG | WC_SW_SHDI;
 553         max3110_out(max, config);
 554 }
 555
 556 static void serial_m3110_release_port(struct uart_port *port)
 557 {
 558 }
 559
 560 static int serial_m3110_request_port(struct uart_port *port)
 561 {
 562         return 0;
 563 }
 564
 565 static void serial_m3110_config_port(struct uart_port *port, int flags)
 566 {
 567         port->type = PORT_MAX3100;
 568 }
 569
 570 static int
 571 serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser)
 572 {
 573         /* we don't want the core code to modify any port params */
 574         return -EINVAL;
 575 }
 576
 577
 578 static const char *serial_m3110_type(struct uart_port *port)
 579 {
 580         struct uart_max3110 *max =
 581                 container_of(port, struct uart_max3110, port);
 582         return max->name;
 583 }
 584
 585 static void
 586 serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
 587                        struct ktermios *old)
 588 {
 589         struct uart_max3110 *max =
 590                 container_of(port, struct uart_max3110, port);
 591         unsigned char cval;
 592         unsigned int baud, parity = 0;
 593         int clk_div = -1;
 594         u16 new_conf = max->cur_conf;
 595
 596         switch (termios->c_cflag & CSIZE) {
 597         case CS7:
 598                 cval = UART_LCR_WLEN7;
 599                 new_conf |= WC_7BIT_WORD;
 600                 break;
 601         default:
 602                 /* We only support CS7 & CS8 */
 603                 termios->c_cflag &= ~CSIZE;
 604                 termios->c_cflag |= CS8;
 605         case CS8:
 606                 cval = UART_LCR_WLEN8;
 607                 new_conf |= WC_8BIT_WORD;
 608                 break;
 609         }
 610
 611         baud = uart_get_baud_rate(port, termios, old, 0, 230400);
 612
 613         /* First calc the div for 1.8MHZ clock case */
 614         switch (baud) {
 615         case 300:
 616                 clk_div = WC_BAUD_DR384;
 617                 break;
 618         case 600:
 619                 clk_div = WC_BAUD_DR192;
 620                 break;
 621         case 1200:
 622                 clk_div = WC_BAUD_DR96;
 623                 break;
 624         case 2400:
 625                 clk_div = WC_BAUD_DR48;
 626                 break;
 627         case 4800:
 628                 clk_div = WC_BAUD_DR24;
 629                 break;
 630         case 9600:
 631                 clk_div = WC_BAUD_DR12;
 632                 break;
 633         case 19200:
 634                 clk_div = WC_BAUD_DR6;
 635                 break;
 636         case 38400:
 637                 clk_div = WC_BAUD_DR3;
 638                 break;
 639         case 57600:
 640                 clk_div = WC_BAUD_DR2;
 641                 break;
 642         case 115200:
 643                 clk_div = WC_BAUD_DR1;
 644                 break;
 645         case 230400:
 646                 if (max->clock & MAX3110_HIGH_CLK)
 647                         break;
 648         default:
 649                 /* Pick the previous baud rate */
 650                 baud = max->baud;
 651                 clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
 652                 tty_termios_encode_baud_rate(termios, baud, baud);
 653         }
 654
 655         if (max->clock & MAX3110_HIGH_CLK) {
 656                 clk_div += 1;
 657                 /* High clk version max3110 doesn't support B300 */
 658                 if (baud == 300) {
 659                         baud = 600;
 660                         clk_div = WC_BAUD_DR384;
 661                 }
 662                 if (baud == 230400)
 663                         clk_div = WC_BAUD_DR1;
 664                 tty_termios_encode_baud_rate(termios, baud, baud);
 665         }
 666
 667         new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
 668
 669         if (unlikely(termios->c_cflag & CMSPAR))
 670                 termios->c_cflag &= ~CMSPAR;
 671
 672         if (termios->c_cflag & CSTOPB)
 673                 new_conf |= WC_2_STOPBITS;
 674         else
 675                 new_conf &= ~WC_2_STOPBITS;
 676
 677         if (termios->c_cflag & PARENB) {
 678                 new_conf |= WC_PARITY_ENABLE;
 679                 parity |= UART_LCR_PARITY;
 680         } else
 681                 new_conf &= ~WC_PARITY_ENABLE;
 682
 683         if (!(termios->c_cflag & PARODD))
 684                 parity |= UART_LCR_EPAR;
 685         max->parity = parity;
 686
 687         uart_update_timeout(port, termios->c_cflag, baud);
 688
 689         new_conf |= WC_TAG;
 690         if (new_conf != max->cur_conf) {
 691                 if (!max3110_out(max, new_conf)) {
 692                         max->cur_conf = new_conf;
 693                         max->baud = baud;
 694                 }
 695         }
 696 }
 697
 698 /* Don't handle hw handshaking */
 699 static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
 700 {
 701         return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
 702 }
 703
 704 static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
 705 {
 706 }
 707
 708 static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
 709 {
 710 }
 711
 712 static void serial_m3110_pm(struct uart_port *port, unsigned int state,
 713                         unsigned int oldstate)
 714 {
 715 }
 716
 717 static void serial_m3110_enable_ms(struct uart_port *port)
 718 {
 719 }
 720
 721 struct uart_ops serial_m3110_ops = {
 722         .tx_empty       = serial_m3110_tx_empty,
 723         .set_mctrl      = serial_m3110_set_mctrl,
 724         .get_mctrl      = serial_m3110_get_mctrl,
 725         .stop_tx        = serial_m3110_stop_tx,
 726         .start_tx       = serial_m3110_start_tx,
 727         .stop_rx        = serial_m3110_stop_rx,
 728         .enable_ms      = serial_m3110_enable_ms,
 729         .break_ctl      = serial_m3110_break_ctl,
 730         .startup        = serial_m3110_startup,
 731         .shutdown       = serial_m3110_shutdown,
 732         .set_termios    = serial_m3110_set_termios,
 733         .pm             = serial_m3110_pm,
 734         .type           = serial_m3110_type,
 735         .release_port   = serial_m3110_release_port,
 736         .request_port   = serial_m3110_request_port,
 737         .config_port    = serial_m3110_config_port,
 738         .verify_port    = serial_m3110_verify_port,
 739 };
 740
 741 static struct uart_driver serial_m3110_reg = {
 742         .owner          = THIS_MODULE,
 743         .driver_name    = "MRST serial",
 744         .dev_name       = "ttyS",
 745         .major          = TTY_MAJOR,
 746         .minor          = 64,
 747         .nr             = 1,
 748         .cons           = &serial_m3110_console,
 749 };
 750
 751 #ifdef CONFIG_PM
 752 static int serial_m3110_suspend(struct spi_device *spi, pm_message_t state)
 753 {
 754         struct uart_max3110 *max = spi_get_drvdata(spi);
 755
 756         disable_irq(max->irq);
 757         uart_suspend_port(&serial_m3110_reg, &max->port);
 758         max3110_out(max, max->cur_conf | WC_SW_SHDI);
 759         return 0;
 760 }
 761
 762 static int serial_m3110_resume(struct spi_device *spi)
 763 {
 764         struct uart_max3110 *max = spi_get_drvdata(spi);
 765
 766         max3110_out(max, max->cur_conf);
 767         uart_resume_port(&serial_m3110_reg, &max->port);
 768         enable_irq(max->irq);
 769         return 0;
 770 }
 771 #else
 772 #define serial_m3110_suspend    NULL
 773 #define serial_m3110_resume     NULL
 774 #endif
 775
 776 static int __devinit serial_m3110_probe(struct spi_device *spi)
 777 {
 778         struct uart_max3110 *max;
 779         void *buffer;
 780         u16 res;
 781         int ret = 0;
 782
 783         max = kzalloc(sizeof(*max), GFP_KERNEL);
 784         if (!max)
 785                 return -ENOMEM;
 786
 787         /* Set spi info */
 788         spi->bits_per_word = 16;
 789         max->clock = MAX3110_HIGH_CLK;
 790
 791         spi_setup(spi);
 792
 793         max->port.type = PORT_MAX3100;
 794         max->port.fifosize = 2;         /* Only have 16b buffer */
 795         max->port.ops = &serial_m3110_ops;
 796         max->port.line = 0;
 797         max->port.dev = &spi->dev;
 798         max->port.uartclk = 115200;
 799
 800         max->spi = spi;
 801         strcpy(max->name, spi->modalias);
 802         max->irq = (u16)spi->irq;
 803
 804         mutex_init(&max->thread_mutex);
 805
 806         max->word_7bits = 0;
 807         max->parity = 0;
 808         max->baud = 0;
 809
 810         max->cur_conf = 0;
 811         max->uart_flags = 0;
 812
 813         /* Check if reading configuration register returns something sane */
 814
 815         res = RC_TAG;
 816         ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
 817         if (ret < 0 || res == 0 || res == 0xffff) {
 818                 dev_dbg(&spi->dev, "MAX3111 deemed not present (conf reg %04x)",
 819                                                                         res);
 820                 ret = -ENODEV;
 821                 goto err_get_page;
 822         }
 823
 824         buffer = (void *)__get_free_page(GFP_KERNEL);
 825         if (!buffer) {
 826                 ret = -ENOMEM;
 827                 goto err_get_page;
 828         }
 829         max->con_xmit.buf = buffer;
 830         max->con_xmit.head = 0;
 831         max->con_xmit.tail = 0;
 832
 833         init_waitqueue_head(&max->wq);
 834
 835         max->main_thread = kthread_run(max3110_main_thread,
 836                                         max, "max3110_main");
 837         if (IS_ERR(max->main_thread)) {
 838                 ret = PTR_ERR(max->main_thread);
 839                 goto err_kthread;
 840         }
 841
 842         spi_set_drvdata(spi, max);
 843         pmax = max;
 844
 845         /* Give membase a psudo value to pass serial_core's check */
 846         max->port.membase = (void *)0xff110000;
 847         uart_add_one_port(&serial_m3110_reg, &max->port);
 848
 849         return 0;
 850
 851 err_kthread:
 852         free_page((unsigned long)buffer);
 853 err_get_page:
 854         kfree(max);
 855         return ret;
 856 }
 857
 858 static int __devexit serial_m3110_remove(struct spi_device *dev)
 859 {
 860         struct uart_max3110 *max = spi_get_drvdata(dev);
 861
 862         if (!max)
 863                 return 0;
 864
 865         uart_remove_one_port(&serial_m3110_reg, &max->port);
 866
 867         free_page((unsigned long)max->con_xmit.buf);
 868
 869         if (max->main_thread)
 870                 kthread_stop(max->main_thread);
 871
 872         kfree(max);
 873         return 0;
 874 }
 875
 876 static struct spi_driver uart_max3110_driver = {
 877         .driver = {
 878                         .name   = "spi_max3111",
 879                         .bus    = &spi_bus_type,
 880                         .owner  = THIS_MODULE,
 881         },
 882         .probe          = serial_m3110_probe,
 883         .remove         = __devexit_p(serial_m3110_remove),
 884         .suspend        = serial_m3110_suspend,
 885         .resume         = serial_m3110_resume,
 886 };
 887
 888 static int __init serial_m3110_init(void)
 889 {
 890         int ret = 0;
 891
 892         ret = uart_register_driver(&serial_m3110_reg);
 893         if (ret)
 894                 return ret;
 895
 896         ret = spi_register_driver(&uart_max3110_driver);
 897         if (ret)
 898                 uart_unregister_driver(&serial_m3110_reg);
 899
 900         return ret;
 901 }
 902
 903 static void __exit serial_m3110_exit(void)
 904 {
 905         spi_unregister_driver(&uart_max3110_driver);
 906         uart_unregister_driver(&serial_m3110_reg);
 907 }
 908
 909 module_init(serial_m3110_init);
 910 module_exit(serial_m3110_exit);
 911
 912 MODULE_LICENSE("GPL v2");
 913 MODULE_ALIAS("spi:max3110-uart");