drivers/spi/spi_mpc8xxx.c

   1 /*
   2  * MPC8xxx 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/bug.h>
  18 #include <linux/errno.h>
  19 #include <linux/err.h>
  20 #include <linux/io.h>
  21 #include <linux/completion.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/delay.h>
  24 #include <linux/irq.h>
  25 #include <linux/device.h>
  26 #include <linux/spi/spi.h>
  27 #include <linux/spi/spi_bitbang.h>
  28 #include <linux/platform_device.h>
  29 #include <linux/fsl_devices.h>
  30 #include <linux/of.h>
  31 #include <linux/of_platform.h>
  32 #include <linux/gpio.h>
  33 #include <linux/of_gpio.h>
  34 #include <linux/of_spi.h>
  35
  36 #include <sysdev/fsl_soc.h>
  37 #include <asm/irq.h>
  38
  39 /* SPI Controller registers */
  40 struct mpc8xxx_spi_reg {
  41         u8 res1[0x20];
  42         __be32 mode;
  43         __be32 event;
  44         __be32 mask;
  45         __be32 command;
  46         __be32 transmit;
  47         __be32 receive;
  48 };
  49
  50 /* SPI Controller mode register definitions */
  51 #define SPMODE_LOOP             (1 << 30)
  52 #define SPMODE_CI_INACTIVEHIGH  (1 << 29)
  53 #define SPMODE_CP_BEGIN_EDGECLK (1 << 28)
  54 #define SPMODE_DIV16            (1 << 27)
  55 #define SPMODE_REV              (1 << 26)
  56 #define SPMODE_MS               (1 << 25)
  57 #define SPMODE_ENABLE           (1 << 24)
  58 #define SPMODE_LEN(x)           ((x) << 20)
  59 #define SPMODE_PM(x)            ((x) << 16)
  60 #define SPMODE_OP               (1 << 14)
  61 #define SPMODE_CG(x)            ((x) << 7)
  62
  63 /*
  64  * Default for SPI Mode:
  65  *      SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk
  66  */
  67 #define SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH | SPMODE_DIV16 | SPMODE_REV | \
  68                          SPMODE_MS | SPMODE_LEN(7) | SPMODE_PM(0xf))
  69
  70 /* SPIE register values */
  71 #define SPIE_NE         0x00000200      /* Not empty */
  72 #define SPIE_NF         0x00000100      /* Not full */
  73
  74 /* SPIM register values */
  75 #define SPIM_NE         0x00000200      /* Not empty */
  76 #define SPIM_NF         0x00000100      /* Not full */
  77
  78 /* SPI Controller driver's private data. */
  79 struct mpc8xxx_spi {
  80         struct mpc8xxx_spi_reg __iomem *base;
  81
  82         /* rx & tx bufs from the spi_transfer */
  83         const void *tx;
  84         void *rx;
  85
  86         /* functions to deal with different sized buffers */
  87         void (*get_rx) (u32 rx_data, struct mpc8xxx_spi *);
  88         u32(*get_tx) (struct mpc8xxx_spi *);
  89
  90         unsigned int count;
  91         unsigned int irq;
  92
  93         unsigned nsecs;         /* (clock cycle time)/2 */
  94
  95         u32 spibrg;             /* SPIBRG input clock */
  96         u32 rx_shift;           /* RX data reg shift when in qe mode */
  97         u32 tx_shift;           /* TX data reg shift when in qe mode */
  98
  99         bool qe_mode;
 100
 101         struct workqueue_struct *workqueue;
 102         struct work_struct work;
 103
 104         struct list_head queue;
 105         spinlock_t lock;
 106
 107         struct completion done;
 108 };
 109
 110 struct spi_mpc8xxx_cs {
 111         /* functions to deal with different sized buffers */
 112         void (*get_rx) (u32 rx_data, struct mpc8xxx_spi *);
 113         u32 (*get_tx) (struct mpc8xxx_spi *);
 114         u32 rx_shift;           /* RX data reg shift when in qe mode */
 115         u32 tx_shift;           /* TX data reg shift when in qe mode */
 116         u32 hw_mode;            /* Holds HW mode register settings */
 117 };
 118
 119 static inline void mpc8xxx_spi_write_reg(__be32 __iomem *reg, u32 val)
 120 {
 121         out_be32(reg, val);
 122 }
 123
 124 static inline u32 mpc8xxx_spi_read_reg(__be32 __iomem *reg)
 125 {
 126         return in_be32(reg);
 127 }
 128
 129 #define MPC83XX_SPI_RX_BUF(type)                                          \
 130 static                                                                    \
 131 void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
 132 {                                                                         \
 133         type *rx = mpc8xxx_spi->rx;                                       \
 134         *rx++ = (type)(data >> mpc8xxx_spi->rx_shift);                    \
 135         mpc8xxx_spi->rx = rx;                                             \
 136 }
 137
 138 #define MPC83XX_SPI_TX_BUF(type)                                \
 139 static                                                          \
 140 u32 mpc8xxx_spi_tx_buf_##type(struct mpc8xxx_spi *mpc8xxx_spi)  \
 141 {                                                               \
 142         u32 data;                                               \
 143         const type *tx = mpc8xxx_spi->tx;                       \
 144         if (!tx)                                                \
 145                 return 0;                                       \
 146         data = *tx++ << mpc8xxx_spi->tx_shift;                  \
 147         mpc8xxx_spi->tx = tx;                                   \
 148         return data;                                            \
 149 }
 150
 151 MPC83XX_SPI_RX_BUF(u8)
 152 MPC83XX_SPI_RX_BUF(u16)
 153 MPC83XX_SPI_RX_BUF(u32)
 154 MPC83XX_SPI_TX_BUF(u8)
 155 MPC83XX_SPI_TX_BUF(u16)
 156 MPC83XX_SPI_TX_BUF(u32)
 157
 158 static void mpc8xxx_spi_chipselect(struct spi_device *spi, int value)
 159 {
 160         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
 161         struct fsl_spi_platform_data *pdata = spi->dev.parent->platform_data;
 162         bool pol = spi->mode & SPI_CS_HIGH;
 163         struct spi_mpc8xxx_cs   *cs = spi->controller_state;
 164
 165         if (value == BITBANG_CS_INACTIVE) {
 166                 if (pdata->cs_control)
 167                         pdata->cs_control(spi, !pol);
 168         }
 169
 170         if (value == BITBANG_CS_ACTIVE) {
 171                 u32 regval = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->mode);
 172
 173                 mpc8xxx_spi->rx_shift = cs->rx_shift;
 174                 mpc8xxx_spi->tx_shift = cs->tx_shift;
 175                 mpc8xxx_spi->get_rx = cs->get_rx;
 176                 mpc8xxx_spi->get_tx = cs->get_tx;
 177
 178                 if (cs->hw_mode != regval) {
 179                         unsigned long flags;
 180                         __be32 __iomem *mode = &mpc8xxx_spi->base->mode;
 181
 182                         regval = cs->hw_mode;
 183                         /* Turn off IRQs locally to minimize time that
 184                          * SPI is disabled
 185                          */
 186                         local_irq_save(flags);
 187                         /* Turn off SPI unit prior changing mode */
 188                         mpc8xxx_spi_write_reg(mode, regval & ~SPMODE_ENABLE);
 189                         mpc8xxx_spi_write_reg(mode, regval);
 190                         local_irq_restore(flags);
 191                 }
 192                 if (pdata->cs_control)
 193                         pdata->cs_control(spi, pol);
 194         }
 195 }
 196
 197 static
 198 int mpc8xxx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 199 {
 200         struct mpc8xxx_spi *mpc8xxx_spi;
 201         u32 regval;
 202         u8 bits_per_word, pm;
 203         u32 hz;
 204         struct spi_mpc8xxx_cs   *cs = spi->controller_state;
 205
 206         mpc8xxx_spi = spi_master_get_devdata(spi->master);
 207
 208         if (t) {
 209                 bits_per_word = t->bits_per_word;
 210                 hz = t->speed_hz;
 211         } else {
 212                 bits_per_word = 0;
 213                 hz = 0;
 214         }
 215
 216         /* spi_transfer level calls that work per-word */
 217         if (!bits_per_word)
 218                 bits_per_word = spi->bits_per_word;
 219
 220         /* Make sure its a bit width we support [4..16, 32] */
 221         if ((bits_per_word < 4)
 222             || ((bits_per_word > 16) && (bits_per_word != 32)))
 223                 return -EINVAL;
 224
 225         if (!hz)
 226                 hz = spi->max_speed_hz;
 227
 228         cs->rx_shift = 0;
 229         cs->tx_shift = 0;
 230         if (bits_per_word <= 8) {
 231                 cs->get_rx = mpc8xxx_spi_rx_buf_u8;
 232                 cs->get_tx = mpc8xxx_spi_tx_buf_u8;
 233                 if (mpc8xxx_spi->qe_mode) {
 234                         cs->rx_shift = 16;
 235                         cs->tx_shift = 24;
 236                 }
 237         } else if (bits_per_word <= 16) {
 238                 cs->get_rx = mpc8xxx_spi_rx_buf_u16;
 239                 cs->get_tx = mpc8xxx_spi_tx_buf_u16;
 240                 if (mpc8xxx_spi->qe_mode) {
 241                         cs->rx_shift = 16;
 242                         cs->tx_shift = 16;
 243                 }
 244         } else if (bits_per_word <= 32) {
 245                 cs->get_rx = mpc8xxx_spi_rx_buf_u32;
 246                 cs->get_tx = mpc8xxx_spi_tx_buf_u32;
 247         } else
 248                 return -EINVAL;
 249
 250         if (mpc8xxx_spi->qe_mode && spi->mode & SPI_LSB_FIRST) {
 251                 cs->tx_shift = 0;
 252                 if (bits_per_word <= 8)
 253                         cs->rx_shift = 8;
 254                 else
 255                         cs->rx_shift = 0;
 256         }
 257
 258         mpc8xxx_spi->rx_shift = cs->rx_shift;
 259         mpc8xxx_spi->tx_shift = cs->tx_shift;
 260         mpc8xxx_spi->get_rx = cs->get_rx;
 261         mpc8xxx_spi->get_tx = cs->get_tx;
 262
 263         if (bits_per_word == 32)
 264                 bits_per_word = 0;
 265         else
 266                 bits_per_word = bits_per_word - 1;
 267
 268         /* mask out bits we are going to set */
 269         cs->hw_mode &= ~(SPMODE_LEN(0xF) | SPMODE_DIV16
 270                                   | SPMODE_PM(0xF));
 271
 272         cs->hw_mode |= SPMODE_LEN(bits_per_word);
 273
 274         if ((mpc8xxx_spi->spibrg / hz) > 64) {
 275                 cs->hw_mode |= SPMODE_DIV16;
 276                 pm = mpc8xxx_spi->spibrg / (hz * 64);
 277
 278                 WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
 279                           "Will use %d Hz instead.\n", dev_name(&spi->dev),
 280                           hz, mpc8xxx_spi->spibrg / 1024);
 281                 if (pm > 16)
 282                         pm = 16;
 283         } else
 284                 pm = mpc8xxx_spi->spibrg / (hz * 4);
 285         if (pm)
 286                 pm--;
 287
 288         cs->hw_mode |= SPMODE_PM(pm);
 289         regval =  mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->mode);
 290         if (cs->hw_mode != regval) {
 291                 unsigned long flags;
 292                 __be32 __iomem *mode = &mpc8xxx_spi->base->mode;
 293
 294                 regval = cs->hw_mode;
 295                 /* Turn off IRQs locally to minimize time
 296                  * that SPI is disabled
 297                  */
 298                 local_irq_save(flags);
 299                 /* Turn off SPI unit prior changing mode */
 300                 mpc8xxx_spi_write_reg(mode, regval & ~SPMODE_ENABLE);
 301                 mpc8xxx_spi_write_reg(mode, regval);
 302                 local_irq_restore(flags);
 303         }
 304         return 0;
 305 }
 306
 307 static int mpc8xxx_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
 308 {
 309         struct mpc8xxx_spi *mpc8xxx_spi;
 310         u32 word, len, bits_per_word;
 311
 312         mpc8xxx_spi = spi_master_get_devdata(spi->master);
 313
 314         mpc8xxx_spi->tx = t->tx_buf;
 315         mpc8xxx_spi->rx = t->rx_buf;
 316         bits_per_word = spi->bits_per_word;
 317         if (t->bits_per_word)
 318                 bits_per_word = t->bits_per_word;
 319         len = t->len;
 320         if (bits_per_word > 8) {
 321                 /* invalid length? */
 322                 if (len & 1)
 323                         return -EINVAL;
 324                 len /= 2;
 325         }
 326         if (bits_per_word > 16) {
 327                 /* invalid length? */
 328                 if (len & 1)
 329                         return -EINVAL;
 330                 len /= 2;
 331         }
 332         mpc8xxx_spi->count = len;
 333
 334         INIT_COMPLETION(mpc8xxx_spi->done);
 335
 336         /* enable rx ints */
 337         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mask, SPIM_NE);
 338
 339         /* transmit word */
 340         word = mpc8xxx_spi->get_tx(mpc8xxx_spi);
 341         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->transmit, word);
 342
 343         wait_for_completion(&mpc8xxx_spi->done);
 344
 345         /* disable rx ints */
 346         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mask, 0);
 347
 348         return mpc8xxx_spi->count;
 349 }
 350
 351 static void mpc8xxx_spi_do_one_msg(struct spi_message *m)
 352 {
 353         struct spi_device *spi = m->spi;
 354         struct spi_transfer *t;
 355         unsigned int cs_change;
 356         const int nsecs = 50;
 357         int status;
 358
 359         cs_change = 1;
 360         status = 0;
 361         list_for_each_entry(t, &m->transfers, transfer_list) {
 362                 if (t->bits_per_word || t->speed_hz) {
 363                         /* Don't allow changes if CS is active */
 364                         status = -EINVAL;
 365
 366                         if (cs_change)
 367                                 status = mpc8xxx_spi_setup_transfer(spi, t);
 368                         if (status < 0)
 369                                 break;
 370                 }
 371
 372                 if (cs_change) {
 373                         mpc8xxx_spi_chipselect(spi, BITBANG_CS_ACTIVE);
 374                         ndelay(nsecs);
 375                 }
 376                 cs_change = t->cs_change;
 377                 if (t->len)
 378                         status = mpc8xxx_spi_bufs(spi, t);
 379                 if (status) {
 380                         status = -EMSGSIZE;
 381                         break;
 382                 }
 383                 m->actual_length += t->len;
 384
 385                 if (t->delay_usecs)
 386                         udelay(t->delay_usecs);
 387
 388                 if (cs_change) {
 389                         ndelay(nsecs);
 390                         mpc8xxx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
 391                         ndelay(nsecs);
 392                 }
 393         }
 394
 395         m->status = status;
 396         m->complete(m->context);
 397
 398         if (status || !cs_change) {
 399                 ndelay(nsecs);
 400                 mpc8xxx_spi_chipselect(spi, BITBANG_CS_INACTIVE);
 401         }
 402
 403         mpc8xxx_spi_setup_transfer(spi, NULL);
 404 }
 405
 406 static void mpc8xxx_spi_work(struct work_struct *work)
 407 {
 408         struct mpc8xxx_spi *mpc8xxx_spi = container_of(work, struct mpc8xxx_spi,
 409                                                        work);
 410
 411         spin_lock_irq(&mpc8xxx_spi->lock);
 412         while (!list_empty(&mpc8xxx_spi->queue)) {
 413                 struct spi_message *m = container_of(mpc8xxx_spi->queue.next,
 414                                                    struct spi_message, queue);
 415
 416                 list_del_init(&m->queue);
 417                 spin_unlock_irq(&mpc8xxx_spi->lock);
 418
 419                 mpc8xxx_spi_do_one_msg(m);
 420
 421                 spin_lock_irq(&mpc8xxx_spi->lock);
 422         }
 423         spin_unlock_irq(&mpc8xxx_spi->lock);
 424 }
 425
 426 static int mpc8xxx_spi_setup(struct spi_device *spi)
 427 {
 428         struct mpc8xxx_spi *mpc8xxx_spi;
 429         int retval;
 430         u32 hw_mode;
 431         struct spi_mpc8xxx_cs   *cs = spi->controller_state;
 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         mpc8xxx_spi = spi_master_get_devdata(spi->master);
 443
 444         hw_mode = cs->hw_mode; /* Save orginal settings */
 445         cs->hw_mode = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->mode);
 446         /* mask out bits we are going to set */
 447         cs->hw_mode &= ~(SPMODE_CP_BEGIN_EDGECLK | SPMODE_CI_INACTIVEHIGH
 448                          | SPMODE_REV | SPMODE_LOOP);
 449
 450         if (spi->mode & SPI_CPHA)
 451                 cs->hw_mode |= SPMODE_CP_BEGIN_EDGECLK;
 452         if (spi->mode & SPI_CPOL)
 453                 cs->hw_mode |= SPMODE_CI_INACTIVEHIGH;
 454         if (!(spi->mode & SPI_LSB_FIRST))
 455                 cs->hw_mode |= SPMODE_REV;
 456         if (spi->mode & SPI_LOOP)
 457                 cs->hw_mode |= SPMODE_LOOP;
 458
 459         retval = mpc8xxx_spi_setup_transfer(spi, NULL);
 460         if (retval < 0) {
 461                 cs->hw_mode = hw_mode; /* Restore settings */
 462                 return retval;
 463         }
 464         return 0;
 465 }
 466
 467 static irqreturn_t mpc8xxx_spi_irq(s32 irq, void *context_data)
 468 {
 469         struct mpc8xxx_spi *mpc8xxx_spi = context_data;
 470         u32 event;
 471         irqreturn_t ret = IRQ_NONE;
 472
 473         /* Get interrupt events(tx/rx) */
 474         event = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->event);
 475
 476         /* We need handle RX first */
 477         if (event & SPIE_NE) {
 478                 u32 rx_data = mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->receive);
 479
 480                 if (mpc8xxx_spi->rx)
 481                         mpc8xxx_spi->get_rx(rx_data, mpc8xxx_spi);
 482
 483                 ret = IRQ_HANDLED;
 484         }
 485
 486         if ((event & SPIE_NF) == 0)
 487                 /* spin until TX is done */
 488                 while (((event =
 489                          mpc8xxx_spi_read_reg(&mpc8xxx_spi->base->event)) &
 490                                                 SPIE_NF) == 0)
 491                         cpu_relax();
 492
 493         mpc8xxx_spi->count -= 1;
 494         if (mpc8xxx_spi->count) {
 495                 u32 word = mpc8xxx_spi->get_tx(mpc8xxx_spi);
 496                 mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->transmit, word);
 497         } else {
 498                 complete(&mpc8xxx_spi->done);
 499         }
 500
 501         /* Clear the events */
 502         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->event, event);
 503
 504         return ret;
 505 }
 506 static int mpc8xxx_spi_transfer(struct spi_device *spi,
 507                                 struct spi_message *m)
 508 {
 509         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
 510         unsigned long flags;
 511
 512         m->actual_length = 0;
 513         m->status = -EINPROGRESS;
 514
 515         spin_lock_irqsave(&mpc8xxx_spi->lock, flags);
 516         list_add_tail(&m->queue, &mpc8xxx_spi->queue);
 517         queue_work(mpc8xxx_spi->workqueue, &mpc8xxx_spi->work);
 518         spin_unlock_irqrestore(&mpc8xxx_spi->lock, flags);
 519
 520         return 0;
 521 }
 522
 523
 524 static void mpc8xxx_spi_cleanup(struct spi_device *spi)
 525 {
 526         kfree(spi->controller_state);
 527 }
 528
 529 static struct spi_master * __devinit
 530 mpc8xxx_spi_probe(struct device *dev, struct resource *mem, unsigned int irq)
 531 {
 532         struct fsl_spi_platform_data *pdata = dev->platform_data;
 533         struct spi_master *master;
 534         struct mpc8xxx_spi *mpc8xxx_spi;
 535         u32 regval;
 536         int ret = 0;
 537
 538         master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
 539         if (master == NULL) {
 540                 ret = -ENOMEM;
 541                 goto err;
 542         }
 543
 544         dev_set_drvdata(dev, master);
 545
 546         /* the spi->mode bits understood by this driver: */
 547         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
 548                         | SPI_LSB_FIRST | SPI_LOOP;
 549
 550         master->setup = mpc8xxx_spi_setup;
 551         master->transfer = mpc8xxx_spi_transfer;
 552         master->cleanup = mpc8xxx_spi_cleanup;
 553
 554         mpc8xxx_spi = spi_master_get_devdata(master);
 555         mpc8xxx_spi->qe_mode = pdata->qe_mode;
 556         mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
 557         mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
 558         mpc8xxx_spi->spibrg = pdata->sysclk;
 559
 560         mpc8xxx_spi->rx_shift = 0;
 561         mpc8xxx_spi->tx_shift = 0;
 562         if (mpc8xxx_spi->qe_mode) {
 563                 mpc8xxx_spi->rx_shift = 16;
 564                 mpc8xxx_spi->tx_shift = 24;
 565         }
 566
 567         init_completion(&mpc8xxx_spi->done);
 568
 569         mpc8xxx_spi->base = ioremap(mem->start, mem->end - mem->start + 1);
 570         if (mpc8xxx_spi->base == NULL) {
 571                 ret = -ENOMEM;
 572                 goto put_master;
 573         }
 574
 575         mpc8xxx_spi->irq = irq;
 576
 577         /* Register for SPI Interrupt */
 578         ret = request_irq(mpc8xxx_spi->irq, mpc8xxx_spi_irq,
 579                           0, "mpc8xxx_spi", mpc8xxx_spi);
 580
 581         if (ret != 0)
 582                 goto unmap_io;
 583
 584         master->bus_num = pdata->bus_num;
 585         master->num_chipselect = pdata->max_chipselect;
 586
 587         /* SPI controller initializations */
 588         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mode, 0);
 589         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mask, 0);
 590         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->command, 0);
 591         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->event, 0xffffffff);
 592
 593         /* Enable SPI interface */
 594         regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
 595         if (pdata->qe_mode)
 596                 regval |= SPMODE_OP;
 597
 598         mpc8xxx_spi_write_reg(&mpc8xxx_spi->base->mode, regval);
 599         spin_lock_init(&mpc8xxx_spi->lock);
 600         init_completion(&mpc8xxx_spi->done);
 601         INIT_WORK(&mpc8xxx_spi->work, mpc8xxx_spi_work);
 602         INIT_LIST_HEAD(&mpc8xxx_spi->queue);
 603
 604         mpc8xxx_spi->workqueue = create_singlethread_workqueue(
 605                 dev_name(master->dev.parent));
 606         if (mpc8xxx_spi->workqueue == NULL) {
 607                 ret = -EBUSY;
 608                 goto free_irq;
 609         }
 610
 611         ret = spi_register_master(master);
 612         if (ret < 0)
 613                 goto unreg_master;
 614
 615         printk(KERN_INFO
 616                "%s: MPC8xxx SPI Controller driver at 0x%p (irq = %d)\n",
 617                dev_name(dev), mpc8xxx_spi->base, mpc8xxx_spi->irq);
 618
 619         return master;
 620
 621 unreg_master:
 622         destroy_workqueue(mpc8xxx_spi->workqueue);
 623 free_irq:
 624         free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
 625 unmap_io:
 626         iounmap(mpc8xxx_spi->base);
 627 put_master:
 628         spi_master_put(master);
 629 err:
 630         return ERR_PTR(ret);
 631 }
 632
 633 static int __devexit mpc8xxx_spi_remove(struct device *dev)
 634 {
 635         struct mpc8xxx_spi *mpc8xxx_spi;
 636         struct spi_master *master;
 637
 638         master = dev_get_drvdata(dev);
 639         mpc8xxx_spi = spi_master_get_devdata(master);
 640
 641         flush_workqueue(mpc8xxx_spi->workqueue);
 642         destroy_workqueue(mpc8xxx_spi->workqueue);
 643         spi_unregister_master(master);
 644
 645         free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
 646         iounmap(mpc8xxx_spi->base);
 647
 648         return 0;
 649 }
 650
 651 struct mpc8xxx_spi_probe_info {
 652         struct fsl_spi_platform_data pdata;
 653         int *gpios;
 654         bool *alow_flags;
 655 };
 656
 657 static struct mpc8xxx_spi_probe_info *
 658 to_of_pinfo(struct fsl_spi_platform_data *pdata)
 659 {
 660         return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
 661 }
 662
 663 static void mpc8xxx_spi_cs_control(struct spi_device *spi, bool on)
 664 {
 665         struct device *dev = spi->dev.parent;
 666         struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(dev->platform_data);
 667         u16 cs = spi->chip_select;
 668         int gpio = pinfo->gpios[cs];
 669         bool alow = pinfo->alow_flags[cs];
 670
 671         gpio_set_value(gpio, on ^ alow);
 672 }
 673
 674 static int of_mpc8xxx_spi_get_chipselects(struct device *dev)
 675 {
 676         struct device_node *np = dev_archdata_get_node(&dev->archdata);
 677         struct fsl_spi_platform_data *pdata = dev->platform_data;
 678         struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
 679         unsigned int ngpios;
 680         int i = 0;
 681         int ret;
 682
 683         ngpios = of_gpio_count(np);
 684         if (!ngpios) {
 685                 /*
 686                  * SPI w/o chip-select line. One SPI device is still permitted
 687                  * though.
 688                  */
 689                 pdata->max_chipselect = 1;
 690                 return 0;
 691         }
 692
 693         pinfo->gpios = kmalloc(ngpios * sizeof(*pinfo->gpios), GFP_KERNEL);
 694         if (!pinfo->gpios)
 695                 return -ENOMEM;
 696         memset(pinfo->gpios, -1, ngpios * sizeof(*pinfo->gpios));
 697
 698         pinfo->alow_flags = kzalloc(ngpios * sizeof(*pinfo->alow_flags),
 699                                     GFP_KERNEL);
 700         if (!pinfo->alow_flags) {
 701                 ret = -ENOMEM;
 702                 goto err_alloc_flags;
 703         }
 704
 705         for (; i < ngpios; i++) {
 706                 int gpio;
 707                 enum of_gpio_flags flags;
 708
 709                 gpio = of_get_gpio_flags(np, i, &flags);
 710                 if (!gpio_is_valid(gpio)) {
 711                         dev_err(dev, "invalid gpio #%d: %d\n", i, gpio);
 712                         goto err_loop;
 713                 }
 714
 715                 ret = gpio_request(gpio, dev_name(dev));
 716                 if (ret) {
 717                         dev_err(dev, "can't request gpio #%d: %d\n", i, ret);
 718                         goto err_loop;
 719                 }
 720
 721                 pinfo->gpios[i] = gpio;
 722                 pinfo->alow_flags[i] = flags & OF_GPIO_ACTIVE_LOW;
 723
 724                 ret = gpio_direction_output(pinfo->gpios[i],
 725                                             pinfo->alow_flags[i]);
 726                 if (ret) {
 727                         dev_err(dev, "can't set output direction for gpio "
 728                                 "#%d: %d\n", i, ret);
 729                         goto err_loop;
 730                 }
 731         }
 732
 733         pdata->max_chipselect = ngpios;
 734         pdata->cs_control = mpc8xxx_spi_cs_control;
 735
 736         return 0;
 737
 738 err_loop:
 739         while (i >= 0) {
 740                 if (gpio_is_valid(pinfo->gpios[i]))
 741                         gpio_free(pinfo->gpios[i]);
 742                 i--;
 743         }
 744
 745         kfree(pinfo->alow_flags);
 746         pinfo->alow_flags = NULL;
 747 err_alloc_flags:
 748         kfree(pinfo->gpios);
 749         pinfo->gpios = NULL;
 750         return ret;
 751 }
 752
 753 static int of_mpc8xxx_spi_free_chipselects(struct device *dev)
 754 {
 755         struct fsl_spi_platform_data *pdata = dev->platform_data;
 756         struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata);
 757         int i;
 758
 759         if (!pinfo->gpios)
 760                 return 0;
 761
 762         for (i = 0; i < pdata->max_chipselect; i++) {
 763                 if (gpio_is_valid(pinfo->gpios[i]))
 764                         gpio_free(pinfo->gpios[i]);
 765         }
 766
 767         kfree(pinfo->gpios);
 768         kfree(pinfo->alow_flags);
 769         return 0;
 770 }
 771
 772 static int __devinit of_mpc8xxx_spi_probe(struct of_device *ofdev,
 773                                           const struct of_device_id *ofid)
 774 {
 775         struct device *dev = &ofdev->dev;
 776         struct device_node *np = ofdev->node;
 777         struct mpc8xxx_spi_probe_info *pinfo;
 778         struct fsl_spi_platform_data *pdata;
 779         struct spi_master *master;
 780         struct resource mem;
 781         struct resource irq;
 782         const void *prop;
 783         int ret = -ENOMEM;
 784
 785         pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
 786         if (!pinfo)
 787                 return -ENOMEM;
 788
 789         pdata = &pinfo->pdata;
 790         dev->platform_data = pdata;
 791
 792         /* Allocate bus num dynamically. */
 793         pdata->bus_num = -1;
 794
 795         /* SPI controller is either clocked from QE or SoC clock. */
 796         pdata->sysclk = get_brgfreq();
 797         if (pdata->sysclk == -1) {
 798                 pdata->sysclk = fsl_get_sys_freq();
 799                 if (pdata->sysclk == -1) {
 800                         ret = -ENODEV;
 801                         goto err_clk;
 802                 }
 803         }
 804
 805         prop = of_get_property(np, "mode", NULL);
 806         if (prop && !strcmp(prop, "cpu-qe"))
 807                 pdata->qe_mode = 1;
 808
 809         ret = of_mpc8xxx_spi_get_chipselects(dev);
 810         if (ret)
 811                 goto err;
 812
 813         ret = of_address_to_resource(np, 0, &mem);
 814         if (ret)
 815                 goto err;
 816
 817         ret = of_irq_to_resource(np, 0, &irq);
 818         if (!ret) {
 819                 ret = -EINVAL;
 820                 goto err;
 821         }
 822
 823         master = mpc8xxx_spi_probe(dev, &mem, irq.start);
 824         if (IS_ERR(master)) {
 825                 ret = PTR_ERR(master);
 826                 goto err;
 827         }
 828
 829         of_register_spi_devices(master, np);
 830
 831         return 0;
 832
 833 err:
 834         of_mpc8xxx_spi_free_chipselects(dev);
 835 err_clk:
 836         kfree(pinfo);
 837         return ret;
 838 }
 839
 840 static int __devexit of_mpc8xxx_spi_remove(struct of_device *ofdev)
 841 {
 842         int ret;
 843
 844         ret = mpc8xxx_spi_remove(&ofdev->dev);
 845         if (ret)
 846                 return ret;
 847         of_mpc8xxx_spi_free_chipselects(&ofdev->dev);
 848         return 0;
 849 }
 850
 851 static const struct of_device_id of_mpc8xxx_spi_match[] = {
 852         { .compatible = "fsl,spi" },
 853         {},
 854 };
 855 MODULE_DEVICE_TABLE(of, of_mpc8xxx_spi_match);
 856
 857 static struct of_platform_driver of_mpc8xxx_spi_driver = {
 858         .name           = "mpc8xxx_spi",
 859         .match_table    = of_mpc8xxx_spi_match,
 860         .probe          = of_mpc8xxx_spi_probe,
 861         .remove         = __devexit_p(of_mpc8xxx_spi_remove),
 862 };
 863
 864 #ifdef CONFIG_MPC832x_RDB
 865 /*
 866  *                              XXX XXX XXX
 867  * This is "legacy" platform driver, was used by the MPC8323E-RDB boards
 868  * only. The driver should go away soon, since newer MPC8323E-RDB's device
 869  * tree can work with OpenFirmware driver. But for now we support old trees
 870  * as well.
 871  */
 872 static int __devinit plat_mpc8xxx_spi_probe(struct platform_device *pdev)
 873 {
 874         struct resource *mem;
 875         unsigned int irq;
 876         struct spi_master *master;
 877
 878         if (!pdev->dev.platform_data)
 879                 return -EINVAL;
 880
 881         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 882         if (!mem)
 883                 return -EINVAL;
 884
 885         irq = platform_get_irq(pdev, 0);
 886         if (!irq)
 887                 return -EINVAL;
 888
 889         master = mpc8xxx_spi_probe(&pdev->dev, mem, irq);
 890         if (IS_ERR(master))
 891                 return PTR_ERR(master);
 892         return 0;
 893 }
 894
 895 static int __devexit plat_mpc8xxx_spi_remove(struct platform_device *pdev)
 896 {
 897         return mpc8xxx_spi_remove(&pdev->dev);
 898 }
 899
 900 MODULE_ALIAS("platform:mpc8xxx_spi");
 901 static struct platform_driver mpc8xxx_spi_driver = {
 902         .probe = plat_mpc8xxx_spi_probe,
 903         .remove = __exit_p(plat_mpc8xxx_spi_remove),
 904         .driver = {
 905                 .name = "mpc8xxx_spi",
 906                 .owner = THIS_MODULE,
 907         },
 908 };
 909
 910 static bool legacy_driver_failed;
 911
 912 static void __init legacy_driver_register(void)
 913 {
 914         legacy_driver_failed = platform_driver_register(&mpc8xxx_spi_driver);
 915 }
 916
 917 static void __exit legacy_driver_unregister(void)
 918 {
 919         if (legacy_driver_failed)
 920                 return;
 921         platform_driver_unregister(&mpc8xxx_spi_driver);
 922 }
 923 #else
 924 static void __init legacy_driver_register(void) {}
 925 static void __exit legacy_driver_unregister(void) {}
 926 #endif /* CONFIG_MPC832x_RDB */
 927
 928 static int __init mpc8xxx_spi_init(void)
 929 {
 930         legacy_driver_register();
 931         return of_register_platform_driver(&of_mpc8xxx_spi_driver);
 932 }
 933
 934 static void __exit mpc8xxx_spi_exit(void)
 935 {
 936         of_unregister_platform_driver(&of_mpc8xxx_spi_driver);
 937         legacy_driver_unregister();
 938 }
 939
 940 module_init(mpc8xxx_spi_init);
 941 module_exit(mpc8xxx_spi_exit);
 942
 943 MODULE_AUTHOR("Kumar Gala");
 944 MODULE_DESCRIPTION("Simple MPC8xxx SPI Driver");
 945 MODULE_LICENSE("GPL");