drivers/spi/spi_s3c24xx.c

   1 /* linux/drivers/spi/spi_s3c24xx.c
   2  *
   3  * Copyright (c) 2006 Ben Dooks
   4  * Copyright 2006-2009 Simtec Electronics
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11 */
  12
  13 #include <linux/init.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/workqueue.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/delay.h>
  18 #include <linux/errno.h>
  19 #include <linux/err.h>
  20 #include <linux/clk.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/gpio.h>
  23 #include <linux/io.h>
  24
  25 #include <linux/spi/spi.h>
  26 #include <linux/spi/spi_bitbang.h>
  27
  28 #include <plat/regs-spi.h>
  29 #include <mach/spi.h>
  30
  31 #include <plat/fiq.h>
  32 #include <asm/fiq.h>
  33
  34 #include "spi_s3c24xx_fiq.h"
  35
  36 /**
  37  * s3c24xx_spi_devstate - per device data
  38  * @hz: Last frequency calculated for @sppre field.
  39  * @mode: Last mode setting for the @spcon field.
  40  * @spcon: Value to write to the SPCON register.
  41  * @sppre: Value to write to the SPPRE register.
  42  */
  43 struct s3c24xx_spi_devstate {
  44         unsigned int    hz;
  45         unsigned int    mode;
  46         u8              spcon;
  47         u8              sppre;
  48 };
  49
  50 enum spi_fiq_mode {
  51         FIQ_MODE_NONE   = 0,
  52         FIQ_MODE_TX     = 1,
  53         FIQ_MODE_RX     = 2,
  54         FIQ_MODE_TXRX   = 3,
  55 };
  56
  57 struct s3c24xx_spi {
  58         /* bitbang has to be first */
  59         struct spi_bitbang       bitbang;
  60         struct completion        done;
  61
  62         void __iomem            *regs;
  63         int                      irq;
  64         int                      len;
  65         int                      count;
  66
  67         struct fiq_handler       fiq_handler;
  68         enum spi_fiq_mode        fiq_mode;
  69         unsigned char            fiq_inuse;
  70         unsigned char            fiq_claimed;
  71
  72         void                    (*set_cs)(struct s3c2410_spi_info *spi,
  73                                           int cs, int pol);
  74
  75         /* data buffers */
  76         const unsigned char     *tx;
  77         unsigned char           *rx;
  78
  79         struct clk              *clk;
  80         struct resource         *ioarea;
  81         struct spi_master       *master;
  82         struct spi_device       *curdev;
  83         struct device           *dev;
  84         struct s3c2410_spi_info *pdata;
  85 };
  86
  87
  88 #define SPCON_DEFAULT (S3C2410_SPCON_MSTR | S3C2410_SPCON_SMOD_INT)
  89 #define SPPIN_DEFAULT (S3C2410_SPPIN_KEEP)
  90
  91 static inline struct s3c24xx_spi *to_hw(struct spi_device *sdev)
  92 {
  93         return spi_master_get_devdata(sdev->master);
  94 }
  95
  96 static void s3c24xx_spi_gpiocs(struct s3c2410_spi_info *spi, int cs, int pol)
  97 {
  98         gpio_set_value(spi->pin_cs, pol);
  99 }
 100
 101 static void s3c24xx_spi_chipsel(struct spi_device *spi, int value)
 102 {
 103         struct s3c24xx_spi_devstate *cs = spi->controller_state;
 104         struct s3c24xx_spi *hw = to_hw(spi);
 105         unsigned int cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
 106
 107         /* change the chipselect state and the state of the spi engine clock */
 108
 109         switch (value) {
 110         case BITBANG_CS_INACTIVE:
 111                 hw->set_cs(hw->pdata, spi->chip_select, cspol^1);
 112                 writeb(cs->spcon, hw->regs + S3C2410_SPCON);
 113                 break;
 114
 115         case BITBANG_CS_ACTIVE:
 116                 writeb(cs->spcon | S3C2410_SPCON_ENSCK,
 117                        hw->regs + S3C2410_SPCON);
 118                 hw->set_cs(hw->pdata, spi->chip_select, cspol);
 119                 break;
 120         }
 121 }
 122
 123 static int s3c24xx_spi_update_state(struct spi_device *spi,
 124                                     struct spi_transfer *t)
 125 {
 126         struct s3c24xx_spi *hw = to_hw(spi);
 127         struct s3c24xx_spi_devstate *cs = spi->controller_state;
 128         unsigned int bpw;
 129         unsigned int hz;
 130         unsigned int div;
 131         unsigned long clk;
 132
 133         bpw = t ? t->bits_per_word : spi->bits_per_word;
 134         hz  = t ? t->speed_hz : spi->max_speed_hz;
 135
 136         if (!bpw)
 137                 bpw = 8;
 138
 139         if (!hz)
 140                 hz = spi->max_speed_hz;
 141
 142         if (bpw != 8) {
 143                 dev_err(&spi->dev, "invalid bits-per-word (%d)\n", bpw);
 144                 return -EINVAL;
 145         }
 146
 147         if (spi->mode != cs->mode) {
 148                 u8 spcon = SPCON_DEFAULT | S3C2410_SPCON_ENSCK;
 149
 150                 if (spi->mode & SPI_CPHA)
 151                         spcon |= S3C2410_SPCON_CPHA_FMTB;
 152
 153                 if (spi->mode & SPI_CPOL)
 154                         spcon |= S3C2410_SPCON_CPOL_HIGH;
 155
 156                 cs->mode = spi->mode;
 157                 cs->spcon = spcon;
 158         }
 159
 160         if (cs->hz != hz) {
 161                 clk = clk_get_rate(hw->clk);
 162                 div = DIV_ROUND_UP(clk, hz * 2) - 1;
 163
 164                 if (div > 255)
 165                         div = 255;
 166
 167                 dev_dbg(&spi->dev, "pre-scaler=%d (wanted %d, got %ld)\n",
 168                         div, hz, clk / (2 * (div + 1)));
 169
 170                 cs->hz = hz;
 171                 cs->sppre = div;
 172         }
 173
 174         return 0;
 175 }
 176
 177 static int s3c24xx_spi_setupxfer(struct spi_device *spi,
 178                                  struct spi_transfer *t)
 179 {
 180         struct s3c24xx_spi_devstate *cs = spi->controller_state;
 181         struct s3c24xx_spi *hw = to_hw(spi);
 182         int ret;
 183
 184         ret = s3c24xx_spi_update_state(spi, t);
 185         if (!ret)
 186                 writeb(cs->sppre, hw->regs + S3C2410_SPPRE);
 187
 188         return ret;
 189 }
 190
 191 static int s3c24xx_spi_setup(struct spi_device *spi)
 192 {
 193         struct s3c24xx_spi_devstate *cs = spi->controller_state;
 194         struct s3c24xx_spi *hw = to_hw(spi);
 195         int ret;
 196
 197         /* allocate settings on the first call */
 198         if (!cs) {
 199                 cs = kzalloc(sizeof(struct s3c24xx_spi_devstate), GFP_KERNEL);
 200                 if (!cs) {
 201                         dev_err(&spi->dev, "no memory for controller state\n");
 202                         return -ENOMEM;
 203                 }
 204
 205                 cs->spcon = SPCON_DEFAULT;
 206                 cs->hz = -1;
 207                 spi->controller_state = cs;
 208         }
 209
 210         /* initialise the state from the device */
 211         ret = s3c24xx_spi_update_state(spi, NULL);
 212         if (ret)
 213                 return ret;
 214
 215         spin_lock(&hw->bitbang.lock);
 216         if (!hw->bitbang.busy) {
 217                 hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE);
 218                 /* need to ndelay for 0.5 clocktick ? */
 219         }
 220         spin_unlock(&hw->bitbang.lock);
 221
 222         return 0;
 223 }
 224
 225 static void s3c24xx_spi_cleanup(struct spi_device *spi)
 226 {
 227         kfree(spi->controller_state);
 228 }
 229
 230 static inline unsigned int hw_txbyte(struct s3c24xx_spi *hw, int count)
 231 {
 232         return hw->tx ? hw->tx[count] : 0;
 233 }
 234
 235 #ifdef CONFIG_SPI_S3C24XX_FIQ
 236 /* Support for FIQ based pseudo-DMA to improve the transfer speed.
 237  *
 238  * This code uses the assembly helper in spi_s3c24xx_spi.S which is
 239  * used by the FIQ core to move data between main memory and the peripheral
 240  * block. Since this is code running on the processor, there is no problem
 241  * with cache coherency of the buffers, so we can use any buffer we like.
 242  */
 243
 244 /**
 245  * struct spi_fiq_code - FIQ code and header
 246  * @length: The length of the code fragment, excluding this header.
 247  * @ack_offset: The offset from @data to the word to place the IRQ ACK bit at.
 248  * @data: The code itself to install as a FIQ handler.
 249  */
 250 struct spi_fiq_code {
 251         u32     length;
 252         u32     ack_offset;
 253         u8      data[0];
 254 };
 255
 256 extern struct spi_fiq_code s3c24xx_spi_fiq_txrx;
 257 extern struct spi_fiq_code s3c24xx_spi_fiq_tx;
 258 extern struct spi_fiq_code s3c24xx_spi_fiq_rx;
 259
 260 /**
 261  * ack_bit - turn IRQ into IRQ acknowledgement bit
 262  * @irq: The interrupt number
 263  *
 264  * Returns the bit to write to the interrupt acknowledge register.
 265  */
 266 static inline u32 ack_bit(unsigned int irq)
 267 {
 268         return 1 << (irq - IRQ_EINT0);
 269 }
 270
 271 /**
 272  * s3c24xx_spi_tryfiq - attempt to claim and setup FIQ for transfer
 273  * @hw: The hardware state.
 274  *
 275  * Claim the FIQ handler (only one can be active at any one time) and
 276  * then setup the correct transfer code for this transfer.
 277  *
 278  * This call updates all the necessary state information if sucessful,
 279  * so the caller does not need to do anything more than start the transfer
 280  * as normal, since the IRQ will have been re-routed to the FIQ handler.
 281 */
 282 void s3c24xx_spi_tryfiq(struct s3c24xx_spi *hw)
 283 {
 284         struct pt_regs regs;
 285         enum spi_fiq_mode mode;
 286         struct spi_fiq_code *code;
 287         int ret;
 288
 289         if (!hw->fiq_claimed) {
 290                 /* try and claim fiq if we haven't got it, and if not
 291                  * then return and simply use another transfer method */
 292
 293                 ret = claim_fiq(&hw->fiq_handler);
 294                 if (ret)
 295                         return;
 296         }
 297
 298         if (hw->tx && !hw->rx)
 299                 mode = FIQ_MODE_TX;
 300         else if (hw->rx && !hw->tx)
 301                 mode = FIQ_MODE_RX;
 302         else
 303                 mode = FIQ_MODE_TXRX;
 304
 305         regs.uregs[fiq_rspi] = (long)hw->regs;
 306         regs.uregs[fiq_rrx]  = (long)hw->rx;
 307         regs.uregs[fiq_rtx]  = (long)hw->tx + 1;
 308         regs.uregs[fiq_rcount] = hw->len - 1;
 309         regs.uregs[fiq_rirq] = (long)S3C24XX_VA_IRQ;
 310
 311         set_fiq_regs(&regs);
 312
 313         if (hw->fiq_mode != mode) {
 314                 u32 *ack_ptr;
 315
 316                 hw->fiq_mode = mode;
 317
 318                 switch (mode) {
 319                 case FIQ_MODE_TX:
 320                         code = &s3c24xx_spi_fiq_tx;
 321                         break;
 322                 case FIQ_MODE_RX:
 323                         code = &s3c24xx_spi_fiq_rx;
 324                         break;
 325                 case FIQ_MODE_TXRX:
 326                         code = &s3c24xx_spi_fiq_txrx;
 327                         break;
 328                 default:
 329                         code = NULL;
 330                 }
 331
 332                 BUG_ON(!code);
 333
 334                 ack_ptr = (u32 *)&code->data[code->ack_offset];
 335                 *ack_ptr = ack_bit(hw->irq);
 336
 337                 set_fiq_handler(&code->data, code->length);
 338         }
 339
 340         s3c24xx_set_fiq(hw->irq, true);
 341
 342         hw->fiq_mode = mode;
 343         hw->fiq_inuse = 1;
 344 }
 345
 346 /**
 347  * s3c24xx_spi_fiqop - FIQ core code callback
 348  * @pw: Data registered with the handler
 349  * @release: Whether this is a release or a return.
 350  *
 351  * Called by the FIQ code when another module wants to use the FIQ, so
 352  * return whether we are currently using this or not and then update our
 353  * internal state.
 354  */
 355 static int s3c24xx_spi_fiqop(void *pw, int release)
 356 {
 357         struct s3c24xx_spi *hw = pw;
 358         int ret = 0;
 359
 360         if (release) {
 361                 if (hw->fiq_inuse)
 362                         ret = -EBUSY;
 363
 364                 /* note, we do not need to unroute the FIQ, as the FIQ
 365                  * vector code de-routes it to signal the end of transfer */
 366
 367                 hw->fiq_mode = FIQ_MODE_NONE;
 368                 hw->fiq_claimed = 0;
 369         } else {
 370                 hw->fiq_claimed = 1;
 371         }
 372
 373         return ret;
 374 }
 375
 376 /**
 377  * s3c24xx_spi_initfiq - setup the information for the FIQ core
 378  * @hw: The hardware state.
 379  *
 380  * Setup the fiq_handler block to pass to the FIQ core.
 381  */
 382 static inline void s3c24xx_spi_initfiq(struct s3c24xx_spi *hw)
 383 {
 384         hw->fiq_handler.dev_id = hw;
 385         hw->fiq_handler.name = dev_name(hw->dev);
 386         hw->fiq_handler.fiq_op = s3c24xx_spi_fiqop;
 387 }
 388
 389 /**
 390  * s3c24xx_spi_usefiq - return if we should be using FIQ.
 391  * @hw: The hardware state.
 392  *
 393  * Return true if the platform data specifies whether this channel is
 394  * allowed to use the FIQ.
 395  */
 396 static inline bool s3c24xx_spi_usefiq(struct s3c24xx_spi *hw)
 397 {
 398         return hw->pdata->use_fiq;
 399 }
 400
 401 /**
 402  * s3c24xx_spi_usingfiq - return if channel is using FIQ
 403  * @spi: The hardware state.
 404  *
 405  * Return whether the channel is currently using the FIQ (separate from
 406  * whether the FIQ is claimed).
 407  */
 408 static inline bool s3c24xx_spi_usingfiq(struct s3c24xx_spi *spi)
 409 {
 410         return spi->fiq_inuse;
 411 }
 412 #else
 413
 414 static inline void s3c24xx_spi_initfiq(struct s3c24xx_spi *s) { }
 415 static inline void s3c24xx_spi_tryfiq(struct s3c24xx_spi *s) { }
 416 static inline bool s3c24xx_spi_usefiq(struct s3c24xx_spi *s) { return false; }
 417 static inline bool s3c24xx_spi_usingfiq(struct s3c24xx_spi *s) { return false; }
 418
 419 #endif /* CONFIG_SPI_S3C24XX_FIQ */
 420
 421 static int s3c24xx_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
 422 {
 423         struct s3c24xx_spi *hw = to_hw(spi);
 424
 425         hw->tx = t->tx_buf;
 426         hw->rx = t->rx_buf;
 427         hw->len = t->len;
 428         hw->count = 0;
 429
 430         init_completion(&hw->done);
 431
 432         hw->fiq_inuse = 0;
 433         if (s3c24xx_spi_usefiq(hw) && t->len >= 3)
 434                 s3c24xx_spi_tryfiq(hw);
 435
 436         /* send the first byte */
 437         writeb(hw_txbyte(hw, 0), hw->regs + S3C2410_SPTDAT);
 438
 439         wait_for_completion(&hw->done);
 440         return hw->count;
 441 }
 442
 443 static irqreturn_t s3c24xx_spi_irq(int irq, void *dev)
 444 {
 445         struct s3c24xx_spi *hw = dev;
 446         unsigned int spsta = readb(hw->regs + S3C2410_SPSTA);
 447         unsigned int count = hw->count;
 448
 449         if (spsta & S3C2410_SPSTA_DCOL) {
 450                 dev_dbg(hw->dev, "data-collision\n");
 451                 complete(&hw->done);
 452                 goto irq_done;
 453         }
 454
 455         if (!(spsta & S3C2410_SPSTA_READY)) {
 456                 dev_dbg(hw->dev, "spi not ready for tx?\n");
 457                 complete(&hw->done);
 458                 goto irq_done;
 459         }
 460
 461         if (!s3c24xx_spi_usingfiq(hw)) {
 462                 hw->count++;
 463
 464                 if (hw->rx)
 465                         hw->rx[count] = readb(hw->regs + S3C2410_SPRDAT);
 466
 467                 count++;
 468
 469                 if (count < hw->len)
 470                         writeb(hw_txbyte(hw, count), hw->regs + S3C2410_SPTDAT);
 471                 else
 472                         complete(&hw->done);
 473         } else {
 474                 hw->count = hw->len;
 475                 hw->fiq_inuse = 0;
 476
 477                 if (hw->rx)
 478                         hw->rx[hw->len-1] = readb(hw->regs + S3C2410_SPRDAT);
 479
 480                 complete(&hw->done);
 481         }
 482
 483  irq_done:
 484         return IRQ_HANDLED;
 485 }
 486
 487 static void s3c24xx_spi_initialsetup(struct s3c24xx_spi *hw)
 488 {
 489         /* for the moment, permanently enable the clock */
 490
 491         clk_enable(hw->clk);
 492
 493         /* program defaults into the registers */
 494
 495         writeb(0xff, hw->regs + S3C2410_SPPRE);
 496         writeb(SPPIN_DEFAULT, hw->regs + S3C2410_SPPIN);
 497         writeb(SPCON_DEFAULT, hw->regs + S3C2410_SPCON);
 498
 499         if (hw->pdata) {
 500                 if (hw->set_cs == s3c24xx_spi_gpiocs)
 501                         gpio_direction_output(hw->pdata->pin_cs, 1);
 502
 503                 if (hw->pdata->gpio_setup)
 504                         hw->pdata->gpio_setup(hw->pdata, 1);
 505         }
 506 }
 507
 508 static int __init s3c24xx_spi_probe(struct platform_device *pdev)
 509 {
 510         struct s3c2410_spi_info *pdata;
 511         struct s3c24xx_spi *hw;
 512         struct spi_master *master;
 513         struct resource *res;
 514         int err = 0;
 515
 516         master = spi_alloc_master(&pdev->dev, sizeof(struct s3c24xx_spi));
 517         if (master == NULL) {
 518                 dev_err(&pdev->dev, "No memory for spi_master\n");
 519                 err = -ENOMEM;
 520                 goto err_nomem;
 521         }
 522
 523         hw = spi_master_get_devdata(master);
 524         memset(hw, 0, sizeof(struct s3c24xx_spi));
 525
 526         hw->master = spi_master_get(master);
 527         hw->pdata = pdata = pdev->dev.platform_data;
 528         hw->dev = &pdev->dev;
 529
 530         if (pdata == NULL) {
 531                 dev_err(&pdev->dev, "No platform data supplied\n");
 532                 err = -ENOENT;
 533                 goto err_no_pdata;
 534         }
 535
 536         platform_set_drvdata(pdev, hw);
 537         init_completion(&hw->done);
 538
 539         /* initialise fiq handler */
 540
 541         s3c24xx_spi_initfiq(hw);
 542
 543         /* setup the master state. */
 544
 545         /* the spi->mode bits understood by this driver: */
 546         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
 547
 548         master->num_chipselect = hw->pdata->num_cs;
 549         master->bus_num = pdata->bus_num;
 550
 551         /* setup the state for the bitbang driver */
 552
 553         hw->bitbang.master         = hw->master;
 554         hw->bitbang.setup_transfer = s3c24xx_spi_setupxfer;
 555         hw->bitbang.chipselect     = s3c24xx_spi_chipsel;
 556         hw->bitbang.txrx_bufs      = s3c24xx_spi_txrx;
 557
 558         hw->master->setup  = s3c24xx_spi_setup;
 559         hw->master->cleanup = s3c24xx_spi_cleanup;
 560
 561         dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang);
 562
 563         /* find and map our resources */
 564
 565         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 566         if (res == NULL) {
 567                 dev_err(&pdev->dev, "Cannot get IORESOURCE_MEM\n");
 568                 err = -ENOENT;
 569                 goto err_no_iores;
 570         }
 571
 572         hw->ioarea = request_mem_region(res->start, resource_size(res),
 573                                         pdev->name);
 574
 575         if (hw->ioarea == NULL) {
 576                 dev_err(&pdev->dev, "Cannot reserve region\n");
 577                 err = -ENXIO;
 578                 goto err_no_iores;
 579         }
 580
 581         hw->regs = ioremap(res->start, resource_size(res));
 582         if (hw->regs == NULL) {
 583                 dev_err(&pdev->dev, "Cannot map IO\n");
 584                 err = -ENXIO;
 585                 goto err_no_iomap;
 586         }
 587
 588         hw->irq = platform_get_irq(pdev, 0);
 589         if (hw->irq < 0) {
 590                 dev_err(&pdev->dev, "No IRQ specified\n");
 591                 err = -ENOENT;
 592                 goto err_no_irq;
 593         }
 594
 595         err = request_irq(hw->irq, s3c24xx_spi_irq, 0, pdev->name, hw);
 596         if (err) {
 597                 dev_err(&pdev->dev, "Cannot claim IRQ\n");
 598                 goto err_no_irq;
 599         }
 600
 601         hw->clk = clk_get(&pdev->dev, "spi");
 602         if (IS_ERR(hw->clk)) {
 603                 dev_err(&pdev->dev, "No clock for device\n");
 604                 err = PTR_ERR(hw->clk);
 605                 goto err_no_clk;
 606         }
 607
 608         /* setup any gpio we can */
 609
 610         if (!pdata->set_cs) {
 611                 if (pdata->pin_cs < 0) {
 612                         dev_err(&pdev->dev, "No chipselect pin\n");
 613                         goto err_register;
 614                 }
 615
 616                 err = gpio_request(pdata->pin_cs, dev_name(&pdev->dev));
 617                 if (err) {
 618                         dev_err(&pdev->dev, "Failed to get gpio for cs\n");
 619                         goto err_register;
 620                 }
 621
 622                 hw->set_cs = s3c24xx_spi_gpiocs;
 623                 gpio_direction_output(pdata->pin_cs, 1);
 624         } else
 625                 hw->set_cs = pdata->set_cs;
 626
 627         s3c24xx_spi_initialsetup(hw);
 628
 629         /* register our spi controller */
 630
 631         err = spi_bitbang_start(&hw->bitbang);
 632         if (err) {
 633                 dev_err(&pdev->dev, "Failed to register SPI master\n");
 634                 goto err_register;
 635         }
 636
 637         return 0;
 638
 639  err_register:
 640         if (hw->set_cs == s3c24xx_spi_gpiocs)
 641                 gpio_free(pdata->pin_cs);
 642
 643         clk_disable(hw->clk);
 644         clk_put(hw->clk);
 645
 646  err_no_clk:
 647         free_irq(hw->irq, hw);
 648
 649  err_no_irq:
 650         iounmap(hw->regs);
 651
 652  err_no_iomap:
 653         release_resource(hw->ioarea);
 654         kfree(hw->ioarea);
 655
 656  err_no_iores:
 657  err_no_pdata:
 658         spi_master_put(hw->master);
 659
 660  err_nomem:
 661         return err;
 662 }
 663
 664 static int __exit s3c24xx_spi_remove(struct platform_device *dev)
 665 {
 666         struct s3c24xx_spi *hw = platform_get_drvdata(dev);
 667
 668         platform_set_drvdata(dev, NULL);
 669
 670         spi_unregister_master(hw->master);
 671
 672         clk_disable(hw->clk);
 673         clk_put(hw->clk);
 674
 675         free_irq(hw->irq, hw);
 676         iounmap(hw->regs);
 677
 678         if (hw->set_cs == s3c24xx_spi_gpiocs)
 679                 gpio_free(hw->pdata->pin_cs);
 680
 681         release_resource(hw->ioarea);
 682         kfree(hw->ioarea);
 683
 684         spi_master_put(hw->master);
 685         return 0;
 686 }
 687
 688
 689 #ifdef CONFIG_PM
 690
 691 static int s3c24xx_spi_suspend(struct device *dev)
 692 {
 693         struct s3c24xx_spi *hw = platform_get_drvdata(to_platform_device(dev));
 694
 695         if (hw->pdata && hw->pdata->gpio_setup)
 696                 hw->pdata->gpio_setup(hw->pdata, 0);
 697
 698         clk_disable(hw->clk);
 699         return 0;
 700 }
 701
 702 static int s3c24xx_spi_resume(struct device *dev)
 703 {
 704         struct s3c24xx_spi *hw = platform_get_drvdata(to_platform_device(dev));
 705
 706         s3c24xx_spi_initialsetup(hw);
 707         return 0;
 708 }
 709
 710 static const struct dev_pm_ops s3c24xx_spi_pmops = {
 711         .suspend        = s3c24xx_spi_suspend,
 712         .resume         = s3c24xx_spi_resume,
 713 };
 714
 715 #define S3C24XX_SPI_PMOPS &s3c24xx_spi_pmops
 716 #else
 717 #define S3C24XX_SPI_PMOPS NULL
 718 #endif /* CONFIG_PM */
 719
 720 MODULE_ALIAS("platform:s3c2410-spi");
 721 static struct platform_driver s3c24xx_spi_driver = {
 722         .remove         = __exit_p(s3c24xx_spi_remove),
 723         .driver         = {
 724                 .name   = "s3c2410-spi",
 725                 .owner  = THIS_MODULE,
 726                 .pm     = S3C24XX_SPI_PMOPS,
 727         },
 728 };
 729
 730 static int __init s3c24xx_spi_init(void)
 731 {
 732         return platform_driver_probe(&s3c24xx_spi_driver, s3c24xx_spi_probe);
 733 }
 734
 735 static void __exit s3c24xx_spi_exit(void)
 736 {
 737         platform_driver_unregister(&s3c24xx_spi_driver);
 738 }
 739
 740 module_init(s3c24xx_spi_init);
 741 module_exit(s3c24xx_spi_exit);
 742
 743 MODULE_DESCRIPTION("S3C24XX SPI Driver");
 744 MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
 745 MODULE_LICENSE("GPL");