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/delay.h>
  12 #include <linux/err.h>
  13 #include <linux/fsl_devices.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/irq.h>
  16 #include <linux/module.h>
  17 #include <linux/mm.h>
  18 #include <linux/of.h>
  19 #include <linux/of_address.h>
  20 #include <linux/of_irq.h>
  21 #include <linux/of_platform.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/spi/spi.h>
  24 #include <sysdev/fsl_soc.h>
  25
  26 #include "spi-fsl-lib.h"
  27
  28 /* eSPI Controller registers */
  29 struct fsl_espi_reg {
  30         __be32 mode;            /* 0x000 - eSPI mode register */
  31         __be32 event;           /* 0x004 - eSPI event register */
  32         __be32 mask;            /* 0x008 - eSPI mask register */
  33         __be32 command;         /* 0x00c - eSPI command register */
  34         __be32 transmit;        /* 0x010 - eSPI transmit FIFO access register*/
  35         __be32 receive;         /* 0x014 - eSPI receive FIFO access register*/
  36         u8 res[8];              /* 0x018 - 0x01c reserved */
  37         __be32 csmode[4];       /* 0x020 - 0x02c eSPI cs mode register */
  38 };
  39
  40 struct fsl_espi_transfer {
  41         const void *tx_buf;
  42         void *rx_buf;
  43         unsigned len;
  44         unsigned n_tx;
  45         unsigned n_rx;
  46         unsigned actual_length;
  47         int status;
  48 };
  49
  50 /* eSPI Controller mode register definitions */
  51 #define SPMODE_ENABLE           (1 << 31)
  52 #define SPMODE_LOOP             (1 << 30)
  53 #define SPMODE_TXTHR(x)         ((x) << 8)
  54 #define SPMODE_RXTHR(x)         ((x) << 0)
  55
  56 /* eSPI Controller CS mode register definitions */
  57 #define CSMODE_CI_INACTIVEHIGH  (1 << 31)
  58 #define CSMODE_CP_BEGIN_EDGECLK (1 << 30)
  59 #define CSMODE_REV              (1 << 29)
  60 #define CSMODE_DIV16            (1 << 28)
  61 #define CSMODE_PM(x)            ((x) << 24)
  62 #define CSMODE_POL_1            (1 << 20)
  63 #define CSMODE_LEN(x)           ((x) << 16)
  64 #define CSMODE_BEF(x)           ((x) << 12)
  65 #define CSMODE_AFT(x)           ((x) << 8)
  66 #define CSMODE_CG(x)            ((x) << 3)
  67
  68 /* Default mode/csmode for eSPI controller */
  69 #define SPMODE_INIT_VAL (SPMODE_TXTHR(4) | SPMODE_RXTHR(3))
  70 #define CSMODE_INIT_VAL (CSMODE_POL_1 | CSMODE_BEF(0) \
  71                 | CSMODE_AFT(0) | CSMODE_CG(1))
  72
  73 /* SPIE register values */
  74 #define SPIE_NE         0x00000200      /* Not empty */
  75 #define SPIE_NF         0x00000100      /* Not full */
  76
  77 /* SPIM register values */
  78 #define SPIM_NE         0x00000200      /* Not empty */
  79 #define SPIM_NF         0x00000100      /* Not full */
  80 #define SPIE_RXCNT(reg)     ((reg >> 24) & 0x3F)
  81 #define SPIE_TXCNT(reg)     ((reg >> 16) & 0x3F)
  82
  83 /* SPCOM register values */
  84 #define SPCOM_CS(x)             ((x) << 30)
  85 #define SPCOM_TRANLEN(x)        ((x) << 0)
  86 #define SPCOM_TRANLEN_MAX       0xFFFF  /* Max transaction length */
  87
  88 static void fsl_espi_change_mode(struct spi_device *spi)
  89 {
  90         struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
  91         struct spi_mpc8xxx_cs *cs = spi->controller_state;
  92         struct fsl_espi_reg *reg_base = mspi->reg_base;
  93         __be32 __iomem *mode = &reg_base->csmode[spi->chip_select];
  94         __be32 __iomem *espi_mode = &reg_base->mode;
  95         u32 tmp;
  96         unsigned long flags;
  97
  98         /* Turn off IRQs locally to minimize time that SPI is disabled. */
  99         local_irq_save(flags);
 100
 101         /* Turn off SPI unit prior changing mode */
 102         tmp = mpc8xxx_spi_read_reg(espi_mode);
 103         mpc8xxx_spi_write_reg(espi_mode, tmp & ~SPMODE_ENABLE);
 104         mpc8xxx_spi_write_reg(mode, cs->hw_mode);
 105         mpc8xxx_spi_write_reg(espi_mode, tmp);
 106
 107         local_irq_restore(flags);
 108 }
 109
 110 static u32 fsl_espi_tx_buf_lsb(struct mpc8xxx_spi *mpc8xxx_spi)
 111 {
 112         u32 data;
 113         u16 data_h;
 114         u16 data_l;
 115         const u32 *tx = mpc8xxx_spi->tx;
 116
 117         if (!tx)
 118                 return 0;
 119
 120         data = *tx++ << mpc8xxx_spi->tx_shift;
 121         data_l = data & 0xffff;
 122         data_h = (data >> 16) & 0xffff;
 123         swab16s(&data_l);
 124         swab16s(&data_h);
 125         data = data_h | data_l;
 126
 127         mpc8xxx_spi->tx = tx;
 128         return data;
 129 }
 130
 131 static int fsl_espi_setup_transfer(struct spi_device *spi,
 132                                         struct spi_transfer *t)
 133 {
 134         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
 135         int bits_per_word = 0;
 136         u8 pm;
 137         u32 hz = 0;
 138         struct spi_mpc8xxx_cs *cs = spi->controller_state;
 139
 140         if (t) {
 141                 bits_per_word = t->bits_per_word;
 142                 hz = t->speed_hz;
 143         }
 144
 145         /* spi_transfer level calls that work per-word */
 146         if (!bits_per_word)
 147                 bits_per_word = spi->bits_per_word;
 148
 149         if (!hz)
 150                 hz = spi->max_speed_hz;
 151
 152         cs->rx_shift = 0;
 153         cs->tx_shift = 0;
 154         cs->get_rx = mpc8xxx_spi_rx_buf_u32;
 155         cs->get_tx = mpc8xxx_spi_tx_buf_u32;
 156         if (bits_per_word <= 8) {
 157                 cs->rx_shift = 8 - bits_per_word;
 158         } else {
 159                 cs->rx_shift = 16 - bits_per_word;
 160                 if (spi->mode & SPI_LSB_FIRST)
 161                         cs->get_tx = fsl_espi_tx_buf_lsb;
 162         }
 163
 164         mpc8xxx_spi->rx_shift = cs->rx_shift;
 165         mpc8xxx_spi->tx_shift = cs->tx_shift;
 166         mpc8xxx_spi->get_rx = cs->get_rx;
 167         mpc8xxx_spi->get_tx = cs->get_tx;
 168
 169         bits_per_word = bits_per_word - 1;
 170
 171         /* mask out bits we are going to set */
 172         cs->hw_mode &= ~(CSMODE_LEN(0xF) | CSMODE_DIV16 | CSMODE_PM(0xF));
 173
 174         cs->hw_mode |= CSMODE_LEN(bits_per_word);
 175
 176         if ((mpc8xxx_spi->spibrg / hz) > 64) {
 177                 cs->hw_mode |= CSMODE_DIV16;
 178                 pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 16 * 4);
 179
 180                 WARN_ONCE(pm > 33, "%s: Requested speed is too low: %d Hz. "
 181                           "Will use %d Hz instead.\n", dev_name(&spi->dev),
 182                                 hz, mpc8xxx_spi->spibrg / (4 * 16 * (32 + 1)));
 183                 if (pm > 33)
 184                         pm = 33;
 185         } else {
 186                 pm = DIV_ROUND_UP(mpc8xxx_spi->spibrg, hz * 4);
 187         }
 188         if (pm)
 189                 pm--;
 190         if (pm < 2)
 191                 pm = 2;
 192
 193         cs->hw_mode |= CSMODE_PM(pm);
 194
 195         fsl_espi_change_mode(spi);
 196         return 0;
 197 }
 198
 199 static int fsl_espi_cpu_bufs(struct mpc8xxx_spi *mspi, struct spi_transfer *t,
 200                 unsigned int len)
 201 {
 202         u32 word;
 203         struct fsl_espi_reg *reg_base = mspi->reg_base;
 204
 205         mspi->count = len;
 206
 207         /* enable rx ints */
 208         mpc8xxx_spi_write_reg(&reg_base->mask, SPIM_NE);
 209
 210         /* transmit word */
 211         word = mspi->get_tx(mspi);
 212         mpc8xxx_spi_write_reg(&reg_base->transmit, word);
 213
 214         return 0;
 215 }
 216
 217 static int fsl_espi_bufs(struct spi_device *spi, struct spi_transfer *t)
 218 {
 219         struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
 220         struct fsl_espi_reg *reg_base = mpc8xxx_spi->reg_base;
 221         unsigned int len = t->len;
 222         int ret;
 223
 224         mpc8xxx_spi->len = t->len;
 225         len = roundup(len, 4) / 4;
 226
 227         mpc8xxx_spi->tx = t->tx_buf;
 228         mpc8xxx_spi->rx = t->rx_buf;
 229
 230         reinit_completion(&mpc8xxx_spi->done);
 231
 232         /* Set SPCOM[CS] and SPCOM[TRANLEN] field */
 233         if ((t->len - 1) > SPCOM_TRANLEN_MAX) {
 234                 dev_err(mpc8xxx_spi->dev, "Transaction length (%d)"
 235                                 " beyond the SPCOM[TRANLEN] field\n", t->len);
 236                 return -EINVAL;
 237         }
 238         mpc8xxx_spi_write_reg(&reg_base->command,
 239                 (SPCOM_CS(spi->chip_select) | SPCOM_TRANLEN(t->len - 1)));
 240
 241         ret = fsl_espi_cpu_bufs(mpc8xxx_spi, t, len);
 242         if (ret)
 243                 return ret;
 244
 245         wait_for_completion(&mpc8xxx_spi->done);
 246
 247         /* disable rx ints */
 248         mpc8xxx_spi_write_reg(&reg_base->mask, 0);
 249
 250         return mpc8xxx_spi->count;
 251 }
 252
 253 static inline void fsl_espi_addr2cmd(unsigned int addr, u8 *cmd)
 254 {
 255         if (cmd) {
 256                 cmd[1] = (u8)(addr >> 16);
 257                 cmd[2] = (u8)(addr >> 8);
 258                 cmd[3] = (u8)(addr >> 0);
 259         }
 260 }
 261
 262 static inline unsigned int fsl_espi_cmd2addr(u8 *cmd)
 263 {
 264         if (cmd)
 265                 return cmd[1] << 16 | cmd[2] << 8 | cmd[3] << 0;
 266
 267         return 0;
 268 }
 269
 270 static void fsl_espi_do_trans(struct spi_message *m,
 271                                 struct fsl_espi_transfer *tr)
 272 {
 273         struct spi_device *spi = m->spi;
 274         struct mpc8xxx_spi *mspi = spi_master_get_devdata(spi->master);
 275         struct fsl_espi_transfer *espi_trans = tr;
 276         struct spi_message message;
 277         struct spi_transfer *t, *first, trans;
 278         int status = 0;
 279
 280         spi_message_init(&message);
 281         memset(&trans, 0, sizeof(trans));
 282
 283         first = list_first_entry(&m->transfers, struct spi_transfer,
 284                         transfer_list);
 285         list_for_each_entry(t, &m->transfers, transfer_list) {
 286                 if ((first->bits_per_word != t->bits_per_word) ||
 287                         (first->speed_hz != t->speed_hz)) {
 288                         espi_trans->status = -EINVAL;
 289                         dev_err(mspi->dev,
 290                                 "bits_per_word/speed_hz should be same for the same SPI transfer\n");
 291                         return;
 292                 }
 293
 294                 trans.speed_hz = t->speed_hz;
 295                 trans.bits_per_word = t->bits_per_word;
 296                 trans.delay_usecs = max(first->delay_usecs, t->delay_usecs);
 297         }
 298
 299         trans.len = espi_trans->len;
 300         trans.tx_buf = espi_trans->tx_buf;
 301         trans.rx_buf = espi_trans->rx_buf;
 302         spi_message_add_tail(&trans, &message);
 303
 304         list_for_each_entry(t, &message.transfers, transfer_list) {
 305                 if (t->bits_per_word || t->speed_hz) {
 306                         status = -EINVAL;
 307
 308                         status = fsl_espi_setup_transfer(spi, t);
 309                         if (status < 0)
 310                                 break;
 311                 }
 312
 313                 if (t->len)
 314                         status = fsl_espi_bufs(spi, t);
 315
 316                 if (status) {
 317                         status = -EMSGSIZE;
 318                         break;
 319                 }
 320
 321                 if (t->delay_usecs)
 322                         udelay(t->delay_usecs);
 323         }
 324
 325         espi_trans->status = status;
 326         fsl_espi_setup_transfer(spi, NULL);
 327 }
 328
 329 static void fsl_espi_cmd_trans(struct spi_message *m,
 330                                 struct fsl_espi_transfer *trans, u8 *rx_buff)
 331 {
 332         struct spi_transfer *t;
 333         u8 *local_buf;
 334         int i = 0;
 335         struct fsl_espi_transfer *espi_trans = trans;
 336
 337         local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
 338         if (!local_buf) {
 339                 espi_trans->status = -ENOMEM;
 340                 return;
 341         }
 342
 343         list_for_each_entry(t, &m->transfers, transfer_list) {
 344                 if (t->tx_buf) {
 345                         memcpy(local_buf + i, t->tx_buf, t->len);
 346                         i += t->len;
 347                 }
 348         }
 349
 350         espi_trans->tx_buf = local_buf;
 351         espi_trans->rx_buf = local_buf;
 352         fsl_espi_do_trans(m, espi_trans);
 353
 354         espi_trans->actual_length = espi_trans->len;
 355         kfree(local_buf);
 356 }
 357
 358 static void fsl_espi_rw_trans(struct spi_message *m,
 359                                 struct fsl_espi_transfer *trans, u8 *rx_buff)
 360 {
 361         struct fsl_espi_transfer *espi_trans = trans;
 362         unsigned int total_len = espi_trans->len;
 363         struct spi_transfer *t;
 364         u8 *local_buf;
 365         u8 *rx_buf = rx_buff;
 366         unsigned int trans_len;
 367         unsigned int addr;
 368         unsigned int tx_only;
 369         unsigned int rx_pos = 0;
 370         unsigned int pos;
 371         int i, loop;
 372
 373         local_buf = kzalloc(SPCOM_TRANLEN_MAX, GFP_KERNEL);
 374         if (!local_buf) {
 375                 espi_trans->status = -ENOMEM;
 376                 return;
 377         }
 378
 379         for (pos = 0, loop = 0; pos < total_len; pos += trans_len, loop++) {
 380                 trans_len = total_len - pos;
 381
 382                 i = 0;
 383                 tx_only = 0;
 384                 list_for_each_entry(t, &m->transfers, transfer_list) {
 385                         if (t->tx_buf) {
 386                                 memcpy(local_buf + i, t->tx_buf, t->len);
 387                                 i += t->len;
 388                                 if (!t->rx_buf)
 389                                         tx_only += t->len;
 390                         }
 391                 }
 392
 393                 /* Add additional TX bytes to compensate SPCOM_TRANLEN_MAX */
 394                 if (loop > 0)
 395                         trans_len += tx_only;
 396
 397                 if (trans_len > SPCOM_TRANLEN_MAX)
 398                         trans_len = SPCOM_TRANLEN_MAX;
 399
 400                 /* Update device offset */
 401                 if (pos > 0) {
 402                         addr = fsl_espi_cmd2addr(local_buf);
 403                         addr += rx_pos;
 404                         fsl_espi_addr2cmd(addr, local_buf);
 405                 }
 406
 407                 espi_trans->len = trans_len;
 408                 espi_trans->tx_buf = local_buf;
 409                 espi_trans->rx_buf = local_buf;
 410                 fsl_espi_do_trans(m, espi_trans);
 411
 412                 /* If there is at least one RX byte then copy it to rx_buf */
 413                 if (tx_only < SPCOM_TRANLEN_MAX)
 414                         memcpy(rx_buf + rx_pos, espi_trans->rx_buf + tx_only,
 415                                         trans_len - tx_only);
 416
 417                 rx_pos += trans_len - tx_only;
 418
 419                 if (loop > 0)
 420                         espi_trans->actual_length += espi_trans->len - tx_only;
 421                 else
 422                         espi_trans->actual_length += espi_trans->len;
 423         }
 424
 425         kfree(local_buf);
 426 }
 427
 428 static int fsl_espi_do_one_msg(struct spi_master *master,
 429                                struct spi_message *m)
 430 {
 431         struct spi_transfer *t;
 432         u8 *rx_buf = NULL;
 433         unsigned int n_tx = 0;
 434         unsigned int n_rx = 0;
 435         unsigned int xfer_len = 0;
 436         struct fsl_espi_transfer espi_trans;
 437
 438         list_for_each_entry(t, &m->transfers, transfer_list) {
 439                 if (t->tx_buf)
 440                         n_tx += t->len;
 441                 if (t->rx_buf) {
 442                         n_rx += t->len;
 443                         rx_buf = t->rx_buf;
 444                 }
 445                 if ((t->tx_buf) || (t->rx_buf))
 446                         xfer_len += t->len;
 447         }
 448
 449         espi_trans.n_tx = n_tx;
 450         espi_trans.n_rx = n_rx;
 451         espi_trans.len = xfer_len;
 452         espi_trans.actual_length = 0;
 453         espi_trans.status = 0;
 454
 455         if (!rx_buf)
 456                 fsl_espi_cmd_trans(m, &espi_trans, NULL);
 457         else
 458                 fsl_espi_rw_trans(m, &espi_trans, rx_buf);
 459
 460         m->actual_length = espi_trans.actual_length;
 461         m->status = espi_trans.status;
 462         spi_finalize_current_message(master);
 463         return 0;
 464 }
 465
 466 static int fsl_espi_setup(struct spi_device *spi)
 467 {
 468         struct mpc8xxx_spi *mpc8xxx_spi;
 469         struct fsl_espi_reg *reg_base;
 470         int retval;
 471         u32 hw_mode;
 472         u32 loop_mode;
 473         struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
 474
 475         if (!spi->max_speed_hz)
 476                 return -EINVAL;
 477
 478         if (!cs) {
 479                 cs = kzalloc(sizeof(*cs), GFP_KERNEL);
 480                 if (!cs)
 481                         return -ENOMEM;
 482                 spi_set_ctldata(spi, cs);
 483         }
 484
 485         mpc8xxx_spi = spi_master_get_devdata(spi->master);
 486         reg_base = mpc8xxx_spi->reg_base;
 487
 488         hw_mode = cs->hw_mode; /* Save original settings */
 489         cs->hw_mode = mpc8xxx_spi_read_reg(
 490                         &reg_base->csmode[spi->chip_select]);
 491         /* mask out bits we are going to set */
 492         cs->hw_mode &= ~(CSMODE_CP_BEGIN_EDGECLK | CSMODE_CI_INACTIVEHIGH
 493                          | CSMODE_REV);
 494
 495         if (spi->mode & SPI_CPHA)
 496                 cs->hw_mode |= CSMODE_CP_BEGIN_EDGECLK;
 497         if (spi->mode & SPI_CPOL)
 498                 cs->hw_mode |= CSMODE_CI_INACTIVEHIGH;
 499         if (!(spi->mode & SPI_LSB_FIRST))
 500                 cs->hw_mode |= CSMODE_REV;
 501
 502         /* Handle the loop mode */
 503         loop_mode = mpc8xxx_spi_read_reg(&reg_base->mode);
 504         loop_mode &= ~SPMODE_LOOP;
 505         if (spi->mode & SPI_LOOP)
 506                 loop_mode |= SPMODE_LOOP;
 507         mpc8xxx_spi_write_reg(&reg_base->mode, loop_mode);
 508
 509         retval = fsl_espi_setup_transfer(spi, NULL);
 510         if (retval < 0) {
 511                 cs->hw_mode = hw_mode; /* Restore settings */
 512                 return retval;
 513         }
 514         return 0;
 515 }
 516
 517 static void fsl_espi_cleanup(struct spi_device *spi)
 518 {
 519         struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
 520
 521         kfree(cs);
 522         spi_set_ctldata(spi, NULL);
 523 }
 524
 525 void fsl_espi_cpu_irq(struct mpc8xxx_spi *mspi, u32 events)
 526 {
 527         struct fsl_espi_reg *reg_base = mspi->reg_base;
 528
 529         /* We need handle RX first */
 530         if (events & SPIE_NE) {
 531                 u32 rx_data, tmp;
 532                 u8 rx_data_8;
 533
 534                 /* Spin until RX is done */
 535                 while (SPIE_RXCNT(events) < min(4, mspi->len)) {
 536                         cpu_relax();
 537                         events = mpc8xxx_spi_read_reg(&reg_base->event);
 538                 }
 539
 540                 if (mspi->len >= 4) {
 541                         rx_data = mpc8xxx_spi_read_reg(&reg_base->receive);
 542                 } else {
 543                         tmp = mspi->len;
 544                         rx_data = 0;
 545                         while (tmp--) {
 546                                 rx_data_8 = in_8((u8 *)&reg_base->receive);
 547                                 rx_data |= (rx_data_8 << (tmp * 8));
 548                         }
 549
 550                         rx_data <<= (4 - mspi->len) * 8;
 551                 }
 552
 553                 mspi->len -= 4;
 554
 555                 if (mspi->rx)
 556                         mspi->get_rx(rx_data, mspi);
 557         }
 558
 559         if (!(events & SPIE_NF)) {
 560                 int ret;
 561
 562                 /* spin until TX is done */
 563                 ret = spin_event_timeout(((events = mpc8xxx_spi_read_reg(
 564                                 &reg_base->event)) & SPIE_NF), 1000, 0);
 565                 if (!ret) {
 566                         dev_err(mspi->dev, "tired waiting for SPIE_NF\n");
 567
 568                         /* Clear the SPIE bits */
 569                         mpc8xxx_spi_write_reg(&reg_base->event, events);
 570                         complete(&mspi->done);
 571                         return;
 572                 }
 573         }
 574
 575         /* Clear the events */
 576         mpc8xxx_spi_write_reg(&reg_base->event, events);
 577
 578         mspi->count -= 1;
 579         if (mspi->count) {
 580                 u32 word = mspi->get_tx(mspi);
 581
 582                 mpc8xxx_spi_write_reg(&reg_base->transmit, word);
 583         } else {
 584                 complete(&mspi->done);
 585         }
 586 }
 587
 588 static irqreturn_t fsl_espi_irq(s32 irq, void *context_data)
 589 {
 590         struct mpc8xxx_spi *mspi = context_data;
 591         struct fsl_espi_reg *reg_base = mspi->reg_base;
 592         irqreturn_t ret = IRQ_NONE;
 593         u32 events;
 594
 595         /* Get interrupt events(tx/rx) */
 596         events = mpc8xxx_spi_read_reg(&reg_base->event);
 597         if (events)
 598                 ret = IRQ_HANDLED;
 599
 600         dev_vdbg(mspi->dev, "%s: events %x\n", __func__, events);
 601
 602         fsl_espi_cpu_irq(mspi, events);
 603
 604         return ret;
 605 }
 606
 607 static void fsl_espi_remove(struct mpc8xxx_spi *mspi)
 608 {
 609         iounmap(mspi->reg_base);
 610 }
 611
 612 static int fsl_espi_suspend(struct spi_master *master)
 613 {
 614         struct mpc8xxx_spi *mpc8xxx_spi;
 615         struct fsl_espi_reg *reg_base;
 616         u32 regval;
 617
 618         mpc8xxx_spi = spi_master_get_devdata(master);
 619         reg_base = mpc8xxx_spi->reg_base;
 620
 621         regval = mpc8xxx_spi_read_reg(&reg_base->mode);
 622         regval &= ~SPMODE_ENABLE;
 623         mpc8xxx_spi_write_reg(&reg_base->mode, regval);
 624
 625         return 0;
 626 }
 627
 628 static int fsl_espi_resume(struct spi_master *master)
 629 {
 630         struct mpc8xxx_spi *mpc8xxx_spi;
 631         struct fsl_espi_reg *reg_base;
 632         u32 regval;
 633
 634         mpc8xxx_spi = spi_master_get_devdata(master);
 635         reg_base = mpc8xxx_spi->reg_base;
 636
 637         regval = mpc8xxx_spi_read_reg(&reg_base->mode);
 638         regval |= SPMODE_ENABLE;
 639         mpc8xxx_spi_write_reg(&reg_base->mode, regval);
 640
 641         return 0;
 642 }
 643
 644 static struct spi_master * fsl_espi_probe(struct device *dev,
 645                 struct resource *mem, unsigned int irq)
 646 {
 647         struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
 648         struct spi_master *master;
 649         struct mpc8xxx_spi *mpc8xxx_spi;
 650         struct fsl_espi_reg *reg_base;
 651         struct device_node *nc;
 652         const __be32 *prop;
 653         u32 regval, csmode;
 654         int i, len, ret = 0;
 655
 656         master = spi_alloc_master(dev, sizeof(struct mpc8xxx_spi));
 657         if (!master) {
 658                 ret = -ENOMEM;
 659                 goto err;
 660         }
 661
 662         dev_set_drvdata(dev, master);
 663
 664         mpc8xxx_spi_probe(dev, mem, irq);
 665
 666         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
 667         master->setup = fsl_espi_setup;
 668         master->cleanup = fsl_espi_cleanup;
 669         master->transfer_one_message = fsl_espi_do_one_msg;
 670         master->prepare_transfer_hardware = fsl_espi_resume;
 671         master->unprepare_transfer_hardware = fsl_espi_suspend;
 672
 673         mpc8xxx_spi = spi_master_get_devdata(master);
 674         mpc8xxx_spi->spi_remove = fsl_espi_remove;
 675
 676         mpc8xxx_spi->reg_base = ioremap(mem->start, resource_size(mem));
 677         if (!mpc8xxx_spi->reg_base) {
 678                 ret = -ENOMEM;
 679                 goto err_probe;
 680         }
 681
 682         reg_base = mpc8xxx_spi->reg_base;
 683
 684         /* Register for SPI Interrupt */
 685         ret = request_irq(mpc8xxx_spi->irq, fsl_espi_irq,
 686                           0, "fsl_espi", mpc8xxx_spi);
 687         if (ret)
 688                 goto free_irq;
 689
 690         if (mpc8xxx_spi->flags & SPI_QE_CPU_MODE) {
 691                 mpc8xxx_spi->rx_shift = 16;
 692                 mpc8xxx_spi->tx_shift = 24;
 693         }
 694
 695         /* SPI controller initializations */
 696         mpc8xxx_spi_write_reg(&reg_base->mode, 0);
 697         mpc8xxx_spi_write_reg(&reg_base->mask, 0);
 698         mpc8xxx_spi_write_reg(&reg_base->command, 0);
 699         mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
 700
 701         /* Init eSPI CS mode register */
 702         for_each_available_child_of_node(master->dev.of_node, nc) {
 703                 /* get chip select */
 704                 prop = of_get_property(nc, "reg", &len);
 705                 if (!prop || len < sizeof(*prop))
 706                         continue;
 707                 i = be32_to_cpup(prop);
 708                 if (i < 0 || i >= pdata->max_chipselect)
 709                         continue;
 710
 711                 csmode = CSMODE_INIT_VAL;
 712                 /* check if CSBEF is set in device tree */
 713                 prop = of_get_property(nc, "fsl,csbef", &len);
 714                 if (prop && len >= sizeof(*prop)) {
 715                         csmode &= ~(CSMODE_BEF(0xf));
 716                         csmode |= CSMODE_BEF(be32_to_cpup(prop));
 717                 }
 718                 /* check if CSAFT is set in device tree */
 719                 prop = of_get_property(nc, "fsl,csaft", &len);
 720                 if (prop && len >= sizeof(*prop)) {
 721                         csmode &= ~(CSMODE_AFT(0xf));
 722                         csmode |= CSMODE_AFT(be32_to_cpup(prop));
 723                 }
 724                 mpc8xxx_spi_write_reg(&reg_base->csmode[i], csmode);
 725
 726                 dev_info(dev, "cs=%d, init_csmode=0x%x\n", i, csmode);
 727         }
 728
 729         /* Enable SPI interface */
 730         regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
 731
 732         mpc8xxx_spi_write_reg(&reg_base->mode, regval);
 733
 734         ret = spi_register_master(master);
 735         if (ret < 0)
 736                 goto unreg_master;
 737
 738         dev_info(dev, "at 0x%p (irq = %d)\n", reg_base, mpc8xxx_spi->irq);
 739
 740         return master;
 741
 742 unreg_master:
 743         free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
 744 free_irq:
 745         iounmap(mpc8xxx_spi->reg_base);
 746 err_probe:
 747         spi_master_put(master);
 748 err:
 749         return ERR_PTR(ret);
 750 }
 751
 752 static int of_fsl_espi_get_chipselects(struct device *dev)
 753 {
 754         struct device_node *np = dev->of_node;
 755         struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
 756         const u32 *prop;
 757         int len;
 758
 759         prop = of_get_property(np, "fsl,espi-num-chipselects", &len);
 760         if (!prop || len < sizeof(*prop)) {
 761                 dev_err(dev, "No 'fsl,espi-num-chipselects' property\n");
 762                 return -EINVAL;
 763         }
 764
 765         pdata->max_chipselect = *prop;
 766         pdata->cs_control = NULL;
 767
 768         return 0;
 769 }
 770
 771 static int of_fsl_espi_probe(struct platform_device *ofdev)
 772 {
 773         struct device *dev = &ofdev->dev;
 774         struct device_node *np = ofdev->dev.of_node;
 775         struct spi_master *master;
 776         struct resource mem;
 777         unsigned int irq;
 778         int ret = -ENOMEM;
 779
 780         ret = of_mpc8xxx_spi_probe(ofdev);
 781         if (ret)
 782                 return ret;
 783
 784         ret = of_fsl_espi_get_chipselects(dev);
 785         if (ret)
 786                 goto err;
 787
 788         ret = of_address_to_resource(np, 0, &mem);
 789         if (ret)
 790                 goto err;
 791
 792         irq = irq_of_parse_and_map(np, 0);
 793         if (!irq) {
 794                 ret = -EINVAL;
 795                 goto err;
 796         }
 797
 798         master = fsl_espi_probe(dev, &mem, irq);
 799         if (IS_ERR(master)) {
 800                 ret = PTR_ERR(master);
 801                 goto err;
 802         }
 803
 804         return 0;
 805
 806 err:
 807         return ret;
 808 }
 809
 810 static int of_fsl_espi_remove(struct platform_device *dev)
 811 {
 812         return mpc8xxx_spi_remove(&dev->dev);
 813 }
 814
 815 #ifdef CONFIG_PM_SLEEP
 816 static int of_fsl_espi_suspend(struct device *dev)
 817 {
 818         struct spi_master *master = dev_get_drvdata(dev);
 819         int ret;
 820
 821         ret = spi_master_suspend(master);
 822         if (ret) {
 823                 dev_warn(dev, "cannot suspend master\n");
 824                 return ret;
 825         }
 826
 827         return fsl_espi_suspend(master);
 828 }
 829
 830 static int of_fsl_espi_resume(struct device *dev)
 831 {
 832         struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
 833         struct spi_master *master = dev_get_drvdata(dev);
 834         struct mpc8xxx_spi *mpc8xxx_spi;
 835         struct fsl_espi_reg *reg_base;
 836         u32 regval;
 837         int i;
 838
 839         mpc8xxx_spi = spi_master_get_devdata(master);
 840         reg_base = mpc8xxx_spi->reg_base;
 841
 842         /* SPI controller initializations */
 843         mpc8xxx_spi_write_reg(&reg_base->mode, 0);
 844         mpc8xxx_spi_write_reg(&reg_base->mask, 0);
 845         mpc8xxx_spi_write_reg(&reg_base->command, 0);
 846         mpc8xxx_spi_write_reg(&reg_base->event, 0xffffffff);
 847
 848         /* Init eSPI CS mode register */
 849         for (i = 0; i < pdata->max_chipselect; i++)
 850                 mpc8xxx_spi_write_reg(&reg_base->csmode[i], CSMODE_INIT_VAL);
 851
 852         /* Enable SPI interface */
 853         regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
 854
 855         mpc8xxx_spi_write_reg(&reg_base->mode, regval);
 856
 857         return spi_master_resume(master);
 858 }
 859 #endif /* CONFIG_PM_SLEEP */
 860
 861 static const struct dev_pm_ops espi_pm = {
 862         SET_SYSTEM_SLEEP_PM_OPS(of_fsl_espi_suspend, of_fsl_espi_resume)
 863 };
 864
 865 static const struct of_device_id of_fsl_espi_match[] = {
 866         { .compatible = "fsl,mpc8536-espi" },
 867         {}
 868 };
 869 MODULE_DEVICE_TABLE(of, of_fsl_espi_match);
 870
 871 static struct platform_driver fsl_espi_driver = {
 872         .driver = {
 873                 .name = "fsl_espi",
 874                 .of_match_table = of_fsl_espi_match,
 875                 .pm = &espi_pm,
 876         },
 877         .probe          = of_fsl_espi_probe,
 878         .remove         = of_fsl_espi_remove,
 879 };
 880 module_platform_driver(fsl_espi_driver);
 881
 882 MODULE_AUTHOR("Mingkai Hu");
 883 MODULE_DESCRIPTION("Enhanced Freescale SPI Driver");
 884 MODULE_LICENSE("GPL");