drivers/spi/spi_imx.c

   1 /*
   2  * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
   3  * Copyright (C) 2008 Juergen Beisert
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the
  16  * Free Software Foundation
  17  * 51 Franklin Street, Fifth Floor
  18  * Boston, MA  02110-1301, USA.
  19  */
  20
  21 #include <linux/clk.h>
  22 #include <linux/completion.h>
  23 #include <linux/delay.h>
  24 #include <linux/err.h>
  25 #include <linux/gpio.h>
  26 #include <linux/init.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/io.h>
  29 #include <linux/irq.h>
  30 #include <linux/kernel.h>
  31 #include <linux/module.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/spi/spi.h>
  34 #include <linux/spi/spi_bitbang.h>
  35 #include <linux/types.h>
  36
  37 #include <mach/spi.h>
  38
  39 #define DRIVER_NAME "spi_imx"
  40
  41 #define MXC_CSPIRXDATA          0x00
  42 #define MXC_CSPITXDATA          0x04
  43 #define MXC_CSPICTRL            0x08
  44 #define MXC_CSPIINT             0x0c
  45 #define MXC_RESET               0x1c
  46
  47 #define MX3_CSPISTAT            0x14
  48 #define MX3_CSPISTAT_RR         (1 << 3)
  49
  50 /* generic defines to abstract from the different register layouts */
  51 #define MXC_INT_RR      (1 << 0) /* Receive data ready interrupt */
  52 #define MXC_INT_TE      (1 << 1) /* Transmit FIFO empty interrupt */
  53
  54 struct spi_imx_config {
  55         unsigned int speed_hz;
  56         unsigned int bpw;
  57         unsigned int mode;
  58         int cs;
  59 };
  60
  61 struct spi_imx_data {
  62         struct spi_bitbang bitbang;
  63
  64         struct completion xfer_done;
  65         void *base;
  66         int irq;
  67         struct clk *clk;
  68         unsigned long spi_clk;
  69         int *chipselect;
  70
  71         unsigned int count;
  72         void (*tx)(struct spi_imx_data *);
  73         void (*rx)(struct spi_imx_data *);
  74         void *rx_buf;
  75         const void *tx_buf;
  76         unsigned int txfifo; /* number of words pushed in tx FIFO */
  77
  78         /* SoC specific functions */
  79         void (*intctrl)(struct spi_imx_data *, int);
  80         int (*config)(struct spi_imx_data *, struct spi_imx_config *);
  81         void (*trigger)(struct spi_imx_data *);
  82         int (*rx_available)(struct spi_imx_data *);
  83 };
  84
  85 #define MXC_SPI_BUF_RX(type)                                            \
  86 static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx)         \
  87 {                                                                       \
  88         unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA);       \
  89                                                                         \
  90         if (spi_imx->rx_buf) {                                          \
  91                 *(type *)spi_imx->rx_buf = val;                         \
  92                 spi_imx->rx_buf += sizeof(type);                        \
  93         }                                                               \
  94 }
  95
  96 #define MXC_SPI_BUF_TX(type)                                            \
  97 static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx)         \
  98 {                                                                       \
  99         type val = 0;                                                   \
 100                                                                         \
 101         if (spi_imx->tx_buf) {                                          \
 102                 val = *(type *)spi_imx->tx_buf;                         \
 103                 spi_imx->tx_buf += sizeof(type);                        \
 104         }                                                               \
 105                                                                         \
 106         spi_imx->count -= sizeof(type);                                 \
 107                                                                         \
 108         writel(val, spi_imx->base + MXC_CSPITXDATA);                    \
 109 }
 110
 111 MXC_SPI_BUF_RX(u8)
 112 MXC_SPI_BUF_TX(u8)
 113 MXC_SPI_BUF_RX(u16)
 114 MXC_SPI_BUF_TX(u16)
 115 MXC_SPI_BUF_RX(u32)
 116 MXC_SPI_BUF_TX(u32)
 117
 118 /* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
 119  * (which is currently not the case in this driver)
 120  */
 121 static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
 122         256, 384, 512, 768, 1024};
 123
 124 /* MX21, MX27 */
 125 static unsigned int spi_imx_clkdiv_1(unsigned int fin,
 126                 unsigned int fspi)
 127 {
 128         int i, max;
 129
 130         if (cpu_is_mx21())
 131                 max = 18;
 132         else
 133                 max = 16;
 134
 135         for (i = 2; i < max; i++)
 136                 if (fspi * mxc_clkdivs[i] >= fin)
 137                         return i;
 138
 139         return max;
 140 }
 141
 142 /* MX1, MX31, MX35 */
 143 static unsigned int spi_imx_clkdiv_2(unsigned int fin,
 144                 unsigned int fspi)
 145 {
 146         int i, div = 4;
 147
 148         for (i = 0; i < 7; i++) {
 149                 if (fspi * div >= fin)
 150                         return i;
 151                 div <<= 1;
 152         }
 153
 154         return 7;
 155 }
 156
 157 #define MX31_INTREG_TEEN        (1 << 0)
 158 #define MX31_INTREG_RREN        (1 << 3)
 159
 160 #define MX31_CSPICTRL_ENABLE    (1 << 0)
 161 #define MX31_CSPICTRL_MASTER    (1 << 1)
 162 #define MX31_CSPICTRL_XCH       (1 << 2)
 163 #define MX31_CSPICTRL_POL       (1 << 4)
 164 #define MX31_CSPICTRL_PHA       (1 << 5)
 165 #define MX31_CSPICTRL_SSCTL     (1 << 6)
 166 #define MX31_CSPICTRL_SSPOL     (1 << 7)
 167 #define MX31_CSPICTRL_BC_SHIFT  8
 168 #define MX35_CSPICTRL_BL_SHIFT  20
 169 #define MX31_CSPICTRL_CS_SHIFT  24
 170 #define MX35_CSPICTRL_CS_SHIFT  12
 171 #define MX31_CSPICTRL_DR_SHIFT  16
 172
 173 #define MX31_CSPISTATUS         0x14
 174 #define MX31_STATUS_RR          (1 << 3)
 175
 176 /* These functions also work for the i.MX35, but be aware that
 177  * the i.MX35 has a slightly different register layout for bits
 178  * we do not use here.
 179  */
 180 static void mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
 181 {
 182         unsigned int val = 0;
 183
 184         if (enable & MXC_INT_TE)
 185                 val |= MX31_INTREG_TEEN;
 186         if (enable & MXC_INT_RR)
 187                 val |= MX31_INTREG_RREN;
 188
 189         writel(val, spi_imx->base + MXC_CSPIINT);
 190 }
 191
 192 static void mx31_trigger(struct spi_imx_data *spi_imx)
 193 {
 194         unsigned int reg;
 195
 196         reg = readl(spi_imx->base + MXC_CSPICTRL);
 197         reg |= MX31_CSPICTRL_XCH;
 198         writel(reg, spi_imx->base + MXC_CSPICTRL);
 199 }
 200
 201 static int mx31_config(struct spi_imx_data *spi_imx,
 202                 struct spi_imx_config *config)
 203 {
 204         unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
 205
 206         reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
 207                 MX31_CSPICTRL_DR_SHIFT;
 208
 209         if (cpu_is_mx31())
 210                 reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT;
 211         else if (cpu_is_mx25() || cpu_is_mx35()) {
 212                 reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
 213                 reg |= MX31_CSPICTRL_SSCTL;
 214         }
 215
 216         if (config->mode & SPI_CPHA)
 217                 reg |= MX31_CSPICTRL_PHA;
 218         if (config->mode & SPI_CPOL)
 219                 reg |= MX31_CSPICTRL_POL;
 220         if (config->mode & SPI_CS_HIGH)
 221                 reg |= MX31_CSPICTRL_SSPOL;
 222         if (config->cs < 0) {
 223                 if (cpu_is_mx31())
 224                         reg |= (config->cs + 32) << MX31_CSPICTRL_CS_SHIFT;
 225                 else if (cpu_is_mx25() || cpu_is_mx35())
 226                         reg |= (config->cs + 32) << MX35_CSPICTRL_CS_SHIFT;
 227         }
 228
 229         writel(reg, spi_imx->base + MXC_CSPICTRL);
 230
 231         return 0;
 232 }
 233
 234 static int mx31_rx_available(struct spi_imx_data *spi_imx)
 235 {
 236         return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
 237 }
 238
 239 #define MX27_INTREG_RR          (1 << 4)
 240 #define MX27_INTREG_TEEN        (1 << 9)
 241 #define MX27_INTREG_RREN        (1 << 13)
 242
 243 #define MX27_CSPICTRL_POL       (1 << 5)
 244 #define MX27_CSPICTRL_PHA       (1 << 6)
 245 #define MX27_CSPICTRL_SSPOL     (1 << 8)
 246 #define MX27_CSPICTRL_XCH       (1 << 9)
 247 #define MX27_CSPICTRL_ENABLE    (1 << 10)
 248 #define MX27_CSPICTRL_MASTER    (1 << 11)
 249 #define MX27_CSPICTRL_DR_SHIFT  14
 250 #define MX27_CSPICTRL_CS_SHIFT  19
 251
 252 static void mx27_intctrl(struct spi_imx_data *spi_imx, int enable)
 253 {
 254         unsigned int val = 0;
 255
 256         if (enable & MXC_INT_TE)
 257                 val |= MX27_INTREG_TEEN;
 258         if (enable & MXC_INT_RR)
 259                 val |= MX27_INTREG_RREN;
 260
 261         writel(val, spi_imx->base + MXC_CSPIINT);
 262 }
 263
 264 static void mx27_trigger(struct spi_imx_data *spi_imx)
 265 {
 266         unsigned int reg;
 267
 268         reg = readl(spi_imx->base + MXC_CSPICTRL);
 269         reg |= MX27_CSPICTRL_XCH;
 270         writel(reg, spi_imx->base + MXC_CSPICTRL);
 271 }
 272
 273 static int mx27_config(struct spi_imx_data *spi_imx,
 274                 struct spi_imx_config *config)
 275 {
 276         unsigned int reg = MX27_CSPICTRL_ENABLE | MX27_CSPICTRL_MASTER;
 277
 278         reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz) <<
 279                 MX27_CSPICTRL_DR_SHIFT;
 280         reg |= config->bpw - 1;
 281
 282         if (config->mode & SPI_CPHA)
 283                 reg |= MX27_CSPICTRL_PHA;
 284         if (config->mode & SPI_CPOL)
 285                 reg |= MX27_CSPICTRL_POL;
 286         if (config->mode & SPI_CS_HIGH)
 287                 reg |= MX27_CSPICTRL_SSPOL;
 288         if (config->cs < 0)
 289                 reg |= (config->cs + 32) << MX27_CSPICTRL_CS_SHIFT;
 290
 291         writel(reg, spi_imx->base + MXC_CSPICTRL);
 292
 293         return 0;
 294 }
 295
 296 static int mx27_rx_available(struct spi_imx_data *spi_imx)
 297 {
 298         return readl(spi_imx->base + MXC_CSPIINT) & MX27_INTREG_RR;
 299 }
 300
 301 #define MX1_INTREG_RR           (1 << 3)
 302 #define MX1_INTREG_TEEN         (1 << 8)
 303 #define MX1_INTREG_RREN         (1 << 11)
 304
 305 #define MX1_CSPICTRL_POL        (1 << 4)
 306 #define MX1_CSPICTRL_PHA        (1 << 5)
 307 #define MX1_CSPICTRL_XCH        (1 << 8)
 308 #define MX1_CSPICTRL_ENABLE     (1 << 9)
 309 #define MX1_CSPICTRL_MASTER     (1 << 10)
 310 #define MX1_CSPICTRL_DR_SHIFT   13
 311
 312 static void mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
 313 {
 314         unsigned int val = 0;
 315
 316         if (enable & MXC_INT_TE)
 317                 val |= MX1_INTREG_TEEN;
 318         if (enable & MXC_INT_RR)
 319                 val |= MX1_INTREG_RREN;
 320
 321         writel(val, spi_imx->base + MXC_CSPIINT);
 322 }
 323
 324 static void mx1_trigger(struct spi_imx_data *spi_imx)
 325 {
 326         unsigned int reg;
 327
 328         reg = readl(spi_imx->base + MXC_CSPICTRL);
 329         reg |= MX1_CSPICTRL_XCH;
 330         writel(reg, spi_imx->base + MXC_CSPICTRL);
 331 }
 332
 333 static int mx1_config(struct spi_imx_data *spi_imx,
 334                 struct spi_imx_config *config)
 335 {
 336         unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
 337
 338         reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
 339                 MX1_CSPICTRL_DR_SHIFT;
 340         reg |= config->bpw - 1;
 341
 342         if (config->mode & SPI_CPHA)
 343                 reg |= MX1_CSPICTRL_PHA;
 344         if (config->mode & SPI_CPOL)
 345                 reg |= MX1_CSPICTRL_POL;
 346
 347         writel(reg, spi_imx->base + MXC_CSPICTRL);
 348
 349         return 0;
 350 }
 351
 352 static int mx1_rx_available(struct spi_imx_data *spi_imx)
 353 {
 354         return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
 355 }
 356
 357 static void spi_imx_chipselect(struct spi_device *spi, int is_active)
 358 {
 359         struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 360         int gpio = spi_imx->chipselect[spi->chip_select];
 361         int active = is_active != BITBANG_CS_INACTIVE;
 362         int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
 363
 364         if (gpio < 0)
 365                 return;
 366
 367         gpio_set_value(gpio, dev_is_lowactive ^ active);
 368 }
 369
 370 static void spi_imx_push(struct spi_imx_data *spi_imx)
 371 {
 372         while (spi_imx->txfifo < 8) {
 373                 if (!spi_imx->count)
 374                         break;
 375                 spi_imx->tx(spi_imx);
 376                 spi_imx->txfifo++;
 377         }
 378
 379         spi_imx->trigger(spi_imx);
 380 }
 381
 382 static irqreturn_t spi_imx_isr(int irq, void *dev_id)
 383 {
 384         struct spi_imx_data *spi_imx = dev_id;
 385
 386         while (spi_imx->rx_available(spi_imx)) {
 387                 spi_imx->rx(spi_imx);
 388                 spi_imx->txfifo--;
 389         }
 390
 391         if (spi_imx->count) {
 392                 spi_imx_push(spi_imx);
 393                 return IRQ_HANDLED;
 394         }
 395
 396         if (spi_imx->txfifo) {
 397                 /* No data left to push, but still waiting for rx data,
 398                  * enable receive data available interrupt.
 399                  */
 400                 spi_imx->intctrl(spi_imx, MXC_INT_RR);
 401                 return IRQ_HANDLED;
 402         }
 403
 404         spi_imx->intctrl(spi_imx, 0);
 405         complete(&spi_imx->xfer_done);
 406
 407         return IRQ_HANDLED;
 408 }
 409
 410 static int spi_imx_setupxfer(struct spi_device *spi,
 411                                  struct spi_transfer *t)
 412 {
 413         struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 414         struct spi_imx_config config;
 415
 416         config.bpw = t ? t->bits_per_word : spi->bits_per_word;
 417         config.speed_hz  = t ? t->speed_hz : spi->max_speed_hz;
 418         config.mode = spi->mode;
 419         config.cs = spi_imx->chipselect[spi->chip_select];
 420
 421         if (!config.speed_hz)
 422                 config.speed_hz = spi->max_speed_hz;
 423         if (!config.bpw)
 424                 config.bpw = spi->bits_per_word;
 425         if (!config.speed_hz)
 426                 config.speed_hz = spi->max_speed_hz;
 427
 428         /* Initialize the functions for transfer */
 429         if (config.bpw <= 8) {
 430                 spi_imx->rx = spi_imx_buf_rx_u8;
 431                 spi_imx->tx = spi_imx_buf_tx_u8;
 432         } else if (config.bpw <= 16) {
 433                 spi_imx->rx = spi_imx_buf_rx_u16;
 434                 spi_imx->tx = spi_imx_buf_tx_u16;
 435         } else if (config.bpw <= 32) {
 436                 spi_imx->rx = spi_imx_buf_rx_u32;
 437                 spi_imx->tx = spi_imx_buf_tx_u32;
 438         } else
 439                 BUG();
 440
 441         spi_imx->config(spi_imx, &config);
 442
 443         return 0;
 444 }
 445
 446 static int spi_imx_transfer(struct spi_device *spi,
 447                                 struct spi_transfer *transfer)
 448 {
 449         struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 450
 451         spi_imx->tx_buf = transfer->tx_buf;
 452         spi_imx->rx_buf = transfer->rx_buf;
 453         spi_imx->count = transfer->len;
 454         spi_imx->txfifo = 0;
 455
 456         init_completion(&spi_imx->xfer_done);
 457
 458         spi_imx_push(spi_imx);
 459
 460         spi_imx->intctrl(spi_imx, MXC_INT_TE);
 461
 462         wait_for_completion(&spi_imx->xfer_done);
 463
 464         return transfer->len;
 465 }
 466
 467 static int spi_imx_setup(struct spi_device *spi)
 468 {
 469         struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
 470         int gpio = spi_imx->chipselect[spi->chip_select];
 471
 472         dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
 473                  spi->mode, spi->bits_per_word, spi->max_speed_hz);
 474
 475         if (gpio >= 0)
 476                 gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
 477
 478         spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
 479
 480         return 0;
 481 }
 482
 483 static void spi_imx_cleanup(struct spi_device *spi)
 484 {
 485 }
 486
 487 static int __devinit spi_imx_probe(struct platform_device *pdev)
 488 {
 489         struct spi_imx_master *mxc_platform_info;
 490         struct spi_master *master;
 491         struct spi_imx_data *spi_imx;
 492         struct resource *res;
 493         int i, ret;
 494
 495         mxc_platform_info = dev_get_platdata(&pdev->dev);
 496         if (!mxc_platform_info) {
 497                 dev_err(&pdev->dev, "can't get the platform data\n");
 498                 return -EINVAL;
 499         }
 500
 501         master = spi_alloc_master(&pdev->dev, sizeof(struct spi_imx_data));
 502         if (!master)
 503                 return -ENOMEM;
 504
 505         platform_set_drvdata(pdev, master);
 506
 507         master->bus_num = pdev->id;
 508         master->num_chipselect = mxc_platform_info->num_chipselect;
 509
 510         spi_imx = spi_master_get_devdata(master);
 511         spi_imx->bitbang.master = spi_master_get(master);
 512         spi_imx->chipselect = mxc_platform_info->chipselect;
 513
 514         for (i = 0; i < master->num_chipselect; i++) {
 515                 if (spi_imx->chipselect[i] < 0)
 516                         continue;
 517                 ret = gpio_request(spi_imx->chipselect[i], DRIVER_NAME);
 518                 if (ret) {
 519                         while (i > 0) {
 520                                 i--;
 521                                 if (spi_imx->chipselect[i] >= 0)
 522                                         gpio_free(spi_imx->chipselect[i]);
 523                         }
 524                         dev_err(&pdev->dev, "can't get cs gpios\n");
 525                         goto out_master_put;
 526                 }
 527         }
 528
 529         spi_imx->bitbang.chipselect = spi_imx_chipselect;
 530         spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
 531         spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
 532         spi_imx->bitbang.master->setup = spi_imx_setup;
 533         spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
 534         spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 535
 536         init_completion(&spi_imx->xfer_done);
 537
 538         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 539         if (!res) {
 540                 dev_err(&pdev->dev, "can't get platform resource\n");
 541                 ret = -ENOMEM;
 542                 goto out_gpio_free;
 543         }
 544
 545         if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
 546                 dev_err(&pdev->dev, "request_mem_region failed\n");
 547                 ret = -EBUSY;
 548                 goto out_gpio_free;
 549         }
 550
 551         spi_imx->base = ioremap(res->start, resource_size(res));
 552         if (!spi_imx->base) {
 553                 ret = -EINVAL;
 554                 goto out_release_mem;
 555         }
 556
 557         spi_imx->irq = platform_get_irq(pdev, 0);
 558         if (spi_imx->irq <= 0) {
 559                 ret = -EINVAL;
 560                 goto out_iounmap;
 561         }
 562
 563         ret = request_irq(spi_imx->irq, spi_imx_isr, 0, DRIVER_NAME, spi_imx);
 564         if (ret) {
 565                 dev_err(&pdev->dev, "can't get irq%d: %d\n", spi_imx->irq, ret);
 566                 goto out_iounmap;
 567         }
 568
 569         if (cpu_is_mx25() || cpu_is_mx31() || cpu_is_mx35()) {
 570                 spi_imx->intctrl = mx31_intctrl;
 571                 spi_imx->config = mx31_config;
 572                 spi_imx->trigger = mx31_trigger;
 573                 spi_imx->rx_available = mx31_rx_available;
 574         } else  if (cpu_is_mx27() || cpu_is_mx21()) {
 575                 spi_imx->intctrl = mx27_intctrl;
 576                 spi_imx->config = mx27_config;
 577                 spi_imx->trigger = mx27_trigger;
 578                 spi_imx->rx_available = mx27_rx_available;
 579         } else if (cpu_is_mx1()) {
 580                 spi_imx->intctrl = mx1_intctrl;
 581                 spi_imx->config = mx1_config;
 582                 spi_imx->trigger = mx1_trigger;
 583                 spi_imx->rx_available = mx1_rx_available;
 584         } else
 585                 BUG();
 586
 587         spi_imx->clk = clk_get(&pdev->dev, NULL);
 588         if (IS_ERR(spi_imx->clk)) {
 589                 dev_err(&pdev->dev, "unable to get clock\n");
 590                 ret = PTR_ERR(spi_imx->clk);
 591                 goto out_free_irq;
 592         }
 593
 594         clk_enable(spi_imx->clk);
 595         spi_imx->spi_clk = clk_get_rate(spi_imx->clk);
 596
 597         if (cpu_is_mx1() || cpu_is_mx21() || cpu_is_mx27())
 598                 writel(1, spi_imx->base + MXC_RESET);
 599
 600         /* drain receive buffer */
 601         if (cpu_is_mx25() || cpu_is_mx31() || cpu_is_mx35())
 602                 while (readl(spi_imx->base + MX3_CSPISTAT) & MX3_CSPISTAT_RR)
 603                         readl(spi_imx->base + MXC_CSPIRXDATA);
 604
 605         spi_imx->intctrl(spi_imx, 0);
 606
 607         ret = spi_bitbang_start(&spi_imx->bitbang);
 608         if (ret) {
 609                 dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
 610                 goto out_clk_put;
 611         }
 612
 613         dev_info(&pdev->dev, "probed\n");
 614
 615         return ret;
 616
 617 out_clk_put:
 618         clk_disable(spi_imx->clk);
 619         clk_put(spi_imx->clk);
 620 out_free_irq:
 621         free_irq(spi_imx->irq, spi_imx);
 622 out_iounmap:
 623         iounmap(spi_imx->base);
 624 out_release_mem:
 625         release_mem_region(res->start, resource_size(res));
 626 out_gpio_free:
 627         for (i = 0; i < master->num_chipselect; i++)
 628                 if (spi_imx->chipselect[i] >= 0)
 629                         gpio_free(spi_imx->chipselect[i]);
 630 out_master_put:
 631         spi_master_put(master);
 632         kfree(master);
 633         platform_set_drvdata(pdev, NULL);
 634         return ret;
 635 }
 636
 637 static int __devexit spi_imx_remove(struct platform_device *pdev)
 638 {
 639         struct spi_master *master = platform_get_drvdata(pdev);
 640         struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 641         struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
 642         int i;
 643
 644         spi_bitbang_stop(&spi_imx->bitbang);
 645
 646         writel(0, spi_imx->base + MXC_CSPICTRL);
 647         clk_disable(spi_imx->clk);
 648         clk_put(spi_imx->clk);
 649         free_irq(spi_imx->irq, spi_imx);
 650         iounmap(spi_imx->base);
 651
 652         for (i = 0; i < master->num_chipselect; i++)
 653                 if (spi_imx->chipselect[i] >= 0)
 654                         gpio_free(spi_imx->chipselect[i]);
 655
 656         spi_master_put(master);
 657
 658         release_mem_region(res->start, resource_size(res));
 659
 660         platform_set_drvdata(pdev, NULL);
 661
 662         return 0;
 663 }
 664
 665 static struct platform_driver spi_imx_driver = {
 666         .driver = {
 667                    .name = DRIVER_NAME,
 668                    .owner = THIS_MODULE,
 669                    },
 670         .probe = spi_imx_probe,
 671         .remove = __devexit_p(spi_imx_remove),
 672 };
 673
 674 static int __init spi_imx_init(void)
 675 {
 676         return platform_driver_register(&spi_imx_driver);
 677 }
 678
 679 static void __exit spi_imx_exit(void)
 680 {
 681         platform_driver_unregister(&spi_imx_driver);
 682 }
 683
 684 module_init(spi_imx_init);
 685 module_exit(spi_imx_exit);
 686
 687 MODULE_DESCRIPTION("SPI Master Controller driver");
 688 MODULE_AUTHOR("Sascha Hauer, Pengutronix");
 689 MODULE_LICENSE("GPL");