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