drivers/spi/spi-fsl-espi.c

   1 /*
   2  * Freescale eSPI controller driver.
   3  *
   4  * Copyright 2010 Freescale Semiconductor, Inc.
   5  *
   6  * This program is free software; you can redistribute  it and/or modify it
   7  * under  the terms of  the GNU General  Public License as published by the
   8  * Free Software Foundation;  either version 2 of the  License, or (at your
   9  * option) any later version.
  10  */
  11 #include <linux/module.h>
  12 #include <linux/delay.h>
  13 #include <linux/irq.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/fsl_devices.h>
  17 #include <linux/mm.h>
  18 #include <linux/of.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/of_spi.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/err.h>
  23 #include <sysdev/fsl_soc.h>
  24
  25 #include "spi-fsl-lib.h"
  26
  27 /* eSPI Controller registers */
  28 struct fsl_espi_reg {
  29         __be32 mode;            /* 0x000 - eSPI mode register */
  30         __be32 event;           /* 0x004 - eSPI event register */
  31         __be32 mask;            /* 0x008 - eSPI mask register */
  32         __be32 command;         /* 0x00c - eSPI command register */
  33         __be32 transmit;        /* 0x010 - eSPI transmit FIFO access register*/
  34         __be32 receive;         /* 0x014 - eSPI receive FIFO access register*/
  35         u8 res[8];              /* 0x018 - 0x01c reserved */
  36         __be32 csmode[4];       /* 0x020 - 0x02c eSPI cs mode register */
  37 };
  38
  39 struct fsl_espi_transfer {
  40         const void *tx_buf;
  41         void *rx_buf;
  42         unsigned len;
  43         unsigned n_tx;
  44         unsigned n_rx;
  45         unsigned actual_length;
  46         int status;
  47 };
  48
  49 /* eSPI Controller mode register definitions */
  50 #define SPMODE_ENABLE           (1 << 31)
  51 #define SPMODE_LOOP             (1 << 30)
  52 #define SPMODE_TXTHR(x)         ((x) << 8)
  53 #define SPMODE_RXTHR(x)         ((x) << 0)
  54
  55 /* eSPI Controller CS mode register definitions */
  56 #define CSMODE_CI_INACTIVEHIGH  (1 << 31)
  57 #define CSMODE_CP_BEGIN_EDGECLK (1 << 30)
  58 #define CSMODE_REV              (1 << 29)
  59 #define CSMODE_DIV16            (1 << 28)
  60 #define CSMODE_PM(x)            ((x) << 24)
  61 #define CSMODE_POL_1            (1 << 20)
  62 #define CSMODE_LEN(x)           ((x) << 16)
  63 #define CSMODE_BEF(x)           ((x) << 12)
  64 #define CSMODE_AFT(x)           ((x) << 8)
  65 #define CSMODE_CG(x)            ((x) << 3)
  66
  67 /* Default mode/csmode for eSPI controller */
  68 #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3))
  69 #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
  70                 | CSMODE_AFT(0) | CSMODE_CG(1))
  71
  72 /* SPIE register values */
  73 #define SPIE_NE         0x00000200      /* Not empty */
  74 #define SPIE_NF         0x00000100      /* Not full */
  75
  76 /* SPIM register values */
  77 #define SPIM_NE         0x00000200      /* Not empty */
  78 #define SPIM_NF         0x00000100      /* Not full */
  79 #define SPIE_RXCNT(reg)     ((reg >> 24) & 0x3F)
  80 #define SPIE_TXCNT(reg)     ((reg >> 16) & 0x3F)
  81
  82 /* SPCOM register values */
  83 #define SPCOM_CS(x)             ((x) << 30)
  84 #define SPCOM_TRANLEN(x)        ((x) << 0)
  85 #define SPCOM_TRANLEN_MAX       0xFFFF  /* Max transaction length */
  86
  87 static void fsl_espi_change_mode(struct spi_device *spi)
  88 {
  89         struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
  90         struct spi_mpc8xxx_cs *cs = spi->controller_state;
  91         struct fsl_espi_reg *reg_base = mspi->reg_base;
  92         __be32 __iomem *mode = &reg_base->csmode[spi->chip_select];
  93         __be32 __iomem *espi_mode = &reg_base->mode;
  94         u32 tmp;
  95         unsigned long flags;
  96
  97         /* Turn off IRQs locally to minimize time that SPI is disabled. */
  98         local_irq_save(flags);
  99
 100         /* Turn off SPI unit prior changing mode */
 101         tmp = mpc8xxx_spi_read_reg(espi_mode);
 102         mpc8xxx_spi_write_reg(espi_mode, tmp & ~SPMODE_ENABLE);
 103         mpc8xxx_spi_write_reg(mode, cs->hw_mode);
 104         mpc8xxx_spi_write_reg(espi_mode, tmp);
 105
 106         local_irq_restore(flags);
 107 }
 108
 109 static u32 fsl_espi_tx_buf_lsb(struct mpc8xxx_spi *mpc8xxx_spi)
 110 {
 111         u32 data;
 112         u16 data_h;
 113         u16 data_l;
 114         const u32 *tx = mpc8xxx_spi->tx;
 115
 116         if (!tx)
 117                 return 0;
 118
 119         data = *tx++ << mpc8xxx_spi->tx_shift;
 120         data_l = data & 0xffff;
 121         data_h = (data >> 16) & 0xffff;
 122         swab16s(&data_l);
 123         swab16s(&data_h);
 124         data = data_h | data_l;
 125
 126         mpc8xxx_spi->tx = tx;
 127         return data;
 128 }
 129
 130 static int fsl_espi_setup_transfer(struct spi_device *spi,
 131                                         struct spi_transfer *t)
 132 {
 133         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
 134         int bits_per_word = 0;
 135         u8 pm;
 136         u32 hz = 0;
 137         struct spi_mpc8xxx_cs *cs = spi->controller_state;
 138
 139         if (t) {
 140                 bits_per_word = t->bits_per_word;
 141                 hz = t->speed_hz;
 142         }
 143
 144         /* spi_transfer level calls that work per-word */
 145         if (!bits_per_word)
 146                 bits_per_word = spi->bits_per_word;
 147
 148         /* Make sure its a bit width we support [4..16] */
 149         if ((bits_per_word < 4) || (bits_per_word > 16))
 150                 return -EINVAL;
 151
 152         if (!hz)
 153                 hz = spi->max_speed_hz;
 154
 155         cs->rx_shift = 0;
 156         cs->tx_shift = 0;
 157         cs->get_rx = mpc8xxx_spi_rx_buf_u32;
 158         cs->get_tx = mpc8xxx_spi_tx_buf_u32;
 159         if (bits_per_word <= 8) {
 160                 cs->rx_shift = 8 - bits_per_word;
 161         } else if (bits_per_word <= 16) {
 162                 cs->rx_shift = 16 - bits_per_word;
 163                 if (spi->mode & SPI_LSB_FIRST)
 164                         cs->get_tx = fsl_espi_tx_buf_lsb;
 165         } else {
 166                 return -EINVAL;
 167         }
 168
 169         mpc8xxx_spi->rx_shift = cs->rx_shift;
 170         mpc8xxx_spi->tx_shift = cs->tx_shift;
 171         mpc8xxx_spi->get_rx = cs->get_rx;
 172         mpc8xxx_spi->get_tx = cs->get_tx;
 173
 174         bits_per_word = bits_per_word - 1;
 175
 176         /* mask out bits we are going to set */
 177         cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF));
 178
 179         cs->hw_mode |= CSMODE_LEN(bits_per_word);
 180
 181         if ((mpc8xxx_spi->spibrg / hz) > 64) {
 182                 cs->hw_mode |= CSMODE_DIV16;
 183                 pm = (mpc8xxx_spi->spibrg - 1) / (hz * 64) + 1;
 184
 185                 WARN_ONCE(pm > 16, "%s: Requested speed is too low: %d Hz. "
 186                           "Will use %d Hz instead.\n", dev_name(&spi->dev),
 187                           hz, mpc8xxx_spi->spibrg / 1024);
 188                 if (pm > 16)
 189                         pm = 16;
 190         } else {
 191                 pm = (mpc8xxx_spi->spibrg - 1) / (hz * 4) + 1;
 192         }
 193         if (pm)
 194                 pm--;
 195
 196         cs->hw_mode |= CSMODE_PM(pm);
 197
 198         fsl_espi_change_mode(spi);
 199         return 0;
 200 }
 201
 202 static int fsl_espi_cpu_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t,
 203                 unsigned int len)
 204 {
 205         u32 word;
 206         struct fsl_espi_reg *reg_base = mspi->reg_base;
 207
 208         mspi->count = len;
 209
 210         /* enable rx ints */
 211         mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
 212
 213         /* transmit word */
 214         word = mspi->get_tx(mspi);
 215         mpc8xxx_spi_write_reg(&reg_base->transmit, word);
 216
 217         return 0;
 218 }
 219
 220 static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
 221 {
 222         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
 223         struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
 224         unsigned int len = t->len;
 225         u8 bits_per_word;
 226         int ret;
 227
 228         bits_per_word = spi->bits_per_word;
 229         if (t->bits_per_word)
 230                 bits_per_word = t->bits_per_word;
 231
 232         mpc8xxx_spi->len = t->len;
 233         len = roundup(len, 4) / 4;
 234
 235         mpc8xxx_spi->tx = t->tx_buf;
 236         mpc8xxx_spi->rx = t->rx_buf;
 237
 238         INIT_COMPLETION(mpc8xxx_spi->done);
 239
 240         /* Set SPCOM[CS] and SPCOM[TRANLEN] field */
 241         if ((t->len - 1) > SPCOM_TRANLEN_MAX) {
 242                 dev_err(mpc8xxx_spi->dev, "Transaction length (%d)"
 243                                 " beyond the SPCOM[TRANLEN] field\n", t->len);
 244                 return -EINVAL;
 245         }
 246         mpc8xxx_spi_write_reg(&reg_base->command,
 247                 (SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1)));
 248
 249         ret = fsl_espi_cpu_bufs(mpc8xxx_spi, t, len);
 250         if (ret)
 251                 return ret;
 252
 253         wait_for_completion(&mpc8xxx_spi->done);
 254
 255         /* disable rx ints */
 256         mpc8xxx_spi_write_reg(&reg_base->mask, 0);
 257
 258         return mpc8xxx_spi->count;
 259 }
 260
 261 static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
 262 {
 263         if (cmd) {
 264                 cmd[1] = (u8)(addr >> 16);
 265                 cmd[2] = (u8)(addr >> 8);
 266                 cmd[3] = (u8)(addr >> 0);
 267         }
 268 }
 269
 270 static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)
 271 {
 272         if (cmd)
 273                 return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;
 274
 275         return 0;
 276 }
 277
 278 static void fsl_espi_do_trans(struct spi_message *m,
 279                                 struct fsl_espi_transfer *tr)
 280 {
 281         struct spi_device *spi = m->spi;
 282         struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
 283         struct fsl_espi_transfer *espi_trans = tr;
 284         struct spi_message message;
 285         struct spi_transfer *t, *first, trans;
 286         int status = 0;
 287
 288         spi_message_init(&message);
 289         memset(&trans, 0, sizeof(trans));
 290
 291         first = list_first_entry(&m->transfers, struct spi_transfer,
 292                         transfer_list);
 293         list_for_each_entry(t, &m->transfers, transfer_list) {
 294                 if ((first->bits_per_word != t->bits_per_word) ||
 295                         (first->speed_hz != t->speed_hz)) {
 296                         espi_trans->status = -EINVAL;
 297                         dev_err(mspi->dev, "bits_per_word/speed_hz should be"
 298                                         " same for the same SPI transfer\n");
 299                         return;
 300                 }
 301
 302                 trans.speed_hz = t->speed_hz;
 303                 trans.bits_per_word = t->bits_per_word;
 304                 trans.delay_usecs = max(first->delay_usecs, t->delay_usecs);
 305         }
 306
 307         trans.len = espi_trans->len;
 308         trans.tx_buf = espi_trans->tx_buf;
 309         trans.rx_buf = espi_trans->rx_buf;
 310         spi_message_add_tail(&trans, &message);
 311
 312         list_for_each_entry(t, &message.transfers, transfer_list) {
 313                 if (t->bits_per_word || t->speed_hz) {
 314                         status = -EINVAL;
 315
 316                         status = fsl_espi_setup_transfer(spi, t);
 317                         if (status < 0)
 318                                 break;
 319                 }
 320
 321                 if (t->len)
 322                         status = fsl_espi_bufs(spi, t);
 323
 324                 if (status) {
 325                         status = -EMSGSIZE;
 326                         break;
 327                 }
 328
 329                 if (t->delay_usecs)
 330                         udelay(t->delay_usecs);
 331         }
 332
 333         espi_trans->status = status;
 334         fsl_espi_setup_transfer(spi, NULL);
 335 }
 336
 337 static void fsl_espi_cmd_trans(struct spi_message *m,
 338                                 struct fsl_espi_transfer *trans, u8 *rx_buff)
 339 {
 340         struct spi_transfer *t;
 341         u8 *local_buf;
 342         int i = 0;
 343         struct fsl_espi_transfer *espi_trans = trans;
 344
 345         local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
 346         if (!local_buf) {
 347                 espi_trans->status = -ENOMEM;
 348                 return;
 349         }
 350
 351         list_for_each_entry(t, &m->transfers, transfer_list) {
 352                 if (t->tx_buf) {
 353                         memcpy(local_buf + i, t->tx_buf, t->len);
 354                         i += t->len;
 355                 }
 356         }
 357
 358         espi_trans->tx_buf = local_buf;
 359         espi_trans->rx_buf = local_buf + espi_trans->n_tx;
 360         fsl_espi_do_trans(m, espi_trans);
 361
 362         espi_trans->actual_length = espi_trans->len;
 363         kfree(local_buf);
 364 }
 365
 366 static void fsl_espi_rw_trans(struct spi_message *m,
 367                                 struct fsl_espi_transfer *trans, u8 *rx_buff)
 368 {
 369         struct fsl_espi_transfer *espi_trans = trans;
 370         unsigned int n_tx = espi_trans->n_tx;
 371         unsigned int n_rx = espi_trans->n_rx;
 372         struct spi_transfer *t;
 373         u8 *local_buf;
 374         u8 *rx_buf = rx_buff;
 375         unsigned int trans_len;
 376         unsigned int addr;
 377         int i, pos, loop;
 378
 379         local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
 380         if (!local_buf) {
 381                 espi_trans->status = -ENOMEM;
 382                 return;
 383         }
 384
 385         for (pos = 0, loop = 0; pos < n_rx; pos += trans_len, loop++) {
 386                 trans_len = n_rx - pos;
 387                 if (trans_len > SPCOM_TRANLEN_MAX - n_tx)
 388                         trans_len = SPCOM_TRANLEN_MAX - n_tx;
 389
 390                 i = 0;
 391                 list_for_each_entry(t, &m->transfers, transfer_list) {
 392                         if (t->tx_buf) {
 393                                 memcpy(local_buf + i, t->tx_buf, t->len);
 394                                 i += t->len;
 395                         }
 396                 }
 397
 398                 if (pos > 0) {
 399                         addr = fsl_espi_cmd2addr(local_buf);
 400                         addr += pos;
 401                         fsl_espi_addr2cmd(addr, local_buf);
 402                 }
 403
 404                 espi_trans->n_tx = n_tx;
 405                 espi_trans->n_rx = trans_len;
 406                 espi_trans->len = trans_len + n_tx;
 407                 espi_trans->tx_buf = local_buf;
 408                 espi_trans->rx_buf = local_buf + n_tx;
 409                 fsl_espi_do_trans(m, espi_trans);
 410
 411                 memcpy(rx_buf + pos, espi_trans->rx_buf + n_tx, trans_len);
 412
 413                 if (loop > 0)
 414                         espi_trans->actual_length += espi_trans->len - n_tx;
 415                 else
 416                         espi_trans->actual_length += espi_trans->len;
 417         }
 418
 419         kfree(local_buf);
 420 }
 421
 422 static void fsl_espi_do_one_msg(struct spi_message *m)
 423 {
 424         struct spi_transfer *t;
 425         u8 *rx_buf = NULL;
 426         unsigned int n_tx = 0;
 427         unsigned int n_rx = 0;
 428         struct fsl_espi_transfer espi_trans;
 429
 430         list_for_each_entry(t, &m->transfers, transfer_list) {
 431                 if (t->tx_buf)
 432                         n_tx += t->len;
 433                 if (t->rx_buf) {
 434                         n_rx += t->len;
 435                         rx_buf = t->rx_buf;
 436                 }
 437         }
 438
 439         espi_trans.n_tx = n_tx;
 440         espi_trans.n_rx = n_rx;
 441         espi_trans.len = n_tx + n_rx;
 442         espi_trans.actual_length = 0;
 443         espi_trans.status = 0;
 444
 445         if (!rx_buf)
 446                 fsl_espi_cmd_trans(m, &espi_trans, NULL);
 447         else
 448                 fsl_espi_rw_trans(m, &espi_trans, rx_buf);
 449
 450         m->actual_length = espi_trans.actual_length;
 451         m->status = espi_trans.status;
 452         m->complete(m->context);
 453 }
 454
 455 static int fsl_espi_setup(struct spi_device *spi)
 456 {
 457         struct mpc8xxx_spi *mpc8xxx_spi;
 458         struct fsl_espi_reg *reg_base;
 459         int retval;
 460         u32 hw_mode;
 461         u32 loop_mode;
 462         struct spi_mpc8xxx_cs *cs = spi->controller_state;
 463
 464         if (!spi->max_speed_hz)
 465                 return -EINVAL;
 466
 467         if (!cs) {
 468                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
 469                 if (!cs)
 470                         return -ENOMEM;
 471                 spi->controller_state = cs;
 472         }
 473
 474         mpc8xxx_spi = spi_master_get_devdata(spi->master);
 475         reg_base = mpc8xxx_spi->reg_base;
 476
 477         hw_mode = cs->hw_mode; /* Save original settings */
 478         cs->hw_mode = mpc8xxx_spi_read_reg(
 479                         &reg_base->csmode[spi->chip_select]);
 480         /* mask out bits we are going to set */
 481         cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH
 482                          | CSMODE_REV);
 483
 484         if (spi->mode & SPI_CPHA)
 485                 cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK;
 486         if (spi->mode & SPI_CPOL)
 487                 cs->hw_mode |= CSMODE_CI_INACTIVEHIGH;
 488         if (!(spi->mode & SPI_LSB_FIRST))
 489                 cs->hw_mode |= CSMODE_REV;
 490
 491         /* Handle the loop mode */
 492         loop_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
 493         loop_mode &= ~SPMODE_LOOP;
 494         if (spi->mode & SPI_LOOP)
 495                 loop_mode |= SPMODE_LOOP;
 496         mpc8xxx_spi_write_reg(&reg_base->mode, loop_mode);
 497
 498         retval = fsl_espi_setup_transfer(spi, NULL);
 499         if (retval < 0) {
 500                 cs->hw_mode = hw_mode; /* Restore settings */
 501                 return retval;
 502         }
 503         return 0;
 504 }
 505
 506 void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
 507 {
 508         struct fsl_espi_reg *reg_base = mspi->reg_base;
 509
 510         /* We need handle RX first */
 511         if (events & SPIE_NE) {
 512                 u32 rx_data, tmp;
 513                 u8 rx_data_8;
 514
 515                 /* Spin until RX is done */
 516                 while (SPIE_RXCNT(events) < min(4, mspi->len)) {
 517                         cpu_relax();
 518                         events = mpc8xxx_spi_read_reg(&reg_base->event);
 519                 }
 520
 521                 if (mspi->len >= 4) {
 522                         rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
 523                 } else {
 524                         tmp = mspi->len;
 525                         rx_data = 0;
 526                         while (tmp--) {
 527                                 rx_data_8 = in_8((u8 *)&reg_base->receive);
 528                                 rx_data |= (rx_data_8 << (tmp * 8));
 529                         }
 530
 531                         rx_data <<= (4 - mspi->len) * 8;
 532                 }
 533
 534                 mspi->len -= 4;
 535
 536                 if (mspi->rx)
 537                         mspi->get_rx(rx_data, mspi);
 538         }
 539
 540         if (!(events & SPIE_NF)) {
 541                 int ret;
 542
 543                 /* spin until TX is done */
 544                 ret = spin_event_timeout(((events = mpc8xxx_spi_read_reg(
 545                                 &reg_base->event)) & SPIE_NF) == 0, 1000, 0);
 546                 if (!ret) {
 547                         dev_err(mspi->dev, "tired waiting for SPIE_NF\n");
 548                         return;
 549                 }
 550         }
 551
 552         /* Clear the events */
 553         mpc8xxx_spi_write_reg(&reg_base->event, events);
 554
 555         mspi->count -= 1;
 556         if (mspi->count) {
 557                 u32 word = mspi->get_tx(mspi);
 558
 559                 mpc8xxx_spi_write_reg(&reg_base->transmit, word);
 560         } else {
 561                 complete(&mspi->done);
 562         }
 563 }
 564
 565 static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
 566 {
 567         struct mpc8xxx_spi *mspi = context_data;
 568         struct fsl_espi_reg *reg_base = mspi->reg_base;
 569         irqreturn_t ret = IRQ_NONE;
 570         u32 events;
 571
 572         /* Get interrupt events(tx/rx) */
 573         events = mpc8xxx_spi_read_reg(&reg_base->event);
 574         if (events)
 575                 ret = IRQ_HANDLED;
 576
 577         dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events);
 578
 579         fsl_espi_cpu_irq(mspi, events);
 580
 581         return ret;
 582 }
 583
 584 static void fsl_espi_remove(struct mpc8xxx_spi *mspi)
 585 {
 586         iounmap(mspi->reg_base);
 587 }
 588
 589 static struct spi_master * __devinit fsl_espi_probe(struct device *dev,
 590                 struct resource *mem, unsigned int irq)
 591 {
 592         struct fsl_spi_platform_data *pdata = dev->platform_data;
 593         struct spi_master *master;
 594         struct mpc8xxx_spi *mpc8xxx_spi;
 595         struct fsl_espi_reg *reg_base;
 596         u32 regval;
 597         int i, ret = 0;
 598
 599         master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
 600         if (!master) {
 601                 ret = -ENOMEM;
 602                 goto err;
 603         }
 604
 605         dev_set_drvdata(dev, master);
 606
 607         ret = mpc8xxx_spi_probe(dev, mem, irq);
 608         if (ret)
 609                 goto err_probe;
 610
 611         master->setup = fsl_espi_setup;
 612
 613         mpc8xxx_spi = spi_master_get_devdata(master);
 614         mpc8xxx_spi->spi_do_one_msg = fsl_espi_do_one_msg;
 615         mpc8xxx_spi->spi_remove = fsl_espi_remove;
 616
 617         mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
 618         if (!mpc8xxx_spi->reg_base) {
 619                 ret = -ENOMEM;
 620                 goto err_probe;
 621         }
 622
 623         reg_base = mpc8xxx_spi->reg_base;
 624
 625         /* Register for SPI Interrupt */
 626         ret = request_irq(mpc8xxx_spi->irq, fsl_espi_irq,
 627                           0, "fsl_espi", mpc8xxx_spi);
 628         if (ret)
 629                 goto free_irq;
 630
 631         if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
 632                 mpc8xxx_spi->rx_shift = 16;
 633                 mpc8xxx_spi->tx_shift = 24;
 634         }
 635
 636         /* SPI controller initializations */
 637         mpc8xxx_spi_write_reg(&reg_base->mode, 0);
 638         mpc8xxx_spi_write_reg(&reg_base->mask, 0);
 639         mpc8xxx_spi_write_reg(&reg_base->command, 0);
 640         mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
 641
 642         /* Init eSPI CS mode register */
 643         for (i = 0; i < pdata->max_chipselect; i++)
 644                 mpc8xxx_spi_write_reg(&reg_base->csmode[i], CSMODE_INIT_VAL);
 645
 646         /* Enable SPI interface */
 647         regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
 648
 649         mpc8xxx_spi_write_reg(&reg_base->mode, regval);
 650
 651         ret = spi_register_master(master);
 652         if (ret < 0)
 653                 goto unreg_master;
 654
 655         dev_info(dev, "at 0x%p (irq = %d)\n", reg_base, mpc8xxx_spi->irq);
 656
 657         return master;
 658
 659 unreg_master:
 660         free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
 661 free_irq:
 662         iounmap(mpc8xxx_spi->reg_base);
 663 err_probe:
 664         spi_master_put(master);
 665 err:
 666         return ERR_PTR(ret);
 667 }
 668
 669 static int of_fsl_espi_get_chipselects(struct device *dev)
 670 {
 671         struct device_node *np = dev->of_node;
 672         struct fsl_spi_platform_data *pdata = dev->platform_data;
 673         const u32 *prop;
 674         int len;
 675
 676         prop = of_get_property(np, "fsl,espi-num-chipselects", &len);
 677         if (!prop || len < sizeof(*prop)) {
 678                 dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
 679                 return -EINVAL;
 680         }
 681
 682         pdata->max_chipselect = *prop;
 683         pdata->cs_control = NULL;
 684
 685         return 0;
 686 }
 687
 688 static int __devinit of_fsl_espi_probe(struct platform_device *ofdev)
 689 {
 690         struct device *dev = &ofdev->dev;
 691         struct device_node *np = ofdev->dev.of_node;
 692         struct spi_master *master;
 693         struct resource mem;
 694         struct resource irq;
 695         int ret = -ENOMEM;
 696
 697         ret = of_mpc8xxx_spi_probe(ofdev);
 698         if (ret)
 699                 return ret;
 700
 701         ret = of_fsl_espi_get_chipselects(dev);
 702         if (ret)
 703                 goto err;
 704
 705         ret = of_address_to_resource(np, 0, &mem);
 706         if (ret)
 707                 goto err;
 708
 709         ret = of_irq_to_resource(np, 0, &irq);
 710         if (!ret) {
 711                 ret = -EINVAL;
 712                 goto err;
 713         }
 714
 715         master = fsl_espi_probe(dev, &mem, irq.start);
 716         if (IS_ERR(master)) {
 717                 ret = PTR_ERR(master);
 718                 goto err;
 719         }
 720
 721         return 0;
 722
 723 err:
 724         return ret;
 725 }
 726
 727 static int __devexit of_fsl_espi_remove(struct platform_device *dev)
 728 {
 729         return mpc8xxx_spi_remove(&dev->dev);
 730 }
 731
 732 static const struct of_device_id of_fsl_espi_match[] = {
 733         { .compatible = "fsl,mpc8536-espi" },
 734         {}
 735 };
 736 MODULE_DEVICE_TABLE(of, of_fsl_espi_match);
 737
 738 static struct platform_driver fsl_espi_driver = {
 739         .driver = {
 740                 .name = "fsl_espi",
 741                 .owner = THIS_MODULE,
 742                 .of_match_table = of_fsl_espi_match,
 743         },
 744         .probe          = of_fsl_espi_probe,
 745         .remove         = __devexit_p(of_fsl_espi_remove),
 746 };
 747 module_platform_driver(fsl_espi_driver);
 748
 749 MODULE_AUTHOR("Mingkai Hu");
 750 MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
 751 MODULE_LICENSE("GPL");