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