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