release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/serial/mrst_max3110.c

   1 /*
   2  *  max3110.c - spi uart protocol driver for Maxim 3110 on Moorestown
   3  *
   4  *  Copyright (C) Intel 2008 Feng Tang <feng.tang@intel.com>
   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 availabe interrrupt is used, no need for waiting TXE
  27  *    interrupt for a low speed UART device
  28  */
  29
  30 #include <linux/module.h>
  31 #include <linux/ioport.h>
  32 #include <linux/irq.h>
  33 #include <linux/init.h>
  34 #include <linux/console.h>
  35 #include <linux/sysrq.h>
  36 #include <linux/platform_device.h>
  37 #include <linux/tty.h>
  38 #include <linux/tty_flip.h>
  39 #include <linux/serial_core.h>
  40 #include <linux/serial_reg.h>
  41
  42 #include <linux/kthread.h>
  43 #include <linux/delay.h>
  44 #include <asm/atomic.h>
  45 #include <linux/spi/spi.h>
  46 #include <linux/spi/dw_spi.h>
  47
  48 #include "mrst_max3110.h"
  49
  50 #define PR_FMT  "mrst_max3110: "
  51
  52 #define UART_TX_NEEDED 1
  53 #define CON_TX_NEEDED  2
  54 #define BIT_IRQ_PENDING    3
  55
  56 struct uart_max3110 {
  57         struct uart_port port;
  58         struct spi_device *spi;
  59         char *name;
  60
  61         wait_queue_head_t wq;
  62         struct task_struct *main_thread;
  63         struct task_struct *read_thread;
  64         struct mutex thread_mutex;;
  65
  66         u32 baud;
  67         u16 cur_conf;
  68         u8 clock;
  69         u8 parity, word_7bits;
  70
  71         unsigned long uart_flags;
  72
  73         /* console related */
  74         struct circ_buf con_xmit;
  75
  76         /* irq related */
  77         u16 irq;
  78 };
  79
  80 /* global data structure, may need be removed */
  81 struct uart_max3110 *pmax;
  82 static inline void receive_char(struct uart_max3110 *max, u8 ch);
  83 static void receive_chars(struct uart_max3110 *max,
  84                                 unsigned char *str, int len);
  85 static int max3110_read_multi(struct uart_max3110 *max, int len, u8 *buf);
  86 static void max3110_console_receive(struct uart_max3110 *max);
  87
  88 int max3110_write_then_read(struct uart_max3110 *max,
  89                 const u8 *txbuf, u8 *rxbuf, unsigned len, int always_fast)
  90 {
  91         struct spi_device *spi = max->spi;
  92         struct spi_message      message;
  93         struct spi_transfer     x;
  94         int ret;
  95
  96         if (!txbuf || !rxbuf)
  97                 return -EINVAL;
  98
  99         spi_message_init(&message);
 100         memset(&x, 0, sizeof x);
 101         x.len = len;
 102         x.tx_buf = txbuf;
 103         x.rx_buf = rxbuf;
 104         spi_message_add_tail(&x, &message);
 105
 106         if (always_fast)
 107                 x.speed_hz = 3125000;
 108         else if (max->baud)
 109                 x.speed_hz = max->baud;
 110
 111         /* Do the i/o */
 112         ret = spi_sync(spi, &message);
 113         return ret;
 114 }
 115
 116 /* Write a u16 to the device, and return one u16 read back */
 117 int max3110_out(struct uart_max3110 *max, const u16 out)
 118 {
 119         u16 tmp;
 120         int ret;
 121
 122         ret = max3110_write_then_read(max, (u8 *)&out, (u8 *)&tmp, 2, 1);
 123         if (ret)
 124                 return ret;
 125
 126         /* If some valid data is read back */
 127         if (tmp & MAX3110_READ_DATA_AVAILABLE)
 128                 receive_char(max, (tmp & 0xff));
 129
 130         return ret;
 131 }
 132
 133 #define MAX_READ_LEN    20
 134 /*
 135  * This is usually used to read data from SPIC RX FIFO, which doesn't
 136  * need any delay like flushing character out. It returns how many
 137  * valide bytes are read back
 138  */
 139 static int max3110_read_multi(struct uart_max3110 *max, int len, u8 *buf)
 140 {
 141         u16 out[MAX_READ_LEN], in[MAX_READ_LEN];
 142         u8 *pbuf, valid_str[MAX_READ_LEN];
 143         int i, j, bytelen;
 144
 145         if (len > MAX_READ_LEN) {
 146                 pr_err(PR_FMT "read len %d is too large\n", len);
 147                 return 0;
 148         }
 149
 150         bytelen = len * 2;
 151         memset(out, 0, bytelen);
 152         memset(in, 0, bytelen);
 153
 154         if (max3110_write_then_read(max, (u8 *)out, (u8 *)in, bytelen, 1))
 155                 return 0;
 156
 157         /* If caller don't provide a buffer, then handle received char */
 158         pbuf = buf ? buf : valid_str;
 159
 160         for (i = 0, j = 0; i < len; i++) {
 161                 if (in[i] & MAX3110_READ_DATA_AVAILABLE)
 162                         pbuf[j++] = (u8)(in[i] & 0xff);
 163         }
 164
 165         if (j && (pbuf == valid_str))
 166                 receive_chars(max, valid_str, j);
 167
 168         return j;
 169 }
 170
 171 static void serial_m3110_con_putchar(struct uart_port *port, int ch)
 172 {
 173         struct uart_max3110 *max =
 174                 container_of(port, struct uart_max3110, port);
 175         struct circ_buf *xmit = &max->con_xmit;
 176
 177         if (uart_circ_chars_free(xmit)) {
 178                 xmit->buf[xmit->head] = (char)ch;
 179                 xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
 180         }
 181
 182
 183         if (!test_and_set_bit(CON_TX_NEEDED, &max->uart_flags))
 184                 wake_up_process(max->main_thread);
 185 }
 186
 187 /*
 188  * Print a string to the serial port trying not to disturb
 189  * any possible real use of the port...
 190  *
 191  *      The console_lock must be held when we get here.
 192  */
 193 static void serial_m3110_con_write(struct console *co,
 194                                 const char *s, unsigned int count)
 195 {
 196         if (!pmax)
 197                 return;
 198
 199         uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
 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 (!max) {
 214                 pr_err(PR_FMT "pmax is NULL, return");
 215                 return -ENODEV;
 216         }
 217
 218         if (options)
 219                 uart_parse_options(options, &baud, &parity, &bits, &flow);
 220
 221         return uart_set_options(&max->port, co, baud, parity, bits, flow);
 222 }
 223
 224 static struct tty_driver *serial_m3110_con_device(struct console *co,
 225                                                         int *index)
 226 {
 227         struct uart_driver *p = co->data;
 228         *index = co->index;
 229         return p->tty_driver;
 230 }
 231
 232 static struct uart_driver serial_m3110_reg;
 233 static struct console serial_m3110_console = {
 234         .name           = "ttyS",
 235         .write          = serial_m3110_con_write,
 236         .device         = serial_m3110_con_device,
 237         .setup          = serial_m3110_con_setup,
 238         .flags          = CON_PRINTBUFFER,
 239         .index          = -1,
 240         .data           = &serial_m3110_reg,
 241 };
 242
 243 #define MRST_CONSOLE    (&serial_m3110_console)
 244
 245 static unsigned int serial_m3110_tx_empty(struct uart_port *port)
 246 {
 247         return 1;
 248 }
 249
 250 static void serial_m3110_stop_tx(struct uart_port *port)
 251 {
 252         return;
 253 }
 254
 255 /* stop_rx will be called in spin_lock env */
 256 static void serial_m3110_stop_rx(struct uart_port *port)
 257 {
 258         return;
 259 }
 260
 261 #define WORDS_PER_XFER  128
 262 static inline void send_circ_buf(struct uart_max3110 *max,
 263                                 struct circ_buf *xmit)
 264 {
 265         int len, left = 0;
 266         u16 obuf[WORDS_PER_XFER], ibuf[WORDS_PER_XFER];
 267         u8 valid_str[WORDS_PER_XFER];
 268         int i, j;
 269
 270         while (!uart_circ_empty(xmit)) {
 271                 left = uart_circ_chars_pending(xmit);
 272                 while (left) {
 273                         len = (left >= WORDS_PER_XFER) ? WORDS_PER_XFER : left;
 274
 275                         memset(obuf, 0, len * 2);
 276                         memset(ibuf, 0, len * 2);
 277                         for (i = 0; i < len; i++) {
 278                                 obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG;
 279                                 xmit->tail = (xmit->tail + 1) &
 280                                                 (UART_XMIT_SIZE - 1);
 281                         }
 282                         max3110_write_then_read(max, (u8 *)obuf,
 283                                                 (u8 *)ibuf, len * 2, 0);
 284
 285                         for (i = 0, j = 0; i < len; i++) {
 286                                 if (ibuf[i] & MAX3110_READ_DATA_AVAILABLE)
 287                                         valid_str[j++] = (u8)(ibuf[i] & 0xff);
 288                         }
 289
 290                         if (j)
 291                                 receive_chars(max, valid_str, j);
 292
 293                         max->port.icount.tx += len;
 294                         left -= len;
 295                 }
 296         }
 297 }
 298
 299 static void transmit_char(struct uart_max3110 *max)
 300 {
 301         struct uart_port *port = &max->port;
 302         struct circ_buf *xmit = &port->state->xmit;
 303
 304         if (uart_circ_empty(xmit) || uart_tx_stopped(port))
 305                 return;
 306
 307         send_circ_buf(max, xmit);
 308
 309         if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 310                 uart_write_wakeup(port);
 311
 312         if (uart_circ_empty(xmit))
 313                 serial_m3110_stop_tx(port);
 314 }
 315
 316 /* This will be called by uart_write() and tty_write, can't
 317  * go to sleep */
 318 static void serial_m3110_start_tx(struct uart_port *port)
 319 {
 320         struct uart_max3110 *max =
 321                 container_of(port, struct uart_max3110, port);
 322
 323         if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
 324                 wake_up_process(max->main_thread);
 325 }
 326
 327 static void receive_chars(struct uart_max3110 *max, unsigned char *str, int len)
 328 {
 329         struct uart_port *port = &max->port;
 330         struct tty_struct *tty;
 331         int usable;
 332
 333         /* If uart is not opened, just return */
 334         if (!port->state)
 335                 return;
 336
 337         tty = port->state->port.tty;
 338         if (!tty)
 339                 return; /* receive some char before the tty is opened */
 340
 341         while (len) {
 342                 usable = tty_buffer_request_room(tty, len);
 343                 if (usable) {
 344                         tty_insert_flip_string(tty, str, usable);
 345                         str += usable;
 346                         port->icount.rx += usable;
 347                         tty_flip_buffer_push(tty);
 348                 }
 349                 len -= usable;
 350         }
 351 }
 352
 353 static inline void receive_char(struct uart_max3110 *max, u8 ch)
 354 {
 355         receive_chars(max, &ch, 1);
 356 }
 357
 358 static void max3110_console_receive(struct uart_max3110 *max)
 359 {
 360         int loop = 1, num, total = 0;
 361         u8 recv_buf[512], *pbuf;
 362
 363         pbuf = recv_buf;
 364         do {
 365                 num = max3110_read_multi(max, 8, pbuf);
 366
 367                 if (num) {
 368                         loop = 10;
 369                         pbuf += num;
 370                         total += num;
 371
 372                         if (total >= 500) {
 373                                 receive_chars(max, recv_buf, total);
 374                                 pbuf = recv_buf;
 375                                 total = 0;
 376                         }
 377                 }
 378         } while (--loop);
 379
 380         if (total)
 381                 receive_chars(max, recv_buf, total);
 382 }
 383
 384 static int max3110_main_thread(void *_max)
 385 {
 386         struct uart_max3110 *max = _max;
 387         wait_queue_head_t *wq = &max->wq;
 388         int ret = 0;
 389         struct circ_buf *xmit = &max->con_xmit;
 390
 391         init_waitqueue_head(wq);
 392         pr_info(PR_FMT "start main thread\n");
 393
 394         do {
 395                 wait_event_interruptible(*wq, max->uart_flags || kthread_should_stop());
 396
 397                 mutex_lock(&max->thread_mutex);
 398
 399                 if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
 400                         max3110_console_receive(max);
 401
 402                 /* first handle console output */
 403                 if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
 404                         send_circ_buf(max, xmit);
 405
 406                 /* handle uart output */
 407                 if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
 408                         transmit_char(max);
 409
 410                 mutex_unlock(&max->thread_mutex);
 411
 412         } while (!kthread_should_stop());
 413
 414         return ret;
 415 }
 416
 417 #ifdef CONFIG_MRST_MAX3110_IRQ
 418 static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
 419 {
 420         struct uart_max3110 *max = dev_id;
 421
 422         /* max3110's irq is a falling edge, not level triggered,
 423          * so no need to disable the irq */
 424         if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
 425                 wake_up_process(max->main_thread);
 426
 427         return IRQ_HANDLED;
 428 }
 429 #else
 430 /* if don't use RX IRQ, then need a thread to polling read */
 431 static int max3110_read_thread(void *_max)
 432 {
 433         struct uart_max3110 *max = _max;
 434
 435         pr_info(PR_FMT "start read thread\n");
 436         do {
 437                 mutex_lock(&max->thread_mutex);
 438                 max3110_console_receive(max);
 439                 mutex_unlock(&max->thread_mutex);
 440
 441                 set_current_state(TASK_INTERRUPTIBLE);
 442                 schedule_timeout(HZ / 20);
 443         } while (!kthread_should_stop());
 444
 445         return 0;
 446 }
 447 #endif
 448
 449 static int serial_m3110_startup(struct uart_port *port)
 450 {
 451         struct uart_max3110 *max =
 452                 container_of(port, struct uart_max3110, port);
 453         u16 config = 0;
 454         int ret = 0;
 455
 456         if (port->line != 0)
 457                 pr_err(PR_FMT "uart port startup failed\n");
 458
 459         /* firstly disable all IRQ and config it to 115200, 8n1 */
 460         config = WC_TAG | WC_FIFO_ENABLE
 461                         | WC_1_STOPBITS
 462                         | WC_8BIT_WORD
 463                         | WC_BAUD_DR2;
 464         ret = max3110_out(max, config);
 465
 466         /* as we use thread to handle tx/rx, need set low latency */
 467         port->state->port.tty->low_latency = 1;
 468
 469 #ifdef CONFIG_MRST_MAX3110_IRQ
 470         ret = request_irq(max->irq, serial_m3110_irq,
 471                                 IRQ_TYPE_EDGE_FALLING, "max3110", max);
 472         if (ret)
 473                 return ret;
 474
 475         /* enable RX IRQ only */
 476         config |= WC_RXA_IRQ_ENABLE;
 477         max3110_out(max, config);
 478 #else
 479         /* if IRQ is disabled, start a read thread for input data */
 480         max->read_thread =
 481                 kthread_run(max3110_read_thread, max, "max3110_read");
 482 #endif
 483
 484         max->cur_conf = config;
 485         return 0;
 486 }
 487
 488 static void serial_m3110_shutdown(struct uart_port *port)
 489 {
 490         struct uart_max3110 *max =
 491                 container_of(port, struct uart_max3110, port);
 492         u16 config;
 493
 494         if (max->read_thread) {
 495                 kthread_stop(max->read_thread);
 496                 max->read_thread = NULL;
 497         }
 498
 499 #ifdef CONFIG_MRST_MAX3110_IRQ
 500         free_irq(max->irq, max);
 501 #endif
 502
 503         /* Disable interrupts from this port */
 504         config = WC_TAG | WC_SW_SHDI;
 505         max3110_out(max, config);
 506 }
 507
 508 static void serial_m3110_release_port(struct uart_port *port)
 509 {
 510 }
 511
 512 static int serial_m3110_request_port(struct uart_port *port)
 513 {
 514         return 0;
 515 }
 516
 517 static void serial_m3110_config_port(struct uart_port *port, int flags)
 518 {
 519         /* give it fake type */
 520         port->type = PORT_PXA;
 521 }
 522
 523 static int
 524 serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser)
 525 {
 526         /* we don't want the core code to modify any port params */
 527         return -EINVAL;
 528 }
 529
 530
 531 static const char *serial_m3110_type(struct uart_port *port)
 532 {
 533         struct uart_max3110 *max =
 534                 container_of(port, struct uart_max3110, port);
 535         return max->name;
 536 }
 537
 538 static void
 539 serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
 540                        struct ktermios *old)
 541 {
 542         struct uart_max3110 *max =
 543                 container_of(port, struct uart_max3110, port);
 544         unsigned char cval;
 545         unsigned int baud, parity = 0;
 546         int clk_div = -1;
 547         u16 new_conf = max->cur_conf;
 548
 549         switch (termios->c_cflag & CSIZE) {
 550         case CS7:
 551                 cval = UART_LCR_WLEN7;
 552                 new_conf |= WC_7BIT_WORD;
 553                 break;
 554         default:
 555         case CS8:
 556                 cval = UART_LCR_WLEN8;
 557                 new_conf |= WC_8BIT_WORD;
 558                 break;
 559         }
 560
 561         baud = uart_get_baud_rate(port, termios, old, 0, 230400);
 562
 563         /* first calc the div for 1.8MHZ clock case */
 564         switch (baud) {
 565         case 300:
 566                 clk_div = WC_BAUD_DR384;
 567                 break;
 568         case 600:
 569                 clk_div = WC_BAUD_DR192;
 570                 break;
 571         case 1200:
 572                 clk_div = WC_BAUD_DR96;
 573                 break;
 574         case 2400:
 575                 clk_div = WC_BAUD_DR48;
 576                 break;
 577         case 4800:
 578                 clk_div = WC_BAUD_DR24;
 579                 break;
 580         case 9600:
 581                 clk_div = WC_BAUD_DR12;
 582                 break;
 583         case 19200:
 584                 clk_div = WC_BAUD_DR6;
 585                 break;
 586         case 38400:
 587                 clk_div = WC_BAUD_DR3;
 588                 break;
 589         case 57600:
 590                 clk_div = WC_BAUD_DR2;
 591                 break;
 592         case 115200:
 593                 clk_div = WC_BAUD_DR1;
 594                 break;
 595         case 230400:
 596                 if (max->clock & MAX3110_HIGH_CLK)
 597                         break;
 598         default:
 599                 /* pick the previous baud rate */
 600                 baud = max->baud;
 601                 clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
 602                 tty_termios_encode_baud_rate(termios, baud, baud);
 603         }
 604
 605         if (max->clock & MAX3110_HIGH_CLK) {
 606                 clk_div += 1;
 607                 /* high clk version max3110 doesn't support B300 */
 608                 if (baud == 300)
 609                         baud = 600;
 610                 if (baud == 230400)
 611                         clk_div = WC_BAUD_DR1;
 612                 tty_termios_encode_baud_rate(termios, baud, baud);
 613         }
 614
 615         new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
 616         if (termios->c_cflag & CSTOPB)
 617                 new_conf |= WC_2_STOPBITS;
 618         else
 619                 new_conf &= ~WC_2_STOPBITS;
 620
 621         if (termios->c_cflag & PARENB) {
 622                 new_conf |= WC_PARITY_ENABLE;
 623                 parity |= UART_LCR_PARITY;
 624         } else
 625                 new_conf &= ~WC_PARITY_ENABLE;
 626
 627         if (!(termios->c_cflag & PARODD))
 628                 parity |= UART_LCR_EPAR;
 629         max->parity = parity;
 630
 631         uart_update_timeout(port, termios->c_cflag, baud);
 632
 633         new_conf |= WC_TAG;
 634         if (new_conf != max->cur_conf) {
 635                 max3110_out(max, new_conf);
 636                 max->cur_conf = new_conf;
 637                 max->baud = baud;
 638         }
 639 }
 640
 641 /* don't handle hw handshaking */
 642 static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
 643 {
 644         return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
 645 }
 646
 647 static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
 648 {
 649 }
 650
 651 static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
 652 {
 653 }
 654
 655 static void serial_m3110_pm(struct uart_port *port, unsigned int state,
 656                         unsigned int oldstate)
 657 {
 658 }
 659
 660 static void serial_m3110_enable_ms(struct uart_port *port)
 661 {
 662 }
 663
 664 struct uart_ops serial_m3110_ops = {
 665         .tx_empty       = serial_m3110_tx_empty,
 666         .set_mctrl      = serial_m3110_set_mctrl,
 667         .get_mctrl      = serial_m3110_get_mctrl,
 668         .stop_tx        = serial_m3110_stop_tx,
 669         .start_tx       = serial_m3110_start_tx,
 670         .stop_rx        = serial_m3110_stop_rx,
 671         .enable_ms      = serial_m3110_enable_ms,
 672         .break_ctl      = serial_m3110_break_ctl,
 673         .startup        = serial_m3110_startup,
 674         .shutdown       = serial_m3110_shutdown,
 675         .set_termios    = serial_m3110_set_termios,     /* must have */
 676         .pm             = serial_m3110_pm,
 677         .type           = serial_m3110_type,
 678         .release_port   = serial_m3110_release_port,
 679         .request_port   = serial_m3110_request_port,
 680         .config_port    = serial_m3110_config_port,
 681         .verify_port    = serial_m3110_verify_port,
 682 };
 683
 684 static struct uart_driver serial_m3110_reg = {
 685         .owner          = THIS_MODULE,
 686         .driver_name    = "MRST serial",
 687         .dev_name       = "ttyS",
 688         .major          = TTY_MAJOR,
 689         .minor          = 64,
 690         .nr             = 1,
 691         .cons           = MRST_CONSOLE,
 692 };
 693
 694 static int serial_m3110_suspend(struct spi_device *spi, pm_message_t state)
 695 {
 696         return 0;
 697 }
 698
 699 static int serial_m3110_resume(struct spi_device *spi)
 700 {
 701         return 0;
 702 }
 703
 704 static struct dw_spi_chip spi0_uart = {
 705         .poll_mode = 1,
 706         .enable_dma = 0,
 707         .type = SPI_FRF_SPI,
 708 };
 709
 710 static int serial_m3110_probe(struct spi_device *spi)
 711 {
 712         struct uart_max3110 *max;
 713         int ret;
 714         unsigned char *buffer;
 715         u16 res;
 716         max = kzalloc(sizeof(*max), GFP_KERNEL);
 717         if (!max)
 718                 return -ENOMEM;
 719
 720         /* set spi info */
 721         spi->mode = SPI_MODE_0;
 722         spi->bits_per_word = 16;
 723         max->clock = MAX3110_HIGH_CLK;
 724         spi->controller_data = &spi0_uart;
 725
 726         spi_setup(spi);
 727
 728         max->port.type = PORT_PXA;      /* need apply for a max3110 type */
 729         max->port.fifosize = 2;         /* only have 16b buffer */
 730         max->port.ops = &serial_m3110_ops;
 731         max->port.line = 0;
 732         max->port.dev = &spi->dev;
 733         max->port.uartclk = 115200;
 734
 735         max->spi = spi;
 736         max->name = spi->modalias;      /* use spi name as the name */
 737         max->irq = (u16)spi->irq;
 738
 739         mutex_init(&max->thread_mutex);
 740
 741         max->word_7bits = 0;
 742         max->parity = 0;
 743         max->baud = 0;
 744
 745         max->cur_conf = 0;
 746         max->uart_flags = 0;
 747
 748         /* Check if reading configuration register returns something sane */
 749
 750         res = RC_TAG;
 751         ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
 752         if (ret < 0 || res == 0 || res == 0xffff) {
 753                 printk(KERN_ERR "MAX3111 deemed not present (conf reg %04x)",
 754                                                                         res);
 755                 ret = -ENODEV;
 756                 goto err_get_page;
 757         }
 758         buffer = (unsigned char *)__get_free_page(GFP_KERNEL);
 759         if (!buffer) {
 760                 ret = -ENOMEM;
 761                 goto err_get_page;
 762         }
 763         max->con_xmit.buf = (unsigned char *)buffer;
 764         max->con_xmit.head = max->con_xmit.tail = 0;
 765
 766         max->main_thread = kthread_run(max3110_main_thread,
 767                                         max, "max3110_main");
 768         if (IS_ERR(max->main_thread)) {
 769                 ret = PTR_ERR(max->main_thread);
 770                 goto err_kthread;
 771         }
 772
 773         pmax = max;
 774         /* give membase a psudo value to pass serial_core's check */
 775         max->port.membase = (void *)0xff110000;
 776         uart_add_one_port(&serial_m3110_reg, &max->port);
 777
 778         return 0;
 779
 780 err_kthread:
 781         free_page((unsigned long)buffer);
 782 err_get_page:
 783         pmax = NULL;
 784         kfree(max);
 785         return ret;
 786 }
 787
 788 static int max3110_remove(struct spi_device *dev)
 789 {
 790         struct uart_max3110 *max = pmax;
 791
 792         if (!pmax)
 793                 return 0;
 794
 795         pmax = NULL;
 796         uart_remove_one_port(&serial_m3110_reg, &max->port);
 797
 798         free_page((unsigned long)max->con_xmit.buf);
 799
 800         if (max->main_thread)
 801                 kthread_stop(max->main_thread);
 802
 803         kfree(max);
 804         return 0;
 805 }
 806
 807 static struct spi_driver uart_max3110_driver = {
 808         .driver = {
 809                         .name   = "spi_max3111",
 810                         .bus    = &spi_bus_type,
 811                         .owner  = THIS_MODULE,
 812         },
 813         .probe          = serial_m3110_probe,
 814         .remove         = __devexit_p(max3110_remove),
 815         .suspend        = serial_m3110_suspend,
 816         .resume         = serial_m3110_resume,
 817 };
 818
 819
 820 int __init serial_m3110_init(void)
 821 {
 822         int ret = 0;
 823
 824         ret = uart_register_driver(&serial_m3110_reg);
 825         if (ret)
 826                 return ret;
 827
 828         ret = spi_register_driver(&uart_max3110_driver);
 829         if (ret)
 830                 uart_unregister_driver(&serial_m3110_reg);
 831
 832         return ret;
 833 }
 834
 835 void __exit serial_m3110_exit(void)
 836 {
 837         spi_unregister_driver(&uart_max3110_driver);
 838         uart_unregister_driver(&serial_m3110_reg);
 839 }
 840
 841 module_init(serial_m3110_init);
 842 module_exit(serial_m3110_exit);
 843
 844 MODULE_LICENSE("GPL");
 845 MODULE_ALIAS("max3110-uart");