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 <asm/arch/dma.h>
  39 #include <asm/arch/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         /* SPI1 has 4 channels, while SPI2 has 2 */
 123         struct omap2_mcspi_dma  *dma_channels;
 124 };
 125
 126 struct omap2_mcspi_cs {
 127         void __iomem            *base;
 128         int                     word_len;
 129 };
 130
 131 static struct workqueue_struct *omap2_mcspi_wq;
 132
 133 #define MOD_REG_BIT(val, mask, set) do { \
 134         if (set) \
 135                 val |= mask; \
 136         else \
 137                 val &= ~mask; \
 138 } while (0)
 139
 140 static inline void mcspi_write_reg(struct spi_master *master,
 141                 int idx, u32 val)
 142 {
 143         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
 144
 145         __raw_writel(val, mcspi->base + idx);
 146 }
 147
 148 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
 149 {
 150         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
 151
 152         return __raw_readl(mcspi->base + idx);
 153 }
 154
 155 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
 156                 int idx, u32 val)
 157 {
 158         struct omap2_mcspi_cs   *cs = spi->controller_state;
 159
 160         __raw_writel(val, cs->base +  idx);
 161 }
 162
 163 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
 164 {
 165         struct omap2_mcspi_cs   *cs = spi->controller_state;
 166
 167         return __raw_readl(cs->base + idx);
 168 }
 169
 170 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
 171                 int is_read, int enable)
 172 {
 173         u32 l, rw;
 174
 175         l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 176
 177         if (is_read) /* 1 is read, 0 write */
 178                 rw = OMAP2_MCSPI_CHCONF_DMAR;
 179         else
 180                 rw = OMAP2_MCSPI_CHCONF_DMAW;
 181
 182         MOD_REG_BIT(l, rw, enable);
 183         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
 184 }
 185
 186 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
 187 {
 188         u32 l;
 189
 190         l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
 191         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
 192 }
 193
 194 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
 195 {
 196         u32 l;
 197
 198         l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 199         MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
 200         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
 201 }
 202
 203 static void omap2_mcspi_set_master_mode(struct spi_master *master)
 204 {
 205         u32 l;
 206
 207         /* setup when switching from (reset default) slave mode
 208          * to single-channel master mode
 209          */
 210         l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
 211         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_STEST, 0);
 212         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0);
 213         MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);
 214         mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
 215 }
 216
 217 static unsigned
 218 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
 219 {
 220         struct omap2_mcspi      *mcspi;
 221         struct omap2_mcspi_cs   *cs = spi->controller_state;
 222         struct omap2_mcspi_dma  *mcspi_dma;
 223         unsigned int            count, c;
 224         unsigned long           base, tx_reg, rx_reg;
 225         int                     word_len, data_type, element_count;
 226         u8                      * rx;
 227         const u8                * tx;
 228
 229         mcspi = spi_master_get_devdata(spi->master);
 230         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 231
 232         count = xfer->len;
 233         c = count;
 234         word_len = cs->word_len;
 235
 236         base = (unsigned long) io_v2p(cs->base);
 237         tx_reg = base + OMAP2_MCSPI_TX0;
 238         rx_reg = base + OMAP2_MCSPI_RX0;
 239         rx = xfer->rx_buf;
 240         tx = xfer->tx_buf;
 241
 242         if (word_len <= 8) {
 243                 data_type = OMAP_DMA_DATA_TYPE_S8;
 244                 element_count = count;
 245         } else if (word_len <= 16) {
 246                 data_type = OMAP_DMA_DATA_TYPE_S16;
 247                 element_count = count >> 1;
 248         } else /* word_len <= 32 */ {
 249                 data_type = OMAP_DMA_DATA_TYPE_S32;
 250                 element_count = count >> 2;
 251         }
 252
 253         if (tx != NULL) {
 254                 omap_set_dma_transfer_params(mcspi_dma->dma_tx_channel,
 255                                 data_type, element_count, 1,
 256                                 OMAP_DMA_SYNC_ELEMENT,
 257                                 mcspi_dma->dma_tx_sync_dev, 0);
 258
 259                 omap_set_dma_dest_params(mcspi_dma->dma_tx_channel, 0,
 260                                 OMAP_DMA_AMODE_CONSTANT,
 261                                 tx_reg, 0, 0);
 262
 263                 omap_set_dma_src_params(mcspi_dma->dma_tx_channel, 0,
 264                                 OMAP_DMA_AMODE_POST_INC,
 265                                 xfer->tx_dma, 0, 0);
 266         }
 267
 268         if (rx != NULL) {
 269                 omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel,
 270                                 data_type, element_count, 1,
 271                                 OMAP_DMA_SYNC_ELEMENT,
 272                                 mcspi_dma->dma_rx_sync_dev, 1);
 273
 274                 omap_set_dma_src_params(mcspi_dma->dma_rx_channel, 0,
 275                                 OMAP_DMA_AMODE_CONSTANT,
 276                                 rx_reg, 0, 0);
 277
 278                 omap_set_dma_dest_params(mcspi_dma->dma_rx_channel, 0,
 279                                 OMAP_DMA_AMODE_POST_INC,
 280                                 xfer->rx_dma, 0, 0);
 281         }
 282
 283         if (tx != NULL) {
 284                 omap_start_dma(mcspi_dma->dma_tx_channel);
 285                 omap2_mcspi_set_dma_req(spi, 0, 1);
 286         }
 287
 288         if (rx != NULL) {
 289                 omap_start_dma(mcspi_dma->dma_rx_channel);
 290                 omap2_mcspi_set_dma_req(spi, 1, 1);
 291         }
 292
 293         if (tx != NULL) {
 294                 wait_for_completion(&mcspi_dma->dma_tx_completion);
 295                 dma_unmap_single(NULL, xfer->tx_dma, count, DMA_TO_DEVICE);
 296         }
 297
 298         if (rx != NULL) {
 299                 wait_for_completion(&mcspi_dma->dma_rx_completion);
 300                 dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE);
 301         }
 302         return count;
 303 }
 304
 305 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
 306 {
 307         unsigned long timeout;
 308
 309         timeout = jiffies + msecs_to_jiffies(1000);
 310         while (!(__raw_readl(reg) & bit)) {
 311                 if (time_after(jiffies, timeout))
 312                         return -1;
 313                 cpu_relax();
 314         }
 315         return 0;
 316 }
 317
 318 static unsigned
 319 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
 320 {
 321         struct omap2_mcspi      *mcspi;
 322         struct omap2_mcspi_cs   *cs = spi->controller_state;
 323         unsigned int            count, c;
 324         u32                     l;
 325         void __iomem            *base = cs->base;
 326         void __iomem            *tx_reg;
 327         void __iomem            *rx_reg;
 328         void __iomem            *chstat_reg;
 329         int                     word_len;
 330
 331         mcspi = spi_master_get_devdata(spi->master);
 332         count = xfer->len;
 333         c = count;
 334         word_len = cs->word_len;
 335
 336         l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 337         l &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
 338
 339         /* We store the pre-calculated register addresses on stack to speed
 340          * up the transfer loop. */
 341         tx_reg          = base + OMAP2_MCSPI_TX0;
 342         rx_reg          = base + OMAP2_MCSPI_RX0;
 343         chstat_reg      = base + OMAP2_MCSPI_CHSTAT0;
 344
 345         if (word_len <= 8) {
 346                 u8              *rx;
 347                 const u8        *tx;
 348
 349                 rx = xfer->rx_buf;
 350                 tx = xfer->tx_buf;
 351
 352                 do {
 353                         if (tx != NULL) {
 354                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 355                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 356                                         dev_err(&spi->dev, "TXS timed out\n");
 357                                         goto out;
 358                                 }
 359 #ifdef VERBOSE
 360                                 dev_dbg(&spi->dev, "write-%d %02x\n",
 361                                                 word_len, *tx);
 362 #endif
 363                                 __raw_writel(*tx++, tx_reg);
 364                         }
 365                         if (rx != NULL) {
 366                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 367                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 368                                         dev_err(&spi->dev, "RXS timed out\n");
 369                                         goto out;
 370                                 }
 371                                 /* prevent last RX_ONLY read from triggering
 372                                  * more word i/o: switch to rx+tx
 373                                  */
 374                                 if (c == 0 && tx == NULL)
 375                                         mcspi_write_cs_reg(spi,
 376                                                         OMAP2_MCSPI_CHCONF0, l);
 377                                 *rx++ = __raw_readl(rx_reg);
 378 #ifdef VERBOSE
 379                                 dev_dbg(&spi->dev, "read-%d %02x\n",
 380                                                 word_len, *(rx - 1));
 381 #endif
 382                         }
 383                         c -= 1;
 384                 } while (c);
 385         } else if (word_len <= 16) {
 386                 u16             *rx;
 387                 const u16       *tx;
 388
 389                 rx = xfer->rx_buf;
 390                 tx = xfer->tx_buf;
 391                 do {
 392                         if (tx != NULL) {
 393                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 394                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 395                                         dev_err(&spi->dev, "TXS timed out\n");
 396                                         goto out;
 397                                 }
 398 #ifdef VERBOSE
 399                                 dev_dbg(&spi->dev, "write-%d %04x\n",
 400                                                 word_len, *tx);
 401 #endif
 402                                 __raw_writel(*tx++, tx_reg);
 403                         }
 404                         if (rx != NULL) {
 405                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 406                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 407                                         dev_err(&spi->dev, "RXS timed out\n");
 408                                         goto out;
 409                                 }
 410                                 /* prevent last RX_ONLY read from triggering
 411                                  * more word i/o: switch to rx+tx
 412                                  */
 413                                 if (c == 0 && tx == NULL)
 414                                         mcspi_write_cs_reg(spi,
 415                                                         OMAP2_MCSPI_CHCONF0, l);
 416                                 *rx++ = __raw_readl(rx_reg);
 417 #ifdef VERBOSE
 418                                 dev_dbg(&spi->dev, "read-%d %04x\n",
 419                                                 word_len, *(rx - 1));
 420 #endif
 421                         }
 422                         c -= 2;
 423                 } while (c);
 424         } else if (word_len <= 32) {
 425                 u32             *rx;
 426                 const u32       *tx;
 427
 428                 rx = xfer->rx_buf;
 429                 tx = xfer->tx_buf;
 430                 do {
 431                         if (tx != NULL) {
 432                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 433                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 434                                         dev_err(&spi->dev, "TXS timed out\n");
 435                                         goto out;
 436                                 }
 437 #ifdef VERBOSE
 438                                 dev_dbg(&spi->dev, "write-%d %04x\n",
 439                                                 word_len, *tx);
 440 #endif
 441                                 __raw_writel(*tx++, tx_reg);
 442                         }
 443                         if (rx != NULL) {
 444                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 445                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 446                                         dev_err(&spi->dev, "RXS timed out\n");
 447                                         goto out;
 448                                 }
 449                                 /* prevent last RX_ONLY read from triggering
 450                                  * more word i/o: switch to rx+tx
 451                                  */
 452                                 if (c == 0 && tx == NULL)
 453                                         mcspi_write_cs_reg(spi,
 454                                                         OMAP2_MCSPI_CHCONF0, l);
 455                                 *rx++ = __raw_readl(rx_reg);
 456 #ifdef VERBOSE
 457                                 dev_dbg(&spi->dev, "read-%d %04x\n",
 458                                                 word_len, *(rx - 1));
 459 #endif
 460                         }
 461                         c -= 4;
 462                 } while (c);
 463         }
 464
 465         /* for TX_ONLY mode, be sure all words have shifted out */
 466         if (xfer->rx_buf == NULL) {
 467                 if (mcspi_wait_for_reg_bit(chstat_reg,
 468                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 469                         dev_err(&spi->dev, "TXS timed out\n");
 470                 } else if (mcspi_wait_for_reg_bit(chstat_reg,
 471                                 OMAP2_MCSPI_CHSTAT_EOT) < 0)
 472                         dev_err(&spi->dev, "EOT timed out\n");
 473         }
 474 out:
 475         return count - c;
 476 }
 477
 478 /* called only when no transfer is active to this device */
 479 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 480                 struct spi_transfer *t)
 481 {
 482         struct omap2_mcspi_cs *cs = spi->controller_state;
 483         struct omap2_mcspi *mcspi;
 484         u32 l = 0, div = 0;
 485         u8 word_len = spi->bits_per_word;
 486
 487         mcspi = spi_master_get_devdata(spi->master);
 488
 489         if (t != NULL && t->bits_per_word)
 490                 word_len = t->bits_per_word;
 491
 492         cs->word_len = word_len;
 493
 494         if (spi->max_speed_hz) {
 495                 while (div <= 15 && (OMAP2_MCSPI_MAX_FREQ / (1 << div))
 496                                         > spi->max_speed_hz)
 497                         div++;
 498         } else
 499                 div = 15;
 500
 501         l = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 502
 503         /* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
 504          * REVISIT: this controller could support SPI_3WIRE mode.
 505          */
 506         l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1);
 507         l |= OMAP2_MCSPI_CHCONF_DPE0;
 508
 509         /* wordlength */
 510         l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
 511         l |= (word_len - 1) << 7;
 512
 513         /* set chipselect polarity; manage with FORCE */
 514         if (!(spi->mode & SPI_CS_HIGH))
 515                 l |= OMAP2_MCSPI_CHCONF_EPOL;   /* active-low; normal */
 516         else
 517                 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
 518
 519         /* set clock divisor */
 520         l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
 521         l |= div << 2;
 522
 523         /* set SPI mode 0..3 */
 524         if (spi->mode & SPI_CPOL)
 525                 l |= OMAP2_MCSPI_CHCONF_POL;
 526         else
 527                 l &= ~OMAP2_MCSPI_CHCONF_POL;
 528         if (spi->mode & SPI_CPHA)
 529                 l |= OMAP2_MCSPI_CHCONF_PHA;
 530         else
 531                 l &= ~OMAP2_MCSPI_CHCONF_PHA;
 532
 533         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, l);
 534
 535         dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
 536                         OMAP2_MCSPI_MAX_FREQ / (1 << div),
 537                         (spi->mode & SPI_CPHA) ? "trailing" : "leading",
 538                         (spi->mode & SPI_CPOL) ? "inverted" : "normal");
 539
 540         return 0;
 541 }
 542
 543 static void omap2_mcspi_dma_rx_callback(int lch, u16 ch_status, void *data)
 544 {
 545         struct spi_device       *spi = data;
 546         struct omap2_mcspi      *mcspi;
 547         struct omap2_mcspi_dma  *mcspi_dma;
 548
 549         mcspi = spi_master_get_devdata(spi->master);
 550         mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
 551
 552         complete(&mcspi_dma->dma_rx_completion);
 553
 554         /* We must disable the DMA RX request */
 555         omap2_mcspi_set_dma_req(spi, 1, 0);
 556 }
 557
 558 static void omap2_mcspi_dma_tx_callback(int lch, u16 ch_status, void *data)
 559 {
 560         struct spi_device       *spi = data;
 561         struct omap2_mcspi      *mcspi;
 562         struct omap2_mcspi_dma  *mcspi_dma;
 563
 564         mcspi = spi_master_get_devdata(spi->master);
 565         mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
 566
 567         complete(&mcspi_dma->dma_tx_completion);
 568
 569         /* We must disable the DMA TX request */
 570         omap2_mcspi_set_dma_req(spi, 0, 0);
 571 }
 572
 573 static int omap2_mcspi_request_dma(struct spi_device *spi)
 574 {
 575         struct spi_master       *master = spi->master;
 576         struct omap2_mcspi      *mcspi;
 577         struct omap2_mcspi_dma  *mcspi_dma;
 578
 579         mcspi = spi_master_get_devdata(master);
 580         mcspi_dma = mcspi->dma_channels + spi->chip_select;
 581
 582         if (omap_request_dma(mcspi_dma->dma_rx_sync_dev, "McSPI RX",
 583                         omap2_mcspi_dma_rx_callback, spi,
 584                         &mcspi_dma->dma_rx_channel)) {
 585                 dev_err(&spi->dev, "no RX DMA channel for McSPI\n");
 586                 return -EAGAIN;
 587         }
 588
 589         if (omap_request_dma(mcspi_dma->dma_tx_sync_dev, "McSPI TX",
 590                         omap2_mcspi_dma_tx_callback, spi,
 591                         &mcspi_dma->dma_tx_channel)) {
 592                 omap_free_dma(mcspi_dma->dma_rx_channel);
 593                 mcspi_dma->dma_rx_channel = -1;
 594                 dev_err(&spi->dev, "no TX DMA channel for McSPI\n");
 595                 return -EAGAIN;
 596         }
 597
 598         init_completion(&mcspi_dma->dma_rx_completion);
 599         init_completion(&mcspi_dma->dma_tx_completion);
 600
 601         return 0;
 602 }
 603
 604 /* the spi->mode bits understood by this driver: */
 605 #define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)
 606
 607 static int omap2_mcspi_setup(struct spi_device *spi)
 608 {
 609         int                     ret;
 610         struct omap2_mcspi      *mcspi;
 611         struct omap2_mcspi_dma  *mcspi_dma;
 612         struct omap2_mcspi_cs   *cs = spi->controller_state;
 613
 614         if (spi->mode & ~MODEBITS) {
 615                 dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
 616                         spi->mode & ~MODEBITS);
 617                 return -EINVAL;
 618         }
 619
 620         if (spi->bits_per_word == 0)
 621                 spi->bits_per_word = 8;
 622         else if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
 623                 dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
 624                         spi->bits_per_word);
 625                 return -EINVAL;
 626         }
 627
 628         mcspi = spi_master_get_devdata(spi->master);
 629         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 630
 631         if (!cs) {
 632                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
 633                 if (!cs)
 634                         return -ENOMEM;
 635                 cs->base = mcspi->base + spi->chip_select * 0x14;
 636                 spi->controller_state = cs;
 637         }
 638
 639         if (mcspi_dma->dma_rx_channel == -1
 640                         || mcspi_dma->dma_tx_channel == -1) {
 641                 ret = omap2_mcspi_request_dma(spi);
 642                 if (ret < 0)
 643                         return ret;
 644         }
 645
 646         clk_enable(mcspi->ick);
 647         clk_enable(mcspi->fck);
 648         ret =  omap2_mcspi_setup_transfer(spi, NULL);
 649         clk_disable(mcspi->fck);
 650         clk_disable(mcspi->ick);
 651
 652         return ret;
 653 }
 654
 655 static void omap2_mcspi_cleanup(struct spi_device *spi)
 656 {
 657         struct omap2_mcspi      *mcspi;
 658         struct omap2_mcspi_dma  *mcspi_dma;
 659
 660         mcspi = spi_master_get_devdata(spi->master);
 661         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 662
 663         kfree(spi->controller_state);
 664
 665         if (mcspi_dma->dma_rx_channel != -1) {
 666                 omap_free_dma(mcspi_dma->dma_rx_channel);
 667                 mcspi_dma->dma_rx_channel = -1;
 668         }
 669         if (mcspi_dma->dma_tx_channel != -1) {
 670                 omap_free_dma(mcspi_dma->dma_tx_channel);
 671                 mcspi_dma->dma_tx_channel = -1;
 672         }
 673 }
 674
 675 static void omap2_mcspi_work(struct work_struct *work)
 676 {
 677         struct omap2_mcspi      *mcspi;
 678
 679         mcspi = container_of(work, struct omap2_mcspi, work);
 680         spin_lock_irq(&mcspi->lock);
 681
 682         clk_enable(mcspi->ick);
 683         clk_enable(mcspi->fck);
 684
 685         /* We only enable one channel at a time -- the one whose message is
 686          * at the head of the queue -- although this controller would gladly
 687          * arbitrate among multiple channels.  This corresponds to "single
 688          * channel" master mode.  As a side effect, we need to manage the
 689          * chipselect with the FORCE bit ... CS != channel enable.
 690          */
 691         while (!list_empty(&mcspi->msg_queue)) {
 692                 struct spi_message              *m;
 693                 struct spi_device               *spi;
 694                 struct spi_transfer             *t = NULL;
 695                 int                             cs_active = 0;
 696                 struct omap2_mcspi_device_config *conf;
 697                 struct omap2_mcspi_cs           *cs;
 698                 int                             par_override = 0;
 699                 int                             status = 0;
 700                 u32                             chconf;
 701
 702                 m = container_of(mcspi->msg_queue.next, struct spi_message,
 703                                  queue);
 704
 705                 list_del_init(&m->queue);
 706                 spin_unlock_irq(&mcspi->lock);
 707
 708                 spi = m->spi;
 709                 conf = spi->controller_data;
 710                 cs = spi->controller_state;
 711
 712                 omap2_mcspi_set_enable(spi, 1);
 713                 list_for_each_entry(t, &m->transfers, transfer_list) {
 714                         if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
 715                                 status = -EINVAL;
 716                                 break;
 717                         }
 718                         if (par_override || t->speed_hz || t->bits_per_word) {
 719                                 par_override = 1;
 720                                 status = omap2_mcspi_setup_transfer(spi, t);
 721                                 if (status < 0)
 722                                         break;
 723                                 if (!t->speed_hz && !t->bits_per_word)
 724                                         par_override = 0;
 725                         }
 726
 727                         if (!cs_active) {
 728                                 omap2_mcspi_force_cs(spi, 1);
 729                                 cs_active = 1;
 730                         }
 731
 732                         chconf = mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 733                         chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
 734                         if (t->tx_buf == NULL)
 735                                 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
 736                         else if (t->rx_buf == NULL)
 737                                 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
 738                         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, chconf);
 739
 740                         if (t->len) {
 741                                 unsigned        count;
 742
 743                                 /* RX_ONLY mode needs dummy data in TX reg */
 744                                 if (t->tx_buf == NULL)
 745                                         __raw_writel(0, cs->base
 746                                                         + OMAP2_MCSPI_TX0);
 747
 748                                 if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)
 749                                         count = omap2_mcspi_txrx_dma(spi, t);
 750                                 else
 751                                         count = omap2_mcspi_txrx_pio(spi, t);
 752                                 m->actual_length += count;
 753
 754                                 if (count != t->len) {
 755                                         status = -EIO;
 756                                         break;
 757                                 }
 758                         }
 759
 760                         if (t->delay_usecs)
 761                                 udelay(t->delay_usecs);
 762
 763                         /* ignore the "leave it on after last xfer" hint */
 764                         if (t->cs_change) {
 765                                 omap2_mcspi_force_cs(spi, 0);
 766                                 cs_active = 0;
 767                         }
 768                 }
 769
 770                 /* Restore defaults if they were overriden */
 771                 if (par_override) {
 772                         par_override = 0;
 773                         status = omap2_mcspi_setup_transfer(spi, NULL);
 774                 }
 775
 776                 if (cs_active)
 777                         omap2_mcspi_force_cs(spi, 0);
 778
 779                 omap2_mcspi_set_enable(spi, 0);
 780
 781                 m->status = status;
 782                 m->complete(m->context);
 783
 784                 spin_lock_irq(&mcspi->lock);
 785         }
 786
 787         clk_disable(mcspi->fck);
 788         clk_disable(mcspi->ick);
 789
 790         spin_unlock_irq(&mcspi->lock);
 791 }
 792
 793 static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
 794 {
 795         struct omap2_mcspi      *mcspi;
 796         unsigned long           flags;
 797         struct spi_transfer     *t;
 798
 799         m->actual_length = 0;
 800         m->status = 0;
 801
 802         /* reject invalid messages and transfers */
 803         if (list_empty(&m->transfers) || !m->complete)
 804                 return -EINVAL;
 805         list_for_each_entry(t, &m->transfers, transfer_list) {
 806                 const void      *tx_buf = t->tx_buf;
 807                 void            *rx_buf = t->rx_buf;
 808                 unsigned        len = t->len;
 809
 810                 if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
 811                                 || (len && !(rx_buf || tx_buf))
 812                                 || (t->bits_per_word &&
 813                                         (  t->bits_per_word < 4
 814                                         || t->bits_per_word > 32))) {
 815                         dev_dbg(&spi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
 816                                         t->speed_hz,
 817                                         len,
 818                                         tx_buf ? "tx" : "",
 819                                         rx_buf ? "rx" : "",
 820                                         t->bits_per_word);
 821                         return -EINVAL;
 822                 }
 823                 if (t->speed_hz && t->speed_hz < OMAP2_MCSPI_MAX_FREQ/(1<<16)) {
 824                         dev_dbg(&spi->dev, "%d Hz max exceeds %d\n",
 825                                         t->speed_hz,
 826                                         OMAP2_MCSPI_MAX_FREQ/(1<<16));
 827                         return -EINVAL;
 828                 }
 829
 830                 if (m->is_dma_mapped || len < DMA_MIN_BYTES)
 831                         continue;
 832
 833                 /* Do DMA mapping "early" for better error reporting and
 834                  * dcache use.  Note that if dma_unmap_single() ever starts
 835                  * to do real work on ARM, we'd need to clean up mappings
 836                  * for previous transfers on *ALL* exits of this loop...
 837                  */
 838                 if (tx_buf != NULL) {
 839                         t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf,
 840                                         len, DMA_TO_DEVICE);
 841                         if (dma_mapping_error(t->tx_dma)) {
 842                                 dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
 843                                                 'T', len);
 844                                 return -EINVAL;
 845                         }
 846                 }
 847                 if (rx_buf != NULL) {
 848                         t->rx_dma = dma_map_single(&spi->dev, rx_buf, t->len,
 849                                         DMA_FROM_DEVICE);
 850                         if (dma_mapping_error(t->rx_dma)) {
 851                                 dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
 852                                                 'R', len);
 853                                 if (tx_buf != NULL)
 854                                         dma_unmap_single(NULL, t->tx_dma,
 855                                                         len, DMA_TO_DEVICE);
 856                                 return -EINVAL;
 857                         }
 858                 }
 859         }
 860
 861         mcspi = spi_master_get_devdata(spi->master);
 862
 863         spin_lock_irqsave(&mcspi->lock, flags);
 864         list_add_tail(&m->queue, &mcspi->msg_queue);
 865         queue_work(omap2_mcspi_wq, &mcspi->work);
 866         spin_unlock_irqrestore(&mcspi->lock, flags);
 867
 868         return 0;
 869 }
 870
 871 static int __init omap2_mcspi_reset(struct omap2_mcspi *mcspi)
 872 {
 873         struct spi_master       *master = mcspi->master;
 874         u32                     tmp;
 875
 876         clk_enable(mcspi->ick);
 877         clk_enable(mcspi->fck);
 878
 879         mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
 880                         OMAP2_MCSPI_SYSCONFIG_SOFTRESET);
 881         do {
 882                 tmp = mcspi_read_reg(master, OMAP2_MCSPI_SYSSTATUS);
 883         } while (!(tmp & OMAP2_MCSPI_SYSSTATUS_RESETDONE));
 884
 885         mcspi_write_reg(master, OMAP2_MCSPI_SYSCONFIG,
 886                         /* (3 << 8) | (2 << 3) | */
 887                         OMAP2_MCSPI_SYSCONFIG_AUTOIDLE);
 888
 889         omap2_mcspi_set_master_mode(master);
 890
 891         clk_disable(mcspi->fck);
 892         clk_disable(mcspi->ick);
 893         return 0;
 894 }
 895
 896 static u8 __initdata spi1_rxdma_id [] = {
 897         OMAP24XX_DMA_SPI1_RX0,
 898         OMAP24XX_DMA_SPI1_RX1,
 899         OMAP24XX_DMA_SPI1_RX2,
 900         OMAP24XX_DMA_SPI1_RX3,
 901 };
 902
 903 static u8 __initdata spi1_txdma_id [] = {
 904         OMAP24XX_DMA_SPI1_TX0,
 905         OMAP24XX_DMA_SPI1_TX1,
 906         OMAP24XX_DMA_SPI1_TX2,
 907         OMAP24XX_DMA_SPI1_TX3,
 908 };
 909
 910 static u8 __initdata spi2_rxdma_id[] = {
 911         OMAP24XX_DMA_SPI2_RX0,
 912         OMAP24XX_DMA_SPI2_RX1,
 913 };
 914
 915 static u8 __initdata spi2_txdma_id[] = {
 916         OMAP24XX_DMA_SPI2_TX0,
 917         OMAP24XX_DMA_SPI2_TX1,
 918 };
 919
 920 static int __init omap2_mcspi_probe(struct platform_device *pdev)
 921 {
 922         struct spi_master       *master;
 923         struct omap2_mcspi      *mcspi;
 924         struct resource         *r;
 925         int                     status = 0, i;
 926         const u8                *rxdma_id, *txdma_id;
 927         unsigned                num_chipselect;
 928
 929         switch (pdev->id) {
 930         case 1:
 931                 rxdma_id = spi1_rxdma_id;
 932                 txdma_id = spi1_txdma_id;
 933                 num_chipselect = 4;
 934                 break;
 935         case 2:
 936                 rxdma_id = spi2_rxdma_id;
 937                 txdma_id = spi2_txdma_id;
 938                 num_chipselect = 2;
 939                 break;
 940         /* REVISIT omap2430 has a third McSPI ... */
 941         default:
 942                 return -EINVAL;
 943         }
 944
 945         master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
 946         if (master == NULL) {
 947                 dev_dbg(&pdev->dev, "master allocation failed\n");
 948                 return -ENOMEM;
 949         }
 950
 951         if (pdev->id != -1)
 952                 master->bus_num = pdev->id;
 953
 954         master->setup = omap2_mcspi_setup;
 955         master->transfer = omap2_mcspi_transfer;
 956         master->cleanup = omap2_mcspi_cleanup;
 957         master->num_chipselect = num_chipselect;
 958
 959         dev_set_drvdata(&pdev->dev, master);
 960
 961         mcspi = spi_master_get_devdata(master);
 962         mcspi->master = master;
 963
 964         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 965         if (r == NULL) {
 966                 status = -ENODEV;
 967                 goto err1;
 968         }
 969         if (!request_mem_region(r->start, (r->end - r->start) + 1,
 970                         pdev->dev.bus_id)) {
 971                 status = -EBUSY;
 972                 goto err1;
 973         }
 974
 975         mcspi->base = (void __iomem *) io_p2v(r->start);
 976
 977         INIT_WORK(&mcspi->work, omap2_mcspi_work);
 978
 979         spin_lock_init(&mcspi->lock);
 980         INIT_LIST_HEAD(&mcspi->msg_queue);
 981
 982         mcspi->ick = clk_get(&pdev->dev, "mcspi_ick");
 983         if (IS_ERR(mcspi->ick)) {
 984                 dev_dbg(&pdev->dev, "can't get mcspi_ick\n");
 985                 status = PTR_ERR(mcspi->ick);
 986                 goto err1a;
 987         }
 988         mcspi->fck = clk_get(&pdev->dev, "mcspi_fck");
 989         if (IS_ERR(mcspi->fck)) {
 990                 dev_dbg(&pdev->dev, "can't get mcspi_fck\n");
 991                 status = PTR_ERR(mcspi->fck);
 992                 goto err2;
 993         }
 994
 995         mcspi->dma_channels = kcalloc(master->num_chipselect,
 996                         sizeof(struct omap2_mcspi_dma),
 997                         GFP_KERNEL);
 998
 999         if (mcspi->dma_channels == NULL)
1000                 goto err3;
1001
1002         for (i = 0; i < num_chipselect; i++) {
1003                 mcspi->dma_channels[i].dma_rx_channel = -1;
1004                 mcspi->dma_channels[i].dma_rx_sync_dev = rxdma_id[i];
1005                 mcspi->dma_channels[i].dma_tx_channel = -1;
1006                 mcspi->dma_channels[i].dma_tx_sync_dev = txdma_id[i];
1007         }
1008
1009         if (omap2_mcspi_reset(mcspi) < 0)
1010                 goto err4;
1011
1012         status = spi_register_master(master);
1013         if (status < 0)
1014                 goto err4;
1015
1016         return status;
1017
1018 err4:
1019         kfree(mcspi->dma_channels);
1020 err3:
1021         clk_put(mcspi->fck);
1022 err2:
1023         clk_put(mcspi->ick);
1024 err1a:
1025         release_mem_region(r->start, (r->end - r->start) + 1);
1026 err1:
1027         spi_master_put(master);
1028         return status;
1029 }
1030
1031 static int __exit omap2_mcspi_remove(struct platform_device *pdev)
1032 {
1033         struct spi_master       *master;
1034         struct omap2_mcspi      *mcspi;
1035         struct omap2_mcspi_dma  *dma_channels;
1036         struct resource         *r;
1037
1038         master = dev_get_drvdata(&pdev->dev);
1039         mcspi = spi_master_get_devdata(master);
1040         dma_channels = mcspi->dma_channels;
1041
1042         clk_put(mcspi->fck);
1043         clk_put(mcspi->ick);
1044
1045         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1046         release_mem_region(r->start, (r->end - r->start) + 1);
1047
1048         spi_unregister_master(master);
1049         kfree(dma_channels);
1050
1051         return 0;
1052 }
1053
1054 static struct platform_driver omap2_mcspi_driver = {
1055         .driver = {
1056                 .name =         "omap2_mcspi",
1057                 .owner =        THIS_MODULE,
1058         },
1059         .remove =       __exit_p(omap2_mcspi_remove),
1060 };
1061
1062
1063 static int __init omap2_mcspi_init(void)
1064 {
1065         omap2_mcspi_wq = create_singlethread_workqueue(
1066                                 omap2_mcspi_driver.driver.name);
1067         if (omap2_mcspi_wq == NULL)
1068                 return -1;
1069         return platform_driver_probe(&omap2_mcspi_driver, omap2_mcspi_probe);
1070 }
1071 subsys_initcall(omap2_mcspi_init);
1072
1073 static void __exit omap2_mcspi_exit(void)
1074 {
1075         platform_driver_unregister(&omap2_mcspi_driver);
1076
1077         destroy_workqueue(omap2_mcspi_wq);
1078 }
1079 module_exit(omap2_mcspi_exit);
1080
1081 MODULE_LICENSE("GPL");