drivers/spi/spi_bfin5xx.c

   1 /*
   2  * Blackfin On-Chip SPI Driver
   3  *
   4  * Copyright 2004-2010 Analog Devices Inc.
   5  *
   6  * Enter bugs at http://blackfin.uclinux.org/
   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/slab.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/dma-mapping.h>
  23 #include <linux/spi/spi.h>
  24 #include <linux/workqueue.h>
  25
  26 #include <asm/dma.h>
  27 #include <asm/portmux.h>
  28 #include <asm/bfin5xx_spi.h>
  29 #include <asm/cacheflush.h>
  30
  31 #define DRV_NAME        "bfin-spi"
  32 #define DRV_AUTHOR      "Bryan Wu, Luke Yang"
  33 #define DRV_DESC        "Blackfin on-chip SPI Controller Driver"
  34 #define DRV_VERSION     "1.0"
  35
  36 MODULE_AUTHOR(DRV_AUTHOR);
  37 MODULE_DESCRIPTION(DRV_DESC);
  38 MODULE_LICENSE("GPL");
  39
  40 #define START_STATE     ((void *)0)
  41 #define RUNNING_STATE   ((void *)1)
  42 #define DONE_STATE      ((void *)2)
  43 #define ERROR_STATE     ((void *)-1)
  44
  45 struct bfin_spi_master_data;
  46
  47 struct bfin_spi_transfer_ops {
  48         void (*write) (struct bfin_spi_master_data *);
  49         void (*read) (struct bfin_spi_master_data *);
  50         void (*duplex) (struct bfin_spi_master_data *);
  51 };
  52
  53 struct bfin_spi_master_data {
  54         /* Driver model hookup */
  55         struct platform_device *pdev;
  56
  57         /* SPI framework hookup */
  58         struct spi_master *master;
  59
  60         /* Regs base of SPI controller */
  61         void __iomem *regs_base;
  62
  63         /* Pin request list */
  64         u16 *pin_req;
  65
  66         /* BFIN hookup */
  67         struct bfin5xx_spi_master *master_info;
  68
  69         /* Driver message queue */
  70         struct workqueue_struct *workqueue;
  71         struct work_struct pump_messages;
  72         spinlock_t lock;
  73         struct list_head queue;
  74         int busy;
  75         bool running;
  76
  77         /* Message Transfer pump */
  78         struct tasklet_struct pump_transfers;
  79
  80         /* Current message transfer state info */
  81         struct spi_message *cur_msg;
  82         struct spi_transfer *cur_transfer;
  83         struct bfin_spi_slave_data *cur_chip;
  84         size_t len_in_bytes;
  85         size_t len;
  86         void *tx;
  87         void *tx_end;
  88         void *rx;
  89         void *rx_end;
  90
  91         /* DMA stuffs */
  92         int dma_channel;
  93         int dma_mapped;
  94         int dma_requested;
  95         dma_addr_t rx_dma;
  96         dma_addr_t tx_dma;
  97
  98         int irq_requested;
  99         int spi_irq;
 100
 101         size_t rx_map_len;
 102         size_t tx_map_len;
 103         u8 n_bytes;
 104         u16 ctrl_reg;
 105         u16 flag_reg;
 106
 107         int cs_change;
 108         const struct bfin_spi_transfer_ops *ops;
 109 };
 110
 111 struct bfin_spi_slave_data {
 112         u16 ctl_reg;
 113         u16 baud;
 114         u16 flag;
 115
 116         u8 chip_select_num;
 117         u8 enable_dma;
 118         u16 cs_chg_udelay;      /* Some devices require > 255usec delay */
 119         u32 cs_gpio;
 120         u16 idle_tx_val;
 121         u8 pio_interrupt;       /* use spi data irq */
 122         const struct bfin_spi_transfer_ops *ops;
 123 };
 124
 125 #define DEFINE_SPI_REG(reg, off) \
 126 static inline u16 read_##reg(struct bfin_spi_master_data *drv_data) \
 127         { return bfin_read16(drv_data->regs_base + off); } \
 128 static inline void write_##reg(struct bfin_spi_master_data *drv_data, u16 v) \
 129         { bfin_write16(drv_data->regs_base + off, v); }
 130
 131 DEFINE_SPI_REG(CTRL, 0x00)
 132 DEFINE_SPI_REG(FLAG, 0x04)
 133 DEFINE_SPI_REG(STAT, 0x08)
 134 DEFINE_SPI_REG(TDBR, 0x0C)
 135 DEFINE_SPI_REG(RDBR, 0x10)
 136 DEFINE_SPI_REG(BAUD, 0x14)
 137 DEFINE_SPI_REG(SHAW, 0x18)
 138
 139 static void bfin_spi_enable(struct bfin_spi_master_data *drv_data)
 140 {
 141         u16 cr;
 142
 143         cr = read_CTRL(drv_data);
 144         write_CTRL(drv_data, (cr | BIT_CTL_ENABLE));
 145 }
 146
 147 static void bfin_spi_disable(struct bfin_spi_master_data *drv_data)
 148 {
 149         u16 cr;
 150
 151         cr = read_CTRL(drv_data);
 152         write_CTRL(drv_data, (cr & (~BIT_CTL_ENABLE)));
 153 }
 154
 155 /* Caculate the SPI_BAUD register value based on input HZ */
 156 static u16 hz_to_spi_baud(u32 speed_hz)
 157 {
 158         u_long sclk = get_sclk();
 159         u16 spi_baud = (sclk / (2 * speed_hz));
 160
 161         if ((sclk % (2 * speed_hz)) > 0)
 162                 spi_baud++;
 163
 164         if (spi_baud < MIN_SPI_BAUD_VAL)
 165                 spi_baud = MIN_SPI_BAUD_VAL;
 166
 167         return spi_baud;
 168 }
 169
 170 static int bfin_spi_flush(struct bfin_spi_master_data *drv_data)
 171 {
 172         unsigned long limit = loops_per_jiffy << 1;
 173
 174         /* wait for stop and clear stat */
 175         while (!(read_STAT(drv_data) & BIT_STAT_SPIF) && --limit)
 176                 cpu_relax();
 177
 178         write_STAT(drv_data, BIT_STAT_CLR);
 179
 180         return limit;
 181 }
 182
 183 /* Chip select operation functions for cs_change flag */
 184 static void bfin_spi_cs_active(struct bfin_spi_master_data *drv_data, struct bfin_spi_slave_data *chip)
 185 {
 186         if (likely(chip->chip_select_num < MAX_CTRL_CS)) {
 187                 u16 flag = read_FLAG(drv_data);
 188
 189                 flag &= ~chip->flag;
 190
 191                 write_FLAG(drv_data, flag);
 192         } else {
 193                 gpio_set_value(chip->cs_gpio, 0);
 194         }
 195 }
 196
 197 static void bfin_spi_cs_deactive(struct bfin_spi_master_data *drv_data,
 198                                  struct bfin_spi_slave_data *chip)
 199 {
 200         if (likely(chip->chip_select_num < MAX_CTRL_CS)) {
 201                 u16 flag = read_FLAG(drv_data);
 202
 203                 flag |= chip->flag;
 204
 205                 write_FLAG(drv_data, flag);
 206         } else {
 207                 gpio_set_value(chip->cs_gpio, 1);
 208         }
 209
 210         /* Move delay here for consistency */
 211         if (chip->cs_chg_udelay)
 212                 udelay(chip->cs_chg_udelay);
 213 }
 214
 215 /* enable or disable the pin muxed by GPIO and SPI CS to work as SPI CS */
 216 static inline void bfin_spi_cs_enable(struct bfin_spi_master_data *drv_data,
 217                                       struct bfin_spi_slave_data *chip)
 218 {
 219         if (chip->chip_select_num < MAX_CTRL_CS) {
 220                 u16 flag = read_FLAG(drv_data);
 221
 222                 flag |= (chip->flag >> 8);
 223
 224                 write_FLAG(drv_data, flag);
 225         }
 226 }
 227
 228 static inline void bfin_spi_cs_disable(struct bfin_spi_master_data *drv_data,
 229                                        struct bfin_spi_slave_data *chip)
 230 {
 231         if (chip->chip_select_num < MAX_CTRL_CS) {
 232                 u16 flag = read_FLAG(drv_data);
 233
 234                 flag &= ~(chip->flag >> 8);
 235
 236                 write_FLAG(drv_data, flag);
 237         }
 238 }
 239
 240 /* stop controller and re-config current chip*/
 241 static void bfin_spi_restore_state(struct bfin_spi_master_data *drv_data)
 242 {
 243         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
 244
 245         /* Clear status and disable clock */
 246         write_STAT(drv_data, BIT_STAT_CLR);
 247         bfin_spi_disable(drv_data);
 248         dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");
 249
 250         SSYNC();
 251
 252         /* Load the registers */
 253         write_CTRL(drv_data, chip->ctl_reg);
 254         write_BAUD(drv_data, chip->baud);
 255
 256         bfin_spi_enable(drv_data);
 257         bfin_spi_cs_active(drv_data, chip);
 258 }
 259
 260 /* used to kick off transfer in rx mode and read unwanted RX data */
 261 static inline void bfin_spi_dummy_read(struct bfin_spi_master_data *drv_data)
 262 {
 263         (void) read_RDBR(drv_data);
 264 }
 265
 266 static void bfin_spi_u8_writer(struct bfin_spi_master_data *drv_data)
 267 {
 268         /* clear RXS (we check for RXS inside the loop) */
 269         bfin_spi_dummy_read(drv_data);
 270
 271         while (drv_data->tx < drv_data->tx_end) {
 272                 write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
 273                 /* wait until transfer finished.
 274                    checking SPIF or TXS may not guarantee transfer completion */
 275                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
 276                         cpu_relax();
 277                 /* discard RX data and clear RXS */
 278                 bfin_spi_dummy_read(drv_data);
 279         }
 280 }
 281
 282 static void bfin_spi_u8_reader(struct bfin_spi_master_data *drv_data)
 283 {
 284         u16 tx_val = drv_data->cur_chip->idle_tx_val;
 285
 286         /* discard old RX data and clear RXS */
 287         bfin_spi_dummy_read(drv_data);
 288
 289         while (drv_data->rx < drv_data->rx_end) {
 290                 write_TDBR(drv_data, tx_val);
 291                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
 292                         cpu_relax();
 293                 *(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
 294         }
 295 }
 296
 297 static void bfin_spi_u8_duplex(struct bfin_spi_master_data *drv_data)
 298 {
 299         /* discard old RX data and clear RXS */
 300         bfin_spi_dummy_read(drv_data);
 301
 302         while (drv_data->rx < drv_data->rx_end) {
 303                 write_TDBR(drv_data, (*(u8 *) (drv_data->tx++)));
 304                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
 305                         cpu_relax();
 306                 *(u8 *) (drv_data->rx++) = read_RDBR(drv_data);
 307         }
 308 }
 309
 310 static const struct bfin_spi_transfer_ops bfin_bfin_spi_transfer_ops_u8 = {
 311         .write  = bfin_spi_u8_writer,
 312         .read   = bfin_spi_u8_reader,
 313         .duplex = bfin_spi_u8_duplex,
 314 };
 315
 316 static void bfin_spi_u16_writer(struct bfin_spi_master_data *drv_data)
 317 {
 318         /* clear RXS (we check for RXS inside the loop) */
 319         bfin_spi_dummy_read(drv_data);
 320
 321         while (drv_data->tx < drv_data->tx_end) {
 322                 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
 323                 drv_data->tx += 2;
 324                 /* wait until transfer finished.
 325                    checking SPIF or TXS may not guarantee transfer completion */
 326                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
 327                         cpu_relax();
 328                 /* discard RX data and clear RXS */
 329                 bfin_spi_dummy_read(drv_data);
 330         }
 331 }
 332
 333 static void bfin_spi_u16_reader(struct bfin_spi_master_data *drv_data)
 334 {
 335         u16 tx_val = drv_data->cur_chip->idle_tx_val;
 336
 337         /* discard old RX data and clear RXS */
 338         bfin_spi_dummy_read(drv_data);
 339
 340         while (drv_data->rx < drv_data->rx_end) {
 341                 write_TDBR(drv_data, tx_val);
 342                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
 343                         cpu_relax();
 344                 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
 345                 drv_data->rx += 2;
 346         }
 347 }
 348
 349 static void bfin_spi_u16_duplex(struct bfin_spi_master_data *drv_data)
 350 {
 351         /* discard old RX data and clear RXS */
 352         bfin_spi_dummy_read(drv_data);
 353
 354         while (drv_data->rx < drv_data->rx_end) {
 355                 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
 356                 drv_data->tx += 2;
 357                 while (!(read_STAT(drv_data) & BIT_STAT_RXS))
 358                         cpu_relax();
 359                 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
 360                 drv_data->rx += 2;
 361         }
 362 }
 363
 364 static const struct bfin_spi_transfer_ops bfin_bfin_spi_transfer_ops_u16 = {
 365         .write  = bfin_spi_u16_writer,
 366         .read   = bfin_spi_u16_reader,
 367         .duplex = bfin_spi_u16_duplex,
 368 };
 369
 370 /* test if there is more transfer to be done */
 371 static void *bfin_spi_next_transfer(struct bfin_spi_master_data *drv_data)
 372 {
 373         struct spi_message *msg = drv_data->cur_msg;
 374         struct spi_transfer *trans = drv_data->cur_transfer;
 375
 376         /* Move to next transfer */
 377         if (trans->transfer_list.next != &msg->transfers) {
 378                 drv_data->cur_transfer =
 379                     list_entry(trans->transfer_list.next,
 380                                struct spi_transfer, transfer_list);
 381                 return RUNNING_STATE;
 382         } else
 383                 return DONE_STATE;
 384 }
 385
 386 /*
 387  * caller already set message->status;
 388  * dma and pio irqs are blocked give finished message back
 389  */
 390 static void bfin_spi_giveback(struct bfin_spi_master_data *drv_data)
 391 {
 392         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
 393         struct spi_transfer *last_transfer;
 394         unsigned long flags;
 395         struct spi_message *msg;
 396
 397         spin_lock_irqsave(&drv_data->lock, flags);
 398         msg = drv_data->cur_msg;
 399         drv_data->cur_msg = NULL;
 400         drv_data->cur_transfer = NULL;
 401         drv_data->cur_chip = NULL;
 402         queue_work(drv_data->workqueue, &drv_data->pump_messages);
 403         spin_unlock_irqrestore(&drv_data->lock, flags);
 404
 405         last_transfer = list_entry(msg->transfers.prev,
 406                                    struct spi_transfer, transfer_list);
 407
 408         msg->state = NULL;
 409
 410         if (!drv_data->cs_change)
 411                 bfin_spi_cs_deactive(drv_data, chip);
 412
 413         /* Not stop spi in autobuffer mode */
 414         if (drv_data->tx_dma != 0xFFFF)
 415                 bfin_spi_disable(drv_data);
 416
 417         if (msg->complete)
 418                 msg->complete(msg->context);
 419 }
 420
 421 /* spi data irq handler */
 422 static irqreturn_t bfin_spi_pio_irq_handler(int irq, void *dev_id)
 423 {
 424         struct bfin_spi_master_data *drv_data = dev_id;
 425         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
 426         struct spi_message *msg = drv_data->cur_msg;
 427         int n_bytes = drv_data->n_bytes;
 428         int loop = 0;
 429
 430         /* wait until transfer finished. */
 431         while (!(read_STAT(drv_data) & BIT_STAT_RXS))
 432                 cpu_relax();
 433
 434         if ((drv_data->tx && drv_data->tx >= drv_data->tx_end) ||
 435                 (drv_data->rx && drv_data->rx >= (drv_data->rx_end - n_bytes))) {
 436                 /* last read */
 437                 if (drv_data->rx) {
 438                         dev_dbg(&drv_data->pdev->dev, "last read\n");
 439                         if (n_bytes % 2) {
 440                                 u16 *buf = (u16 *)drv_data->rx;
 441                                 for (loop = 0; loop < n_bytes / 2; loop++)
 442                                         *buf++ = read_RDBR(drv_data);
 443                         } else {
 444                                 u8 *buf = (u8 *)drv_data->rx;
 445                                 for (loop = 0; loop < n_bytes; loop++)
 446                                         *buf++ = read_RDBR(drv_data);
 447                         }
 448                         drv_data->rx += n_bytes;
 449                 }
 450
 451                 msg->actual_length += drv_data->len_in_bytes;
 452                 if (drv_data->cs_change)
 453                         bfin_spi_cs_deactive(drv_data, chip);
 454                 /* Move to next transfer */
 455                 msg->state = bfin_spi_next_transfer(drv_data);
 456
 457                 disable_irq_nosync(drv_data->spi_irq);
 458
 459                 /* Schedule transfer tasklet */
 460                 tasklet_schedule(&drv_data->pump_transfers);
 461                 return IRQ_HANDLED;
 462         }
 463
 464         if (drv_data->rx && drv_data->tx) {
 465                 /* duplex */
 466                 dev_dbg(&drv_data->pdev->dev, "duplex: write_TDBR\n");
 467                 if (n_bytes % 2) {
 468                         u16 *buf = (u16 *)drv_data->rx;
 469                         u16 *buf2 = (u16 *)drv_data->tx;
 470                         for (loop = 0; loop < n_bytes / 2; loop++) {
 471                                 *buf++ = read_RDBR(drv_data);
 472                                 write_TDBR(drv_data, *buf2++);
 473                         }
 474                 } else {
 475                         u8 *buf = (u8 *)drv_data->rx;
 476                         u8 *buf2 = (u8 *)drv_data->tx;
 477                         for (loop = 0; loop < n_bytes; loop++) {
 478                                 *buf++ = read_RDBR(drv_data);
 479                                 write_TDBR(drv_data, *buf2++);
 480                         }
 481                 }
 482         } else if (drv_data->rx) {
 483                 /* read */
 484                 dev_dbg(&drv_data->pdev->dev, "read: write_TDBR\n");
 485                 if (n_bytes % 2) {
 486                         u16 *buf = (u16 *)drv_data->rx;
 487                         for (loop = 0; loop < n_bytes / 2; loop++) {
 488                                 *buf++ = read_RDBR(drv_data);
 489                                 write_TDBR(drv_data, chip->idle_tx_val);
 490                         }
 491                 } else {
 492                         u8 *buf = (u8 *)drv_data->rx;
 493                         for (loop = 0; loop < n_bytes; loop++) {
 494                                 *buf++ = read_RDBR(drv_data);
 495                                 write_TDBR(drv_data, chip->idle_tx_val);
 496                         }
 497                 }
 498         } else if (drv_data->tx) {
 499                 /* write */
 500                 dev_dbg(&drv_data->pdev->dev, "write: write_TDBR\n");
 501                 if (n_bytes % 2) {
 502                         u16 *buf = (u16 *)drv_data->tx;
 503                         for (loop = 0; loop < n_bytes / 2; loop++) {
 504                                 read_RDBR(drv_data);
 505                                 write_TDBR(drv_data, *buf++);
 506                         }
 507                 } else {
 508                         u8 *buf = (u8 *)drv_data->tx;
 509                         for (loop = 0; loop < n_bytes; loop++) {
 510                                 read_RDBR(drv_data);
 511                                 write_TDBR(drv_data, *buf++);
 512                         }
 513                 }
 514         }
 515
 516         if (drv_data->tx)
 517                 drv_data->tx += n_bytes;
 518         if (drv_data->rx)
 519                 drv_data->rx += n_bytes;
 520
 521         return IRQ_HANDLED;
 522 }
 523
 524 static irqreturn_t bfin_spi_dma_irq_handler(int irq, void *dev_id)
 525 {
 526         struct bfin_spi_master_data *drv_data = dev_id;
 527         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
 528         struct spi_message *msg = drv_data->cur_msg;
 529         unsigned long timeout;
 530         unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel);
 531         u16 spistat = read_STAT(drv_data);
 532
 533         dev_dbg(&drv_data->pdev->dev,
 534                 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
 535                 dmastat, spistat);
 536
 537         if (drv_data->rx != NULL) {
 538                 u16 cr = read_CTRL(drv_data);
 539                 /* discard old RX data and clear RXS */
 540                 bfin_spi_dummy_read(drv_data);
 541                 write_CTRL(drv_data, cr & ~BIT_CTL_ENABLE); /* Disable SPI */
 542                 write_CTRL(drv_data, cr & ~BIT_CTL_TIMOD); /* Restore State */
 543                 write_STAT(drv_data, BIT_STAT_CLR); /* Clear Status */
 544         }
 545
 546         clear_dma_irqstat(drv_data->dma_channel);
 547
 548         /*
 549          * wait for the last transaction shifted out.  HRM states:
 550          * at this point there may still be data in the SPI DMA FIFO waiting
 551          * to be transmitted ... software needs to poll TXS in the SPI_STAT
 552          * register until it goes low for 2 successive reads
 553          */
 554         if (drv_data->tx != NULL) {
 555                 while ((read_STAT(drv_data) & BIT_STAT_TXS) ||
 556                        (read_STAT(drv_data) & BIT_STAT_TXS))
 557                         cpu_relax();
 558         }
 559
 560         dev_dbg(&drv_data->pdev->dev,
 561                 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
 562                 dmastat, read_STAT(drv_data));
 563
 564         timeout = jiffies + HZ;
 565         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
 566                 if (!time_before(jiffies, timeout)) {
 567                         dev_warn(&drv_data->pdev->dev, "timeout waiting for SPIF");
 568                         break;
 569                 } else
 570                         cpu_relax();
 571
 572         if ((dmastat & DMA_ERR) && (spistat & BIT_STAT_RBSY)) {
 573                 msg->state = ERROR_STATE;
 574                 dev_err(&drv_data->pdev->dev, "dma receive: fifo/buffer overflow\n");
 575         } else {
 576                 msg->actual_length += drv_data->len_in_bytes;
 577
 578                 if (drv_data->cs_change)
 579                         bfin_spi_cs_deactive(drv_data, chip);
 580
 581                 /* Move to next transfer */
 582                 msg->state = bfin_spi_next_transfer(drv_data);
 583         }
 584
 585         /* Schedule transfer tasklet */
 586         tasklet_schedule(&drv_data->pump_transfers);
 587
 588         /* free the irq handler before next transfer */
 589         dev_dbg(&drv_data->pdev->dev,
 590                 "disable dma channel irq%d\n",
 591                 drv_data->dma_channel);
 592         dma_disable_irq_nosync(drv_data->dma_channel);
 593
 594         return IRQ_HANDLED;
 595 }
 596
 597 static void bfin_spi_pump_transfers(unsigned long data)
 598 {
 599         struct bfin_spi_master_data *drv_data = (struct bfin_spi_master_data *)data;
 600         struct spi_message *message = NULL;
 601         struct spi_transfer *transfer = NULL;
 602         struct spi_transfer *previous = NULL;
 603         struct bfin_spi_slave_data *chip = NULL;
 604         unsigned int bits_per_word;
 605         u16 cr, cr_width, dma_width, dma_config;
 606         u32 tranf_success = 1;
 607         u8 full_duplex = 0;
 608
 609         /* Get current state information */
 610         message = drv_data->cur_msg;
 611         transfer = drv_data->cur_transfer;
 612         chip = drv_data->cur_chip;
 613
 614         /*
 615          * if msg is error or done, report it back using complete() callback
 616          */
 617
 618          /* Handle for abort */
 619         if (message->state == ERROR_STATE) {
 620                 dev_dbg(&drv_data->pdev->dev, "transfer: we've hit an error\n");
 621                 message->status = -EIO;
 622                 bfin_spi_giveback(drv_data);
 623                 return;
 624         }
 625
 626         /* Handle end of message */
 627         if (message->state == DONE_STATE) {
 628                 dev_dbg(&drv_data->pdev->dev, "transfer: all done!\n");
 629                 message->status = 0;
 630                 bfin_spi_giveback(drv_data);
 631                 return;
 632         }
 633
 634         /* Delay if requested at end of transfer */
 635         if (message->state == RUNNING_STATE) {
 636                 dev_dbg(&drv_data->pdev->dev, "transfer: still running ...\n");
 637                 previous = list_entry(transfer->transfer_list.prev,
 638                                       struct spi_transfer, transfer_list);
 639                 if (previous->delay_usecs)
 640                         udelay(previous->delay_usecs);
 641         }
 642
 643         /* Flush any existing transfers that may be sitting in the hardware */
 644         if (bfin_spi_flush(drv_data) == 0) {
 645                 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
 646                 message->status = -EIO;
 647                 bfin_spi_giveback(drv_data);
 648                 return;
 649         }
 650
 651         if (transfer->len == 0) {
 652                 /* Move to next transfer of this msg */
 653                 message->state = bfin_spi_next_transfer(drv_data);
 654                 /* Schedule next transfer tasklet */
 655                 tasklet_schedule(&drv_data->pump_transfers);
 656                 return;
 657         }
 658
 659         if (transfer->tx_buf != NULL) {
 660                 drv_data->tx = (void *)transfer->tx_buf;
 661                 drv_data->tx_end = drv_data->tx + transfer->len;
 662                 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
 663                         transfer->tx_buf, drv_data->tx_end);
 664         } else {
 665                 drv_data->tx = NULL;
 666         }
 667
 668         if (transfer->rx_buf != NULL) {
 669                 full_duplex = transfer->tx_buf != NULL;
 670                 drv_data->rx = transfer->rx_buf;
 671                 drv_data->rx_end = drv_data->rx + transfer->len;
 672                 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
 673                         transfer->rx_buf, drv_data->rx_end);
 674         } else {
 675                 drv_data->rx = NULL;
 676         }
 677
 678         drv_data->rx_dma = transfer->rx_dma;
 679         drv_data->tx_dma = transfer->tx_dma;
 680         drv_data->len_in_bytes = transfer->len;
 681         drv_data->cs_change = transfer->cs_change;
 682
 683         /* Bits per word setup */
 684         bits_per_word = transfer->bits_per_word ? : message->spi->bits_per_word;
 685         if ((bits_per_word > 0) && (bits_per_word % 16 == 0)) {
 686                 drv_data->n_bytes = bits_per_word/8;
 687                 drv_data->len = (transfer->len) >> 1;
 688                 cr_width = BIT_CTL_WORDSIZE;
 689                 drv_data->ops = &bfin_bfin_spi_transfer_ops_u16;
 690         } else if ((bits_per_word > 0) && (bits_per_word % 8 == 0)) {
 691                 drv_data->n_bytes = bits_per_word/8;
 692                 drv_data->len = transfer->len;
 693                 cr_width = 0;
 694                 drv_data->ops = &bfin_bfin_spi_transfer_ops_u8;
 695         } else {
 696                 dev_err(&drv_data->pdev->dev, "transfer: unsupported bits_per_word\n");
 697                 message->status = -EINVAL;
 698                 bfin_spi_giveback(drv_data);
 699                 return;
 700         }
 701         cr = read_CTRL(drv_data) & ~(BIT_CTL_TIMOD | BIT_CTL_WORDSIZE);
 702         cr |= cr_width;
 703         write_CTRL(drv_data, cr);
 704
 705         dev_dbg(&drv_data->pdev->dev,
 706                 "transfer: drv_data->ops is %p, chip->ops is %p, u8_ops is %p\n",
 707                 drv_data->ops, chip->ops, &bfin_bfin_spi_transfer_ops_u8);
 708
 709         message->state = RUNNING_STATE;
 710         dma_config = 0;
 711
 712         /* Speed setup (surely valid because already checked) */
 713         if (transfer->speed_hz)
 714                 write_BAUD(drv_data, hz_to_spi_baud(transfer->speed_hz));
 715         else
 716                 write_BAUD(drv_data, chip->baud);
 717
 718         write_STAT(drv_data, BIT_STAT_CLR);
 719         bfin_spi_cs_active(drv_data, chip);
 720
 721         dev_dbg(&drv_data->pdev->dev,
 722                 "now pumping a transfer: width is %d, len is %d\n",
 723                 cr_width, transfer->len);
 724
 725         /*
 726          * Try to map dma buffer and do a dma transfer.  If successful use,
 727          * different way to r/w according to the enable_dma settings and if
 728          * we are not doing a full duplex transfer (since the hardware does
 729          * not support full duplex DMA transfers).
 730          */
 731         if (!full_duplex && drv_data->cur_chip->enable_dma
 732                                 && drv_data->len > 6) {
 733
 734                 unsigned long dma_start_addr, flags;
 735
 736                 disable_dma(drv_data->dma_channel);
 737                 clear_dma_irqstat(drv_data->dma_channel);
 738
 739                 /* config dma channel */
 740                 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
 741                 set_dma_x_count(drv_data->dma_channel, drv_data->len);
 742                 if (cr_width == BIT_CTL_WORDSIZE) {
 743                         set_dma_x_modify(drv_data->dma_channel, 2);
 744                         dma_width = WDSIZE_16;
 745                 } else {
 746                         set_dma_x_modify(drv_data->dma_channel, 1);
 747                         dma_width = WDSIZE_8;
 748                 }
 749
 750                 /* poll for SPI completion before start */
 751                 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
 752                         cpu_relax();
 753
 754                 /* dirty hack for autobuffer DMA mode */
 755                 if (drv_data->tx_dma == 0xFFFF) {
 756                         dev_dbg(&drv_data->pdev->dev,
 757                                 "doing autobuffer DMA out.\n");
 758
 759                         /* no irq in autobuffer mode */
 760                         dma_config =
 761                             (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
 762                         set_dma_config(drv_data->dma_channel, dma_config);
 763                         set_dma_start_addr(drv_data->dma_channel,
 764                                         (unsigned long)drv_data->tx);
 765                         enable_dma(drv_data->dma_channel);
 766
 767                         /* start SPI transfer */
 768                         write_CTRL(drv_data, cr | BIT_CTL_TIMOD_DMA_TX);
 769
 770                         /* just return here, there can only be one transfer
 771                          * in this mode
 772                          */
 773                         message->status = 0;
 774                         bfin_spi_giveback(drv_data);
 775                         return;
 776                 }
 777
 778                 /* In dma mode, rx or tx must be NULL in one transfer */
 779                 dma_config = (RESTART | dma_width | DI_EN);
 780                 if (drv_data->rx != NULL) {
 781                         /* set transfer mode, and enable SPI */
 782                         dev_dbg(&drv_data->pdev->dev, "doing DMA in to %p (size %zx)\n",
 783                                 drv_data->rx, drv_data->len_in_bytes);
 784
 785                         /* invalidate caches, if needed */
 786                         if (bfin_addr_dcacheable((unsigned long) drv_data->rx))
 787                                 invalidate_dcache_range((unsigned long) drv_data->rx,
 788                                                         (unsigned long) (drv_data->rx +
 789                                                         drv_data->len_in_bytes));
 790
 791                         dma_config |= WNR;
 792                         dma_start_addr = (unsigned long)drv_data->rx;
 793                         cr |= BIT_CTL_TIMOD_DMA_RX | BIT_CTL_SENDOPT;
 794
 795                 } else if (drv_data->tx != NULL) {
 796                         dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
 797
 798                         /* flush caches, if needed */
 799                         if (bfin_addr_dcacheable((unsigned long) drv_data->tx))
 800                                 flush_dcache_range((unsigned long) drv_data->tx,
 801                                                 (unsigned long) (drv_data->tx +
 802                                                 drv_data->len_in_bytes));
 803
 804                         dma_start_addr = (unsigned long)drv_data->tx;
 805                         cr |= BIT_CTL_TIMOD_DMA_TX;
 806
 807                 } else
 808                         BUG();
 809
 810                 /* oh man, here there be monsters ... and i dont mean the
 811                  * fluffy cute ones from pixar, i mean the kind that'll eat
 812                  * your data, kick your dog, and love it all.  do *not* try
 813                  * and change these lines unless you (1) heavily test DMA
 814                  * with SPI flashes on a loaded system (e.g. ping floods),
 815                  * (2) know just how broken the DMA engine interaction with
 816                  * the SPI peripheral is, and (3) have someone else to blame
 817                  * when you screw it all up anyways.
 818                  */
 819                 set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
 820                 set_dma_config(drv_data->dma_channel, dma_config);
 821                 local_irq_save(flags);
 822                 SSYNC();
 823                 write_CTRL(drv_data, cr);
 824                 enable_dma(drv_data->dma_channel);
 825                 dma_enable_irq(drv_data->dma_channel);
 826                 local_irq_restore(flags);
 827
 828                 return;
 829         }
 830
 831         /*
 832          * We always use SPI_WRITE mode (transfer starts with TDBR write).
 833          * SPI_READ mode (transfer starts with RDBR read) seems to have
 834          * problems with setting up the output value in TDBR prior to the
 835          * start of the transfer.
 836          */
 837         write_CTRL(drv_data, cr | BIT_CTL_TXMOD);
 838
 839         if (chip->pio_interrupt) {
 840                 /* SPI irq should have been disabled by now */
 841
 842                 /* discard old RX data and clear RXS */
 843                 bfin_spi_dummy_read(drv_data);
 844
 845                 /* start transfer */
 846                 if (drv_data->tx == NULL)
 847                         write_TDBR(drv_data, chip->idle_tx_val);
 848                 else {
 849                         int loop;
 850                         if (bits_per_word % 16 == 0) {
 851                                 u16 *buf = (u16 *)drv_data->tx;
 852                                 for (loop = 0; loop < bits_per_word / 16;
 853                                                 loop++) {
 854                                         write_TDBR(drv_data, *buf++);
 855                                 }
 856                         } else if (bits_per_word % 8 == 0) {
 857                                 u8 *buf = (u8 *)drv_data->tx;
 858                                 for (loop = 0; loop < bits_per_word / 8; loop++)
 859                                         write_TDBR(drv_data, *buf++);
 860                         }
 861
 862                         drv_data->tx += drv_data->n_bytes;
 863                 }
 864
 865                 /* once TDBR is empty, interrupt is triggered */
 866                 enable_irq(drv_data->spi_irq);
 867                 return;
 868         }
 869
 870         /* IO mode */
 871         dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
 872
 873         if (full_duplex) {
 874                 /* full duplex mode */
 875                 BUG_ON((drv_data->tx_end - drv_data->tx) !=
 876                        (drv_data->rx_end - drv_data->rx));
 877                 dev_dbg(&drv_data->pdev->dev,
 878                         "IO duplex: cr is 0x%x\n", cr);
 879
 880                 drv_data->ops->duplex(drv_data);
 881
 882                 if (drv_data->tx != drv_data->tx_end)
 883                         tranf_success = 0;
 884         } else if (drv_data->tx != NULL) {
 885                 /* write only half duplex */
 886                 dev_dbg(&drv_data->pdev->dev,
 887                         "IO write: cr is 0x%x\n", cr);
 888
 889                 drv_data->ops->write(drv_data);
 890
 891                 if (drv_data->tx != drv_data->tx_end)
 892                         tranf_success = 0;
 893         } else if (drv_data->rx != NULL) {
 894                 /* read only half duplex */
 895                 dev_dbg(&drv_data->pdev->dev,
 896                         "IO read: cr is 0x%x\n", cr);
 897
 898                 drv_data->ops->read(drv_data);
 899                 if (drv_data->rx != drv_data->rx_end)
 900                         tranf_success = 0;
 901         }
 902
 903         if (!tranf_success) {
 904                 dev_dbg(&drv_data->pdev->dev,
 905                         "IO write error!\n");
 906                 message->state = ERROR_STATE;
 907         } else {
 908                 /* Update total byte transferred */
 909                 message->actual_length += drv_data->len_in_bytes;
 910                 /* Move to next transfer of this msg */
 911                 message->state = bfin_spi_next_transfer(drv_data);
 912                 if (drv_data->cs_change)
 913                         bfin_spi_cs_deactive(drv_data, chip);
 914         }
 915
 916         /* Schedule next transfer tasklet */
 917         tasklet_schedule(&drv_data->pump_transfers);
 918 }
 919
 920 /* pop a msg from queue and kick off real transfer */
 921 static void bfin_spi_pump_messages(struct work_struct *work)
 922 {
 923         struct bfin_spi_master_data *drv_data;
 924         unsigned long flags;
 925
 926         drv_data = container_of(work, struct bfin_spi_master_data, pump_messages);
 927
 928         /* Lock queue and check for queue work */
 929         spin_lock_irqsave(&drv_data->lock, flags);
 930         if (list_empty(&drv_data->queue) || !drv_data->running) {
 931                 /* pumper kicked off but no work to do */
 932                 drv_data->busy = 0;
 933                 spin_unlock_irqrestore(&drv_data->lock, flags);
 934                 return;
 935         }
 936
 937         /* Make sure we are not already running a message */
 938         if (drv_data->cur_msg) {
 939                 spin_unlock_irqrestore(&drv_data->lock, flags);
 940                 return;
 941         }
 942
 943         /* Extract head of queue */
 944         drv_data->cur_msg = list_entry(drv_data->queue.next,
 945                                        struct spi_message, queue);
 946
 947         /* Setup the SSP using the per chip configuration */
 948         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
 949         bfin_spi_restore_state(drv_data);
 950
 951         list_del_init(&drv_data->cur_msg->queue);
 952
 953         /* Initial message state */
 954         drv_data->cur_msg->state = START_STATE;
 955         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
 956                                             struct spi_transfer, transfer_list);
 957
 958         dev_dbg(&drv_data->pdev->dev, "got a message to pump, "
 959                 "state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
 960                 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
 961                 drv_data->cur_chip->ctl_reg);
 962
 963         dev_dbg(&drv_data->pdev->dev,
 964                 "the first transfer len is %d\n",
 965                 drv_data->cur_transfer->len);
 966
 967         /* Mark as busy and launch transfers */
 968         tasklet_schedule(&drv_data->pump_transfers);
 969
 970         drv_data->busy = 1;
 971         spin_unlock_irqrestore(&drv_data->lock, flags);
 972 }
 973
 974 /*
 975  * got a msg to transfer, queue it in drv_data->queue.
 976  * And kick off message pumper
 977  */
 978 static int bfin_spi_transfer(struct spi_device *spi, struct spi_message *msg)
 979 {
 980         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
 981         unsigned long flags;
 982
 983         spin_lock_irqsave(&drv_data->lock, flags);
 984
 985         if (!drv_data->running) {
 986                 spin_unlock_irqrestore(&drv_data->lock, flags);
 987                 return -ESHUTDOWN;
 988         }
 989
 990         msg->actual_length = 0;
 991         msg->status = -EINPROGRESS;
 992         msg->state = START_STATE;
 993
 994         dev_dbg(&spi->dev, "adding an msg in transfer() \n");
 995         list_add_tail(&msg->queue, &drv_data->queue);
 996
 997         if (drv_data->running && !drv_data->busy)
 998                 queue_work(drv_data->workqueue, &drv_data->pump_messages);
 999
1000         spin_unlock_irqrestore(&drv_data->lock, flags);
1001
1002         return 0;
1003 }
1004
1005 #define MAX_SPI_SSEL    7
1006
1007 static u16 ssel[][MAX_SPI_SSEL] = {
1008         {P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
1009         P_SPI0_SSEL4, P_SPI0_SSEL5,
1010         P_SPI0_SSEL6, P_SPI0_SSEL7},
1011
1012         {P_SPI1_SSEL1, P_SPI1_SSEL2, P_SPI1_SSEL3,
1013         P_SPI1_SSEL4, P_SPI1_SSEL5,
1014         P_SPI1_SSEL6, P_SPI1_SSEL7},
1015
1016         {P_SPI2_SSEL1, P_SPI2_SSEL2, P_SPI2_SSEL3,
1017         P_SPI2_SSEL4, P_SPI2_SSEL5,
1018         P_SPI2_SSEL6, P_SPI2_SSEL7},
1019 };
1020
1021 /* setup for devices (may be called multiple times -- not just first setup) */
1022 static int bfin_spi_setup(struct spi_device *spi)
1023 {
1024         struct bfin5xx_spi_chip *chip_info;
1025         struct bfin_spi_slave_data *chip = NULL;
1026         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
1027         u16 bfin_ctl_reg;
1028         int ret = -EINVAL;
1029
1030         /* Only alloc (or use chip_info) on first setup */
1031         chip_info = NULL;
1032         chip = spi_get_ctldata(spi);
1033         if (chip == NULL) {
1034                 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1035                 if (!chip) {
1036                         dev_err(&spi->dev, "cannot allocate chip data\n");
1037                         ret = -ENOMEM;
1038                         goto error;
1039                 }
1040
1041                 chip->enable_dma = 0;
1042                 chip_info = spi->controller_data;
1043         }
1044
1045         /* Let people set non-standard bits directly */
1046         bfin_ctl_reg = BIT_CTL_OPENDRAIN | BIT_CTL_EMISO |
1047                 BIT_CTL_PSSE | BIT_CTL_GM | BIT_CTL_SZ;
1048
1049         /* chip_info isn't always needed */
1050         if (chip_info) {
1051                 /* Make sure people stop trying to set fields via ctl_reg
1052                  * when they should actually be using common SPI framework.
1053                  * Currently we let through: WOM EMISO PSSE GM SZ.
1054                  * Not sure if a user actually needs/uses any of these,
1055                  * but let's assume (for now) they do.
1056                  */
1057                 if (chip_info->ctl_reg & ~bfin_ctl_reg) {
1058                         dev_err(&spi->dev, "do not set bits in ctl_reg "
1059                                 "that the SPI framework manages\n");
1060                         goto error;
1061                 }
1062                 chip->enable_dma = chip_info->enable_dma != 0
1063                     && drv_data->master_info->enable_dma;
1064                 chip->ctl_reg = chip_info->ctl_reg;
1065                 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
1066                 chip->idle_tx_val = chip_info->idle_tx_val;
1067                 chip->pio_interrupt = chip_info->pio_interrupt;
1068                 spi->bits_per_word = chip_info->bits_per_word;
1069         } else {
1070                 /* force a default base state */
1071                 chip->ctl_reg &= bfin_ctl_reg;
1072         }
1073
1074         if (spi->bits_per_word % 8) {
1075                 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1076                                 spi->bits_per_word);
1077                 goto error;
1078         }
1079
1080         /* translate common spi framework into our register */
1081         if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
1082                 dev_err(&spi->dev, "unsupported spi modes detected\n");
1083                 goto error;
1084         }
1085         if (spi->mode & SPI_CPOL)
1086                 chip->ctl_reg |= BIT_CTL_CPOL;
1087         if (spi->mode & SPI_CPHA)
1088                 chip->ctl_reg |= BIT_CTL_CPHA;
1089         if (spi->mode & SPI_LSB_FIRST)
1090                 chip->ctl_reg |= BIT_CTL_LSBF;
1091         /* we dont support running in slave mode (yet?) */
1092         chip->ctl_reg |= BIT_CTL_MASTER;
1093
1094         /*
1095          * Notice: for blackfin, the speed_hz is the value of register
1096          * SPI_BAUD, not the real baudrate
1097          */
1098         chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1099         chip->chip_select_num = spi->chip_select;
1100         if (chip->chip_select_num < MAX_CTRL_CS) {
1101                 if (!(spi->mode & SPI_CPHA))
1102                         dev_warn(&spi->dev, "Warning: SPI CPHA not set:"
1103                                 " Slave Select not under software control!\n"
1104                                 " See Documentation/blackfin/bfin-spi-notes.txt");
1105
1106                 chip->flag = (1 << spi->chip_select) << 8;
1107         } else
1108                 chip->cs_gpio = chip->chip_select_num - MAX_CTRL_CS;
1109
1110         if (chip->enable_dma && chip->pio_interrupt) {
1111                 dev_err(&spi->dev, "enable_dma is set, "
1112                                 "do not set pio_interrupt\n");
1113                 goto error;
1114         }
1115         /*
1116          * if any one SPI chip is registered and wants DMA, request the
1117          * DMA channel for it
1118          */
1119         if (chip->enable_dma && !drv_data->dma_requested) {
1120                 /* register dma irq handler */
1121                 ret = request_dma(drv_data->dma_channel, "BFIN_SPI_DMA");
1122                 if (ret) {
1123                         dev_err(&spi->dev,
1124                                 "Unable to request BlackFin SPI DMA channel\n");
1125                         goto error;
1126                 }
1127                 drv_data->dma_requested = 1;
1128
1129                 ret = set_dma_callback(drv_data->dma_channel,
1130                         bfin_spi_dma_irq_handler, drv_data);
1131                 if (ret) {
1132                         dev_err(&spi->dev, "Unable to set dma callback\n");
1133                         goto error;
1134                 }
1135                 dma_disable_irq(drv_data->dma_channel);
1136         }
1137
1138         if (chip->pio_interrupt && !drv_data->irq_requested) {
1139                 ret = request_irq(drv_data->spi_irq, bfin_spi_pio_irq_handler,
1140                         IRQF_DISABLED, "BFIN_SPI", drv_data);
1141                 if (ret) {
1142                         dev_err(&spi->dev, "Unable to register spi IRQ\n");
1143                         goto error;
1144                 }
1145                 drv_data->irq_requested = 1;
1146                 /* we use write mode, spi irq has to be disabled here */
1147                 disable_irq(drv_data->spi_irq);
1148         }
1149
1150         if (chip->chip_select_num >= MAX_CTRL_CS) {
1151                 /* Only request on first setup */
1152                 if (spi_get_ctldata(spi) == NULL) {
1153                         ret = gpio_request(chip->cs_gpio, spi->modalias);
1154                         if (ret) {
1155                                 dev_err(&spi->dev, "gpio_request() error\n");
1156                                 goto pin_error;
1157                         }
1158                         gpio_direction_output(chip->cs_gpio, 1);
1159                 }
1160         }
1161
1162         dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
1163                         spi->modalias, spi->bits_per_word, chip->enable_dma);
1164         dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1165                         chip->ctl_reg, chip->flag);
1166
1167         spi_set_ctldata(spi, chip);
1168
1169         dev_dbg(&spi->dev, "chip select number is %d\n", chip->chip_select_num);
1170         if (chip->chip_select_num < MAX_CTRL_CS) {
1171                 ret = peripheral_request(ssel[spi->master->bus_num]
1172                                          [chip->chip_select_num-1], spi->modalias);
1173                 if (ret) {
1174                         dev_err(&spi->dev, "peripheral_request() error\n");
1175                         goto pin_error;
1176                 }
1177         }
1178
1179         bfin_spi_cs_enable(drv_data, chip);
1180         bfin_spi_cs_deactive(drv_data, chip);
1181
1182         return 0;
1183
1184  pin_error:
1185         if (chip->chip_select_num >= MAX_CTRL_CS)
1186                 gpio_free(chip->cs_gpio);
1187         else
1188                 peripheral_free(ssel[spi->master->bus_num]
1189                         [chip->chip_select_num - 1]);
1190  error:
1191         if (chip) {
1192                 if (drv_data->dma_requested)
1193                         free_dma(drv_data->dma_channel);
1194                 drv_data->dma_requested = 0;
1195
1196                 kfree(chip);
1197                 /* prevent free 'chip' twice */
1198                 spi_set_ctldata(spi, NULL);
1199         }
1200
1201         return ret;
1202 }
1203
1204 /*
1205  * callback for spi framework.
1206  * clean driver specific data
1207  */
1208 static void bfin_spi_cleanup(struct spi_device *spi)
1209 {
1210         struct bfin_spi_slave_data *chip = spi_get_ctldata(spi);
1211         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
1212
1213         if (!chip)
1214                 return;
1215
1216         if (chip->chip_select_num < MAX_CTRL_CS) {
1217                 peripheral_free(ssel[spi->master->bus_num]
1218                                         [chip->chip_select_num-1]);
1219                 bfin_spi_cs_disable(drv_data, chip);
1220         } else
1221                 gpio_free(chip->cs_gpio);
1222
1223         kfree(chip);
1224         /* prevent free 'chip' twice */
1225         spi_set_ctldata(spi, NULL);
1226 }
1227
1228 static inline int bfin_spi_init_queue(struct bfin_spi_master_data *drv_data)
1229 {
1230         INIT_LIST_HEAD(&drv_data->queue);
1231         spin_lock_init(&drv_data->lock);
1232
1233         drv_data->running = false;
1234         drv_data->busy = 0;
1235
1236         /* init transfer tasklet */
1237         tasklet_init(&drv_data->pump_transfers,
1238                      bfin_spi_pump_transfers, (unsigned long)drv_data);
1239
1240         /* init messages workqueue */
1241         INIT_WORK(&drv_data->pump_messages, bfin_spi_pump_messages);
1242         drv_data->workqueue = create_singlethread_workqueue(
1243                                 dev_name(drv_data->master->dev.parent));
1244         if (drv_data->workqueue == NULL)
1245                 return -EBUSY;
1246
1247         return 0;
1248 }
1249
1250 static inline int bfin_spi_start_queue(struct bfin_spi_master_data *drv_data)
1251 {
1252         unsigned long flags;
1253
1254         spin_lock_irqsave(&drv_data->lock, flags);
1255
1256         if (drv_data->running || drv_data->busy) {
1257                 spin_unlock_irqrestore(&drv_data->lock, flags);
1258                 return -EBUSY;
1259         }
1260
1261         drv_data->running = true;
1262         drv_data->cur_msg = NULL;
1263         drv_data->cur_transfer = NULL;
1264         drv_data->cur_chip = NULL;
1265         spin_unlock_irqrestore(&drv_data->lock, flags);
1266
1267         queue_work(drv_data->workqueue, &drv_data->pump_messages);
1268
1269         return 0;
1270 }
1271
1272 static inline int bfin_spi_stop_queue(struct bfin_spi_master_data *drv_data)
1273 {
1274         unsigned long flags;
1275         unsigned limit = 500;
1276         int status = 0;
1277
1278         spin_lock_irqsave(&drv_data->lock, flags);
1279
1280         /*
1281          * This is a bit lame, but is optimized for the common execution path.
1282          * A wait_queue on the drv_data->busy could be used, but then the common
1283          * execution path (pump_messages) would be required to call wake_up or
1284          * friends on every SPI message. Do this instead
1285          */
1286         drv_data->running = false;
1287         while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1288                 spin_unlock_irqrestore(&drv_data->lock, flags);
1289                 msleep(10);
1290                 spin_lock_irqsave(&drv_data->lock, flags);
1291         }
1292
1293         if (!list_empty(&drv_data->queue) || drv_data->busy)
1294                 status = -EBUSY;
1295
1296         spin_unlock_irqrestore(&drv_data->lock, flags);
1297
1298         return status;
1299 }
1300
1301 static inline int bfin_spi_destroy_queue(struct bfin_spi_master_data *drv_data)
1302 {
1303         int status;
1304
1305         status = bfin_spi_stop_queue(drv_data);
1306         if (status != 0)
1307                 return status;
1308
1309         destroy_workqueue(drv_data->workqueue);
1310
1311         return 0;
1312 }
1313
1314 static int __init bfin_spi_probe(struct platform_device *pdev)
1315 {
1316         struct device *dev = &pdev->dev;
1317         struct bfin5xx_spi_master *platform_info;
1318         struct spi_master *master;
1319         struct bfin_spi_master_data *drv_data;
1320         struct resource *res;
1321         int status = 0;
1322
1323         platform_info = dev->platform_data;
1324
1325         /* Allocate master with space for drv_data */
1326         master = spi_alloc_master(dev, sizeof(*drv_data));
1327         if (!master) {
1328                 dev_err(&pdev->dev, "can not alloc spi_master\n");
1329                 return -ENOMEM;
1330         }
1331
1332         drv_data = spi_master_get_devdata(master);
1333         drv_data->master = master;
1334         drv_data->master_info = platform_info;
1335         drv_data->pdev = pdev;
1336         drv_data->pin_req = platform_info->pin_req;
1337
1338         /* the spi->mode bits supported by this driver: */
1339         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
1340
1341         master->bus_num = pdev->id;
1342         master->num_chipselect = platform_info->num_chipselect;
1343         master->cleanup = bfin_spi_cleanup;
1344         master->setup = bfin_spi_setup;
1345         master->transfer = bfin_spi_transfer;
1346
1347         /* Find and map our resources */
1348         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1349         if (res == NULL) {
1350                 dev_err(dev, "Cannot get IORESOURCE_MEM\n");
1351                 status = -ENOENT;
1352                 goto out_error_get_res;
1353         }
1354
1355         drv_data->regs_base = ioremap(res->start, resource_size(res));
1356         if (drv_data->regs_base == NULL) {
1357                 dev_err(dev, "Cannot map IO\n");
1358                 status = -ENXIO;
1359                 goto out_error_ioremap;
1360         }
1361
1362         res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1363         if (res == NULL) {
1364                 dev_err(dev, "No DMA channel specified\n");
1365                 status = -ENOENT;
1366                 goto out_error_free_io;
1367         }
1368         drv_data->dma_channel = res->start;
1369
1370         drv_data->spi_irq = platform_get_irq(pdev, 0);
1371         if (drv_data->spi_irq < 0) {
1372                 dev_err(dev, "No spi pio irq specified\n");
1373                 status = -ENOENT;
1374                 goto out_error_free_io;
1375         }
1376
1377         /* Initial and start queue */
1378         status = bfin_spi_init_queue(drv_data);
1379         if (status != 0) {
1380                 dev_err(dev, "problem initializing queue\n");
1381                 goto out_error_queue_alloc;
1382         }
1383
1384         status = bfin_spi_start_queue(drv_data);
1385         if (status != 0) {
1386                 dev_err(dev, "problem starting queue\n");
1387                 goto out_error_queue_alloc;
1388         }
1389
1390         status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
1391         if (status != 0) {
1392                 dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
1393                 goto out_error_queue_alloc;
1394         }
1395
1396         /* Reset SPI registers. If these registers were used by the boot loader,
1397          * the sky may fall on your head if you enable the dma controller.
1398          */
1399         write_CTRL(drv_data, BIT_CTL_CPHA | BIT_CTL_MASTER);
1400         write_FLAG(drv_data, 0xFF00);
1401
1402         /* Register with the SPI framework */
1403         platform_set_drvdata(pdev, drv_data);
1404         status = spi_register_master(master);
1405         if (status != 0) {
1406                 dev_err(dev, "problem registering spi master\n");
1407                 goto out_error_queue_alloc;
1408         }
1409
1410         dev_info(dev, "%s, Version %s, regs_base@%p, dma channel@%d\n",
1411                 DRV_DESC, DRV_VERSION, drv_data->regs_base,
1412                 drv_data->dma_channel);
1413         return status;
1414
1415 out_error_queue_alloc:
1416         bfin_spi_destroy_queue(drv_data);
1417 out_error_free_io:
1418         iounmap((void *) drv_data->regs_base);
1419 out_error_ioremap:
1420 out_error_get_res:
1421         spi_master_put(master);
1422
1423         return status;
1424 }
1425
1426 /* stop hardware and remove the driver */
1427 static int __devexit bfin_spi_remove(struct platform_device *pdev)
1428 {
1429         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1430         int status = 0;
1431
1432         if (!drv_data)
1433                 return 0;
1434
1435         /* Remove the queue */
1436         status = bfin_spi_destroy_queue(drv_data);
1437         if (status != 0)
1438                 return status;
1439
1440         /* Disable the SSP at the peripheral and SOC level */
1441         bfin_spi_disable(drv_data);
1442
1443         /* Release DMA */
1444         if (drv_data->master_info->enable_dma) {
1445                 if (dma_channel_active(drv_data->dma_channel))
1446                         free_dma(drv_data->dma_channel);
1447         }
1448
1449         if (drv_data->irq_requested) {
1450                 free_irq(drv_data->spi_irq, drv_data);
1451                 drv_data->irq_requested = 0;
1452         }
1453
1454         /* Disconnect from the SPI framework */
1455         spi_unregister_master(drv_data->master);
1456
1457         peripheral_free_list(drv_data->pin_req);
1458
1459         /* Prevent double remove */
1460         platform_set_drvdata(pdev, NULL);
1461
1462         return 0;
1463 }
1464
1465 #ifdef CONFIG_PM
1466 static int bfin_spi_suspend(struct platform_device *pdev, pm_message_t state)
1467 {
1468         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1469         int status = 0;
1470
1471         status = bfin_spi_stop_queue(drv_data);
1472         if (status != 0)
1473                 return status;
1474
1475         drv_data->ctrl_reg = read_CTRL(drv_data);
1476         drv_data->flag_reg = read_FLAG(drv_data);
1477
1478         /*
1479          * reset SPI_CTL and SPI_FLG registers
1480          */
1481         write_CTRL(drv_data, BIT_CTL_CPHA | BIT_CTL_MASTER);
1482         write_FLAG(drv_data, 0xFF00);
1483
1484         return 0;
1485 }
1486
1487 static int bfin_spi_resume(struct platform_device *pdev)
1488 {
1489         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1490         int status = 0;
1491
1492         write_CTRL(drv_data, drv_data->ctrl_reg);
1493         write_FLAG(drv_data, drv_data->flag_reg);
1494
1495         /* Start the queue running */
1496         status = bfin_spi_start_queue(drv_data);
1497         if (status != 0) {
1498                 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1499                 return status;
1500         }
1501
1502         return 0;
1503 }
1504 #else
1505 #define bfin_spi_suspend NULL
1506 #define bfin_spi_resume NULL
1507 #endif                          /* CONFIG_PM */
1508
1509 MODULE_ALIAS("platform:bfin-spi");
1510 static struct platform_driver bfin_spi_driver = {
1511         .driver = {
1512                 .name   = DRV_NAME,
1513                 .owner  = THIS_MODULE,
1514         },
1515         .suspend        = bfin_spi_suspend,
1516         .resume         = bfin_spi_resume,
1517         .remove         = __devexit_p(bfin_spi_remove),
1518 };
1519
1520 static int __init bfin_spi_init(void)
1521 {
1522         return platform_driver_probe(&bfin_spi_driver, bfin_spi_probe);
1523 }
1524 subsys_initcall(bfin_spi_init);
1525
1526 static void __exit bfin_spi_exit(void)
1527 {
1528         platform_driver_unregister(&bfin_spi_driver);
1529 }
1530 module_exit(bfin_spi_exit);