drivers/spi/spi_mpc83xx.c

   1 /*
   2  * MPC83xx SPI controller driver.
   3  *
   4  * Maintainer: Kumar Gala
   5  *
   6  * Copyright (C) 2006 Polycom, Inc.
   7  *
   8  * This program is free software; you can redistribute  it and/or modify it
   9  * under  the terms of  the GNU General  Public License as published by the
  10  * Free Software Foundation;  either version 2 of the  License, or (at your
  11  * option) any later version.
  12  */
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/kernel.h>
  17 #include <linux/completion.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/delay.h>
  20 #include <linux/irq.h>
  21 #include <linux/device.h>
  22 #include <linux/spi/spi.h>
  23 #include <linux/spi/spi_bitbang.h>
  24 #include <linux/platform_device.h>
  25 #include <linux/fsl_devices.h>
  26
  27 #include <asm/irq.h>
  28 #include <asm/io.h>
  29
  30 /* SPI Controller registers */
  31 struct mpc83xx_spi_reg {
  32         u8 res1[0x20];
  33         __be32 mode;
  34         __be32 event;
  35         __be32 mask;
  36         __be32 command;
  37         __be32 transmit;
  38         __be32 receive;
  39 };
  40
  41 /* SPI Controller mode register definitions */
  42 #define SPMODE_LOOP             (1 << 30)
  43 #define SPMODE_CI_INACTIVEHIGH  (1 << 29)
  44 #define SPMODE_CP_BEGIN_EDGECLK (1 << 28)
  45 #define SPMODE_DIV16            (1 << 27)
  46 #define SPMODE_REV              (1 << 26)
  47 #define SPMODE_MS               (1 << 25)
  48 #define SPMODE_ENABLE           (1 << 24)
  49 #define SPMODE_LEN(x)           ((x) << 20)
  50 #define SPMODE_PM(x)            ((x) << 16)
  51 #define SPMODE_OP               (1 << 14)
  52 #define SPMODE_CG(x)            ((x) << 7)
  53
  54 /*
  55  * Default for SPI Mode:
  56  *      SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk
  57  */
  58 #define SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH | SPMODE_DIV16 | SPMODE_REV | \
  59                          SPMODE_MS | SPMODE_LEN(7) | SPMODE_PM(0xf))
  60
  61 /* SPIE register values */
  62 #define SPIE_NE         0x00000200      /* Not empty */
  63 #define SPIE_NF         0x00000100      /* Not full */
  64
  65 /* SPIM register values */
  66 #define SPIM_NE         0x00000200      /* Not empty */
  67 #define SPIM_NF         0x00000100      /* Not full */
  68
  69 /* SPI Controller driver's private data. */
  70 struct mpc83xx_spi {
  71         struct mpc83xx_spi_reg __iomem *base;
  72
  73         /* rx & tx bufs from the spi_transfer */
  74         const void *tx;
  75         void *rx;
  76
  77         /* functions to deal with different sized buffers */
  78         void (*get_rx) (u32 rx_data, struct mpc83xx_spi *);
  79         u32(*get_tx) (struct mpc83xx_spi *);
  80
  81         unsigned int count;
  82         int irq;
  83
  84         unsigned nsecs;         /* (clock cycle time)/2 */
  85
  86         u32 spibrg;             /* SPIBRG input clock */
  87         u32 rx_shift;           /* RX data reg shift when in qe mode */
  88         u32 tx_shift;           /* TX data reg shift when in qe mode */
  89
  90         bool qe_mode;
  91
  92         void (*activate_cs) (u8 cs, u8 polarity);
  93         void (*deactivate_cs) (u8 cs, u8 polarity);
  94
  95         u8 busy;
  96
  97         struct workqueue_struct *workqueue;
  98         struct work_struct work;
  99
 100         struct list_head queue;
 101         spinlock_t lock;
 102
 103         struct completion done;
 104 };
 105
 106 struct spi_mpc83xx_cs {
 107         /* functions to deal with different sized buffers */
 108         void (*get_rx) (u32 rx_data, struct mpc83xx_spi *);
 109         u32 (*get_tx) (struct mpc83xx_spi *);
 110         u32 rx_shift;           /* RX data reg shift when in qe mode */
 111         u32 tx_shift;           /* TX data reg shift when in qe mode */
 112         u32 hw_mode;            /* Holds HW mode register settings */
 113 };
 114
 115 static inline void mpc83xx_spi_write_reg(__be32 __iomem * reg, u32 val)
 116 {
 117         out_be32(reg, val);
 118 }
 119
 120 static inline u32 mpc83xx_spi_read_reg(__be32 __iomem * reg)
 121 {
 122         return in_be32(reg);
 123 }
 124
 125 #define MPC83XX_SPI_RX_BUF(type)                                          \
 126 void mpc83xx_spi_rx_buf_##type(u32 data, struct mpc83xx_spi *mpc83xx_spi) \
 127 {                                                                         \
 128         type * rx = mpc83xx_spi->rx;                                      \
 129         *rx++ = (type)(data >> mpc83xx_spi->rx_shift);                    \
 130         mpc83xx_spi->rx = rx;                                             \
 131 }
 132
 133 #define MPC83XX_SPI_TX_BUF(type)                                \
 134 u32 mpc83xx_spi_tx_buf_##type(struct mpc83xx_spi *mpc83xx_spi)  \
 135 {                                                               \
 136         u32 data;                                               \
 137         const type * tx = mpc83xx_spi->tx;                      \
 138         if (!tx)                                                \
 139                 return 0;                                       \
 140         data = *tx++ << mpc83xx_spi->tx_shift;                  \
 141         mpc83xx_spi->tx = tx;                                   \
 142         return data;                                            \
 143 }
 144
 145 MPC83XX_SPI_RX_BUF(u8)
 146 MPC83XX_SPI_RX_BUF(u16)
 147 MPC83XX_SPI_RX_BUF(u32)
 148 MPC83XX_SPI_TX_BUF(u8)
 149 MPC83XX_SPI_TX_BUF(u16)
 150 MPC83XX_SPI_TX_BUF(u32)
 151
 152 static void mpc83xx_spi_chipselect(struct spi_device *spi, int value)
 153 {
 154         struct mpc83xx_spi *mpc83xx_spi;
 155         u8 pol = spi->mode & SPI_CS_HIGH ? 1 : 0;
 156         struct spi_mpc83xx_cs   *cs = spi->controller_state;
 157
 158         mpc83xx_spi = spi_master_get_devdata(spi->master);
 159
 160         if (value == BITBANG_CS_INACTIVE) {
 161                 if (mpc83xx_spi->deactivate_cs)
 162                         mpc83xx_spi->deactivate_cs(spi->chip_select, pol);
 163         }
 164
 165         if (value == BITBANG_CS_ACTIVE) {
 166                 u32 regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
 167
 168                 mpc83xx_spi->rx_shift = cs->rx_shift;
 169                 mpc83xx_spi->tx_shift = cs->tx_shift;
 170                 mpc83xx_spi->get_rx = cs->get_rx;
 171                 mpc83xx_spi->get_tx = cs->get_tx;
 172
 173                 if (cs->hw_mode != regval) {
 174                         unsigned long flags;
 175                         void *tmp_ptr = &mpc83xx_spi->base->mode;
 176
 177                         regval = cs->hw_mode;
 178                         /* Turn off IRQs locally to minimize time that
 179                          * SPI is disabled
 180                          */
 181                         local_irq_save(flags);
 182                         /* Turn off SPI unit prior changing mode */
 183                         mpc83xx_spi_write_reg(tmp_ptr, regval & ~SPMODE_ENABLE);
 184                         mpc83xx_spi_write_reg(tmp_ptr, regval);
 185                         local_irq_restore(flags);
 186                 }
 187                 if (mpc83xx_spi->activate_cs)
 188                         mpc83xx_spi->activate_cs(spi->chip_select, pol);
 189         }
 190 }
 191
 192 static
 193 int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 194 {
 195         struct mpc83xx_spi *mpc83xx_spi;
 196         u32 regval;
 197         u8 bits_per_word, pm;
 198         u32 hz;
 199         struct spi_mpc83xx_cs   *cs = spi->controller_state;
 200
 201         mpc83xx_spi = spi_master_get_devdata(spi->master);
 202
 203         if (t) {
 204                 bits_per_word = t->bits_per_word;
 205                 hz = t->speed_hz;
 206         } else {
 207                 bits_per_word = 0;
 208                 hz = 0;
 209         }
 210
 211         /* spi_transfer level calls that work per-word */
 212         if (!bits_per_word)
 213                 bits_per_word = spi->bits_per_word;
 214
 215         /* Make sure its a bit width we support [4..16, 32] */
 216         if ((bits_per_word < 4)
 217             || ((bits_per_word > 16) && (bits_per_word != 32)))
 218                 return -EINVAL;
 219
 220         if (!hz)
 221                 hz = spi->max_speed_hz;
 222
 223         cs->rx_shift = 0;
 224         cs->tx_shift = 0;
 225         if (bits_per_word <= 8) {
 226                 cs->get_rx = mpc83xx_spi_rx_buf_u8;
 227                 cs->get_tx = mpc83xx_spi_tx_buf_u8;
 228                 if (mpc83xx_spi->qe_mode) {
 229                         cs->rx_shift = 16;
 230                         cs->tx_shift = 24;
 231                 }
 232         } else if (bits_per_word <= 16) {
 233                 cs->get_rx = mpc83xx_spi_rx_buf_u16;
 234                 cs->get_tx = mpc83xx_spi_tx_buf_u16;
 235                 if (mpc83xx_spi->qe_mode) {
 236                         cs->rx_shift = 16;
 237                         cs->tx_shift = 16;
 238                 }
 239         } else if (bits_per_word <= 32) {
 240                 cs->get_rx = mpc83xx_spi_rx_buf_u32;
 241                 cs->get_tx = mpc83xx_spi_tx_buf_u32;
 242         } else
 243                 return -EINVAL;
 244
 245         if (mpc83xx_spi->qe_mode && spi->mode & SPI_LSB_FIRST) {
 246                 cs->tx_shift = 0;
 247                 if (bits_per_word <= 8)
 248                         cs->rx_shift = 8;
 249                 else
 250                         cs->rx_shift = 0;
 251         }
 252
 253         mpc83xx_spi->rx_shift = cs->rx_shift;
 254         mpc83xx_spi->tx_shift = cs->tx_shift;
 255         mpc83xx_spi->get_rx = cs->get_rx;
 256         mpc83xx_spi->get_tx = cs->get_tx;
 257
 258         if (bits_per_word == 32)
 259                 bits_per_word = 0;
 260         else
 261                 bits_per_word = bits_per_word - 1;
 262
 263         /* mask out bits we are going to set */
 264         cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
 265                                   | SPMODE_PM(0xF));
 266
 267         cs->hw_mode |= SPMODE_LEN(bits_per_word);
 268
 269         if ((mpc83xx_spi->spibrg / hz) > 64) {
 270                 cs->hw_mode |= SPMODE_DIV16;
 271                 pm = mpc83xx_spi->spibrg / (hz * 64);
 272                 if (pm > 16) {
 273                         dev_err(&spi->dev, "Requested speed is too "
 274                                 "low: %d Hz. Will use %d Hz instead.\n",
 275                                 hz, mpc83xx_spi->spibrg / 1024);
 276                         pm = 16;
 277                 }
 278         } else
 279                 pm = mpc83xx_spi->spibrg / (hz * 4);
 280         if (pm)
 281                 pm--;
 282
 283         cs->hw_mode |= SPMODE_PM(pm);
 284         regval =  mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
 285         if (cs->hw_mode != regval) {
 286                 unsigned long flags;
 287                 void *tmp_ptr = &mpc83xx_spi->base->mode;
 288
 289                 regval = cs->hw_mode;
 290                 /* Turn off IRQs locally to minimize time
 291                  * that SPI is disabled
 292                  */
 293                 local_irq_save(flags);
 294                 /* Turn off SPI unit prior changing mode */
 295                 mpc83xx_spi_write_reg(tmp_ptr, regval & ~SPMODE_ENABLE);
 296                 mpc83xx_spi_write_reg(tmp_ptr, regval);
 297                 local_irq_restore(flags);
 298         }
 299         return 0;
 300 }
 301
 302 static int mpc83xx_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 303 {
 304         struct mpc83xx_spi *mpc83xx_spi;
 305         u32 word, len, bits_per_word;
 306
 307         mpc83xx_spi = spi_master_get_devdata(spi->master);
 308
 309         mpc83xx_spi->tx = t->tx_buf;
 310         mpc83xx_spi->rx = t->rx_buf;
 311         bits_per_word = spi->bits_per_word;
 312         if (t->bits_per_word)
 313                 bits_per_word = t->bits_per_word;
 314         len = t->len;
 315         if (bits_per_word > 8) {
 316                 /* invalid length? */
 317                 if (len & 1)
 318                         return -EINVAL;
 319                 len /= 2;
 320         }
 321         if (bits_per_word > 16) {
 322                 /* invalid length? */
 323                 if (len & 1)
 324                         return -EINVAL;
 325                 len /= 2;
 326         }
 327         mpc83xx_spi->count = len;
 328
 329         INIT_COMPLETION(mpc83xx_spi->done);
 330
 331         /* enable rx ints */
 332         mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, SPIM_NE);
 333
 334         /* transmit word */
 335         word = mpc83xx_spi->get_tx(mpc83xx_spi);
 336         mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);
 337
 338         wait_for_completion(&mpc83xx_spi->done);
 339
 340         /* disable rx ints */
 341         mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
 342
 343         return mpc83xx_spi->count;
 344 }
 345
 346 static void mpc83xx_spi_work(struct work_struct *work)
 347 {
 348         struct mpc83xx_spi *mpc83xx_spi =
 349                 container_of(work, struct mpc83xx_spi, work);
 350
 351         spin_lock_irq(&mpc83xx_spi->lock);
 352         mpc83xx_spi->busy = 1;
 353         while (!list_empty(&mpc83xx_spi->queue)) {
 354                 struct spi_message *m;
 355                 struct spi_device *spi;
 356                 struct spi_transfer *t = NULL;
 357                 unsigned cs_change;
 358                 int status, nsecs = 50;
 359
 360                 m = container_of(mpc83xx_spi->queue.next,
 361                                 struct spi_message, queue);
 362                 list_del_init(&m->queue);
 363                 spin_unlock_irq(&mpc83xx_spi->lock);
 364
 365                 spi = m->spi;
 366                 cs_change = 1;
 367                 status = 0;
 368                 list_for_each_entry(t, &m->transfers, transfer_list) {
 369                         if (t->bits_per_word || t->speed_hz) {
 370                                 /* Don't allow changes if CS is active */
 371                                 status = -EINVAL;
 372
 373                                 if (cs_change)
 374                                         status = mpc83xx_spi_setup_transfer(spi, t);
 375                                 if (status < 0)
 376                                         break;
 377                         }
 378
 379                         if (cs_change)
 380                                 mpc83xx_spi_chipselect(spi, BITBANG_CS_ACTIVE);
 381                         cs_change = t->cs_change;
 382                         if (t->len)
 383                                 status = mpc83xx_spi_bufs(spi, t);
 384                         if (status) {
 385                                 status = -EMSGSIZE;
 386                                 break;
 387                         }
 388                         m->actual_length += t->len;
 389
 390                         if (t->delay_usecs)
 391                                 udelay(t->delay_usecs);
 392
 393                         if (cs_change) {
 394                                 ndelay(nsecs);
 395                                 mpc83xx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
 396                                 ndelay(nsecs);
 397                         }
 398                 }
 399
 400                 m->status = status;
 401                 m->complete(m->context);
 402
 403                 if (status || !cs_change) {
 404                         ndelay(nsecs);
 405                         mpc83xx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
 406                 }
 407
 408                 mpc83xx_spi_setup_transfer(spi, NULL);
 409
 410                 spin_lock_irq(&mpc83xx_spi->lock);
 411         }
 412         mpc83xx_spi->busy = 0;
 413         spin_unlock_irq(&mpc83xx_spi->lock);
 414 }
 415
 416 /* the spi->mode bits understood by this driver: */
 417 #define MODEBITS        (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH \
 418                         | SPI_LSB_FIRST | SPI_LOOP)
 419
 420 static int mpc83xx_spi_setup(struct spi_device *spi)
 421 {
 422         struct mpc83xx_spi *mpc83xx_spi;
 423         int retval;
 424         u32 hw_mode;
 425         struct spi_mpc83xx_cs   *cs = spi->controller_state;
 426
 427         if (spi->mode & ~MODEBITS) {
 428                 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
 429                         spi->mode & ~MODEBITS);
 430                 return -EINVAL;
 431         }
 432
 433         if (!spi->max_speed_hz)
 434                 return -EINVAL;
 435
 436         if (!cs) {
 437                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
 438                 if (!cs)
 439                         return -ENOMEM;
 440                 spi->controller_state = cs;
 441         }
 442         mpc83xx_spi = spi_master_get_devdata(spi->master);
 443
 444         if (!spi->bits_per_word)
 445                 spi->bits_per_word = 8;
 446
 447         hw_mode = cs->hw_mode; /* Save orginal settings */
 448         cs->hw_mode = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
 449         /* mask out bits we are going to set */
 450         cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
 451                          | SPMODE_REV | SPMODE_LOOP);
 452
 453         if (spi->mode & SPI_CPHA)
 454                 cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
 455         if (spi->mode & SPI_CPOL)
 456                 cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
 457         if (!(spi->mode & SPI_LSB_FIRST))
 458                 cs->hw_mode |= SPMODE_REV;
 459         if (spi->mode & SPI_LOOP)
 460                 cs->hw_mode |= SPMODE_LOOP;
 461
 462         retval = mpc83xx_spi_setup_transfer(spi, NULL);
 463         if (retval < 0) {
 464                 cs->hw_mode = hw_mode; /* Restore settings */
 465                 return retval;
 466         }
 467
 468         dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u Hz\n",
 469                 __func__, spi->mode & (SPI_CPOL | SPI_CPHA),
 470                 spi->bits_per_word, spi->max_speed_hz);
 471 #if 0 /* Don't think this is needed */
 472         /* NOTE we _need_ to call chipselect() early, ideally with adapter
 473          * setup, unless the hardware defaults cooperate to avoid confusion
 474          * between normal (active low) and inverted chipselects.
 475          */
 476
 477         /* deselect chip (low or high) */
 478         spin_lock(&mpc83xx_spi->lock);
 479         if (!mpc83xx_spi->busy)
 480                 mpc83xx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
 481         spin_unlock(&mpc83xx_spi->lock);
 482 #endif
 483         return 0;
 484 }
 485
 486 irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data)
 487 {
 488         struct mpc83xx_spi *mpc83xx_spi = context_data;
 489         u32 event;
 490         irqreturn_t ret = IRQ_NONE;
 491
 492         /* Get interrupt events(tx/rx) */
 493         event = mpc83xx_spi_read_reg(&mpc83xx_spi->base->event);
 494
 495         /* We need handle RX first */
 496         if (event & SPIE_NE) {
 497                 u32 rx_data = mpc83xx_spi_read_reg(&mpc83xx_spi->base->receive);
 498
 499                 if (mpc83xx_spi->rx)
 500                         mpc83xx_spi->get_rx(rx_data, mpc83xx_spi);
 501
 502                 ret = IRQ_HANDLED;
 503         }
 504
 505         if ((event & SPIE_NF) == 0)
 506                 /* spin until TX is done */
 507                 while (((event =
 508                          mpc83xx_spi_read_reg(&mpc83xx_spi->base->event)) &
 509                                                 SPIE_NF) == 0)
 510                          cpu_relax();
 511
 512         mpc83xx_spi->count -= 1;
 513         if (mpc83xx_spi->count) {
 514                 u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
 515                 mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);
 516         } else {
 517                 complete(&mpc83xx_spi->done);
 518         }
 519
 520         /* Clear the events */
 521         mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, event);
 522
 523         return ret;
 524 }
 525 static int mpc83xx_spi_transfer(struct spi_device *spi,
 526                                 struct spi_message *m)
 527 {
 528         struct mpc83xx_spi *mpc83xx_spi = spi_master_get_devdata(spi->master);
 529         unsigned long flags;
 530
 531         m->actual_length = 0;
 532         m->status = -EINPROGRESS;
 533
 534         spin_lock_irqsave(&mpc83xx_spi->lock, flags);
 535         list_add_tail(&m->queue, &mpc83xx_spi->queue);
 536         queue_work(mpc83xx_spi->workqueue, &mpc83xx_spi->work);
 537         spin_unlock_irqrestore(&mpc83xx_spi->lock, flags);
 538
 539         return 0;
 540 }
 541
 542
 543 static void mpc83xx_spi_cleanup(struct spi_device *spi)
 544 {
 545         kfree(spi->controller_state);
 546 }
 547
 548 static int __init mpc83xx_spi_probe(struct platform_device *dev)
 549 {
 550         struct spi_master *master;
 551         struct mpc83xx_spi *mpc83xx_spi;
 552         struct fsl_spi_platform_data *pdata;
 553         struct resource *r;
 554         u32 regval;
 555         int ret = 0;
 556
 557         /* Get resources(memory, IRQ) associated with the device */
 558         master = spi_alloc_master(&dev->dev, sizeof(struct mpc83xx_spi));
 559
 560         if (master == NULL) {
 561                 ret = -ENOMEM;
 562                 goto err;
 563         }
 564
 565         platform_set_drvdata(dev, master);
 566         pdata = dev->dev.platform_data;
 567
 568         if (pdata == NULL) {
 569                 ret = -ENODEV;
 570                 goto free_master;
 571         }
 572
 573         r = platform_get_resource(dev, IORESOURCE_MEM, 0);
 574         if (r == NULL) {
 575                 ret = -ENODEV;
 576                 goto free_master;
 577         }
 578         master->setup = mpc83xx_spi_setup;
 579         master->transfer = mpc83xx_spi_transfer;
 580         master->cleanup = mpc83xx_spi_cleanup;
 581
 582         mpc83xx_spi = spi_master_get_devdata(master);
 583         mpc83xx_spi->activate_cs = pdata->activate_cs;
 584         mpc83xx_spi->deactivate_cs = pdata->deactivate_cs;
 585         mpc83xx_spi->qe_mode = pdata->qe_mode;
 586         mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
 587         mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
 588         mpc83xx_spi->spibrg = pdata->sysclk;
 589
 590         mpc83xx_spi->rx_shift = 0;
 591         mpc83xx_spi->tx_shift = 0;
 592         if (mpc83xx_spi->qe_mode) {
 593                 mpc83xx_spi->rx_shift = 16;
 594                 mpc83xx_spi->tx_shift = 24;
 595         }
 596
 597         init_completion(&mpc83xx_spi->done);
 598
 599         mpc83xx_spi->base = ioremap(r->start, r->end - r->start + 1);
 600         if (mpc83xx_spi->base == NULL) {
 601                 ret = -ENOMEM;
 602                 goto put_master;
 603         }
 604
 605         mpc83xx_spi->irq = platform_get_irq(dev, 0);
 606
 607         if (mpc83xx_spi->irq < 0) {
 608                 ret = -ENXIO;
 609                 goto unmap_io;
 610         }
 611
 612         /* Register for SPI Interrupt */
 613         ret = request_irq(mpc83xx_spi->irq, mpc83xx_spi_irq,
 614                           0, "mpc83xx_spi", mpc83xx_spi);
 615
 616         if (ret != 0)
 617                 goto unmap_io;
 618
 619         master->bus_num = pdata->bus_num;
 620         master->num_chipselect = pdata->max_chipselect;
 621
 622         /* SPI controller initializations */
 623         mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
 624         mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
 625         mpc83xx_spi_write_reg(&mpc83xx_spi->base->command, 0);
 626         mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, 0xffffffff);
 627
 628         /* Enable SPI interface */
 629         regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
 630         if (pdata->qe_mode)
 631                 regval |= SPMODE_OP;
 632
 633         mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
 634         spin_lock_init(&mpc83xx_spi->lock);
 635         init_completion(&mpc83xx_spi->done);
 636         INIT_WORK(&mpc83xx_spi->work, mpc83xx_spi_work);
 637         INIT_LIST_HEAD(&mpc83xx_spi->queue);
 638
 639         mpc83xx_spi->workqueue = create_singlethread_workqueue(
 640                 dev_name(master->dev.parent));
 641         if (mpc83xx_spi->workqueue == NULL) {
 642                 ret = -EBUSY;
 643                 goto free_irq;
 644         }
 645
 646         ret = spi_register_master(master);
 647         if (ret < 0)
 648                 goto unreg_master;
 649
 650         printk(KERN_INFO
 651                "%s: MPC83xx SPI Controller driver at 0x%p (irq = %d)\n",
 652                dev_name(&dev->dev), mpc83xx_spi->base, mpc83xx_spi->irq);
 653
 654         return ret;
 655
 656 unreg_master:
 657         destroy_workqueue(mpc83xx_spi->workqueue);
 658 free_irq:
 659         free_irq(mpc83xx_spi->irq, mpc83xx_spi);
 660 unmap_io:
 661         iounmap(mpc83xx_spi->base);
 662 put_master:
 663         spi_master_put(master);
 664 free_master:
 665         kfree(master);
 666 err:
 667         return ret;
 668 }
 669
 670 static int __exit mpc83xx_spi_remove(struct platform_device *dev)
 671 {
 672         struct mpc83xx_spi *mpc83xx_spi;
 673         struct spi_master *master;
 674
 675         master = platform_get_drvdata(dev);
 676         mpc83xx_spi = spi_master_get_devdata(master);
 677
 678         flush_workqueue(mpc83xx_spi->workqueue);
 679         destroy_workqueue(mpc83xx_spi->workqueue);
 680         spi_unregister_master(master);
 681
 682         free_irq(mpc83xx_spi->irq, mpc83xx_spi);
 683         iounmap(mpc83xx_spi->base);
 684
 685         return 0;
 686 }
 687
 688 MODULE_ALIAS("platform:mpc83xx_spi");
 689 static struct platform_driver mpc83xx_spi_driver = {
 690         .remove = __exit_p(mpc83xx_spi_remove),
 691         .driver = {
 692                 .name = "mpc83xx_spi",
 693                 .owner = THIS_MODULE,
 694         },
 695 };
 696
 697 static int __init mpc83xx_spi_init(void)
 698 {
 699         return platform_driver_probe(&mpc83xx_spi_driver, mpc83xx_spi_probe);
 700 }
 701
 702 static void __exit mpc83xx_spi_exit(void)
 703 {
 704         platform_driver_unregister(&mpc83xx_spi_driver);
 705 }
 706
 707 module_init(mpc83xx_spi_init);
 708 module_exit(mpc83xx_spi_exit);
 709
 710 MODULE_AUTHOR("Kumar Gala");
 711 MODULE_DESCRIPTION("Simple MPC83xx SPI Driver");
 712 MODULE_LICENSE("GPL");