linux/drivers/spi/spi-fsl-espi.c
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   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 */
  28struct 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
  39struct 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
  87static 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
 109static 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
 130static 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 = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 16 * 4);
 184
 185                WARN_ONCE(pm > 33, "%s: Requested speed is too low: %d Hz. "
 186                          "Will use %d Hz instead.\n", dev_name(&spi->dev),
 187                                hz, mpc8xxx_spi->spibrg / (4 * 16 * (32 + 1)));
 188                if (pm > 33)
 189                        pm = 33;
 190        } else {
 191                pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 4);
 192        }
 193        if (pm)
 194                pm--;
 195        if (pm < 2)
 196                pm = 2;
 197
 198        cs->hw_mode |= CSMODE_PM(pm);
 199
 200        fsl_espi_change_mode(spi);
 201        return 0;
 202}
 203
 204static int fsl_espi_cpu_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t,
 205                unsigned int len)
 206{
 207        u32 word;
 208        struct fsl_espi_reg *reg_base = mspi->reg_base;
 209
 210        mspi->count = len;
 211
 212        /* enable rx ints */
 213        mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
 214
 215        /* transmit word */
 216        word = mspi->get_tx(mspi);
 217        mpc8xxx_spi_write_reg(&reg_base->transmit, word);
 218
 219        return 0;
 220}
 221
 222static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
 223{
 224        struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
 225        struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
 226        unsigned int len = t->len;
 227        u8 bits_per_word;
 228        int ret;
 229
 230        bits_per_word = spi->bits_per_word;
 231        if (t->bits_per_word)
 232                bits_per_word = t->bits_per_word;
 233
 234        mpc8xxx_spi->len = t->len;
 235        len = roundup(len, 4) / 4;
 236
 237        mpc8xxx_spi->tx = t->tx_buf;
 238        mpc8xxx_spi->rx = t->rx_buf;
 239
 240        INIT_COMPLETION(mpc8xxx_spi->done);
 241
 242        /* Set SPCOM[CS] and SPCOM[TRANLEN] field */
 243        if ((t->len - 1) > SPCOM_TRANLEN_MAX) {
 244                dev_err(mpc8xxx_spi->dev, "Transaction length (%d)"
 245                                " beyond the SPCOM[TRANLEN] field\n", t->len);
 246                return -EINVAL;
 247        }
 248        mpc8xxx_spi_write_reg(&reg_base->command,
 249                (SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1)));
 250
 251        ret = fsl_espi_cpu_bufs(mpc8xxx_spi, t, len);
 252        if (ret)
 253                return ret;
 254
 255        wait_for_completion(&mpc8xxx_spi->done);
 256
 257        /* disable rx ints */
 258        mpc8xxx_spi_write_reg(&reg_base->mask, 0);
 259
 260        return mpc8xxx_spi->count;
 261}
 262
 263static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
 264{
 265        if (cmd) {
 266                cmd[1] = (u8)(addr >> 16);
 267                cmd[2] = (u8)(addr >> 8);
 268                cmd[3] = (u8)(addr >> 0);
 269        }
 270}
 271
 272static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)
 273{
 274        if (cmd)
 275                return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;
 276
 277        return 0;
 278}
 279
 280static void fsl_espi_do_trans(struct spi_message *m,
 281                                struct fsl_espi_transfer *tr)
 282{
 283        struct spi_device *spi = m->spi;
 284        struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
 285        struct fsl_espi_transfer *espi_trans = tr;
 286        struct spi_message message;
 287        struct spi_transfer *t, *first, trans;
 288        int status = 0;
 289
 290        spi_message_init(&message);
 291        memset(&trans, 0, sizeof(trans));
 292
 293        first = list_first_entry(&m->transfers, struct spi_transfer,
 294                        transfer_list);
 295        list_for_each_entry(t, &m->transfers, transfer_list) {
 296                if ((first->bits_per_word != t->bits_per_word) ||
 297                        (first->speed_hz != t->speed_hz)) {
 298                        espi_trans->status = -EINVAL;
 299                        dev_err(mspi->dev, "bits_per_word/speed_hz should be"
 300                                        " same for the same SPI transfer\n");
 301                        return;
 302                }
 303
 304                trans.speed_hz = t->speed_hz;
 305                trans.bits_per_word = t->bits_per_word;
 306                trans.delay_usecs = max(first->delay_usecs, t->delay_usecs);
 307        }
 308
 309        trans.len = espi_trans->len;
 310        trans.tx_buf = espi_trans->tx_buf;
 311        trans.rx_buf = espi_trans->rx_buf;
 312        spi_message_add_tail(&trans, &message);
 313
 314        list_for_each_entry(t, &message.transfers, transfer_list) {
 315                if (t->bits_per_word || t->speed_hz) {
 316                        status = -EINVAL;
 317
 318                        status = fsl_espi_setup_transfer(spi, t);
 319                        if (status < 0)
 320                                break;
 321                }
 322
 323                if (t->len)
 324                        status = fsl_espi_bufs(spi, t);
 325
 326                if (status) {
 327                        status = -EMSGSIZE;
 328                        break;
 329                }
 330
 331                if (t->delay_usecs)
 332                        udelay(t->delay_usecs);
 333        }
 334
 335        espi_trans->status = status;
 336        fsl_espi_setup_transfer(spi, NULL);
 337}
 338
 339static void fsl_espi_cmd_trans(struct spi_message *m,
 340                                struct fsl_espi_transfer *trans, u8 *rx_buff)
 341{
 342        struct spi_transfer *t;
 343        u8 *local_buf;
 344        int i = 0;
 345        struct fsl_espi_transfer *espi_trans = trans;
 346
 347        local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
 348        if (!local_buf) {
 349                espi_trans->status = -ENOMEM;
 350                return;
 351        }
 352
 353        list_for_each_entry(t, &m->transfers, transfer_list) {
 354                if (t->tx_buf) {
 355                        memcpy(local_buf + i, t->tx_buf, t->len);
 356                        i += t->len;
 357                }
 358        }
 359
 360        espi_trans->tx_buf = local_buf;
 361        espi_trans->rx_buf = local_buf + espi_trans->n_tx;
 362        fsl_espi_do_trans(m, espi_trans);
 363
 364        espi_trans->actual_length = espi_trans->len;
 365        kfree(local_buf);
 366}
 367
 368static void fsl_espi_rw_trans(struct spi_message *m,
 369                                struct fsl_espi_transfer *trans, u8 *rx_buff)
 370{
 371        struct fsl_espi_transfer *espi_trans = trans;
 372        unsigned int n_tx = espi_trans->n_tx;
 373        unsigned int n_rx = espi_trans->n_rx;
 374        struct spi_transfer *t;
 375        u8 *local_buf;
 376        u8 *rx_buf = rx_buff;
 377        unsigned int trans_len;
 378        unsigned int addr;
 379        int i, pos, loop;
 380
 381        local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
 382        if (!local_buf) {
 383                espi_trans->status = -ENOMEM;
 384                return;
 385        }
 386
 387        for (pos = 0, loop = 0; pos < n_rx; pos += trans_len, loop++) {
 388                trans_len = n_rx - pos;
 389                if (trans_len > SPCOM_TRANLEN_MAX - n_tx)
 390                        trans_len = SPCOM_TRANLEN_MAX - n_tx;
 391
 392                i = 0;
 393                list_for_each_entry(t, &m->transfers, transfer_list) {
 394                        if (t->tx_buf) {
 395                                memcpy(local_buf + i, t->tx_buf, t->len);
 396                                i += t->len;
 397                        }
 398                }
 399
 400                if (pos > 0) {
 401                        addr = fsl_espi_cmd2addr(local_buf);
 402                        addr += pos;
 403                        fsl_espi_addr2cmd(addr, local_buf);
 404                }
 405
 406                espi_trans->n_tx = n_tx;
 407                espi_trans->n_rx = trans_len;
 408                espi_trans->len = trans_len + n_tx;
 409                espi_trans->tx_buf = local_buf;
 410                espi_trans->rx_buf = local_buf + n_tx;
 411                fsl_espi_do_trans(m, espi_trans);
 412
 413                memcpy(rx_buf + pos, espi_trans->rx_buf + n_tx, trans_len);
 414
 415                if (loop > 0)
 416                        espi_trans->actual_length += espi_trans->len - n_tx;
 417                else
 418                        espi_trans->actual_length += espi_trans->len;
 419        }
 420
 421        kfree(local_buf);
 422}
 423
 424static void fsl_espi_do_one_msg(struct spi_message *m)
 425{
 426        struct spi_transfer *t;
 427        u8 *rx_buf = NULL;
 428        unsigned int n_tx = 0;
 429        unsigned int n_rx = 0;
 430        struct fsl_espi_transfer espi_trans;
 431
 432        list_for_each_entry(t, &m->transfers, transfer_list) {
 433                if (t->tx_buf)
 434                        n_tx += t->len;
 435                if (t->rx_buf) {
 436                        n_rx += t->len;
 437                        rx_buf = t->rx_buf;
 438                }
 439        }
 440
 441        espi_trans.n_tx = n_tx;
 442        espi_trans.n_rx = n_rx;
 443        espi_trans.len = n_tx + n_rx;
 444        espi_trans.actual_length = 0;
 445        espi_trans.status = 0;
 446
 447        if (!rx_buf)
 448                fsl_espi_cmd_trans(m, &espi_trans, NULL);
 449        else
 450                fsl_espi_rw_trans(m, &espi_trans, rx_buf);
 451
 452        m->actual_length = espi_trans.actual_length;
 453        m->status = espi_trans.status;
 454        m->complete(m->context);
 455}
 456
 457static int fsl_espi_setup(struct spi_device *spi)
 458{
 459        struct mpc8xxx_spi *mpc8xxx_spi;
 460        struct fsl_espi_reg *reg_base;
 461        int retval;
 462        u32 hw_mode;
 463        u32 loop_mode;
 464        struct spi_mpc8xxx_cs *cs = spi->controller_state;
 465
 466        if (!spi->max_speed_hz)
 467                return -EINVAL;
 468
 469        if (!cs) {
 470                cs = kzalloc(sizeof *cs, GFP_KERNEL);
 471                if (!cs)
 472                        return -ENOMEM;
 473                spi->controller_state = cs;
 474        }
 475
 476        mpc8xxx_spi = spi_master_get_devdata(spi->master);
 477        reg_base = mpc8xxx_spi->reg_base;
 478
 479        hw_mode = cs->hw_mode; /* Save original settings */
 480        cs->hw_mode = mpc8xxx_spi_read_reg(
 481                        &reg_base->csmode[spi->chip_select]);
 482        /* mask out bits we are going to set */
 483        cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH
 484                         | CSMODE_REV);
 485
 486        if (spi->mode & SPI_CPHA)
 487                cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK;
 488        if (spi->mode & SPI_CPOL)
 489                cs->hw_mode |= CSMODE_CI_INACTIVEHIGH;
 490        if (!(spi->mode & SPI_LSB_FIRST))
 491                cs->hw_mode |= CSMODE_REV;
 492
 493        /* Handle the loop mode */
 494        loop_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
 495        loop_mode &= ~SPMODE_LOOP;
 496        if (spi->mode & SPI_LOOP)
 497                loop_mode |= SPMODE_LOOP;
 498        mpc8xxx_spi_write_reg(&reg_base->mode, loop_mode);
 499
 500        retval = fsl_espi_setup_transfer(spi, NULL);
 501        if (retval < 0) {
 502                cs->hw_mode = hw_mode; /* Restore settings */
 503                return retval;
 504        }
 505        return 0;
 506}
 507
 508void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
 509{
 510        struct fsl_espi_reg *reg_base = mspi->reg_base;
 511
 512        /* We need handle RX first */
 513        if (events & SPIE_NE) {
 514                u32 rx_data, tmp;
 515                u8 rx_data_8;
 516
 517                /* Spin until RX is done */
 518                while (SPIE_RXCNT(events) < min(4, mspi->len)) {
 519                        cpu_relax();
 520                        events = mpc8xxx_spi_read_reg(&reg_base->event);
 521                }
 522
 523                if (mspi->len >= 4) {
 524                        rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
 525                } else {
 526                        tmp = mspi->len;
 527                        rx_data = 0;
 528                        while (tmp--) {
 529                                rx_data_8 = in_8((u8 *)&reg_base->receive);
 530                                rx_data |= (rx_data_8 << (tmp * 8));
 531                        }
 532
 533                        rx_data <<= (4 - mspi->len) * 8;
 534                }
 535
 536                mspi->len -= 4;
 537
 538                if (mspi->rx)
 539                        mspi->get_rx(rx_data, mspi);
 540        }
 541
 542        if (!(events & SPIE_NF)) {
 543                int ret;
 544
 545                /* spin until TX is done */
 546                ret = spin_event_timeout(((events = mpc8xxx_spi_read_reg(
 547                                &reg_base->event)) & SPIE_NF) == 0, 1000, 0);
 548                if (!ret) {
 549                        dev_err(mspi->dev, "tired waiting for SPIE_NF\n");
 550                        return;
 551                }
 552        }
 553
 554        /* Clear the events */
 555        mpc8xxx_spi_write_reg(&reg_base->event, events);
 556
 557        mspi->count -= 1;
 558        if (mspi->count) {
 559                u32 word = mspi->get_tx(mspi);
 560
 561                mpc8xxx_spi_write_reg(&reg_base->transmit, word);
 562        } else {
 563                complete(&mspi->done);
 564        }
 565}
 566
 567static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
 568{
 569        struct mpc8xxx_spi *mspi = context_data;
 570        struct fsl_espi_reg *reg_base = mspi->reg_base;
 571        irqreturn_t ret = IRQ_NONE;
 572        u32 events;
 573
 574        /* Get interrupt events(tx/rx) */
 575        events = mpc8xxx_spi_read_reg(&reg_base->event);
 576        if (events)
 577                ret = IRQ_HANDLED;
 578
 579        dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events);
 580
 581        fsl_espi_cpu_irq(mspi, events);
 582
 583        return ret;
 584}
 585
 586static void fsl_espi_remove(struct mpc8xxx_spi *mspi)
 587{
 588        iounmap(mspi->reg_base);
 589}
 590
 591static struct spi_master * __devinit fsl_espi_probe(struct device *dev,
 592                struct resource *mem, unsigned int irq)
 593{
 594        struct fsl_spi_platform_data *pdata = dev->platform_data;
 595        struct spi_master *master;
 596        struct mpc8xxx_spi *mpc8xxx_spi;
 597        struct fsl_espi_reg *reg_base;
 598        u32 regval;
 599        int i, ret = 0;
 600
 601        master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
 602        if (!master) {
 603                ret = -ENOMEM;
 604                goto err;
 605        }
 606
 607        dev_set_drvdata(dev, master);
 608
 609        ret = mpc8xxx_spi_probe(dev, mem, irq);
 610        if (ret)
 611                goto err_probe;
 612
 613        master->setup = fsl_espi_setup;
 614
 615        mpc8xxx_spi = spi_master_get_devdata(master);
 616        mpc8xxx_spi->spi_do_one_msg = fsl_espi_do_one_msg;
 617        mpc8xxx_spi->spi_remove = fsl_espi_remove;
 618
 619        mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
 620        if (!mpc8xxx_spi->reg_base) {
 621                ret = -ENOMEM;
 622                goto err_probe;
 623        }
 624
 625        reg_base = mpc8xxx_spi->reg_base;
 626
 627        /* Register for SPI Interrupt */
 628        ret = request_irq(mpc8xxx_spi->irq, fsl_espi_irq,
 629                          0, "fsl_espi", mpc8xxx_spi);
 630        if (ret)
 631                goto free_irq;
 632
 633        if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
 634                mpc8xxx_spi->rx_shift = 16;
 635                mpc8xxx_spi->tx_shift = 24;
 636        }
 637
 638        /* SPI controller initializations */
 639        mpc8xxx_spi_write_reg(&reg_base->mode, 0);
 640        mpc8xxx_spi_write_reg(&reg_base->mask, 0);
 641        mpc8xxx_spi_write_reg(&reg_base->command, 0);
 642        mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
 643
 644        /* Init eSPI CS mode register */
 645        for (i = 0; i < pdata->max_chipselect; i++)
 646                mpc8xxx_spi_write_reg(&reg_base->csmode[i], CSMODE_INIT_VAL);
 647
 648        /* Enable SPI interface */
 649        regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
 650
 651        mpc8xxx_spi_write_reg(&reg_base->mode, regval);
 652
 653        ret = spi_register_master(master);
 654        if (ret < 0)
 655                goto unreg_master;
 656
 657        dev_info(dev, "at 0x%p (irq = %d)\n", reg_base, mpc8xxx_spi->irq);
 658
 659        return master;
 660
 661unreg_master:
 662        free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
 663free_irq:
 664        iounmap(mpc8xxx_spi->reg_base);
 665err_probe:
 666        spi_master_put(master);
 667err:
 668        return ERR_PTR(ret);
 669}
 670
 671static int of_fsl_espi_get_chipselects(struct device *dev)
 672{
 673        struct device_node *np = dev->of_node;
 674        struct fsl_spi_platform_data *pdata = dev->platform_data;
 675        const u32 *prop;
 676        int len;
 677
 678        prop = of_get_property(np, "fsl,espi-num-chipselects", &len);
 679        if (!prop || len < sizeof(*prop)) {
 680                dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
 681                return -EINVAL;
 682        }
 683
 684        pdata->max_chipselect = *prop;
 685        pdata->cs_control = NULL;
 686
 687        return 0;
 688}
 689
 690static int __devinit of_fsl_espi_probe(struct platform_device *ofdev)
 691{
 692        struct device *dev = &ofdev->dev;
 693        struct device_node *np = ofdev->dev.of_node;
 694        struct spi_master *master;
 695        struct resource mem;
 696        struct resource irq;
 697        int ret = -ENOMEM;
 698
 699        ret = of_mpc8xxx_spi_probe(ofdev);
 700        if (ret)
 701                return ret;
 702
 703        ret = of_fsl_espi_get_chipselects(dev);
 704        if (ret)
 705                goto err;
 706
 707        ret = of_address_to_resource(np, 0, &mem);
 708        if (ret)
 709                goto err;
 710
 711        ret = of_irq_to_resource(np, 0, &irq);
 712        if (!ret) {
 713                ret = -EINVAL;
 714                goto err;
 715        }
 716
 717        master = fsl_espi_probe(dev, &mem, irq.start);
 718        if (IS_ERR(master)) {
 719                ret = PTR_ERR(master);
 720                goto err;
 721        }
 722
 723        return 0;
 724
 725err:
 726        return ret;
 727}
 728
 729static int __devexit of_fsl_espi_remove(struct platform_device *dev)
 730{
 731        return mpc8xxx_spi_remove(&dev->dev);
 732}
 733
 734static const struct of_device_id of_fsl_espi_match[] = {
 735        { .compatible = "fsl,mpc8536-espi" },
 736        {}
 737};
 738MODULE_DEVICE_TABLE(of, of_fsl_espi_match);
 739
 740static struct platform_driver fsl_espi_driver = {
 741        .driver = {
 742                .name = "fsl_espi",
 743                .owner = THIS_MODULE,
 744                .of_match_table = of_fsl_espi_match,
 745        },
 746        .probe          = of_fsl_espi_probe,
 747        .remove         = __devexit_p(of_fsl_espi_remove),
 748};
 749module_platform_driver(fsl_espi_driver);
 750
 751MODULE_AUTHOR("Mingkai Hu");
 752MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
 753MODULE_LICENSE("GPL");
 754