drivers/spi/spi-bfin-sport.c

   1 /*
   2  * SPI bus via the Blackfin SPORT peripheral
   3  *
   4  * Enter bugs at http://blackfin.uclinux.org/
   5  *
   6  * Copyright 2009-2011 Analog Devices Inc.
   7  *
   8  * Licensed under the GPL-2 or later.
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/delay.h>
  14 #include <linux/device.h>
  15 #include <linux/gpio.h>
  16 #include <linux/io.h>
  17 #include <linux/ioport.h>
  18 #include <linux/irq.h>
  19 #include <linux/errno.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/spi/spi.h>
  23 #include <linux/workqueue.h>
  24
  25 #include <asm/portmux.h>
  26 #include <asm/bfin5xx_spi.h>
  27 #include <asm/blackfin.h>
  28 #include <asm/bfin_sport.h>
  29 #include <asm/cacheflush.h>
  30
  31 #define DRV_NAME        "bfin-sport-spi"
  32 #define DRV_DESC        "SPI bus via the Blackfin SPORT"
  33
  34 MODULE_AUTHOR("Cliff Cai");
  35 MODULE_DESCRIPTION(DRV_DESC);
  36 MODULE_LICENSE("GPL");
  37 MODULE_ALIAS("platform:bfin-sport-spi");
  38
  39 enum bfin_sport_spi_state {
  40         START_STATE,
  41         RUNNING_STATE,
  42         DONE_STATE,
  43         ERROR_STATE,
  44 };
  45
  46 struct bfin_sport_spi_master_data;
  47
  48 struct bfin_sport_transfer_ops {
  49         void (*write) (struct bfin_sport_spi_master_data *);
  50         void (*read) (struct bfin_sport_spi_master_data *);
  51         void (*duplex) (struct bfin_sport_spi_master_data *);
  52 };
  53
  54 struct bfin_sport_spi_master_data {
  55         /* Driver model hookup */
  56         struct device *dev;
  57
  58         /* SPI framework hookup */
  59         struct spi_master *master;
  60
  61         /* Regs base of SPI controller */
  62         struct sport_register __iomem *regs;
  63         int err_irq;
  64
  65         /* Pin request list */
  66         u16 *pin_req;
  67
  68         /* Driver message queue */
  69         struct workqueue_struct *workqueue;
  70         struct work_struct pump_messages;
  71         spinlock_t lock;
  72         struct list_head queue;
  73         int busy;
  74         bool run;
  75
  76         /* Message Transfer pump */
  77         struct tasklet_struct pump_transfers;
  78
  79         /* Current message transfer state info */
  80         enum bfin_sport_spi_state state;
  81         struct spi_message *cur_msg;
  82         struct spi_transfer *cur_transfer;
  83         struct bfin_sport_spi_slave_data *cur_chip;
  84         union {
  85                 void *tx;
  86                 u8 *tx8;
  87                 u16 *tx16;
  88         };
  89         void *tx_end;
  90         union {
  91                 void *rx;
  92                 u8 *rx8;
  93                 u16 *rx16;
  94         };
  95         void *rx_end;
  96
  97         int cs_change;
  98         struct bfin_sport_transfer_ops *ops;
  99 };
 100
 101 struct bfin_sport_spi_slave_data {
 102         u16 ctl_reg;
 103         u16 baud;
 104         u16 cs_chg_udelay;      /* Some devices require > 255usec delay */
 105         u32 cs_gpio;
 106         u16 idle_tx_val;
 107         struct bfin_sport_transfer_ops *ops;
 108 };
 109
 110 static void
 111 bfin_sport_spi_enable(struct bfin_sport_spi_master_data *drv_data)
 112 {
 113         bfin_write_or(&drv_data->regs->tcr1, TSPEN);
 114         bfin_write_or(&drv_data->regs->rcr1, TSPEN);
 115         SSYNC();
 116 }
 117
 118 static void
 119 bfin_sport_spi_disable(struct bfin_sport_spi_master_data *drv_data)
 120 {
 121         bfin_write_and(&drv_data->regs->tcr1, ~TSPEN);
 122         bfin_write_and(&drv_data->regs->rcr1, ~TSPEN);
 123         SSYNC();
 124 }
 125
 126 /* Caculate the SPI_BAUD register value based on input HZ */
 127 static u16
 128 bfin_sport_hz_to_spi_baud(u32 speed_hz)
 129 {
 130         u_long clk, sclk = get_sclk();
 131         int div = (sclk / (2 * speed_hz)) - 1;
 132
 133         if (div < 0)
 134                 div = 0;
 135
 136         clk = sclk / (2 * (div + 1));
 137
 138         if (clk > speed_hz)
 139                 div++;
 140
 141         return div;
 142 }
 143
 144 /* Chip select operation functions for cs_change flag */
 145 static void
 146 bfin_sport_spi_cs_active(struct bfin_sport_spi_slave_data *chip)
 147 {
 148         gpio_direction_output(chip->cs_gpio, 0);
 149 }
 150
 151 static void
 152 bfin_sport_spi_cs_deactive(struct bfin_sport_spi_slave_data *chip)
 153 {
 154         gpio_direction_output(chip->cs_gpio, 1);
 155         /* Move delay here for consistency */
 156         if (chip->cs_chg_udelay)
 157                 udelay(chip->cs_chg_udelay);
 158 }
 159
 160 static void
 161 bfin_sport_spi_stat_poll_complete(struct bfin_sport_spi_master_data *drv_data)
 162 {
 163         unsigned long timeout = jiffies + HZ;
 164         while (!(bfin_read(&drv_data->regs->stat) & RXNE)) {
 165                 if (!time_before(jiffies, timeout))
 166                         break;
 167         }
 168 }
 169
 170 static void
 171 bfin_sport_spi_u8_writer(struct bfin_sport_spi_master_data *drv_data)
 172 {
 173         u16 dummy;
 174
 175         while (drv_data->tx < drv_data->tx_end) {
 176                 bfin_write(&drv_data->regs->tx16, *drv_data->tx8++);
 177                 bfin_sport_spi_stat_poll_complete(drv_data);
 178                 dummy = bfin_read(&drv_data->regs->rx16);
 179         }
 180 }
 181
 182 static void
 183 bfin_sport_spi_u8_reader(struct bfin_sport_spi_master_data *drv_data)
 184 {
 185         u16 tx_val = drv_data->cur_chip->idle_tx_val;
 186
 187         while (drv_data->rx < drv_data->rx_end) {
 188                 bfin_write(&drv_data->regs->tx16, tx_val);
 189                 bfin_sport_spi_stat_poll_complete(drv_data);
 190                 *drv_data->rx8++ = bfin_read(&drv_data->regs->rx16);
 191         }
 192 }
 193
 194 static void
 195 bfin_sport_spi_u8_duplex(struct bfin_sport_spi_master_data *drv_data)
 196 {
 197         while (drv_data->rx < drv_data->rx_end) {
 198                 bfin_write(&drv_data->regs->tx16, *drv_data->tx8++);
 199                 bfin_sport_spi_stat_poll_complete(drv_data);
 200                 *drv_data->rx8++ = bfin_read(&drv_data->regs->rx16);
 201         }
 202 }
 203
 204 static struct bfin_sport_transfer_ops bfin_sport_transfer_ops_u8 = {
 205         .write  = bfin_sport_spi_u8_writer,
 206         .read   = bfin_sport_spi_u8_reader,
 207         .duplex = bfin_sport_spi_u8_duplex,
 208 };
 209
 210 static void
 211 bfin_sport_spi_u16_writer(struct bfin_sport_spi_master_data *drv_data)
 212 {
 213         u16 dummy;
 214
 215         while (drv_data->tx < drv_data->tx_end) {
 216                 bfin_write(&drv_data->regs->tx16, *drv_data->tx16++);
 217                 bfin_sport_spi_stat_poll_complete(drv_data);
 218                 dummy = bfin_read(&drv_data->regs->rx16);
 219         }
 220 }
 221
 222 static void
 223 bfin_sport_spi_u16_reader(struct bfin_sport_spi_master_data *drv_data)
 224 {
 225         u16 tx_val = drv_data->cur_chip->idle_tx_val;
 226
 227         while (drv_data->rx < drv_data->rx_end) {
 228                 bfin_write(&drv_data->regs->tx16, tx_val);
 229                 bfin_sport_spi_stat_poll_complete(drv_data);
 230                 *drv_data->rx16++ = bfin_read(&drv_data->regs->rx16);
 231         }
 232 }
 233
 234 static void
 235 bfin_sport_spi_u16_duplex(struct bfin_sport_spi_master_data *drv_data)
 236 {
 237         while (drv_data->rx < drv_data->rx_end) {
 238                 bfin_write(&drv_data->regs->tx16, *drv_data->tx16++);
 239                 bfin_sport_spi_stat_poll_complete(drv_data);
 240                 *drv_data->rx16++ = bfin_read(&drv_data->regs->rx16);
 241         }
 242 }
 243
 244 static struct bfin_sport_transfer_ops bfin_sport_transfer_ops_u16 = {
 245         .write  = bfin_sport_spi_u16_writer,
 246         .read   = bfin_sport_spi_u16_reader,
 247         .duplex = bfin_sport_spi_u16_duplex,
 248 };
 249
 250 /* stop controller and re-config current chip */
 251 static void
 252 bfin_sport_spi_restore_state(struct bfin_sport_spi_master_data *drv_data)
 253 {
 254         struct bfin_sport_spi_slave_data *chip = drv_data->cur_chip;
 255         unsigned int bits = (drv_data->ops == &bfin_sport_transfer_ops_u8 ? 7 : 15);
 256
 257         bfin_sport_spi_disable(drv_data);
 258         dev_dbg(drv_data->dev, "restoring spi ctl state\n");
 259
 260         bfin_write(&drv_data->regs->tcr1, chip->ctl_reg);
 261         bfin_write(&drv_data->regs->tcr2, bits);
 262         bfin_write(&drv_data->regs->tclkdiv, chip->baud);
 263         bfin_write(&drv_data->regs->tfsdiv, bits);
 264         SSYNC();
 265
 266         bfin_write(&drv_data->regs->rcr1, chip->ctl_reg & ~(ITCLK | ITFS));
 267         bfin_write(&drv_data->regs->rcr2, bits);
 268         SSYNC();
 269
 270         bfin_sport_spi_cs_active(chip);
 271 }
 272
 273 /* test if there is more transfer to be done */
 274 static enum bfin_sport_spi_state
 275 bfin_sport_spi_next_transfer(struct bfin_sport_spi_master_data *drv_data)
 276 {
 277         struct spi_message *msg = drv_data->cur_msg;
 278         struct spi_transfer *trans = drv_data->cur_transfer;
 279
 280         /* Move to next transfer */
 281         if (trans->transfer_list.next != &msg->transfers) {
 282                 drv_data->cur_transfer =
 283                     list_entry(trans->transfer_list.next,
 284                                struct spi_transfer, transfer_list);
 285                 return RUNNING_STATE;
 286         }
 287
 288         return DONE_STATE;
 289 }
 290
 291 /*
 292  * caller already set message->status;
 293  * dma and pio irqs are blocked give finished message back
 294  */
 295 static void
 296 bfin_sport_spi_giveback(struct bfin_sport_spi_master_data *drv_data)
 297 {
 298         struct bfin_sport_spi_slave_data *chip = drv_data->cur_chip;
 299         unsigned long flags;
 300         struct spi_message *msg;
 301
 302         spin_lock_irqsave(&drv_data->lock, flags);
 303         msg = drv_data->cur_msg;
 304         drv_data->state = START_STATE;
 305         drv_data->cur_msg = NULL;
 306         drv_data->cur_transfer = NULL;
 307         drv_data->cur_chip = NULL;
 308         queue_work(drv_data->workqueue, &drv_data->pump_messages);
 309         spin_unlock_irqrestore(&drv_data->lock, flags);
 310
 311         if (!drv_data->cs_change)
 312                 bfin_sport_spi_cs_deactive(chip);
 313
 314         if (msg->complete)
 315                 msg->complete(msg->context);
 316 }
 317
 318 static irqreturn_t
 319 sport_err_handler(int irq, void *dev_id)
 320 {
 321         struct bfin_sport_spi_master_data *drv_data = dev_id;
 322         u16 status;
 323
 324         dev_dbg(drv_data->dev, "%s enter\n", __func__);
 325         status = bfin_read(&drv_data->regs->stat) & (TOVF | TUVF | ROVF | RUVF);
 326
 327         if (status) {
 328                 bfin_write(&drv_data->regs->stat, status);
 329                 SSYNC();
 330
 331                 bfin_sport_spi_disable(drv_data);
 332                 dev_err(drv_data->dev, "status error:%s%s%s%s\n",
 333                         status & TOVF ? " TOVF" : "",
 334                         status & TUVF ? " TUVF" : "",
 335                         status & ROVF ? " ROVF" : "",
 336                         status & RUVF ? " RUVF" : "");
 337         }
 338
 339         return IRQ_HANDLED;
 340 }
 341
 342 static void
 343 bfin_sport_spi_pump_transfers(unsigned long data)
 344 {
 345         struct bfin_sport_spi_master_data *drv_data = (void *)data;
 346         struct spi_message *message = NULL;
 347         struct spi_transfer *transfer = NULL;
 348         struct spi_transfer *previous = NULL;
 349         struct bfin_sport_spi_slave_data *chip = NULL;
 350         unsigned int bits_per_word;
 351         u32 tranf_success = 1;
 352         u32 transfer_speed;
 353         u8 full_duplex = 0;
 354
 355         /* Get current state information */
 356         message = drv_data->cur_msg;
 357         transfer = drv_data->cur_transfer;
 358         chip = drv_data->cur_chip;
 359
 360         if (transfer->speed_hz)
 361                 transfer_speed = bfin_sport_hz_to_spi_baud(transfer->speed_hz);
 362         else
 363                 transfer_speed = chip->baud;
 364         bfin_write(&drv_data->regs->tclkdiv, transfer_speed);
 365         SSYNC();
 366
 367         /*
 368          * if msg is error or done, report it back using complete() callback
 369          */
 370
 371          /* Handle for abort */
 372         if (drv_data->state == ERROR_STATE) {
 373                 dev_dbg(drv_data->dev, "transfer: we've hit an error\n");
 374                 message->status = -EIO;
 375                 bfin_sport_spi_giveback(drv_data);
 376                 return;
 377         }
 378
 379         /* Handle end of message */
 380         if (drv_data->state == DONE_STATE) {
 381                 dev_dbg(drv_data->dev, "transfer: all done!\n");
 382                 message->status = 0;
 383                 bfin_sport_spi_giveback(drv_data);
 384                 return;
 385         }
 386
 387         /* Delay if requested at end of transfer */
 388         if (drv_data->state == RUNNING_STATE) {
 389                 dev_dbg(drv_data->dev, "transfer: still running ...\n");
 390                 previous = list_entry(transfer->transfer_list.prev,
 391                                       struct spi_transfer, transfer_list);
 392                 if (previous->delay_usecs)
 393                         udelay(previous->delay_usecs);
 394         }
 395
 396         if (transfer->len == 0) {
 397                 /* Move to next transfer of this msg */
 398                 drv_data->state = bfin_sport_spi_next_transfer(drv_data);
 399                 /* Schedule next transfer tasklet */
 400                 tasklet_schedule(&drv_data->pump_transfers);
 401         }
 402
 403         if (transfer->tx_buf != NULL) {
 404                 drv_data->tx = (void *)transfer->tx_buf;
 405                 drv_data->tx_end = drv_data->tx + transfer->len;
 406                 dev_dbg(drv_data->dev, "tx_buf is %p, tx_end is %p\n",
 407                         transfer->tx_buf, drv_data->tx_end);
 408         } else
 409                 drv_data->tx = NULL;
 410
 411         if (transfer->rx_buf != NULL) {
 412                 full_duplex = transfer->tx_buf != NULL;
 413                 drv_data->rx = transfer->rx_buf;
 414                 drv_data->rx_end = drv_data->rx + transfer->len;
 415                 dev_dbg(drv_data->dev, "rx_buf is %p, rx_end is %p\n",
 416                         transfer->rx_buf, drv_data->rx_end);
 417         } else
 418                 drv_data->rx = NULL;
 419
 420         drv_data->cs_change = transfer->cs_change;
 421
 422         /* Bits per word setup */
 423         bits_per_word = transfer->bits_per_word ? : message->spi->bits_per_word;
 424         if (bits_per_word == 8)
 425                 drv_data->ops = &bfin_sport_transfer_ops_u8;
 426         else
 427                 drv_data->ops = &bfin_sport_transfer_ops_u16;
 428
 429         drv_data->state = RUNNING_STATE;
 430
 431         if (drv_data->cs_change)
 432                 bfin_sport_spi_cs_active(chip);
 433
 434         dev_dbg(drv_data->dev,
 435                 "now pumping a transfer: width is %d, len is %d\n",
 436                 bits_per_word, transfer->len);
 437
 438         /* PIO mode write then read */
 439         dev_dbg(drv_data->dev, "doing IO transfer\n");
 440
 441         bfin_sport_spi_enable(drv_data);
 442         if (full_duplex) {
 443                 /* full duplex mode */
 444                 BUG_ON((drv_data->tx_end - drv_data->tx) !=
 445                        (drv_data->rx_end - drv_data->rx));
 446                 drv_data->ops->duplex(drv_data);
 447
 448                 if (drv_data->tx != drv_data->tx_end)
 449                         tranf_success = 0;
 450         } else if (drv_data->tx != NULL) {
 451                 /* write only half duplex */
 452
 453                 drv_data->ops->write(drv_data);
 454
 455                 if (drv_data->tx != drv_data->tx_end)
 456                         tranf_success = 0;
 457         } else if (drv_data->rx != NULL) {
 458                 /* read only half duplex */
 459
 460                 drv_data->ops->read(drv_data);
 461                 if (drv_data->rx != drv_data->rx_end)
 462                         tranf_success = 0;
 463         }
 464         bfin_sport_spi_disable(drv_data);
 465
 466         if (!tranf_success) {
 467                 dev_dbg(drv_data->dev, "IO write error!\n");
 468                 drv_data->state = ERROR_STATE;
 469         } else {
 470                 /* Update total byte transfered */
 471                 message->actual_length += transfer->len;
 472                 /* Move to next transfer of this msg */
 473                 drv_data->state = bfin_sport_spi_next_transfer(drv_data);
 474                 if (drv_data->cs_change)
 475                         bfin_sport_spi_cs_deactive(chip);
 476         }
 477
 478         /* Schedule next transfer tasklet */
 479         tasklet_schedule(&drv_data->pump_transfers);
 480 }
 481
 482 /* pop a msg from queue and kick off real transfer */
 483 static void
 484 bfin_sport_spi_pump_messages(struct work_struct *work)
 485 {
 486         struct bfin_sport_spi_master_data *drv_data;
 487         unsigned long flags;
 488         struct spi_message *next_msg;
 489
 490         drv_data = container_of(work, struct bfin_sport_spi_master_data, pump_messages);
 491
 492         /* Lock queue and check for queue work */
 493         spin_lock_irqsave(&drv_data->lock, flags);
 494         if (list_empty(&drv_data->queue) || !drv_data->run) {
 495                 /* pumper kicked off but no work to do */
 496                 drv_data->busy = 0;
 497                 spin_unlock_irqrestore(&drv_data->lock, flags);
 498                 return;
 499         }
 500
 501         /* Make sure we are not already running a message */
 502         if (drv_data->cur_msg) {
 503                 spin_unlock_irqrestore(&drv_data->lock, flags);
 504                 return;
 505         }
 506
 507         /* Extract head of queue */
 508         next_msg = list_entry(drv_data->queue.next,
 509                 struct spi_message, queue);
 510
 511         drv_data->cur_msg = next_msg;
 512
 513         /* Setup the SSP using the per chip configuration */
 514         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
 515
 516         list_del_init(&drv_data->cur_msg->queue);
 517
 518         /* Initialize message state */
 519         drv_data->cur_msg->state = START_STATE;
 520         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
 521                                             struct spi_transfer, transfer_list);
 522         bfin_sport_spi_restore_state(drv_data);
 523         dev_dbg(drv_data->dev, "got a message to pump, "
 524                 "state is set to: baud %d, cs_gpio %i, ctl 0x%x\n",
 525                 drv_data->cur_chip->baud, drv_data->cur_chip->cs_gpio,
 526                 drv_data->cur_chip->ctl_reg);
 527
 528         dev_dbg(drv_data->dev,
 529                 "the first transfer len is %d\n",
 530                 drv_data->cur_transfer->len);
 531
 532         /* Mark as busy and launch transfers */
 533         tasklet_schedule(&drv_data->pump_transfers);
 534
 535         drv_data->busy = 1;
 536         spin_unlock_irqrestore(&drv_data->lock, flags);
 537 }
 538
 539 /*
 540  * got a msg to transfer, queue it in drv_data->queue.
 541  * And kick off message pumper
 542  */
 543 static int
 544 bfin_sport_spi_transfer(struct spi_device *spi, struct spi_message *msg)
 545 {
 546         struct bfin_sport_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
 547         unsigned long flags;
 548
 549         spin_lock_irqsave(&drv_data->lock, flags);
 550
 551         if (!drv_data->run) {
 552                 spin_unlock_irqrestore(&drv_data->lock, flags);
 553                 return -ESHUTDOWN;
 554         }
 555
 556         msg->actual_length = 0;
 557         msg->status = -EINPROGRESS;
 558         msg->state = START_STATE;
 559
 560         dev_dbg(&spi->dev, "adding an msg in transfer()\n");
 561         list_add_tail(&msg->queue, &drv_data->queue);
 562
 563         if (drv_data->run && !drv_data->busy)
 564                 queue_work(drv_data->workqueue, &drv_data->pump_messages);
 565
 566         spin_unlock_irqrestore(&drv_data->lock, flags);
 567
 568         return 0;
 569 }
 570
 571 /* Called every time common spi devices change state */
 572 static int
 573 bfin_sport_spi_setup(struct spi_device *spi)
 574 {
 575         struct bfin_sport_spi_slave_data *chip, *first = NULL;
 576         int ret;
 577
 578         /* Only alloc (or use chip_info) on first setup */
 579         chip = spi_get_ctldata(spi);
 580         if (chip == NULL) {
 581                 struct bfin5xx_spi_chip *chip_info;
 582
 583                 chip = first = kzalloc(sizeof(*chip), GFP_KERNEL);
 584                 if (!chip)
 585                         return -ENOMEM;
 586
 587                 /* platform chip_info isn't required */
 588                 chip_info = spi->controller_data;
 589                 if (chip_info) {
 590                         /*
 591                          * DITFS and TDTYPE are only thing we don't set, but
 592                          * they probably shouldn't be changed by people.
 593                          */
 594                         if (chip_info->ctl_reg || chip_info->enable_dma) {
 595                                 ret = -EINVAL;
 596                                 dev_err(&spi->dev, "don't set ctl_reg/enable_dma fields");
 597                                 goto error;
 598                         }
 599                         chip->cs_chg_udelay = chip_info->cs_chg_udelay;
 600                         chip->idle_tx_val = chip_info->idle_tx_val;
 601                         spi->bits_per_word = chip_info->bits_per_word;
 602                 }
 603         }
 604
 605         if (spi->bits_per_word != 8 && spi->bits_per_word != 16) {
 606                 ret = -EINVAL;
 607                 goto error;
 608         }
 609
 610         /* translate common spi framework into our register
 611          * following configure contents are same for tx and rx.
 612          */
 613
 614         if (spi->mode & SPI_CPHA)
 615                 chip->ctl_reg &= ~TCKFE;
 616         else
 617                 chip->ctl_reg |= TCKFE;
 618
 619         if (spi->mode & SPI_LSB_FIRST)
 620                 chip->ctl_reg |= TLSBIT;
 621         else
 622                 chip->ctl_reg &= ~TLSBIT;
 623
 624         /* Sport in master mode */
 625         chip->ctl_reg |= ITCLK | ITFS | TFSR | LATFS | LTFS;
 626
 627         chip->baud = bfin_sport_hz_to_spi_baud(spi->max_speed_hz);
 628
 629         chip->cs_gpio = spi->chip_select;
 630         ret = gpio_request(chip->cs_gpio, spi->modalias);
 631         if (ret)
 632                 goto error;
 633
 634         dev_dbg(&spi->dev, "setup spi chip %s, width is %d\n",
 635                         spi->modalias, spi->bits_per_word);
 636         dev_dbg(&spi->dev, "ctl_reg is 0x%x, GPIO is %i\n",
 637                         chip->ctl_reg, spi->chip_select);
 638
 639         spi_set_ctldata(spi, chip);
 640
 641         bfin_sport_spi_cs_deactive(chip);
 642
 643         return ret;
 644
 645  error:
 646         kfree(first);
 647         return ret;
 648 }
 649
 650 /*
 651  * callback for spi framework.
 652  * clean driver specific data
 653  */
 654 static void
 655 bfin_sport_spi_cleanup(struct spi_device *spi)
 656 {
 657         struct bfin_sport_spi_slave_data *chip = spi_get_ctldata(spi);
 658
 659         if (!chip)
 660                 return;
 661
 662         gpio_free(chip->cs_gpio);
 663
 664         kfree(chip);
 665 }
 666
 667 static int
 668 bfin_sport_spi_init_queue(struct bfin_sport_spi_master_data *drv_data)
 669 {
 670         INIT_LIST_HEAD(&drv_data->queue);
 671         spin_lock_init(&drv_data->lock);
 672
 673         drv_data->run = false;
 674         drv_data->busy = 0;
 675
 676         /* init transfer tasklet */
 677         tasklet_init(&drv_data->pump_transfers,
 678                      bfin_sport_spi_pump_transfers, (unsigned long)drv_data);
 679
 680         /* init messages workqueue */
 681         INIT_WORK(&drv_data->pump_messages, bfin_sport_spi_pump_messages);
 682         drv_data->workqueue =
 683             create_singlethread_workqueue(dev_name(drv_data->master->dev.parent));
 684         if (drv_data->workqueue == NULL)
 685                 return -EBUSY;
 686
 687         return 0;
 688 }
 689
 690 static int
 691 bfin_sport_spi_start_queue(struct bfin_sport_spi_master_data *drv_data)
 692 {
 693         unsigned long flags;
 694
 695         spin_lock_irqsave(&drv_data->lock, flags);
 696
 697         if (drv_data->run || drv_data->busy) {
 698                 spin_unlock_irqrestore(&drv_data->lock, flags);
 699                 return -EBUSY;
 700         }
 701
 702         drv_data->run = true;
 703         drv_data->cur_msg = NULL;
 704         drv_data->cur_transfer = NULL;
 705         drv_data->cur_chip = NULL;
 706         spin_unlock_irqrestore(&drv_data->lock, flags);
 707
 708         queue_work(drv_data->workqueue, &drv_data->pump_messages);
 709
 710         return 0;
 711 }
 712
 713 static inline int
 714 bfin_sport_spi_stop_queue(struct bfin_sport_spi_master_data *drv_data)
 715 {
 716         unsigned long flags;
 717         unsigned limit = 500;
 718         int status = 0;
 719
 720         spin_lock_irqsave(&drv_data->lock, flags);
 721
 722         /*
 723          * This is a bit lame, but is optimized for the common execution path.
 724          * A wait_queue on the drv_data->busy could be used, but then the common
 725          * execution path (pump_messages) would be required to call wake_up or
 726          * friends on every SPI message. Do this instead
 727          */
 728         drv_data->run = false;
 729         while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
 730                 spin_unlock_irqrestore(&drv_data->lock, flags);
 731                 msleep(10);
 732                 spin_lock_irqsave(&drv_data->lock, flags);
 733         }
 734
 735         if (!list_empty(&drv_data->queue) || drv_data->busy)
 736                 status = -EBUSY;
 737
 738         spin_unlock_irqrestore(&drv_data->lock, flags);
 739
 740         return status;
 741 }
 742
 743 static inline int
 744 bfin_sport_spi_destroy_queue(struct bfin_sport_spi_master_data *drv_data)
 745 {
 746         int status;
 747
 748         status = bfin_sport_spi_stop_queue(drv_data);
 749         if (status)
 750                 return status;
 751
 752         destroy_workqueue(drv_data->workqueue);
 753
 754         return 0;
 755 }
 756
 757 static int __devinit
 758 bfin_sport_spi_probe(struct platform_device *pdev)
 759 {
 760         struct device *dev = &pdev->dev;
 761         struct bfin5xx_spi_master *platform_info;
 762         struct spi_master *master;
 763         struct resource *res, *ires;
 764         struct bfin_sport_spi_master_data *drv_data;
 765         int status;
 766
 767         platform_info = dev->platform_data;
 768
 769         /* Allocate master with space for drv_data */
 770         master = spi_alloc_master(dev, sizeof(*master) + 16);
 771         if (!master) {
 772                 dev_err(dev, "cannot alloc spi_master\n");
 773                 return -ENOMEM;
 774         }
 775
 776         drv_data = spi_master_get_devdata(master);
 777         drv_data->master = master;
 778         drv_data->dev = dev;
 779         drv_data->pin_req = platform_info->pin_req;
 780
 781         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
 782         master->bus_num = pdev->id;
 783         master->num_chipselect = platform_info->num_chipselect;
 784         master->cleanup = bfin_sport_spi_cleanup;
 785         master->setup = bfin_sport_spi_setup;
 786         master->transfer = bfin_sport_spi_transfer;
 787
 788         /* Find and map our resources */
 789         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 790         if (res == NULL) {
 791                 dev_err(dev, "cannot get IORESOURCE_MEM\n");
 792                 status = -ENOENT;
 793                 goto out_error_get_res;
 794         }
 795
 796         drv_data->regs = ioremap(res->start, resource_size(res));
 797         if (drv_data->regs == NULL) {
 798                 dev_err(dev, "cannot map registers\n");
 799                 status = -ENXIO;
 800                 goto out_error_ioremap;
 801         }
 802
 803         ires = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 804         if (!ires) {
 805                 dev_err(dev, "cannot get IORESOURCE_IRQ\n");
 806                 status = -ENODEV;
 807                 goto out_error_get_ires;
 808         }
 809         drv_data->err_irq = ires->start;
 810
 811         /* Initial and start queue */
 812         status = bfin_sport_spi_init_queue(drv_data);
 813         if (status) {
 814                 dev_err(dev, "problem initializing queue\n");
 815                 goto out_error_queue_alloc;
 816         }
 817
 818         status = bfin_sport_spi_start_queue(drv_data);
 819         if (status) {
 820                 dev_err(dev, "problem starting queue\n");
 821                 goto out_error_queue_alloc;
 822         }
 823
 824         status = request_irq(drv_data->err_irq, sport_err_handler,
 825                 0, "sport_spi_err", drv_data);
 826         if (status) {
 827                 dev_err(dev, "unable to request sport err irq\n");
 828                 goto out_error_irq;
 829         }
 830
 831         status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
 832         if (status) {
 833                 dev_err(dev, "requesting peripherals failed\n");
 834                 goto out_error_peripheral;
 835         }
 836
 837         /* Register with the SPI framework */
 838         platform_set_drvdata(pdev, drv_data);
 839         status = spi_register_master(master);
 840         if (status) {
 841                 dev_err(dev, "problem registering spi master\n");
 842                 goto out_error_master;
 843         }
 844
 845         dev_info(dev, "%s, regs_base@%p\n", DRV_DESC, drv_data->regs);
 846         return 0;
 847
 848  out_error_master:
 849         peripheral_free_list(drv_data->pin_req);
 850  out_error_peripheral:
 851         free_irq(drv_data->err_irq, drv_data);
 852  out_error_irq:
 853  out_error_queue_alloc:
 854         bfin_sport_spi_destroy_queue(drv_data);
 855  out_error_get_ires:
 856         iounmap(drv_data->regs);
 857  out_error_ioremap:
 858  out_error_get_res:
 859         spi_master_put(master);
 860
 861         return status;
 862 }
 863
 864 /* stop hardware and remove the driver */
 865 static int __devexit
 866 bfin_sport_spi_remove(struct platform_device *pdev)
 867 {
 868         struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
 869         int status = 0;
 870
 871         if (!drv_data)
 872                 return 0;
 873
 874         /* Remove the queue */
 875         status = bfin_sport_spi_destroy_queue(drv_data);
 876         if (status)
 877                 return status;
 878
 879         /* Disable the SSP at the peripheral and SOC level */
 880         bfin_sport_spi_disable(drv_data);
 881
 882         /* Disconnect from the SPI framework */
 883         spi_unregister_master(drv_data->master);
 884
 885         peripheral_free_list(drv_data->pin_req);
 886
 887         /* Prevent double remove */
 888         platform_set_drvdata(pdev, NULL);
 889
 890         return 0;
 891 }
 892
 893 #ifdef CONFIG_PM
 894 static int
 895 bfin_sport_spi_suspend(struct platform_device *pdev, pm_message_t state)
 896 {
 897         struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
 898         int status;
 899
 900         status = bfin_sport_spi_stop_queue(drv_data);
 901         if (status)
 902                 return status;
 903
 904         /* stop hardware */
 905         bfin_sport_spi_disable(drv_data);
 906
 907         return status;
 908 }
 909
 910 static int
 911 bfin_sport_spi_resume(struct platform_device *pdev)
 912 {
 913         struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
 914         int status;
 915
 916         /* Enable the SPI interface */
 917         bfin_sport_spi_enable(drv_data);
 918
 919         /* Start the queue running */
 920         status = bfin_sport_spi_start_queue(drv_data);
 921         if (status)
 922                 dev_err(drv_data->dev, "problem resuming queue\n");
 923
 924         return status;
 925 }
 926 #else
 927 # define bfin_sport_spi_suspend NULL
 928 # define bfin_sport_spi_resume  NULL
 929 #endif
 930
 931 static struct platform_driver bfin_sport_spi_driver = {
 932         .driver = {
 933                 .name = DRV_NAME,
 934                 .owner = THIS_MODULE,
 935         },
 936         .probe   = bfin_sport_spi_probe,
 937         .remove  = __devexit_p(bfin_sport_spi_remove),
 938         .suspend = bfin_sport_spi_suspend,
 939         .resume  = bfin_sport_spi_resume,
 940 };
 941 module_platform_driver(bfin_sport_spi_driver);