drivers/spi/omap2_mcspi.c

   1 /*
   2  * OMAP2 McSPI controller driver
   3  *
   4  * Copyright (C) 2005, 2006 Nokia Corporation
   5  * Author:      Samuel Ortiz <samuel.ortiz@nokia.com> and
   6  *              Juha Yrjölä <juha.yrjola@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  *
  22  */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/init.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/module.h>
  28 #include <linux/device.h>
  29 #include <linux/delay.h>
  30 #include <linux/dma-mapping.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/err.h>
  33 #include <linux/clk.h>
  34 #include <linux/io.h>
  35
  36 #include <linux/spi/spi.h>
  37
  38 #include <mach/dma.h>
  39 #include <mach/clock.h>
  40
  41
  42 #define OMAP2_MCSPI_MAX_FREQ            48000000
  43
  44 #define OMAP2_MCSPI_REVISION            0x00
  45 #define OMAP2_MCSPI_SYSCONFIG           0x10
  46 #define OMAP2_MCSPI_SYSSTATUS           0x14
  47 #define OMAP2_MCSPI_IRQSTATUS           0x18
  48 #define OMAP2_MCSPI_IRQENABLE           0x1c
  49 #define OMAP2_MCSPI_WAKEUPENABLE        0x20
  50 #define OMAP2_MCSPI_SYST                0x24
  51 #define OMAP2_MCSPI_MODULCTRL           0x28
  52
  53 /* per-channel banks, 0x14 bytes each, first is: */
  54 #define OMAP2_MCSPI_CHCONF0             0x2c
  55 #define OMAP2_MCSPI_CHSTAT0             0x30
  56 #define OMAP2_MCSPI_CHCTRL0             0x34
  57 #define OMAP2_MCSPI_TX0                 0x38
  58 #define OMAP2_MCSPI_RX0                 0x3c
  59
  60 /* per-register bitmasks: */
  61
  62 #define OMAP2_MCSPI_SYSCONFIG_AUTOIDLE  (1 << 0)
  63 #define OMAP2_MCSPI_SYSCONFIG_SOFTRESET (1 << 1)
  64
  65 #define OMAP2_MCSPI_SYSSTATUS_RESETDONE (1 << 0)
  66
  67 #define OMAP2_MCSPI_MODULCTRL_SINGLE    (1 << 0)
  68 #define OMAP2_MCSPI_MODULCTRL_MS        (1 << 2)
  69 #define OMAP2_MCSPI_MODULCTRL_STEST     (1 << 3)
  70
  71 #define OMAP2_MCSPI_CHCONF_PHA          (1 << 0)
  72 #define OMAP2_MCSPI_CHCONF_POL          (1 << 1)
  73 #define OMAP2_MCSPI_CHCONF_CLKD_MASK    (0x0f << 2)
  74 #define OMAP2_MCSPI_CHCONF_EPOL         (1 << 6)
  75 #define OMAP2_MCSPI_CHCONF_WL_MASK      (0x1f << 7)
  76 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY  (0x01 << 12)
  77 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY  (0x02 << 12)
  78 #define OMAP2_MCSPI_CHCONF_TRM_MASK     (0x03 << 12)
  79 #define OMAP2_MCSPI_CHCONF_DMAW         (1 << 14)
  80 #define OMAP2_MCSPI_CHCONF_DMAR         (1 << 15)
  81 #define OMAP2_MCSPI_CHCONF_DPE0         (1 << 16)
  82 #define OMAP2_MCSPI_CHCONF_DPE1         (1 << 17)
  83 #define OMAP2_MCSPI_CHCONF_IS           (1 << 18)
  84 #define OMAP2_MCSPI_CHCONF_TURBO        (1 << 19)
  85 #define OMAP2_MCSPI_CHCONF_FORCE        (1 << 20)
  86
  87 #define OMAP2_MCSPI_CHSTAT_RXS          (1 << 0)
  88 #define OMAP2_MCSPI_CHSTAT_TXS          (1 << 1)
  89 #define OMAP2_MCSPI_CHSTAT_EOT          (1 << 2)
  90
  91 #define OMAP2_MCSPI_CHCTRL_EN           (1 << 0)
  92
  93
  94 /* We have 2 DMA channels per CS, one for RX and one for TX */
  95 struct omap2_mcspi_dma {
  96         int dma_tx_channel;
  97         int dma_rx_channel;
  98
  99         int dma_tx_sync_dev;
 100         int dma_rx_sync_dev;
 101
 102         struct completion dma_tx_completion;
 103         struct completion dma_rx_completion;
 104 };
 105
 106 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
 107  * cache operations; better heuristics consider wordsize and bitrate.
 108  */
 109 #define DMA_MIN_BYTES                   8
 110
 111
 112 struct omap2_mcspi {
 113         struct work_struct      work;
 114         /* lock protects queue and registers */
 115         spinlock_t              lock;
 116         struct list_head        msg_queue;
 117         struct spi_master       *master;
 118         struct clk              *ick;
 119         struct clk              *fck;
 120         /* Virtual base address of the controller */
 121         void __iomem            *base;
 122         unsigned long           phys;
 123         /* SPI1 has 4 channels, while SPI2 has 2 */
 124         struct omap2_mcspi_dma  *dma_channels;
 125 };
 126
 127 struct omap2_mcspi_cs {
 128         void __iomem            *base;
 129         unsigned long           phys;
 130         int                     word_len;
 131 };
 132
 133 static struct workqueue_struct *omap2_mcspi_wq;
 134
 135 #define MOD_REG_BIT(val, mask, set) do { \
 136         if (set) \
 137                 val |= mask; \
 138         else \
 139                 val &= ~mask; \
 140 } while (0)
 141
 142 static inline void mcspi_write_reg(struct spi_master *master,
 143                 int idx, u32 val)
 144 {
 145         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
 146
 147         __raw_writel(val, mcspi->base + idx);
 148 }
 149
 150 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
 151 {
 152         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
 153
 154         return __raw_readl(mcspi->base + idx);
 155 }
 156
 157 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
 158                 int idx, u32 val)
 159 {
 160         struct omap2_mcspi_cs   *cs = spi->controller_state;
 161
 162         __raw_writel(val, cs->base +  idx);
 163 }
 164
 165 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
 166 {
 167         struct omap2_mcspi_cs   *cs = spi->controller_state;
 168
 169         return __raw_readl(cs->base + idx);
 170 }
 171
 172 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
 173                 int is_read, int enable)
 174 {
 175         u32 l, rw;
 176
 177         l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 178
 179         if (is_read) /* 1 is read, 0 write */
 180                 rw = OMAP2_MCSPI_CHCONF_DMAR;
 181         else
 182                 rw = OMAP2_MCSPI_CHCONF_DMAW;
 183
 184         MOD_REG_BIT(l, rw, enable);
 185         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
 186 }
 187
 188 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
 189 {
 190         u32 l;
 191
 192         l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
 193         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
 194 }
 195
 196 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
 197 {
 198         u32 l;
 199
 200         l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 201         MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
 202         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
 203 }
 204
 205 static void omap2_mcspi_set_master_mode(struct spi_master *master)
 206 {
 207         u32 l;
 208
 209         /* setup when switching from (reset default) slave mode
 210          * to single-channel master mode
 211          */
 212         l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
 213         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_STEST, 0);
 214         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0);
 215         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);
 216         mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
 217 }
 218
 219 static unsigned
 220 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
 221 {
 222         struct omap2_mcspi      *mcspi;
 223         struct omap2_mcspi_cs   *cs = spi->controller_state;
 224         struct omap2_mcspi_dma  *mcspi_dma;
 225         unsigned int            count, c;
 226         unsigned long           base, tx_reg, rx_reg;
 227         int                     word_len, data_type, element_count;
 228         u8                      * rx;
 229         const u8                * tx;
 230
 231         mcspi = spi_master_get_devdata(spi->master);
 232         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 233
 234         count = xfer->len;
 235         c = count;
 236         word_len = cs->word_len;
 237
 238         base = cs->phys;
 239         tx_reg = base + OMAP2_MCSPI_TX0;
 240         rx_reg = base + OMAP2_MCSPI_RX0;
 241         rx = xfer->rx_buf;
 242         tx = xfer->tx_buf;
 243
 244         if (word_len <= 8) {
 245                 data_type = OMAP_DMA_DATA_TYPE_S8;
 246                 element_count = count;
 247         } else if (word_len <= 16) {
 248                 data_type = OMAP_DMA_DATA_TYPE_S16;
 249                 element_count = count >> 1;
 250         } else /* word_len <= 32 */ {
 251                 data_type = OMAP_DMA_DATA_TYPE_S32;
 252                 element_count = count >> 2;
 253         }
 254
 255         if (tx != NULL) {
 256                 omap_set_dma_transfer_params(mcspi_dma->dma_tx_channel,
 257                                 data_type, element_count, 1,
 258                                 OMAP_DMA_SYNC_ELEMENT,
 259                                 mcspi_dma->dma_tx_sync_dev, 0);
 260
 261                 omap_set_dma_dest_params(mcspi_dma->dma_tx_channel, 0,
 262                                 OMAP_DMA_AMODE_CONSTANT,
 263                                 tx_reg, 0, 0);
 264
 265                 omap_set_dma_src_params(mcspi_dma->dma_tx_channel, 0,
 266                                 OMAP_DMA_AMODE_POST_INC,
 267                                 xfer->tx_dma, 0, 0);
 268         }
 269
 270         if (rx != NULL) {
 271                 omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel,
 272                                 data_type, element_count, 1,
 273                                 OMAP_DMA_SYNC_ELEMENT,
 274                                 mcspi_dma->dma_rx_sync_dev, 1);
 275
 276                 omap_set_dma_src_params(mcspi_dma->dma_rx_channel, 0,
 277                                 OMAP_DMA_AMODE_CONSTANT,
 278                                 rx_reg, 0, 0);
 279
 280                 omap_set_dma_dest_params(mcspi_dma->dma_rx_channel, 0,
 281                                 OMAP_DMA_AMODE_POST_INC,
 282                                 xfer->rx_dma, 0, 0);
 283         }
 284
 285         if (tx != NULL) {
 286                 omap_start_dma(mcspi_dma->dma_tx_channel);
 287                 omap2_mcspi_set_dma_req(spi, 0, 1);
 288         }
 289
 290         if (rx != NULL) {
 291                 omap_start_dma(mcspi_dma->dma_rx_channel);
 292                 omap2_mcspi_set_dma_req(spi, 1, 1);
 293         }
 294
 295         if (tx != NULL) {
 296                 wait_for_completion(&mcspi_dma->dma_tx_completion);
 297                 dma_unmap_single(NULL, xfer->tx_dma, count, DMA_TO_DEVICE);
 298         }
 299
 300         if (rx != NULL) {
 301                 wait_for_completion(&mcspi_dma->dma_rx_completion);
 302                 dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE);
 303         }
 304         return count;
 305 }
 306
 307 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
 308 {
 309         unsigned long timeout;
 310
 311         timeout = jiffies + msecs_to_jiffies(1000);
 312         while (!(__raw_readl(reg) & bit)) {
 313                 if (time_after(jiffies, timeout))
 314                         return -1;
 315                 cpu_relax();
 316         }
 317         return 0;
 318 }
 319
 320 static unsigned
 321 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
 322 {
 323         struct omap2_mcspi      *mcspi;
 324         struct omap2_mcspi_cs   *cs = spi->controller_state;
 325         unsigned int            count, c;
 326         u32                     l;
 327         void __iomem            *base = cs->base;
 328         void __iomem            *tx_reg;
 329         void __iomem            *rx_reg;
 330         void __iomem            *chstat_reg;
 331         int                     word_len;
 332
 333         mcspi = spi_master_get_devdata(spi->master);
 334         count = xfer->len;
 335         c = count;
 336         word_len = cs->word_len;
 337
 338         l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 339         l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
 340
 341         /* We store the pre-calculated register addresses on stack to speed
 342          * up the transfer loop. */
 343         tx_reg          = base + OMAP2_MCSPI_TX0;
 344         rx_reg          = base + OMAP2_MCSPI_RX0;
 345         chstat_reg      = base + OMAP2_MCSPI_CHSTAT0;
 346
 347         if (word_len <= 8) {
 348                 u8              *rx;
 349                 const u8        *tx;
 350
 351                 rx = xfer->rx_buf;
 352                 tx = xfer->tx_buf;
 353
 354                 do {
 355                         c -= 1;
 356                         if (tx != NULL) {
 357                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 358                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 359                                         dev_err(&spi->dev, "TXS timed out\n");
 360                                         goto out;
 361                                 }
 362 #ifdef VERBOSE
 363                                 dev_dbg(&spi->dev, "write-%d %02x\n",
 364                                                 word_len, *tx);
 365 #endif
 366                                 __raw_writel(*tx++, tx_reg);
 367                         }
 368                         if (rx != NULL) {
 369                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 370                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 371                                         dev_err(&spi->dev, "RXS timed out\n");
 372                                         goto out;
 373                                 }
 374                                 /* prevent last RX_ONLY read from triggering
 375                                  * more word i/o: switch to rx+tx
 376                                  */
 377                                 if (c == 0 && tx == NULL)
 378                                         mcspi_write_cs_reg(spi,
 379                                                         OMAP2_MCSPI_CHCONF0, l);
 380                                 *rx++ = __raw_readl(rx_reg);
 381 #ifdef VERBOSE
 382                                 dev_dbg(&spi->dev, "read-%d %02x\n",
 383                                                 word_len, *(rx - 1));
 384 #endif
 385                         }
 386                 } while (c);
 387         } else if (word_len <= 16) {
 388                 u16             *rx;
 389                 const u16       *tx;
 390
 391                 rx = xfer->rx_buf;
 392                 tx = xfer->tx_buf;
 393                 do {
 394                         c -= 2;
 395                         if (tx != NULL) {
 396                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 397                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 398                                         dev_err(&spi->dev, "TXS timed out\n");
 399                                         goto out;
 400                                 }
 401 #ifdef VERBOSE
 402                                 dev_dbg(&spi->dev, "write-%d %04x\n",
 403                                                 word_len, *tx);
 404 #endif
 405                                 __raw_writel(*tx++, tx_reg);
 406                         }
 407                         if (rx != NULL) {
 408                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 409                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 410                                         dev_err(&spi->dev, "RXS timed out\n");
 411                                         goto out;
 412                                 }
 413                                 /* prevent last RX_ONLY read from triggering
 414                                  * more word i/o: switch to rx+tx
 415                                  */
 416                                 if (c == 0 && tx == NULL)
 417                                         mcspi_write_cs_reg(spi,
 418                                                         OMAP2_MCSPI_CHCONF0, l);
 419                                 *rx++ = __raw_readl(rx_reg);
 420 #ifdef VERBOSE
 421                                 dev_dbg(&spi->dev, "read-%d %04x\n",
 422                                                 word_len, *(rx - 1));
 423 #endif
 424                         }
 425                 } while (c);
 426         } else if (word_len <= 32) {
 427                 u32             *rx;
 428                 const u32       *tx;
 429
 430                 rx = xfer->rx_buf;
 431                 tx = xfer->tx_buf;
 432                 do {
 433                         c -= 4;
 434                         if (tx != NULL) {
 435                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 436                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 437                                         dev_err(&spi->dev, "TXS timed out\n");
 438                                         goto out;
 439                                 }
 440 #ifdef VERBOSE
 441                                 dev_dbg(&spi->dev, "write-%d %04x\n",
 442                                                 word_len, *tx);
 443 #endif
 444                                 __raw_writel(*tx++, tx_reg);
 445                         }
 446                         if (rx != NULL) {
 447                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 448                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 449                                         dev_err(&spi->dev, "RXS timed out\n");
 450                                         goto out;
 451                                 }
 452                                 /* prevent last RX_ONLY read from triggering
 453                                  * more word i/o: switch to rx+tx
 454                                  */
 455                                 if (c == 0 && tx == NULL)
 456                                         mcspi_write_cs_reg(spi,
 457                                                         OMAP2_MCSPI_CHCONF0, l);
 458                                 *rx++ = __raw_readl(rx_reg);
 459 #ifdef VERBOSE
 460                                 dev_dbg(&spi->dev, "read-%d %04x\n",
 461                                                 word_len, *(rx - 1));
 462 #endif
 463                         }
 464                 } while (c);
 465         }
 466
 467         /* for TX_ONLY mode, be sure all words have shifted out */
 468         if (xfer->rx_buf == NULL) {
 469                 if (mcspi_wait_for_reg_bit(chstat_reg,
 470                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 471                         dev_err(&spi->dev, "TXS timed out\n");
 472                 } else if (mcspi_wait_for_reg_bit(chstat_reg,
 473                                 OMAP2_MCSPI_CHSTAT_EOT) < 0)
 474                         dev_err(&spi->dev, "EOT timed out\n");
 475         }
 476 out:
 477         return count - c;
 478 }
 479
 480 /* called only when no transfer is active to this device */
 481 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 482                 struct spi_transfer *t)
 483 {
 484         struct omap2_mcspi_cs *cs = spi->controller_state;
 485         struct omap2_mcspi *mcspi;
 486         u32 l = 0, div = 0;
 487         u8 word_len = spi->bits_per_word;
 488
 489         mcspi = spi_master_get_devdata(spi->master);
 490
 491         if (t != NULL && t->bits_per_word)
 492                 word_len = t->bits_per_word;
 493
 494         cs->word_len = word_len;
 495
 496         if (spi->max_speed_hz) {
 497                 while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div))
 498                                         > spi->max_speed_hz)
 499                         div++;
 500         } else
 501                 div = 15;
 502
 503         l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 504
 505         /* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
 506          * REVISIT: this controller could support SPI_3WIRE mode.
 507          */
 508         l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1);
 509         l |= OMAP2_MCSPI_CHCONF_DPE0;
 510
 511         /* wordlength */
 512         l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
 513         l |= (word_len - 1) << 7;
 514
 515         /* set chipselect polarity; manage with FORCE */
 516         if (!(spi->mode & SPI_CS_HIGH))
 517                 l |= OMAP2_MCSPI_CHCONF_EPOL;   /* active-low; normal */
 518         else
 519                 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
 520
 521         /* set clock divisor */
 522         l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
 523         l |= div << 2;
 524
 525         /* set SPI mode 0..3 */
 526         if (spi->mode & SPI_CPOL)
 527                 l |= OMAP2_MCSPI_CHCONF_POL;
 528         else
 529                 l &= ~OMAP2_MCSPI_CHCONF_POL;
 530         if (spi->mode & SPI_CPHA)
 531                 l |= OMAP2_MCSPI_CHCONF_PHA;
 532         else
 533                 l &= ~OMAP2_MCSPI_CHCONF_PHA;
 534
 535         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
 536
 537         dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
 538                         OMAP2_MCSPI_MAX_FREQ / (1 << div),
 539                         (spi->mode & SPI_CPHA) ? "trailing" : "leading",
 540                         (spi->mode & SPI_CPOL) ? "inverted" : "normal");
 541
 542         return 0;
 543 }
 544
 545 static void omap2_mcspi_dma_rx_callback(int lch, u16 ch_status, void *data)
 546 {
 547         struct spi_device       *spi = data;
 548         struct omap2_mcspi      *mcspi;
 549         struct omap2_mcspi_dma  *mcspi_dma;
 550
 551         mcspi = spi_master_get_devdata(spi->master);
 552         mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
 553
 554         complete(&mcspi_dma->dma_rx_completion);
 555
 556         /* We must disable the DMA RX request */
 557         omap2_mcspi_set_dma_req(spi, 1, 0);
 558 }
 559
 560 static void omap2_mcspi_dma_tx_callback(int lch, u16 ch_status, void *data)
 561 {
 562         struct spi_device       *spi = data;
 563         struct omap2_mcspi      *mcspi;
 564         struct omap2_mcspi_dma  *mcspi_dma;
 565
 566         mcspi = spi_master_get_devdata(spi->master);
 567         mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
 568
 569         complete(&mcspi_dma->dma_tx_completion);
 570
 571         /* We must disable the DMA TX request */
 572         omap2_mcspi_set_dma_req(spi, 0, 0);
 573 }
 574
 575 static int omap2_mcspi_request_dma(struct spi_device *spi)
 576 {
 577         struct spi_master       *master = spi->master;
 578         struct omap2_mcspi      *mcspi;
 579         struct omap2_mcspi_dma  *mcspi_dma;
 580
 581         mcspi = spi_master_get_devdata(master);
 582         mcspi_dma = mcspi->dma_channels + spi->chip_select;
 583
 584         if (omap_request_dma(mcspi_dma->dma_rx_sync_dev, "McSPI RX",
 585                         omap2_mcspi_dma_rx_callback, spi,
 586                         &mcspi_dma->dma_rx_channel)) {
 587                 dev_err(&spi->dev, "no RX DMA channel for McSPI\n");
 588                 return -EAGAIN;
 589         }
 590
 591         if (omap_request_dma(mcspi_dma->dma_tx_sync_dev, "McSPI TX",
 592                         omap2_mcspi_dma_tx_callback, spi,
 593                         &mcspi_dma->dma_tx_channel)) {
 594                 omap_free_dma(mcspi_dma->dma_rx_channel);
 595                 mcspi_dma->dma_rx_channel = -1;
 596                 dev_err(&spi->dev, "no TX DMA channel for McSPI\n");
 597                 return -EAGAIN;
 598         }
 599
 600         init_completion(&mcspi_dma->dma_rx_completion);
 601         init_completion(&mcspi_dma->dma_tx_completion);
 602
 603         return 0;
 604 }
 605
 606 /* the spi->mode bits understood by this driver: */
 607 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
 608
 609 static int omap2_mcspi_setup(struct spi_device *spi)
 610 {
 611         int                     ret;
 612         struct omap2_mcspi      *mcspi;
 613         struct omap2_mcspi_dma  *mcspi_dma;
 614         struct omap2_mcspi_cs   *cs = spi->controller_state;
 615
 616         if (spi->mode & ~MODEBITS) {
 617                 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
 618                         spi->mode & ~MODEBITS);
 619                 return -EINVAL;
 620         }
 621
 622         if (spi->bits_per_word == 0)
 623                 spi->bits_per_word = 8;
 624         else if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
 625                 dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
 626                         spi->bits_per_word);
 627                 return -EINVAL;
 628         }
 629
 630         mcspi = spi_master_get_devdata(spi->master);
 631         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 632
 633         if (!cs) {
 634                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
 635                 if (!cs)
 636                         return -ENOMEM;
 637                 cs->base = mcspi->base + spi->chip_select * 0x14;
 638                 cs->phys = mcspi->phys + spi->chip_select * 0x14;
 639                 spi->controller_state = cs;
 640         }
 641
 642         if (mcspi_dma->dma_rx_channel == -1
 643                         || mcspi_dma->dma_tx_channel == -1) {
 644                 ret = omap2_mcspi_request_dma(spi);
 645                 if (ret < 0)
 646                         return ret;
 647         }
 648
 649         clk_enable(mcspi->ick);
 650         clk_enable(mcspi->fck);
 651         ret = omap2_mcspi_setup_transfer(spi, NULL);
 652         clk_disable(mcspi->fck);
 653         clk_disable(mcspi->ick);
 654
 655         return ret;
 656 }
 657
 658 static void omap2_mcspi_cleanup(struct spi_device *spi)
 659 {
 660         struct omap2_mcspi      *mcspi;
 661         struct omap2_mcspi_dma  *mcspi_dma;
 662
 663         mcspi = spi_master_get_devdata(spi->master);
 664         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 665
 666         kfree(spi->controller_state);
 667
 668         if (mcspi_dma->dma_rx_channel != -1) {
 669                 omap_free_dma(mcspi_dma->dma_rx_channel);
 670                 mcspi_dma->dma_rx_channel = -1;
 671         }
 672         if (mcspi_dma->dma_tx_channel != -1) {
 673                 omap_free_dma(mcspi_dma->dma_tx_channel);
 674                 mcspi_dma->dma_tx_channel = -1;
 675         }
 676 }
 677
 678 static void omap2_mcspi_work(struct work_struct *work)
 679 {
 680         struct omap2_mcspi      *mcspi;
 681
 682         mcspi = container_of(work, struct omap2_mcspi, work);
 683         spin_lock_irq(&mcspi->lock);
 684
 685         clk_enable(mcspi->ick);
 686         clk_enable(mcspi->fck);
 687
 688         /* We only enable one channel at a time -- the one whose message is
 689          * at the head of the queue -- although this controller would gladly
 690          * arbitrate among multiple channels.  This corresponds to "single
 691          * channel" master mode.  As a side effect, we need to manage the
 692          * chipselect with the FORCE bit ... CS != channel enable.
 693          */
 694         while (!list_empty(&mcspi->msg_queue)) {
 695                 struct spi_message              *m;
 696                 struct spi_device               *spi;
 697                 struct spi_transfer             *t = NULL;
 698                 int                             cs_active = 0;
 699                 struct omap2_mcspi_cs           *cs;
 700                 int                             par_override = 0;
 701                 int                             status = 0;
 702                 u32                             chconf;
 703
 704                 m = container_of(mcspi->msg_queue.next, struct spi_message,
 705                                  queue);
 706
 707                 list_del_init(&m->queue);
 708                 spin_unlock_irq(&mcspi->lock);
 709
 710                 spi = m->spi;
 711                 cs = spi->controller_state;
 712
 713                 omap2_mcspi_set_enable(spi, 1);
 714                 list_for_each_entry(t, &m->transfers, transfer_list) {
 715                         if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
 716                                 status = -EINVAL;
 717                                 break;
 718                         }
 719                         if (par_override || t->speed_hz || t->bits_per_word) {
 720                                 par_override = 1;
 721                                 status = omap2_mcspi_setup_transfer(spi, t);
 722                                 if (status < 0)
 723                                         break;
 724                                 if (!t->speed_hz && !t->bits_per_word)
 725                                         par_override = 0;
 726                         }
 727
 728                         if (!cs_active) {
 729                                 omap2_mcspi_force_cs(spi, 1);
 730                                 cs_active = 1;
 731                         }
 732
 733                         chconf = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 734                         chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
 735                         if (t->tx_buf == NULL)
 736                                 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
 737                         else if (t->rx_buf == NULL)
 738                                 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
 739                         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, chconf);
 740
 741                         if (t->len) {
 742                                 unsigned        count;
 743
 744                                 /* RX_ONLY mode needs dummy data in TX reg */
 745                                 if (t->tx_buf == NULL)
 746                                         __raw_writel(0, cs->base
 747                                                         + OMAP2_MCSPI_TX0);
 748
 749                                 if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)
 750                                         count = omap2_mcspi_txrx_dma(spi, t);
 751                                 else
 752                                         count = omap2_mcspi_txrx_pio(spi, t);
 753                                 m->actual_length += count;
 754
 755                                 if (count != t->len) {
 756                                         status = -EIO;
 757                                         break;
 758                                 }
 759                         }
 760
 761                         if (t->delay_usecs)
 762                                 udelay(t->delay_usecs);
 763
 764                         /* ignore the "leave it on after last xfer" hint */
 765                         if (t->cs_change) {
 766                                 omap2_mcspi_force_cs(spi, 0);
 767                                 cs_active = 0;
 768                         }
 769                 }
 770
 771                 /* Restore defaults if they were overriden */
 772                 if (par_override) {
 773                         par_override = 0;
 774                         status = omap2_mcspi_setup_transfer(spi, NULL);
 775                 }
 776
 777                 if (cs_active)
 778                         omap2_mcspi_force_cs(spi, 0);
 779
 780                 omap2_mcspi_set_enable(spi, 0);
 781
 782                 m->status = status;
 783                 m->complete(m->context);
 784
 785                 spin_lock_irq(&mcspi->lock);
 786         }
 787
 788         clk_disable(mcspi->fck);
 789         clk_disable(mcspi->ick);
 790
 791         spin_unlock_irq(&mcspi->lock);
 792 }
 793
 794 static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
 795 {
 796         struct omap2_mcspi      *mcspi;
 797         unsigned long           flags;
 798         struct spi_transfer     *t;
 799
 800         m->actual_length = 0;
 801         m->status = 0;
 802
 803         /* reject invalid messages and transfers */
 804         if (list_empty(&m->transfers) || !m->complete)
 805                 return -EINVAL;
 806         list_for_each_entry(t, &m->transfers, transfer_list) {
 807                 const void      *tx_buf = t->tx_buf;
 808                 void            *rx_buf = t->rx_buf;
 809                 unsigned        len = t->len;
 810
 811                 if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
 812                                 || (len && !(rx_buf || tx_buf))
 813                                 || (t->bits_per_word &&
 814                                         (  t->bits_per_word < 4
 815                                         || t->bits_per_word > 32))) {
 816                         dev_dbg(&spi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
 817                                         t->speed_hz,
 818                                         len,
 819                                         tx_buf ? "tx" : "",
 820                                         rx_buf ? "rx" : "",
 821                                         t->bits_per_word);
 822                         return -EINVAL;
 823                 }
 824                 if (t->speed_hz && t->speed_hz < OMAP2_MCSPI_MAX_FREQ/(1<<16)) {
 825                         dev_dbg(&spi->dev, "%d Hz max exceeds %d\n",
 826                                         t->speed_hz,
 827                                         OMAP2_MCSPI_MAX_FREQ/(1<<16));
 828                         return -EINVAL;
 829                 }
 830
 831                 if (m->is_dma_mapped || len < DMA_MIN_BYTES)
 832                         continue;
 833
 834                 /* Do DMA mapping "early" for better error reporting and
 835                  * dcache use.  Note that if dma_unmap_single() ever starts
 836                  * to do real work on ARM, we'd need to clean up mappings
 837                  * for previous transfers on *ALL* exits of this loop...
 838                  */
 839                 if (tx_buf != NULL) {
 840                         t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf,
 841                                         len, DMA_TO_DEVICE);
 842                         if (dma_mapping_error(&spi->dev, t->tx_dma)) {
 843                                 dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
 844                                                 'T', len);
 845                                 return -EINVAL;
 846                         }
 847                 }
 848                 if (rx_buf != NULL) {
 849                         t->rx_dma = dma_map_single(&spi->dev, rx_buf, t->len,
 850                                         DMA_FROM_DEVICE);
 851                         if (dma_mapping_error(&spi->dev, t->rx_dma)) {
 852                                 dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
 853                                                 'R', len);
 854                                 if (tx_buf != NULL)
 855                                         dma_unmap_single(NULL, t->tx_dma,
 856                                                         len, DMA_TO_DEVICE);
 857                                 return -EINVAL;
 858                         }
 859                 }
 860         }
 861
 862         mcspi = spi_master_get_devdata(spi->master);
 863
 864         spin_lock_irqsave(&mcspi->lock, flags);
 865         list_add_tail(&m->queue, &mcspi->msg_queue);
 866         queue_work(omap2_mcspi_wq, &mcspi->work);
 867         spin_unlock_irqrestore(&mcspi->lock, flags);
 868
 869         return 0;
 870 }
 871
 872 static int __init omap2_mcspi_reset(struct omap2_mcspi *mcspi)
 873 {
 874         struct spi_master       *master = mcspi->master;
 875         u32                     tmp;
 876
 877         clk_enable(mcspi->ick);
 878         clk_enable(mcspi->fck);
 879
 880         mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
 881                         OMAP2_MCSPI_SYSCONFIG_SOFTRESET);
 882         do {
 883                 tmp = mcspi_read_reg(master, OMAP2_MCSPI_SYSSTATUS);
 884         } while (!(tmp & OMAP2_MCSPI_SYSSTATUS_RESETDONE));
 885
 886         mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
 887                         /* (3 << 8) | (2 << 3) | */
 888                         OMAP2_MCSPI_SYSCONFIG_AUTOIDLE);
 889
 890         omap2_mcspi_set_master_mode(master);
 891
 892         clk_disable(mcspi->fck);
 893         clk_disable(mcspi->ick);
 894         return 0;
 895 }
 896
 897 static u8 __initdata spi1_rxdma_id [] = {
 898         OMAP24XX_DMA_SPI1_RX0,
 899         OMAP24XX_DMA_SPI1_RX1,
 900         OMAP24XX_DMA_SPI1_RX2,
 901         OMAP24XX_DMA_SPI1_RX3,
 902 };
 903
 904 static u8 __initdata spi1_txdma_id [] = {
 905         OMAP24XX_DMA_SPI1_TX0,
 906         OMAP24XX_DMA_SPI1_TX1,
 907         OMAP24XX_DMA_SPI1_TX2,
 908         OMAP24XX_DMA_SPI1_TX3,
 909 };
 910
 911 static u8 __initdata spi2_rxdma_id[] = {
 912         OMAP24XX_DMA_SPI2_RX0,
 913         OMAP24XX_DMA_SPI2_RX1,
 914 };
 915
 916 static u8 __initdata spi2_txdma_id[] = {
 917         OMAP24XX_DMA_SPI2_TX0,
 918         OMAP24XX_DMA_SPI2_TX1,
 919 };
 920
 921 #if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP34XX)
 922 static u8 __initdata spi3_rxdma_id[] = {
 923         OMAP24XX_DMA_SPI3_RX0,
 924         OMAP24XX_DMA_SPI3_RX1,
 925 };
 926
 927 static u8 __initdata spi3_txdma_id[] = {
 928         OMAP24XX_DMA_SPI3_TX0,
 929         OMAP24XX_DMA_SPI3_TX1,
 930 };
 931 #endif
 932
 933 #ifdef CONFIG_ARCH_OMAP3
 934 static u8 __initdata spi4_rxdma_id[] = {
 935         OMAP34XX_DMA_SPI4_RX0,
 936 };
 937
 938 static u8 __initdata spi4_txdma_id[] = {
 939         OMAP34XX_DMA_SPI4_TX0,
 940 };
 941 #endif
 942
 943 static int __init omap2_mcspi_probe(struct platform_device *pdev)
 944 {
 945         struct spi_master       *master;
 946         struct omap2_mcspi      *mcspi;
 947         struct resource         *r;
 948         int                     status = 0, i;
 949         const u8                *rxdma_id, *txdma_id;
 950         unsigned                num_chipselect;
 951
 952         switch (pdev->id) {
 953         case 1:
 954                 rxdma_id = spi1_rxdma_id;
 955                 txdma_id = spi1_txdma_id;
 956                 num_chipselect = 4;
 957                 break;
 958         case 2:
 959                 rxdma_id = spi2_rxdma_id;
 960                 txdma_id = spi2_txdma_id;
 961                 num_chipselect = 2;
 962                 break;
 963 #if defined(CONFIG_ARCH_OMAP2430) || defined(CONFIG_ARCH_OMAP3)
 964         case 3:
 965                 rxdma_id = spi3_rxdma_id;
 966                 txdma_id = spi3_txdma_id;
 967                 num_chipselect = 2;
 968                 break;
 969 #endif
 970 #ifdef CONFIG_ARCH_OMAP3
 971         case 4:
 972                 rxdma_id = spi4_rxdma_id;
 973                 txdma_id = spi4_txdma_id;
 974                 num_chipselect = 1;
 975                 break;
 976 #endif
 977         default:
 978                 return -EINVAL;
 979         }
 980
 981         master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
 982         if (master == NULL) {
 983                 dev_dbg(&pdev->dev, "master allocation failed\n");
 984                 return -ENOMEM;
 985         }
 986
 987         if (pdev->id != -1)
 988                 master->bus_num = pdev->id;
 989
 990         master->setup = omap2_mcspi_setup;
 991         master->transfer = omap2_mcspi_transfer;
 992         master->cleanup = omap2_mcspi_cleanup;
 993         master->num_chipselect = num_chipselect;
 994
 995         dev_set_drvdata(&pdev->dev, master);
 996
 997         mcspi = spi_master_get_devdata(master);
 998         mcspi->master = master;
 999
1000         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1001         if (r == NULL) {
1002                 status = -ENODEV;
1003                 goto err1;
1004         }
1005         if (!request_mem_region(r->start, (r->end - r->start) + 1,
1006                         pdev->dev.bus_id)) {
1007                 status = -EBUSY;
1008                 goto err1;
1009         }
1010
1011         mcspi->phys = r->start;
1012         mcspi->base = ioremap(r->start, r->end - r->start + 1);
1013         if (!mcspi->base) {
1014                 dev_dbg(&pdev->dev, "can't ioremap MCSPI\n");
1015                 status = -ENOMEM;
1016                 goto err1aa;
1017         }
1018
1019         INIT_WORK(&mcspi->work, omap2_mcspi_work);
1020
1021         spin_lock_init(&mcspi->lock);
1022         INIT_LIST_HEAD(&mcspi->msg_queue);
1023
1024         mcspi->ick = clk_get(&pdev->dev, "mcspi_ick");
1025         if (IS_ERR(mcspi->ick)) {
1026                 dev_dbg(&pdev->dev, "can't get mcspi_ick\n");
1027                 status = PTR_ERR(mcspi->ick);
1028                 goto err1a;
1029         }
1030         mcspi->fck = clk_get(&pdev->dev, "mcspi_fck");
1031         if (IS_ERR(mcspi->fck)) {
1032                 dev_dbg(&pdev->dev, "can't get mcspi_fck\n");
1033                 status = PTR_ERR(mcspi->fck);
1034                 goto err2;
1035         }
1036
1037         mcspi->dma_channels = kcalloc(master->num_chipselect,
1038                         sizeof(struct omap2_mcspi_dma),
1039                         GFP_KERNEL);
1040
1041         if (mcspi->dma_channels == NULL)
1042                 goto err3;
1043
1044         for (i = 0; i < num_chipselect; i++) {
1045                 mcspi->dma_channels[i].dma_rx_channel = -1;
1046                 mcspi->dma_channels[i].dma_rx_sync_dev = rxdma_id[i];
1047                 mcspi->dma_channels[i].dma_tx_channel = -1;
1048                 mcspi->dma_channels[i].dma_tx_sync_dev = txdma_id[i];
1049         }
1050
1051         if (omap2_mcspi_reset(mcspi) < 0)
1052                 goto err4;
1053
1054         status = spi_register_master(master);
1055         if (status < 0)
1056                 goto err4;
1057
1058         return status;
1059
1060 err4:
1061         kfree(mcspi->dma_channels);
1062 err3:
1063         clk_put(mcspi->fck);
1064 err2:
1065         clk_put(mcspi->ick);
1066 err1a:
1067         iounmap(mcspi->base);
1068 err1aa:
1069         release_mem_region(r->start, (r->end - r->start) + 1);
1070 err1:
1071         spi_master_put(master);
1072         return status;
1073 }
1074
1075 static int __exit omap2_mcspi_remove(struct platform_device *pdev)
1076 {
1077         struct spi_master       *master;
1078         struct omap2_mcspi      *mcspi;
1079         struct omap2_mcspi_dma  *dma_channels;
1080         struct resource         *r;
1081         void __iomem *base;
1082
1083         master = dev_get_drvdata(&pdev->dev);
1084         mcspi = spi_master_get_devdata(master);
1085         dma_channels = mcspi->dma_channels;
1086
1087         clk_put(mcspi->fck);
1088         clk_put(mcspi->ick);
1089
1090         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1091         release_mem_region(r->start, (r->end - r->start) + 1);
1092
1093         base = mcspi->base;
1094         spi_unregister_master(master);
1095         iounmap(base);
1096         kfree(dma_channels);
1097
1098         return 0;
1099 }
1100
1101 /* work with hotplug and coldplug */
1102 MODULE_ALIAS("platform:omap2_mcspi");
1103
1104 static struct platform_driver omap2_mcspi_driver = {
1105         .driver = {
1106                 .name =         "omap2_mcspi",
1107                 .owner =        THIS_MODULE,
1108         },
1109         .remove =       __exit_p(omap2_mcspi_remove),
1110 };
1111
1112
1113 static int __init omap2_mcspi_init(void)
1114 {
1115         omap2_mcspi_wq = create_singlethread_workqueue(
1116                                 omap2_mcspi_driver.driver.name);
1117         if (omap2_mcspi_wq == NULL)
1118                 return -1;
1119         return platform_driver_probe(&omap2_mcspi_driver, omap2_mcspi_probe);
1120 }
1121 subsys_initcall(omap2_mcspi_init);
1122
1123 static void __exit omap2_mcspi_exit(void)
1124 {
1125         platform_driver_unregister(&omap2_mcspi_driver);
1126
1127         destroy_workqueue(omap2_mcspi_wq);
1128 }
1129 module_exit(omap2_mcspi_exit);
1130
1131 MODULE_LICENSE("GPL");