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
 429         /* wait until transfer finished. */
 430         while (!(read_STAT(drv_data) & BIT_STAT_RXS))
 431                 cpu_relax();
 432
 433         if ((drv_data->tx && drv_data->tx >= drv_data->tx_end) ||
 434                 (drv_data->rx && drv_data->rx >= (drv_data->rx_end - n_bytes))) {
 435                 /* last read */
 436                 if (drv_data->rx) {
 437                         dev_dbg(&drv_data->pdev->dev, "last read\n");
 438                         if (n_bytes == 2)
 439                                 *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
 440                         else if (n_bytes == 1)
 441                                 *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
 442                         drv_data->rx += n_bytes;
 443                 }
 444
 445                 msg->actual_length += drv_data->len_in_bytes;
 446                 if (drv_data->cs_change)
 447                         bfin_spi_cs_deactive(drv_data, chip);
 448                 /* Move to next transfer */
 449                 msg->state = bfin_spi_next_transfer(drv_data);
 450
 451                 disable_irq_nosync(drv_data->spi_irq);
 452
 453                 /* Schedule transfer tasklet */
 454                 tasklet_schedule(&drv_data->pump_transfers);
 455                 return IRQ_HANDLED;
 456         }
 457
 458         if (drv_data->rx && drv_data->tx) {
 459                 /* duplex */
 460                 dev_dbg(&drv_data->pdev->dev, "duplex: write_TDBR\n");
 461                 if (drv_data->n_bytes == 2) {
 462                         *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
 463                         write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
 464                 } else if (drv_data->n_bytes == 1) {
 465                         *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
 466                         write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
 467                 }
 468         } else if (drv_data->rx) {
 469                 /* read */
 470                 dev_dbg(&drv_data->pdev->dev, "read: write_TDBR\n");
 471                 if (drv_data->n_bytes == 2)
 472                         *(u16 *) (drv_data->rx) = read_RDBR(drv_data);
 473                 else if (drv_data->n_bytes == 1)
 474                         *(u8 *) (drv_data->rx) = read_RDBR(drv_data);
 475                 write_TDBR(drv_data, chip->idle_tx_val);
 476         } else if (drv_data->tx) {
 477                 /* write */
 478                 dev_dbg(&drv_data->pdev->dev, "write: write_TDBR\n");
 479                 bfin_spi_dummy_read(drv_data);
 480                 if (drv_data->n_bytes == 2)
 481                         write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
 482                 else if (drv_data->n_bytes == 1)
 483                         write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
 484         }
 485
 486         if (drv_data->tx)
 487                 drv_data->tx += n_bytes;
 488         if (drv_data->rx)
 489                 drv_data->rx += n_bytes;
 490
 491         return IRQ_HANDLED;
 492 }
 493
 494 static irqreturn_t bfin_spi_dma_irq_handler(int irq, void *dev_id)
 495 {
 496         struct bfin_spi_master_data *drv_data = dev_id;
 497         struct bfin_spi_slave_data *chip = drv_data->cur_chip;
 498         struct spi_message *msg = drv_data->cur_msg;
 499         unsigned long timeout;
 500         unsigned short dmastat = get_dma_curr_irqstat(drv_data->dma_channel);
 501         u16 spistat = read_STAT(drv_data);
 502
 503         dev_dbg(&drv_data->pdev->dev,
 504                 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
 505                 dmastat, spistat);
 506
 507         clear_dma_irqstat(drv_data->dma_channel);
 508
 509         /*
 510          * wait for the last transaction shifted out.  HRM states:
 511          * at this point there may still be data in the SPI DMA FIFO waiting
 512          * to be transmitted ... software needs to poll TXS in the SPI_STAT
 513          * register until it goes low for 2 successive reads
 514          */
 515         if (drv_data->tx != NULL) {
 516                 while ((read_STAT(drv_data) & BIT_STAT_TXS) ||
 517                        (read_STAT(drv_data) & BIT_STAT_TXS))
 518                         cpu_relax();
 519         }
 520
 521         dev_dbg(&drv_data->pdev->dev,
 522                 "in dma_irq_handler dmastat:0x%x spistat:0x%x\n",
 523                 dmastat, read_STAT(drv_data));
 524
 525         timeout = jiffies + HZ;
 526         while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
 527                 if (!time_before(jiffies, timeout)) {
 528                         dev_warn(&drv_data->pdev->dev, "timeout waiting for SPIF");
 529                         break;
 530                 } else
 531                         cpu_relax();
 532
 533         if ((dmastat & DMA_ERR) && (spistat & BIT_STAT_RBSY)) {
 534                 msg->state = ERROR_STATE;
 535                 dev_err(&drv_data->pdev->dev, "dma receive: fifo/buffer overflow\n");
 536         } else {
 537                 msg->actual_length += drv_data->len_in_bytes;
 538
 539                 if (drv_data->cs_change)
 540                         bfin_spi_cs_deactive(drv_data, chip);
 541
 542                 /* Move to next transfer */
 543                 msg->state = bfin_spi_next_transfer(drv_data);
 544         }
 545
 546         /* Schedule transfer tasklet */
 547         tasklet_schedule(&drv_data->pump_transfers);
 548
 549         /* free the irq handler before next transfer */
 550         dev_dbg(&drv_data->pdev->dev,
 551                 "disable dma channel irq%d\n",
 552                 drv_data->dma_channel);
 553         dma_disable_irq_nosync(drv_data->dma_channel);
 554
 555         return IRQ_HANDLED;
 556 }
 557
 558 static void bfin_spi_pump_transfers(unsigned long data)
 559 {
 560         struct bfin_spi_master_data *drv_data = (struct bfin_spi_master_data *)data;
 561         struct spi_message *message = NULL;
 562         struct spi_transfer *transfer = NULL;
 563         struct spi_transfer *previous = NULL;
 564         struct bfin_spi_slave_data *chip = NULL;
 565         unsigned int bits_per_word;
 566         u16 cr, cr_width, dma_width, dma_config;
 567         u32 tranf_success = 1;
 568         u8 full_duplex = 0;
 569
 570         /* Get current state information */
 571         message = drv_data->cur_msg;
 572         transfer = drv_data->cur_transfer;
 573         chip = drv_data->cur_chip;
 574
 575         /*
 576          * if msg is error or done, report it back using complete() callback
 577          */
 578
 579          /* Handle for abort */
 580         if (message->state == ERROR_STATE) {
 581                 dev_dbg(&drv_data->pdev->dev, "transfer: we've hit an error\n");
 582                 message->status = -EIO;
 583                 bfin_spi_giveback(drv_data);
 584                 return;
 585         }
 586
 587         /* Handle end of message */
 588         if (message->state == DONE_STATE) {
 589                 dev_dbg(&drv_data->pdev->dev, "transfer: all done!\n");
 590                 message->status = 0;
 591                 bfin_spi_giveback(drv_data);
 592                 return;
 593         }
 594
 595         /* Delay if requested at end of transfer */
 596         if (message->state == RUNNING_STATE) {
 597                 dev_dbg(&drv_data->pdev->dev, "transfer: still running ...\n");
 598                 previous = list_entry(transfer->transfer_list.prev,
 599                                       struct spi_transfer, transfer_list);
 600                 if (previous->delay_usecs)
 601                         udelay(previous->delay_usecs);
 602         }
 603
 604         /* Flush any existing transfers that may be sitting in the hardware */
 605         if (bfin_spi_flush(drv_data) == 0) {
 606                 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n");
 607                 message->status = -EIO;
 608                 bfin_spi_giveback(drv_data);
 609                 return;
 610         }
 611
 612         if (transfer->len == 0) {
 613                 /* Move to next transfer of this msg */
 614                 message->state = bfin_spi_next_transfer(drv_data);
 615                 /* Schedule next transfer tasklet */
 616                 tasklet_schedule(&drv_data->pump_transfers);
 617         }
 618
 619         if (transfer->tx_buf != NULL) {
 620                 drv_data->tx = (void *)transfer->tx_buf;
 621                 drv_data->tx_end = drv_data->tx + transfer->len;
 622                 dev_dbg(&drv_data->pdev->dev, "tx_buf is %p, tx_end is %p\n",
 623                         transfer->tx_buf, drv_data->tx_end);
 624         } else {
 625                 drv_data->tx = NULL;
 626         }
 627
 628         if (transfer->rx_buf != NULL) {
 629                 full_duplex = transfer->tx_buf != NULL;
 630                 drv_data->rx = transfer->rx_buf;
 631                 drv_data->rx_end = drv_data->rx + transfer->len;
 632                 dev_dbg(&drv_data->pdev->dev, "rx_buf is %p, rx_end is %p\n",
 633                         transfer->rx_buf, drv_data->rx_end);
 634         } else {
 635                 drv_data->rx = NULL;
 636         }
 637
 638         drv_data->rx_dma = transfer->rx_dma;
 639         drv_data->tx_dma = transfer->tx_dma;
 640         drv_data->len_in_bytes = transfer->len;
 641         drv_data->cs_change = transfer->cs_change;
 642
 643         /* Bits per word setup */
 644         bits_per_word = transfer->bits_per_word ? : message->spi->bits_per_word;
 645         if (bits_per_word == 8) {
 646                 drv_data->n_bytes = 1;
 647                 drv_data->len = transfer->len;
 648                 cr_width = 0;
 649                 drv_data->ops = &bfin_bfin_spi_transfer_ops_u8;
 650         } else if (bits_per_word == 16) {
 651                 drv_data->n_bytes = 2;
 652                 drv_data->len = (transfer->len) >> 1;
 653                 cr_width = BIT_CTL_WORDSIZE;
 654                 drv_data->ops = &bfin_bfin_spi_transfer_ops_u16;
 655         } else {
 656                 dev_err(&drv_data->pdev->dev, "transfer: unsupported bits_per_word\n");
 657                 message->status = -EINVAL;
 658                 bfin_spi_giveback(drv_data);
 659                 return;
 660         }
 661         cr = read_CTRL(drv_data) & ~(BIT_CTL_TIMOD | BIT_CTL_WORDSIZE);
 662         cr |= cr_width;
 663         write_CTRL(drv_data, cr);
 664
 665         dev_dbg(&drv_data->pdev->dev,
 666                 "transfer: drv_data->ops is %p, chip->ops is %p, u8_ops is %p\n",
 667                 drv_data->ops, chip->ops, &bfin_bfin_spi_transfer_ops_u8);
 668
 669         message->state = RUNNING_STATE;
 670         dma_config = 0;
 671
 672         /* Speed setup (surely valid because already checked) */
 673         if (transfer->speed_hz)
 674                 write_BAUD(drv_data, hz_to_spi_baud(transfer->speed_hz));
 675         else
 676                 write_BAUD(drv_data, chip->baud);
 677
 678         write_STAT(drv_data, BIT_STAT_CLR);
 679         bfin_spi_cs_active(drv_data, chip);
 680
 681         dev_dbg(&drv_data->pdev->dev,
 682                 "now pumping a transfer: width is %d, len is %d\n",
 683                 cr_width, transfer->len);
 684
 685         /*
 686          * Try to map dma buffer and do a dma transfer.  If successful use,
 687          * different way to r/w according to the enable_dma settings and if
 688          * we are not doing a full duplex transfer (since the hardware does
 689          * not support full duplex DMA transfers).
 690          */
 691         if (!full_duplex && drv_data->cur_chip->enable_dma
 692                                 && drv_data->len > 6) {
 693
 694                 unsigned long dma_start_addr, flags;
 695
 696                 disable_dma(drv_data->dma_channel);
 697                 clear_dma_irqstat(drv_data->dma_channel);
 698
 699                 /* config dma channel */
 700                 dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
 701                 set_dma_x_count(drv_data->dma_channel, drv_data->len);
 702                 if (cr_width == BIT_CTL_WORDSIZE) {
 703                         set_dma_x_modify(drv_data->dma_channel, 2);
 704                         dma_width = WDSIZE_16;
 705                 } else {
 706                         set_dma_x_modify(drv_data->dma_channel, 1);
 707                         dma_width = WDSIZE_8;
 708                 }
 709
 710                 /* poll for SPI completion before start */
 711                 while (!(read_STAT(drv_data) & BIT_STAT_SPIF))
 712                         cpu_relax();
 713
 714                 /* dirty hack for autobuffer DMA mode */
 715                 if (drv_data->tx_dma == 0xFFFF) {
 716                         dev_dbg(&drv_data->pdev->dev,
 717                                 "doing autobuffer DMA out.\n");
 718
 719                         /* no irq in autobuffer mode */
 720                         dma_config =
 721                             (DMAFLOW_AUTO | RESTART | dma_width | DI_EN);
 722                         set_dma_config(drv_data->dma_channel, dma_config);
 723                         set_dma_start_addr(drv_data->dma_channel,
 724                                         (unsigned long)drv_data->tx);
 725                         enable_dma(drv_data->dma_channel);
 726
 727                         /* start SPI transfer */
 728                         write_CTRL(drv_data, cr | BIT_CTL_TIMOD_DMA_TX);
 729
 730                         /* just return here, there can only be one transfer
 731                          * in this mode
 732                          */
 733                         message->status = 0;
 734                         bfin_spi_giveback(drv_data);
 735                         return;
 736                 }
 737
 738                 /* In dma mode, rx or tx must be NULL in one transfer */
 739                 dma_config = (RESTART | dma_width | DI_EN);
 740                 if (drv_data->rx != NULL) {
 741                         /* set transfer mode, and enable SPI */
 742                         dev_dbg(&drv_data->pdev->dev, "doing DMA in to %p (size %zx)\n",
 743                                 drv_data->rx, drv_data->len_in_bytes);
 744
 745                         /* invalidate caches, if needed */
 746                         if (bfin_addr_dcacheable((unsigned long) drv_data->rx))
 747                                 invalidate_dcache_range((unsigned long) drv_data->rx,
 748                                                         (unsigned long) (drv_data->rx +
 749                                                         drv_data->len_in_bytes));
 750
 751                         dma_config |= WNR;
 752                         dma_start_addr = (unsigned long)drv_data->rx;
 753                         cr |= BIT_CTL_TIMOD_DMA_RX | BIT_CTL_SENDOPT;
 754
 755                 } else if (drv_data->tx != NULL) {
 756                         dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
 757
 758                         /* flush caches, if needed */
 759                         if (bfin_addr_dcacheable((unsigned long) drv_data->tx))
 760                                 flush_dcache_range((unsigned long) drv_data->tx,
 761                                                 (unsigned long) (drv_data->tx +
 762                                                 drv_data->len_in_bytes));
 763
 764                         dma_start_addr = (unsigned long)drv_data->tx;
 765                         cr |= BIT_CTL_TIMOD_DMA_TX;
 766
 767                 } else
 768                         BUG();
 769
 770                 /* oh man, here there be monsters ... and i dont mean the
 771                  * fluffy cute ones from pixar, i mean the kind that'll eat
 772                  * your data, kick your dog, and love it all.  do *not* try
 773                  * and change these lines unless you (1) heavily test DMA
 774                  * with SPI flashes on a loaded system (e.g. ping floods),
 775                  * (2) know just how broken the DMA engine interaction with
 776                  * the SPI peripheral is, and (3) have someone else to blame
 777                  * when you screw it all up anyways.
 778                  */
 779                 set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
 780                 set_dma_config(drv_data->dma_channel, dma_config);
 781                 local_irq_save(flags);
 782                 SSYNC();
 783                 write_CTRL(drv_data, cr);
 784                 enable_dma(drv_data->dma_channel);
 785                 dma_enable_irq(drv_data->dma_channel);
 786                 local_irq_restore(flags);
 787
 788                 return;
 789         }
 790
 791         /*
 792          * We always use SPI_WRITE mode (transfer starts with TDBR write).
 793          * SPI_READ mode (transfer starts with RDBR read) seems to have
 794          * problems with setting up the output value in TDBR prior to the
 795          * start of the transfer.
 796          */
 797         write_CTRL(drv_data, cr | BIT_CTL_TXMOD);
 798
 799         if (chip->pio_interrupt) {
 800                 /* SPI irq should have been disabled by now */
 801
 802                 /* discard old RX data and clear RXS */
 803                 bfin_spi_dummy_read(drv_data);
 804
 805                 /* start transfer */
 806                 if (drv_data->tx == NULL)
 807                         write_TDBR(drv_data, chip->idle_tx_val);
 808                 else {
 809                         if (bits_per_word == 8)
 810                                 write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
 811                         else
 812                                 write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
 813                         drv_data->tx += drv_data->n_bytes;
 814                 }
 815
 816                 /* once TDBR is empty, interrupt is triggered */
 817                 enable_irq(drv_data->spi_irq);
 818                 return;
 819         }
 820
 821         /* IO mode */
 822         dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");
 823
 824         if (full_duplex) {
 825                 /* full duplex mode */
 826                 BUG_ON((drv_data->tx_end - drv_data->tx) !=
 827                        (drv_data->rx_end - drv_data->rx));
 828                 dev_dbg(&drv_data->pdev->dev,
 829                         "IO duplex: cr is 0x%x\n", cr);
 830
 831                 drv_data->ops->duplex(drv_data);
 832
 833                 if (drv_data->tx != drv_data->tx_end)
 834                         tranf_success = 0;
 835         } else if (drv_data->tx != NULL) {
 836                 /* write only half duplex */
 837                 dev_dbg(&drv_data->pdev->dev,
 838                         "IO write: cr is 0x%x\n", cr);
 839
 840                 drv_data->ops->write(drv_data);
 841
 842                 if (drv_data->tx != drv_data->tx_end)
 843                         tranf_success = 0;
 844         } else if (drv_data->rx != NULL) {
 845                 /* read only half duplex */
 846                 dev_dbg(&drv_data->pdev->dev,
 847                         "IO read: cr is 0x%x\n", cr);
 848
 849                 drv_data->ops->read(drv_data);
 850                 if (drv_data->rx != drv_data->rx_end)
 851                         tranf_success = 0;
 852         }
 853
 854         if (!tranf_success) {
 855                 dev_dbg(&drv_data->pdev->dev,
 856                         "IO write error!\n");
 857                 message->state = ERROR_STATE;
 858         } else {
 859                 /* Update total byte transfered */
 860                 message->actual_length += drv_data->len_in_bytes;
 861                 /* Move to next transfer of this msg */
 862                 message->state = bfin_spi_next_transfer(drv_data);
 863                 if (drv_data->cs_change)
 864                         bfin_spi_cs_deactive(drv_data, chip);
 865         }
 866
 867         /* Schedule next transfer tasklet */
 868         tasklet_schedule(&drv_data->pump_transfers);
 869 }
 870
 871 /* pop a msg from queue and kick off real transfer */
 872 static void bfin_spi_pump_messages(struct work_struct *work)
 873 {
 874         struct bfin_spi_master_data *drv_data;
 875         unsigned long flags;
 876
 877         drv_data = container_of(work, struct bfin_spi_master_data, pump_messages);
 878
 879         /* Lock queue and check for queue work */
 880         spin_lock_irqsave(&drv_data->lock, flags);
 881         if (list_empty(&drv_data->queue) || !drv_data->running) {
 882                 /* pumper kicked off but no work to do */
 883                 drv_data->busy = 0;
 884                 spin_unlock_irqrestore(&drv_data->lock, flags);
 885                 return;
 886         }
 887
 888         /* Make sure we are not already running a message */
 889         if (drv_data->cur_msg) {
 890                 spin_unlock_irqrestore(&drv_data->lock, flags);
 891                 return;
 892         }
 893
 894         /* Extract head of queue */
 895         drv_data->cur_msg = list_entry(drv_data->queue.next,
 896                                        struct spi_message, queue);
 897
 898         /* Setup the SSP using the per chip configuration */
 899         drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);
 900         bfin_spi_restore_state(drv_data);
 901
 902         list_del_init(&drv_data->cur_msg->queue);
 903
 904         /* Initial message state */
 905         drv_data->cur_msg->state = START_STATE;
 906         drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
 907                                             struct spi_transfer, transfer_list);
 908
 909         dev_dbg(&drv_data->pdev->dev, "got a message to pump, "
 910                 "state is set to: baud %d, flag 0x%x, ctl 0x%x\n",
 911                 drv_data->cur_chip->baud, drv_data->cur_chip->flag,
 912                 drv_data->cur_chip->ctl_reg);
 913
 914         dev_dbg(&drv_data->pdev->dev,
 915                 "the first transfer len is %d\n",
 916                 drv_data->cur_transfer->len);
 917
 918         /* Mark as busy and launch transfers */
 919         tasklet_schedule(&drv_data->pump_transfers);
 920
 921         drv_data->busy = 1;
 922         spin_unlock_irqrestore(&drv_data->lock, flags);
 923 }
 924
 925 /*
 926  * got a msg to transfer, queue it in drv_data->queue.
 927  * And kick off message pumper
 928  */
 929 static int bfin_spi_transfer(struct spi_device *spi, struct spi_message *msg)
 930 {
 931         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
 932         unsigned long flags;
 933
 934         spin_lock_irqsave(&drv_data->lock, flags);
 935
 936         if (!drv_data->running) {
 937                 spin_unlock_irqrestore(&drv_data->lock, flags);
 938                 return -ESHUTDOWN;
 939         }
 940
 941         msg->actual_length = 0;
 942         msg->status = -EINPROGRESS;
 943         msg->state = START_STATE;
 944
 945         dev_dbg(&spi->dev, "adding an msg in transfer() \n");
 946         list_add_tail(&msg->queue, &drv_data->queue);
 947
 948         if (drv_data->running && !drv_data->busy)
 949                 queue_work(drv_data->workqueue, &drv_data->pump_messages);
 950
 951         spin_unlock_irqrestore(&drv_data->lock, flags);
 952
 953         return 0;
 954 }
 955
 956 #define MAX_SPI_SSEL    7
 957
 958 static u16 ssel[][MAX_SPI_SSEL] = {
 959         {P_SPI0_SSEL1, P_SPI0_SSEL2, P_SPI0_SSEL3,
 960         P_SPI0_SSEL4, P_SPI0_SSEL5,
 961         P_SPI0_SSEL6, P_SPI0_SSEL7},
 962
 963         {P_SPI1_SSEL1, P_SPI1_SSEL2, P_SPI1_SSEL3,
 964         P_SPI1_SSEL4, P_SPI1_SSEL5,
 965         P_SPI1_SSEL6, P_SPI1_SSEL7},
 966
 967         {P_SPI2_SSEL1, P_SPI2_SSEL2, P_SPI2_SSEL3,
 968         P_SPI2_SSEL4, P_SPI2_SSEL5,
 969         P_SPI2_SSEL6, P_SPI2_SSEL7},
 970 };
 971
 972 /* setup for devices (may be called multiple times -- not just first setup) */
 973 static int bfin_spi_setup(struct spi_device *spi)
 974 {
 975         struct bfin5xx_spi_chip *chip_info;
 976         struct bfin_spi_slave_data *chip = NULL;
 977         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
 978         u16 bfin_ctl_reg;
 979         int ret = -EINVAL;
 980
 981         /* Only alloc (or use chip_info) on first setup */
 982         chip_info = NULL;
 983         chip = spi_get_ctldata(spi);
 984         if (chip == NULL) {
 985                 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 986                 if (!chip) {
 987                         dev_err(&spi->dev, "cannot allocate chip data\n");
 988                         ret = -ENOMEM;
 989                         goto error;
 990                 }
 991
 992                 chip->enable_dma = 0;
 993                 chip_info = spi->controller_data;
 994         }
 995
 996         /* Let people set non-standard bits directly */
 997         bfin_ctl_reg = BIT_CTL_OPENDRAIN | BIT_CTL_EMISO |
 998                 BIT_CTL_PSSE | BIT_CTL_GM | BIT_CTL_SZ;
 999
1000         /* chip_info isn't always needed */
1001         if (chip_info) {
1002                 /* Make sure people stop trying to set fields via ctl_reg
1003                  * when they should actually be using common SPI framework.
1004                  * Currently we let through: WOM EMISO PSSE GM SZ.
1005                  * Not sure if a user actually needs/uses any of these,
1006                  * but let's assume (for now) they do.
1007                  */
1008                 if (chip_info->ctl_reg & ~bfin_ctl_reg) {
1009                         dev_err(&spi->dev, "do not set bits in ctl_reg "
1010                                 "that the SPI framework manages\n");
1011                         goto error;
1012                 }
1013                 chip->enable_dma = chip_info->enable_dma != 0
1014                     && drv_data->master_info->enable_dma;
1015                 chip->ctl_reg = chip_info->ctl_reg;
1016                 chip->cs_chg_udelay = chip_info->cs_chg_udelay;
1017                 chip->idle_tx_val = chip_info->idle_tx_val;
1018                 chip->pio_interrupt = chip_info->pio_interrupt;
1019                 spi->bits_per_word = chip_info->bits_per_word;
1020         } else {
1021                 /* force a default base state */
1022                 chip->ctl_reg &= bfin_ctl_reg;
1023         }
1024
1025         if (spi->bits_per_word != 8 && spi->bits_per_word != 16) {
1026                 dev_err(&spi->dev, "%d bits_per_word is not supported\n",
1027                                 spi->bits_per_word);
1028                 goto error;
1029         }
1030
1031         /* translate common spi framework into our register */
1032         if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) {
1033                 dev_err(&spi->dev, "unsupported spi modes detected\n");
1034                 goto error;
1035         }
1036         if (spi->mode & SPI_CPOL)
1037                 chip->ctl_reg |= BIT_CTL_CPOL;
1038         if (spi->mode & SPI_CPHA)
1039                 chip->ctl_reg |= BIT_CTL_CPHA;
1040         if (spi->mode & SPI_LSB_FIRST)
1041                 chip->ctl_reg |= BIT_CTL_LSBF;
1042         /* we dont support running in slave mode (yet?) */
1043         chip->ctl_reg |= BIT_CTL_MASTER;
1044
1045         /*
1046          * Notice: for blackfin, the speed_hz is the value of register
1047          * SPI_BAUD, not the real baudrate
1048          */
1049         chip->baud = hz_to_spi_baud(spi->max_speed_hz);
1050         chip->chip_select_num = spi->chip_select;
1051         if (chip->chip_select_num < MAX_CTRL_CS) {
1052                 if (!(spi->mode & SPI_CPHA))
1053                         dev_warn(&spi->dev, "Warning: SPI CPHA not set:"
1054                                 " Slave Select not under software control!\n"
1055                                 " See Documentation/blackfin/bfin-spi-notes.txt");
1056
1057                 chip->flag = (1 << spi->chip_select) << 8;
1058         } else
1059                 chip->cs_gpio = chip->chip_select_num - MAX_CTRL_CS;
1060
1061         if (chip->enable_dma && chip->pio_interrupt) {
1062                 dev_err(&spi->dev, "enable_dma is set, "
1063                                 "do not set pio_interrupt\n");
1064                 goto error;
1065         }
1066         /*
1067          * if any one SPI chip is registered and wants DMA, request the
1068          * DMA channel for it
1069          */
1070         if (chip->enable_dma && !drv_data->dma_requested) {
1071                 /* register dma irq handler */
1072                 ret = request_dma(drv_data->dma_channel, "BFIN_SPI_DMA");
1073                 if (ret) {
1074                         dev_err(&spi->dev,
1075                                 "Unable to request BlackFin SPI DMA channel\n");
1076                         goto error;
1077                 }
1078                 drv_data->dma_requested = 1;
1079
1080                 ret = set_dma_callback(drv_data->dma_channel,
1081                         bfin_spi_dma_irq_handler, drv_data);
1082                 if (ret) {
1083                         dev_err(&spi->dev, "Unable to set dma callback\n");
1084                         goto error;
1085                 }
1086                 dma_disable_irq(drv_data->dma_channel);
1087         }
1088
1089         if (chip->pio_interrupt && !drv_data->irq_requested) {
1090                 ret = request_irq(drv_data->spi_irq, bfin_spi_pio_irq_handler,
1091                         IRQF_DISABLED, "BFIN_SPI", drv_data);
1092                 if (ret) {
1093                         dev_err(&spi->dev, "Unable to register spi IRQ\n");
1094                         goto error;
1095                 }
1096                 drv_data->irq_requested = 1;
1097                 /* we use write mode, spi irq has to be disabled here */
1098                 disable_irq(drv_data->spi_irq);
1099         }
1100
1101         if (chip->chip_select_num >= MAX_CTRL_CS) {
1102                 ret = gpio_request(chip->cs_gpio, spi->modalias);
1103                 if (ret) {
1104                         dev_err(&spi->dev, "gpio_request() error\n");
1105                         goto pin_error;
1106                 }
1107                 gpio_direction_output(chip->cs_gpio, 1);
1108         }
1109
1110         dev_dbg(&spi->dev, "setup spi chip %s, width is %d, dma is %d\n",
1111                         spi->modalias, spi->bits_per_word, chip->enable_dma);
1112         dev_dbg(&spi->dev, "ctl_reg is 0x%x, flag_reg is 0x%x\n",
1113                         chip->ctl_reg, chip->flag);
1114
1115         spi_set_ctldata(spi, chip);
1116
1117         dev_dbg(&spi->dev, "chip select number is %d\n", chip->chip_select_num);
1118         if (chip->chip_select_num < MAX_CTRL_CS) {
1119                 ret = peripheral_request(ssel[spi->master->bus_num]
1120                                          [chip->chip_select_num-1], spi->modalias);
1121                 if (ret) {
1122                         dev_err(&spi->dev, "peripheral_request() error\n");
1123                         goto pin_error;
1124                 }
1125         }
1126
1127         bfin_spi_cs_enable(drv_data, chip);
1128         bfin_spi_cs_deactive(drv_data, chip);
1129
1130         return 0;
1131
1132  pin_error:
1133         if (chip->chip_select_num >= MAX_CTRL_CS)
1134                 gpio_free(chip->cs_gpio);
1135         else
1136                 peripheral_free(ssel[spi->master->bus_num]
1137                         [chip->chip_select_num - 1]);
1138  error:
1139         if (chip) {
1140                 if (drv_data->dma_requested)
1141                         free_dma(drv_data->dma_channel);
1142                 drv_data->dma_requested = 0;
1143
1144                 kfree(chip);
1145                 /* prevent free 'chip' twice */
1146                 spi_set_ctldata(spi, NULL);
1147         }
1148
1149         return ret;
1150 }
1151
1152 /*
1153  * callback for spi framework.
1154  * clean driver specific data
1155  */
1156 static void bfin_spi_cleanup(struct spi_device *spi)
1157 {
1158         struct bfin_spi_slave_data *chip = spi_get_ctldata(spi);
1159         struct bfin_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
1160
1161         if (!chip)
1162                 return;
1163
1164         if (chip->chip_select_num < MAX_CTRL_CS) {
1165                 peripheral_free(ssel[spi->master->bus_num]
1166                                         [chip->chip_select_num-1]);
1167                 bfin_spi_cs_disable(drv_data, chip);
1168         } else
1169                 gpio_free(chip->cs_gpio);
1170
1171         kfree(chip);
1172         /* prevent free 'chip' twice */
1173         spi_set_ctldata(spi, NULL);
1174 }
1175
1176 static inline int bfin_spi_init_queue(struct bfin_spi_master_data *drv_data)
1177 {
1178         INIT_LIST_HEAD(&drv_data->queue);
1179         spin_lock_init(&drv_data->lock);
1180
1181         drv_data->running = false;
1182         drv_data->busy = 0;
1183
1184         /* init transfer tasklet */
1185         tasklet_init(&drv_data->pump_transfers,
1186                      bfin_spi_pump_transfers, (unsigned long)drv_data);
1187
1188         /* init messages workqueue */
1189         INIT_WORK(&drv_data->pump_messages, bfin_spi_pump_messages);
1190         drv_data->workqueue = create_singlethread_workqueue(
1191                                 dev_name(drv_data->master->dev.parent));
1192         if (drv_data->workqueue == NULL)
1193                 return -EBUSY;
1194
1195         return 0;
1196 }
1197
1198 static inline int bfin_spi_start_queue(struct bfin_spi_master_data *drv_data)
1199 {
1200         unsigned long flags;
1201
1202         spin_lock_irqsave(&drv_data->lock, flags);
1203
1204         if (drv_data->running || drv_data->busy) {
1205                 spin_unlock_irqrestore(&drv_data->lock, flags);
1206                 return -EBUSY;
1207         }
1208
1209         drv_data->running = true;
1210         drv_data->cur_msg = NULL;
1211         drv_data->cur_transfer = NULL;
1212         drv_data->cur_chip = NULL;
1213         spin_unlock_irqrestore(&drv_data->lock, flags);
1214
1215         queue_work(drv_data->workqueue, &drv_data->pump_messages);
1216
1217         return 0;
1218 }
1219
1220 static inline int bfin_spi_stop_queue(struct bfin_spi_master_data *drv_data)
1221 {
1222         unsigned long flags;
1223         unsigned limit = 500;
1224         int status = 0;
1225
1226         spin_lock_irqsave(&drv_data->lock, flags);
1227
1228         /*
1229          * This is a bit lame, but is optimized for the common execution path.
1230          * A wait_queue on the drv_data->busy could be used, but then the common
1231          * execution path (pump_messages) would be required to call wake_up or
1232          * friends on every SPI message. Do this instead
1233          */
1234         drv_data->running = false;
1235         while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
1236                 spin_unlock_irqrestore(&drv_data->lock, flags);
1237                 msleep(10);
1238                 spin_lock_irqsave(&drv_data->lock, flags);
1239         }
1240
1241         if (!list_empty(&drv_data->queue) || drv_data->busy)
1242                 status = -EBUSY;
1243
1244         spin_unlock_irqrestore(&drv_data->lock, flags);
1245
1246         return status;
1247 }
1248
1249 static inline int bfin_spi_destroy_queue(struct bfin_spi_master_data *drv_data)
1250 {
1251         int status;
1252
1253         status = bfin_spi_stop_queue(drv_data);
1254         if (status != 0)
1255                 return status;
1256
1257         destroy_workqueue(drv_data->workqueue);
1258
1259         return 0;
1260 }
1261
1262 static int __init bfin_spi_probe(struct platform_device *pdev)
1263 {
1264         struct device *dev = &pdev->dev;
1265         struct bfin5xx_spi_master *platform_info;
1266         struct spi_master *master;
1267         struct bfin_spi_master_data *drv_data;
1268         struct resource *res;
1269         int status = 0;
1270
1271         platform_info = dev->platform_data;
1272
1273         /* Allocate master with space for drv_data */
1274         master = spi_alloc_master(dev, sizeof(*drv_data));
1275         if (!master) {
1276                 dev_err(&pdev->dev, "can not alloc spi_master\n");
1277                 return -ENOMEM;
1278         }
1279
1280         drv_data = spi_master_get_devdata(master);
1281         drv_data->master = master;
1282         drv_data->master_info = platform_info;
1283         drv_data->pdev = pdev;
1284         drv_data->pin_req = platform_info->pin_req;
1285
1286         /* the spi->mode bits supported by this driver: */
1287         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
1288
1289         master->bus_num = pdev->id;
1290         master->num_chipselect = platform_info->num_chipselect;
1291         master->cleanup = bfin_spi_cleanup;
1292         master->setup = bfin_spi_setup;
1293         master->transfer = bfin_spi_transfer;
1294
1295         /* Find and map our resources */
1296         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1297         if (res == NULL) {
1298                 dev_err(dev, "Cannot get IORESOURCE_MEM\n");
1299                 status = -ENOENT;
1300                 goto out_error_get_res;
1301         }
1302
1303         drv_data->regs_base = ioremap(res->start, resource_size(res));
1304         if (drv_data->regs_base == NULL) {
1305                 dev_err(dev, "Cannot map IO\n");
1306                 status = -ENXIO;
1307                 goto out_error_ioremap;
1308         }
1309
1310         res = platform_get_resource(pdev, IORESOURCE_DMA, 0);
1311         if (res == NULL) {
1312                 dev_err(dev, "No DMA channel specified\n");
1313                 status = -ENOENT;
1314                 goto out_error_free_io;
1315         }
1316         drv_data->dma_channel = res->start;
1317
1318         drv_data->spi_irq = platform_get_irq(pdev, 0);
1319         if (drv_data->spi_irq < 0) {
1320                 dev_err(dev, "No spi pio irq specified\n");
1321                 status = -ENOENT;
1322                 goto out_error_free_io;
1323         }
1324
1325         /* Initial and start queue */
1326         status = bfin_spi_init_queue(drv_data);
1327         if (status != 0) {
1328                 dev_err(dev, "problem initializing queue\n");
1329                 goto out_error_queue_alloc;
1330         }
1331
1332         status = bfin_spi_start_queue(drv_data);
1333         if (status != 0) {
1334                 dev_err(dev, "problem starting queue\n");
1335                 goto out_error_queue_alloc;
1336         }
1337
1338         status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
1339         if (status != 0) {
1340                 dev_err(&pdev->dev, ": Requesting Peripherals failed\n");
1341                 goto out_error_queue_alloc;
1342         }
1343
1344         /* Reset SPI registers. If these registers were used by the boot loader,
1345          * the sky may fall on your head if you enable the dma controller.
1346          */
1347         write_CTRL(drv_data, BIT_CTL_CPHA | BIT_CTL_MASTER);
1348         write_FLAG(drv_data, 0xFF00);
1349
1350         /* Register with the SPI framework */
1351         platform_set_drvdata(pdev, drv_data);
1352         status = spi_register_master(master);
1353         if (status != 0) {
1354                 dev_err(dev, "problem registering spi master\n");
1355                 goto out_error_queue_alloc;
1356         }
1357
1358         dev_info(dev, "%s, Version %s, regs_base@%p, dma channel@%d\n",
1359                 DRV_DESC, DRV_VERSION, drv_data->regs_base,
1360                 drv_data->dma_channel);
1361         return status;
1362
1363 out_error_queue_alloc:
1364         bfin_spi_destroy_queue(drv_data);
1365 out_error_free_io:
1366         iounmap((void *) drv_data->regs_base);
1367 out_error_ioremap:
1368 out_error_get_res:
1369         spi_master_put(master);
1370
1371         return status;
1372 }
1373
1374 /* stop hardware and remove the driver */
1375 static int __devexit bfin_spi_remove(struct platform_device *pdev)
1376 {
1377         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1378         int status = 0;
1379
1380         if (!drv_data)
1381                 return 0;
1382
1383         /* Remove the queue */
1384         status = bfin_spi_destroy_queue(drv_data);
1385         if (status != 0)
1386                 return status;
1387
1388         /* Disable the SSP at the peripheral and SOC level */
1389         bfin_spi_disable(drv_data);
1390
1391         /* Release DMA */
1392         if (drv_data->master_info->enable_dma) {
1393                 if (dma_channel_active(drv_data->dma_channel))
1394                         free_dma(drv_data->dma_channel);
1395         }
1396
1397         if (drv_data->irq_requested) {
1398                 free_irq(drv_data->spi_irq, drv_data);
1399                 drv_data->irq_requested = 0;
1400         }
1401
1402         /* Disconnect from the SPI framework */
1403         spi_unregister_master(drv_data->master);
1404
1405         peripheral_free_list(drv_data->pin_req);
1406
1407         /* Prevent double remove */
1408         platform_set_drvdata(pdev, NULL);
1409
1410         return 0;
1411 }
1412
1413 #ifdef CONFIG_PM
1414 static int bfin_spi_suspend(struct platform_device *pdev, pm_message_t state)
1415 {
1416         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1417         int status = 0;
1418
1419         status = bfin_spi_stop_queue(drv_data);
1420         if (status != 0)
1421                 return status;
1422
1423         drv_data->ctrl_reg = read_CTRL(drv_data);
1424         drv_data->flag_reg = read_FLAG(drv_data);
1425
1426         /*
1427          * reset SPI_CTL and SPI_FLG registers
1428          */
1429         write_CTRL(drv_data, BIT_CTL_CPHA | BIT_CTL_MASTER);
1430         write_FLAG(drv_data, 0xFF00);
1431
1432         return 0;
1433 }
1434
1435 static int bfin_spi_resume(struct platform_device *pdev)
1436 {
1437         struct bfin_spi_master_data *drv_data = platform_get_drvdata(pdev);
1438         int status = 0;
1439
1440         write_CTRL(drv_data, drv_data->ctrl_reg);
1441         write_FLAG(drv_data, drv_data->flag_reg);
1442
1443         /* Start the queue running */
1444         status = bfin_spi_start_queue(drv_data);
1445         if (status != 0) {
1446                 dev_err(&pdev->dev, "problem starting queue (%d)\n", status);
1447                 return status;
1448         }
1449
1450         return 0;
1451 }
1452 #else
1453 #define bfin_spi_suspend NULL
1454 #define bfin_spi_resume NULL
1455 #endif                          /* CONFIG_PM */
1456
1457 MODULE_ALIAS("platform:bfin-spi");
1458 static struct platform_driver bfin_spi_driver = {
1459         .driver = {
1460                 .name   = DRV_NAME,
1461                 .owner  = THIS_MODULE,
1462         },
1463         .suspend        = bfin_spi_suspend,
1464         .resume         = bfin_spi_resume,
1465         .remove         = __devexit_p(bfin_spi_remove),
1466 };
1467
1468 static int __init bfin_spi_init(void)
1469 {
1470         return platform_driver_probe(&bfin_spi_driver, bfin_spi_probe);
1471 }
1472 subsys_initcall(bfin_spi_init);
1473
1474 static void __exit bfin_spi_exit(void)
1475 {
1476         platform_driver_unregister(&bfin_spi_driver);
1477 }
1478 module_exit(bfin_spi_exit);