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