drivers/spi/spi-omap2-mcspi.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * OMAP2 McSPI controller driver
   4  *
   5  * Copyright (C) 2005, 2006 Nokia Corporation
   6  * Author:      Samuel Ortiz <samuel.ortiz@nokia.com> and
   7  *              Juha Yrj�l� <juha.yrjola@nokia.com>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/module.h>
  13 #include <linux/device.h>
  14 #include <linux/delay.h>
  15 #include <linux/dma-mapping.h>
  16 #include <linux/dmaengine.h>
  17 #include <linux/pinctrl/consumer.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/err.h>
  20 #include <linux/clk.h>
  21 #include <linux/io.h>
  22 #include <linux/slab.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/of.h>
  25 #include <linux/of_device.h>
  26 #include <linux/gcd.h>
  27 #include <linux/iopoll.h>
  28
  29 #include <linux/spi/spi.h>
  30 #include <linux/gpio.h>
  31
  32 #include <linux/platform_data/spi-omap2-mcspi.h>
  33
  34 #define OMAP2_MCSPI_MAX_FREQ            48000000
  35 #define OMAP2_MCSPI_MAX_DIVIDER         4096
  36 #define OMAP2_MCSPI_MAX_FIFODEPTH       64
  37 #define OMAP2_MCSPI_MAX_FIFOWCNT        0xFFFF
  38 #define SPI_AUTOSUSPEND_TIMEOUT         2000
  39
  40 #define OMAP2_MCSPI_REVISION            0x00
  41 #define OMAP2_MCSPI_SYSSTATUS           0x14
  42 #define OMAP2_MCSPI_IRQSTATUS           0x18
  43 #define OMAP2_MCSPI_IRQENABLE           0x1c
  44 #define OMAP2_MCSPI_WAKEUPENABLE        0x20
  45 #define OMAP2_MCSPI_SYST                0x24
  46 #define OMAP2_MCSPI_MODULCTRL           0x28
  47 #define OMAP2_MCSPI_XFERLEVEL           0x7c
  48
  49 /* per-channel banks, 0x14 bytes each, first is: */
  50 #define OMAP2_MCSPI_CHCONF0             0x2c
  51 #define OMAP2_MCSPI_CHSTAT0             0x30
  52 #define OMAP2_MCSPI_CHCTRL0             0x34
  53 #define OMAP2_MCSPI_TX0                 0x38
  54 #define OMAP2_MCSPI_RX0                 0x3c
  55
  56 /* per-register bitmasks: */
  57 #define OMAP2_MCSPI_IRQSTATUS_EOW       BIT(17)
  58
  59 #define OMAP2_MCSPI_MODULCTRL_SINGLE    BIT(0)
  60 #define OMAP2_MCSPI_MODULCTRL_MS        BIT(2)
  61 #define OMAP2_MCSPI_MODULCTRL_STEST     BIT(3)
  62
  63 #define OMAP2_MCSPI_CHCONF_PHA          BIT(0)
  64 #define OMAP2_MCSPI_CHCONF_POL          BIT(1)
  65 #define OMAP2_MCSPI_CHCONF_CLKD_MASK    (0x0f << 2)
  66 #define OMAP2_MCSPI_CHCONF_EPOL         BIT(6)
  67 #define OMAP2_MCSPI_CHCONF_WL_MASK      (0x1f << 7)
  68 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY  BIT(12)
  69 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY  BIT(13)
  70 #define OMAP2_MCSPI_CHCONF_TRM_MASK     (0x03 << 12)
  71 #define OMAP2_MCSPI_CHCONF_DMAW         BIT(14)
  72 #define OMAP2_MCSPI_CHCONF_DMAR         BIT(15)
  73 #define OMAP2_MCSPI_CHCONF_DPE0         BIT(16)
  74 #define OMAP2_MCSPI_CHCONF_DPE1         BIT(17)
  75 #define OMAP2_MCSPI_CHCONF_IS           BIT(18)
  76 #define OMAP2_MCSPI_CHCONF_TURBO        BIT(19)
  77 #define OMAP2_MCSPI_CHCONF_FORCE        BIT(20)
  78 #define OMAP2_MCSPI_CHCONF_FFET         BIT(27)
  79 #define OMAP2_MCSPI_CHCONF_FFER         BIT(28)
  80 #define OMAP2_MCSPI_CHCONF_CLKG         BIT(29)
  81
  82 #define OMAP2_MCSPI_CHSTAT_RXS          BIT(0)
  83 #define OMAP2_MCSPI_CHSTAT_TXS          BIT(1)
  84 #define OMAP2_MCSPI_CHSTAT_EOT          BIT(2)
  85 #define OMAP2_MCSPI_CHSTAT_TXFFE        BIT(3)
  86
  87 #define OMAP2_MCSPI_CHCTRL_EN           BIT(0)
  88 #define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK  (0xff << 8)
  89
  90 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN   BIT(0)
  91
  92 /* We have 2 DMA channels per CS, one for RX and one for TX */
  93 struct omap2_mcspi_dma {
  94         struct dma_chan *dma_tx;
  95         struct dma_chan *dma_rx;
  96
  97         struct completion dma_tx_completion;
  98         struct completion dma_rx_completion;
  99
 100         char dma_rx_ch_name[14];
 101         char dma_tx_ch_name[14];
 102 };
 103
 104 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
 105  * cache operations; better heuristics consider wordsize and bitrate.
 106  */
 107 #define DMA_MIN_BYTES                   160
 108
 109
 110 /*
 111  * Used for context save and restore, structure members to be updated whenever
 112  * corresponding registers are modified.
 113  */
 114 struct omap2_mcspi_regs {
 115         u32 modulctrl;
 116         u32 wakeupenable;
 117         struct list_head cs;
 118 };
 119
 120 struct omap2_mcspi {
 121         struct completion       txdone;
 122         struct spi_master       *master;
 123         /* Virtual base address of the controller */
 124         void __iomem            *base;
 125         unsigned long           phys;
 126         /* SPI1 has 4 channels, while SPI2 has 2 */
 127         struct omap2_mcspi_dma  *dma_channels;
 128         struct device           *dev;
 129         struct omap2_mcspi_regs ctx;
 130         int                     fifo_depth;
 131         bool                    slave_aborted;
 132         unsigned int            pin_dir:1;
 133 };
 134
 135 struct omap2_mcspi_cs {
 136         void __iomem            *base;
 137         unsigned long           phys;
 138         int                     word_len;
 139         u16                     mode;
 140         struct list_head        node;
 141         /* Context save and restore shadow register */
 142         u32                     chconf0, chctrl0;
 143 };
 144
 145 static inline void mcspi_write_reg(struct spi_master *master,
 146                 int idx, u32 val)
 147 {
 148         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
 149
 150         writel_relaxed(val, mcspi->base + idx);
 151 }
 152
 153 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
 154 {
 155         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
 156
 157         return readl_relaxed(mcspi->base + idx);
 158 }
 159
 160 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
 161                 int idx, u32 val)
 162 {
 163         struct omap2_mcspi_cs   *cs = spi->controller_state;
 164
 165         writel_relaxed(val, cs->base +  idx);
 166 }
 167
 168 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
 169 {
 170         struct omap2_mcspi_cs   *cs = spi->controller_state;
 171
 172         return readl_relaxed(cs->base + idx);
 173 }
 174
 175 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
 176 {
 177         struct omap2_mcspi_cs *cs = spi->controller_state;
 178
 179         return cs->chconf0;
 180 }
 181
 182 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
 183 {
 184         struct omap2_mcspi_cs *cs = spi->controller_state;
 185
 186         cs->chconf0 = val;
 187         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
 188         mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 189 }
 190
 191 static inline int mcspi_bytes_per_word(int word_len)
 192 {
 193         if (word_len <= 8)
 194                 return 1;
 195         else if (word_len <= 16)
 196                 return 2;
 197         else /* word_len <= 32 */
 198                 return 4;
 199 }
 200
 201 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
 202                 int is_read, int enable)
 203 {
 204         u32 l, rw;
 205
 206         l = mcspi_cached_chconf0(spi);
 207
 208         if (is_read) /* 1 is read, 0 write */
 209                 rw = OMAP2_MCSPI_CHCONF_DMAR;
 210         else
 211                 rw = OMAP2_MCSPI_CHCONF_DMAW;
 212
 213         if (enable)
 214                 l |= rw;
 215         else
 216                 l &= ~rw;
 217
 218         mcspi_write_chconf0(spi, l);
 219 }
 220
 221 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
 222 {
 223         struct omap2_mcspi_cs *cs = spi->controller_state;
 224         u32 l;
 225
 226         l = cs->chctrl0;
 227         if (enable)
 228                 l |= OMAP2_MCSPI_CHCTRL_EN;
 229         else
 230                 l &= ~OMAP2_MCSPI_CHCTRL_EN;
 231         cs->chctrl0 = l;
 232         mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
 233         /* Flash post-writes */
 234         mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
 235 }
 236
 237 static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
 238 {
 239         struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
 240         u32 l;
 241
 242         /* The controller handles the inverted chip selects
 243          * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
 244          * the inversion from the core spi_set_cs function.
 245          */
 246         if (spi->mode & SPI_CS_HIGH)
 247                 enable = !enable;
 248
 249         if (spi->controller_state) {
 250                 int err = pm_runtime_get_sync(mcspi->dev);
 251                 if (err < 0) {
 252                         pm_runtime_put_noidle(mcspi->dev);
 253                         dev_err(mcspi->dev, "failed to get sync: %d\n", err);
 254                         return;
 255                 }
 256
 257                 l = mcspi_cached_chconf0(spi);
 258
 259                 if (enable)
 260                         l &= ~OMAP2_MCSPI_CHCONF_FORCE;
 261                 else
 262                         l |= OMAP2_MCSPI_CHCONF_FORCE;
 263
 264                 mcspi_write_chconf0(spi, l);
 265
 266                 pm_runtime_mark_last_busy(mcspi->dev);
 267                 pm_runtime_put_autosuspend(mcspi->dev);
 268         }
 269 }
 270
 271 static void omap2_mcspi_set_mode(struct spi_master *master)
 272 {
 273         struct omap2_mcspi      *mcspi = spi_master_get_devdata(master);
 274         struct omap2_mcspi_regs *ctx = &mcspi->ctx;
 275         u32 l;
 276
 277         /*
 278          * Choose master or slave mode
 279          */
 280         l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
 281         l &= ~(OMAP2_MCSPI_MODULCTRL_STEST);
 282         if (spi_controller_is_slave(master)) {
 283                 l |= (OMAP2_MCSPI_MODULCTRL_MS);
 284         } else {
 285                 l &= ~(OMAP2_MCSPI_MODULCTRL_MS);
 286                 l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
 287         }
 288         mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
 289
 290         ctx->modulctrl = l;
 291 }
 292
 293 static void omap2_mcspi_set_fifo(const struct spi_device *spi,
 294                                 struct spi_transfer *t, int enable)
 295 {
 296         struct spi_master *master = spi->master;
 297         struct omap2_mcspi_cs *cs = spi->controller_state;
 298         struct omap2_mcspi *mcspi;
 299         unsigned int wcnt;
 300         int max_fifo_depth, bytes_per_word;
 301         u32 chconf, xferlevel;
 302
 303         mcspi = spi_master_get_devdata(master);
 304
 305         chconf = mcspi_cached_chconf0(spi);
 306         if (enable) {
 307                 bytes_per_word = mcspi_bytes_per_word(cs->word_len);
 308                 if (t->len % bytes_per_word != 0)
 309                         goto disable_fifo;
 310
 311                 if (t->rx_buf != NULL && t->tx_buf != NULL)
 312                         max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
 313                 else
 314                         max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
 315
 316                 wcnt = t->len / bytes_per_word;
 317                 if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
 318                         goto disable_fifo;
 319
 320                 xferlevel = wcnt << 16;
 321                 if (t->rx_buf != NULL) {
 322                         chconf |= OMAP2_MCSPI_CHCONF_FFER;
 323                         xferlevel |= (bytes_per_word - 1) << 8;
 324                 }
 325
 326                 if (t->tx_buf != NULL) {
 327                         chconf |= OMAP2_MCSPI_CHCONF_FFET;
 328                         xferlevel |= bytes_per_word - 1;
 329                 }
 330
 331                 mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
 332                 mcspi_write_chconf0(spi, chconf);
 333                 mcspi->fifo_depth = max_fifo_depth;
 334
 335                 return;
 336         }
 337
 338 disable_fifo:
 339         if (t->rx_buf != NULL)
 340                 chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
 341
 342         if (t->tx_buf != NULL)
 343                 chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
 344
 345         mcspi_write_chconf0(spi, chconf);
 346         mcspi->fifo_depth = 0;
 347 }
 348
 349 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
 350 {
 351         u32 val;
 352
 353         return readl_poll_timeout(reg, val, val & bit, 1, MSEC_PER_SEC);
 354 }
 355
 356 static int mcspi_wait_for_completion(struct  omap2_mcspi *mcspi,
 357                                      struct completion *x)
 358 {
 359         if (spi_controller_is_slave(mcspi->master)) {
 360                 if (wait_for_completion_interruptible(x) ||
 361                     mcspi->slave_aborted)
 362                         return -EINTR;
 363         } else {
 364                 wait_for_completion(x);
 365         }
 366
 367         return 0;
 368 }
 369
 370 static void omap2_mcspi_rx_callback(void *data)
 371 {
 372         struct spi_device *spi = data;
 373         struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
 374         struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 375
 376         /* We must disable the DMA RX request */
 377         omap2_mcspi_set_dma_req(spi, 1, 0);
 378
 379         complete(&mcspi_dma->dma_rx_completion);
 380 }
 381
 382 static void omap2_mcspi_tx_callback(void *data)
 383 {
 384         struct spi_device *spi = data;
 385         struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
 386         struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 387
 388         /* We must disable the DMA TX request */
 389         omap2_mcspi_set_dma_req(spi, 0, 0);
 390
 391         complete(&mcspi_dma->dma_tx_completion);
 392 }
 393
 394 static void omap2_mcspi_tx_dma(struct spi_device *spi,
 395                                 struct spi_transfer *xfer,
 396                                 struct dma_slave_config cfg)
 397 {
 398         struct omap2_mcspi      *mcspi;
 399         struct omap2_mcspi_dma  *mcspi_dma;
 400         struct dma_async_tx_descriptor *tx;
 401
 402         mcspi = spi_master_get_devdata(spi->master);
 403         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 404
 405         dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
 406
 407         tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
 408                                      xfer->tx_sg.nents,
 409                                      DMA_MEM_TO_DEV,
 410                                      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 411         if (tx) {
 412                 tx->callback = omap2_mcspi_tx_callback;
 413                 tx->callback_param = spi;
 414                 dmaengine_submit(tx);
 415         } else {
 416                 /* FIXME: fall back to PIO? */
 417         }
 418         dma_async_issue_pending(mcspi_dma->dma_tx);
 419         omap2_mcspi_set_dma_req(spi, 0, 1);
 420 }
 421
 422 static unsigned
 423 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 424                                 struct dma_slave_config cfg,
 425                                 unsigned es)
 426 {
 427         struct omap2_mcspi      *mcspi;
 428         struct omap2_mcspi_dma  *mcspi_dma;
 429         unsigned int            count, transfer_reduction = 0;
 430         struct scatterlist      *sg_out[2];
 431         int                     nb_sizes = 0, out_mapped_nents[2], ret, x;
 432         size_t                  sizes[2];
 433         u32                     l;
 434         int                     elements = 0;
 435         int                     word_len, element_count;
 436         struct omap2_mcspi_cs   *cs = spi->controller_state;
 437         void __iomem            *chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
 438         struct dma_async_tx_descriptor *tx;
 439
 440         mcspi = spi_master_get_devdata(spi->master);
 441         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 442         count = xfer->len;
 443
 444         /*
 445          *  In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
 446          *  it mentions reducing DMA transfer length by one element in master
 447          *  normal mode.
 448          */
 449         if (mcspi->fifo_depth == 0)
 450                 transfer_reduction = es;
 451
 452         word_len = cs->word_len;
 453         l = mcspi_cached_chconf0(spi);
 454
 455         if (word_len <= 8)
 456                 element_count = count;
 457         else if (word_len <= 16)
 458                 element_count = count >> 1;
 459         else /* word_len <= 32 */
 460                 element_count = count >> 2;
 461
 462
 463         dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
 464
 465         /*
 466          *  Reduce DMA transfer length by one more if McSPI is
 467          *  configured in turbo mode.
 468          */
 469         if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
 470                 transfer_reduction += es;
 471
 472         if (transfer_reduction) {
 473                 /* Split sgl into two. The second sgl won't be used. */
 474                 sizes[0] = count - transfer_reduction;
 475                 sizes[1] = transfer_reduction;
 476                 nb_sizes = 2;
 477         } else {
 478                 /*
 479                  * Don't bother splitting the sgl. This essentially
 480                  * clones the original sgl.
 481                  */
 482                 sizes[0] = count;
 483                 nb_sizes = 1;
 484         }
 485
 486         ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents, 0, nb_sizes,
 487                        sizes, sg_out, out_mapped_nents, GFP_KERNEL);
 488
 489         if (ret < 0) {
 490                 dev_err(&spi->dev, "sg_split failed\n");
 491                 return 0;
 492         }
 493
 494         tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, sg_out[0],
 495                                      out_mapped_nents[0], DMA_DEV_TO_MEM,
 496                                      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 497         if (tx) {
 498                 tx->callback = omap2_mcspi_rx_callback;
 499                 tx->callback_param = spi;
 500                 dmaengine_submit(tx);
 501         } else {
 502                 /* FIXME: fall back to PIO? */
 503         }
 504
 505         dma_async_issue_pending(mcspi_dma->dma_rx);
 506         omap2_mcspi_set_dma_req(spi, 1, 1);
 507
 508         ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion);
 509         if (ret || mcspi->slave_aborted) {
 510                 dmaengine_terminate_sync(mcspi_dma->dma_rx);
 511                 omap2_mcspi_set_dma_req(spi, 1, 0);
 512                 return 0;
 513         }
 514
 515         for (x = 0; x < nb_sizes; x++)
 516                 kfree(sg_out[x]);
 517
 518         if (mcspi->fifo_depth > 0)
 519                 return count;
 520
 521         /*
 522          *  Due to the DMA transfer length reduction the missing bytes must
 523          *  be read manually to receive all of the expected data.
 524          */
 525         omap2_mcspi_set_enable(spi, 0);
 526
 527         elements = element_count - 1;
 528
 529         if (l & OMAP2_MCSPI_CHCONF_TURBO) {
 530                 elements--;
 531
 532                 if (!mcspi_wait_for_reg_bit(chstat_reg,
 533                                             OMAP2_MCSPI_CHSTAT_RXS)) {
 534                         u32 w;
 535
 536                         w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
 537                         if (word_len <= 8)
 538                                 ((u8 *)xfer->rx_buf)[elements++] = w;
 539                         else if (word_len <= 16)
 540                                 ((u16 *)xfer->rx_buf)[elements++] = w;
 541                         else /* word_len <= 32 */
 542                                 ((u32 *)xfer->rx_buf)[elements++] = w;
 543                 } else {
 544                         int bytes_per_word = mcspi_bytes_per_word(word_len);
 545                         dev_err(&spi->dev, "DMA RX penultimate word empty\n");
 546                         count -= (bytes_per_word << 1);
 547                         omap2_mcspi_set_enable(spi, 1);
 548                         return count;
 549                 }
 550         }
 551         if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
 552                 u32 w;
 553
 554                 w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
 555                 if (word_len <= 8)
 556                         ((u8 *)xfer->rx_buf)[elements] = w;
 557                 else if (word_len <= 16)
 558                         ((u16 *)xfer->rx_buf)[elements] = w;
 559                 else /* word_len <= 32 */
 560                         ((u32 *)xfer->rx_buf)[elements] = w;
 561         } else {
 562                 dev_err(&spi->dev, "DMA RX last word empty\n");
 563                 count -= mcspi_bytes_per_word(word_len);
 564         }
 565         omap2_mcspi_set_enable(spi, 1);
 566         return count;
 567 }
 568
 569 static unsigned
 570 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
 571 {
 572         struct omap2_mcspi      *mcspi;
 573         struct omap2_mcspi_cs   *cs = spi->controller_state;
 574         struct omap2_mcspi_dma  *mcspi_dma;
 575         unsigned int            count;
 576         u8                      *rx;
 577         const u8                *tx;
 578         struct dma_slave_config cfg;
 579         enum dma_slave_buswidth width;
 580         unsigned es;
 581         void __iomem            *chstat_reg;
 582         void __iomem            *irqstat_reg;
 583         int                     wait_res;
 584
 585         mcspi = spi_master_get_devdata(spi->master);
 586         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 587
 588         if (cs->word_len <= 8) {
 589                 width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 590                 es = 1;
 591         } else if (cs->word_len <= 16) {
 592                 width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 593                 es = 2;
 594         } else {
 595                 width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 596                 es = 4;
 597         }
 598
 599         count = xfer->len;
 600
 601         memset(&cfg, 0, sizeof(cfg));
 602         cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
 603         cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
 604         cfg.src_addr_width = width;
 605         cfg.dst_addr_width = width;
 606         cfg.src_maxburst = 1;
 607         cfg.dst_maxburst = 1;
 608
 609         rx = xfer->rx_buf;
 610         tx = xfer->tx_buf;
 611
 612         mcspi->slave_aborted = false;
 613         reinit_completion(&mcspi_dma->dma_tx_completion);
 614         reinit_completion(&mcspi_dma->dma_rx_completion);
 615         reinit_completion(&mcspi->txdone);
 616         if (tx) {
 617                 /* Enable EOW IRQ to know end of tx in slave mode */
 618                 if (spi_controller_is_slave(spi->master))
 619                         mcspi_write_reg(spi->master,
 620                                         OMAP2_MCSPI_IRQENABLE,
 621                                         OMAP2_MCSPI_IRQSTATUS_EOW);
 622                 omap2_mcspi_tx_dma(spi, xfer, cfg);
 623         }
 624
 625         if (rx != NULL)
 626                 count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
 627
 628         if (tx != NULL) {
 629                 int ret;
 630
 631                 ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion);
 632                 if (ret || mcspi->slave_aborted) {
 633                         dmaengine_terminate_sync(mcspi_dma->dma_tx);
 634                         omap2_mcspi_set_dma_req(spi, 0, 0);
 635                         return 0;
 636                 }
 637
 638                 if (spi_controller_is_slave(mcspi->master)) {
 639                         ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone);
 640                         if (ret || mcspi->slave_aborted)
 641                                 return 0;
 642                 }
 643
 644                 if (mcspi->fifo_depth > 0) {
 645                         irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
 646
 647                         if (mcspi_wait_for_reg_bit(irqstat_reg,
 648                                                 OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
 649                                 dev_err(&spi->dev, "EOW timed out\n");
 650
 651                         mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
 652                                         OMAP2_MCSPI_IRQSTATUS_EOW);
 653                 }
 654
 655                 /* for TX_ONLY mode, be sure all words have shifted out */
 656                 if (rx == NULL) {
 657                         chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
 658                         if (mcspi->fifo_depth > 0) {
 659                                 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
 660                                                 OMAP2_MCSPI_CHSTAT_TXFFE);
 661                                 if (wait_res < 0)
 662                                         dev_err(&spi->dev, "TXFFE timed out\n");
 663                         } else {
 664                                 wait_res = mcspi_wait_for_reg_bit(chstat_reg,
 665                                                 OMAP2_MCSPI_CHSTAT_TXS);
 666                                 if (wait_res < 0)
 667                                         dev_err(&spi->dev, "TXS timed out\n");
 668                         }
 669                         if (wait_res >= 0 &&
 670                                 (mcspi_wait_for_reg_bit(chstat_reg,
 671                                         OMAP2_MCSPI_CHSTAT_EOT) < 0))
 672                                 dev_err(&spi->dev, "EOT timed out\n");
 673                 }
 674         }
 675         return count;
 676 }
 677
 678 static unsigned
 679 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
 680 {
 681         struct omap2_mcspi_cs   *cs = spi->controller_state;
 682         unsigned int            count, c;
 683         u32                     l;
 684         void __iomem            *base = cs->base;
 685         void __iomem            *tx_reg;
 686         void __iomem            *rx_reg;
 687         void __iomem            *chstat_reg;
 688         int                     word_len;
 689
 690         count = xfer->len;
 691         c = count;
 692         word_len = cs->word_len;
 693
 694         l = mcspi_cached_chconf0(spi);
 695
 696         /* We store the pre-calculated register addresses on stack to speed
 697          * up the transfer loop. */
 698         tx_reg          = base + OMAP2_MCSPI_TX0;
 699         rx_reg          = base + OMAP2_MCSPI_RX0;
 700         chstat_reg      = base + OMAP2_MCSPI_CHSTAT0;
 701
 702         if (c < (word_len>>3))
 703                 return 0;
 704
 705         if (word_len <= 8) {
 706                 u8              *rx;
 707                 const u8        *tx;
 708
 709                 rx = xfer->rx_buf;
 710                 tx = xfer->tx_buf;
 711
 712                 do {
 713                         c -= 1;
 714                         if (tx != NULL) {
 715                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 716                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 717                                         dev_err(&spi->dev, "TXS timed out\n");
 718                                         goto out;
 719                                 }
 720                                 dev_vdbg(&spi->dev, "write-%d %02x\n",
 721                                                 word_len, *tx);
 722                                 writel_relaxed(*tx++, tx_reg);
 723                         }
 724                         if (rx != NULL) {
 725                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 726                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 727                                         dev_err(&spi->dev, "RXS timed out\n");
 728                                         goto out;
 729                                 }
 730
 731                                 if (c == 1 && tx == NULL &&
 732                                     (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 733                                         omap2_mcspi_set_enable(spi, 0);
 734                                         *rx++ = readl_relaxed(rx_reg);
 735                                         dev_vdbg(&spi->dev, "read-%d %02x\n",
 736                                                     word_len, *(rx - 1));
 737                                         if (mcspi_wait_for_reg_bit(chstat_reg,
 738                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 739                                                 dev_err(&spi->dev,
 740                                                         "RXS timed out\n");
 741                                                 goto out;
 742                                         }
 743                                         c = 0;
 744                                 } else if (c == 0 && tx == NULL) {
 745                                         omap2_mcspi_set_enable(spi, 0);
 746                                 }
 747
 748                                 *rx++ = readl_relaxed(rx_reg);
 749                                 dev_vdbg(&spi->dev, "read-%d %02x\n",
 750                                                 word_len, *(rx - 1));
 751                         }
 752                 } while (c);
 753         } else if (word_len <= 16) {
 754                 u16             *rx;
 755                 const u16       *tx;
 756
 757                 rx = xfer->rx_buf;
 758                 tx = xfer->tx_buf;
 759                 do {
 760                         c -= 2;
 761                         if (tx != NULL) {
 762                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 763                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 764                                         dev_err(&spi->dev, "TXS timed out\n");
 765                                         goto out;
 766                                 }
 767                                 dev_vdbg(&spi->dev, "write-%d %04x\n",
 768                                                 word_len, *tx);
 769                                 writel_relaxed(*tx++, tx_reg);
 770                         }
 771                         if (rx != NULL) {
 772                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 773                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 774                                         dev_err(&spi->dev, "RXS timed out\n");
 775                                         goto out;
 776                                 }
 777
 778                                 if (c == 2 && tx == NULL &&
 779                                     (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 780                                         omap2_mcspi_set_enable(spi, 0);
 781                                         *rx++ = readl_relaxed(rx_reg);
 782                                         dev_vdbg(&spi->dev, "read-%d %04x\n",
 783                                                     word_len, *(rx - 1));
 784                                         if (mcspi_wait_for_reg_bit(chstat_reg,
 785                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 786                                                 dev_err(&spi->dev,
 787                                                         "RXS timed out\n");
 788                                                 goto out;
 789                                         }
 790                                         c = 0;
 791                                 } else if (c == 0 && tx == NULL) {
 792                                         omap2_mcspi_set_enable(spi, 0);
 793                                 }
 794
 795                                 *rx++ = readl_relaxed(rx_reg);
 796                                 dev_vdbg(&spi->dev, "read-%d %04x\n",
 797                                                 word_len, *(rx - 1));
 798                         }
 799                 } while (c >= 2);
 800         } else if (word_len <= 32) {
 801                 u32             *rx;
 802                 const u32       *tx;
 803
 804                 rx = xfer->rx_buf;
 805                 tx = xfer->tx_buf;
 806                 do {
 807                         c -= 4;
 808                         if (tx != NULL) {
 809                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 810                                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 811                                         dev_err(&spi->dev, "TXS timed out\n");
 812                                         goto out;
 813                                 }
 814                                 dev_vdbg(&spi->dev, "write-%d %08x\n",
 815                                                 word_len, *tx);
 816                                 writel_relaxed(*tx++, tx_reg);
 817                         }
 818                         if (rx != NULL) {
 819                                 if (mcspi_wait_for_reg_bit(chstat_reg,
 820                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 821                                         dev_err(&spi->dev, "RXS timed out\n");
 822                                         goto out;
 823                                 }
 824
 825                                 if (c == 4 && tx == NULL &&
 826                                     (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 827                                         omap2_mcspi_set_enable(spi, 0);
 828                                         *rx++ = readl_relaxed(rx_reg);
 829                                         dev_vdbg(&spi->dev, "read-%d %08x\n",
 830                                                     word_len, *(rx - 1));
 831                                         if (mcspi_wait_for_reg_bit(chstat_reg,
 832                                                 OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 833                                                 dev_err(&spi->dev,
 834                                                         "RXS timed out\n");
 835                                                 goto out;
 836                                         }
 837                                         c = 0;
 838                                 } else if (c == 0 && tx == NULL) {
 839                                         omap2_mcspi_set_enable(spi, 0);
 840                                 }
 841
 842                                 *rx++ = readl_relaxed(rx_reg);
 843                                 dev_vdbg(&spi->dev, "read-%d %08x\n",
 844                                                 word_len, *(rx - 1));
 845                         }
 846                 } while (c >= 4);
 847         }
 848
 849         /* for TX_ONLY mode, be sure all words have shifted out */
 850         if (xfer->rx_buf == NULL) {
 851                 if (mcspi_wait_for_reg_bit(chstat_reg,
 852                                 OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 853                         dev_err(&spi->dev, "TXS timed out\n");
 854                 } else if (mcspi_wait_for_reg_bit(chstat_reg,
 855                                 OMAP2_MCSPI_CHSTAT_EOT) < 0)
 856                         dev_err(&spi->dev, "EOT timed out\n");
 857
 858                 /* disable chan to purge rx datas received in TX_ONLY transfer,
 859                  * otherwise these rx datas will affect the direct following
 860                  * RX_ONLY transfer.
 861                  */
 862                 omap2_mcspi_set_enable(spi, 0);
 863         }
 864 out:
 865         omap2_mcspi_set_enable(spi, 1);
 866         return count - c;
 867 }
 868
 869 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
 870 {
 871         u32 div;
 872
 873         for (div = 0; div < 15; div++)
 874                 if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
 875                         return div;
 876
 877         return 15;
 878 }
 879
 880 /* called only when no transfer is active to this device */
 881 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 882                 struct spi_transfer *t)
 883 {
 884         struct omap2_mcspi_cs *cs = spi->controller_state;
 885         struct omap2_mcspi *mcspi;
 886         u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
 887         u8 word_len = spi->bits_per_word;
 888         u32 speed_hz = spi->max_speed_hz;
 889
 890         mcspi = spi_master_get_devdata(spi->master);
 891
 892         if (t != NULL && t->bits_per_word)
 893                 word_len = t->bits_per_word;
 894
 895         cs->word_len = word_len;
 896
 897         if (t && t->speed_hz)
 898                 speed_hz = t->speed_hz;
 899
 900         speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
 901         if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
 902                 clkd = omap2_mcspi_calc_divisor(speed_hz);
 903                 speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
 904                 clkg = 0;
 905         } else {
 906                 div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
 907                 speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
 908                 clkd = (div - 1) & 0xf;
 909                 extclk = (div - 1) >> 4;
 910                 clkg = OMAP2_MCSPI_CHCONF_CLKG;
 911         }
 912
 913         l = mcspi_cached_chconf0(spi);
 914
 915         /* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
 916          * REVISIT: this controller could support SPI_3WIRE mode.
 917          */
 918         if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
 919                 l &= ~OMAP2_MCSPI_CHCONF_IS;
 920                 l &= ~OMAP2_MCSPI_CHCONF_DPE1;
 921                 l |= OMAP2_MCSPI_CHCONF_DPE0;
 922         } else {
 923                 l |= OMAP2_MCSPI_CHCONF_IS;
 924                 l |= OMAP2_MCSPI_CHCONF_DPE1;
 925                 l &= ~OMAP2_MCSPI_CHCONF_DPE0;
 926         }
 927
 928         /* wordlength */
 929         l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
 930         l |= (word_len - 1) << 7;
 931
 932         /* set chipselect polarity; manage with FORCE */
 933         if (!(spi->mode & SPI_CS_HIGH))
 934                 l |= OMAP2_MCSPI_CHCONF_EPOL;   /* active-low; normal */
 935         else
 936                 l &= ~OMAP2_MCSPI_CHCONF_EPOL;
 937
 938         /* set clock divisor */
 939         l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
 940         l |= clkd << 2;
 941
 942         /* set clock granularity */
 943         l &= ~OMAP2_MCSPI_CHCONF_CLKG;
 944         l |= clkg;
 945         if (clkg) {
 946                 cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
 947                 cs->chctrl0 |= extclk << 8;
 948                 mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
 949         }
 950
 951         /* set SPI mode 0..3 */
 952         if (spi->mode & SPI_CPOL)
 953                 l |= OMAP2_MCSPI_CHCONF_POL;
 954         else
 955                 l &= ~OMAP2_MCSPI_CHCONF_POL;
 956         if (spi->mode & SPI_CPHA)
 957                 l |= OMAP2_MCSPI_CHCONF_PHA;
 958         else
 959                 l &= ~OMAP2_MCSPI_CHCONF_PHA;
 960
 961         mcspi_write_chconf0(spi, l);
 962
 963         cs->mode = spi->mode;
 964
 965         dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
 966                         speed_hz,
 967                         (spi->mode & SPI_CPHA) ? "trailing" : "leading",
 968                         (spi->mode & SPI_CPOL) ? "inverted" : "normal");
 969
 970         return 0;
 971 }
 972
 973 /*
 974  * Note that we currently allow DMA only if we get a channel
 975  * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
 976  */
 977 static int omap2_mcspi_request_dma(struct spi_device *spi)
 978 {
 979         struct spi_master       *master = spi->master;
 980         struct omap2_mcspi      *mcspi;
 981         struct omap2_mcspi_dma  *mcspi_dma;
 982         int ret = 0;
 983
 984         mcspi = spi_master_get_devdata(master);
 985         mcspi_dma = mcspi->dma_channels + spi->chip_select;
 986
 987         init_completion(&mcspi_dma->dma_rx_completion);
 988         init_completion(&mcspi_dma->dma_tx_completion);
 989
 990         mcspi_dma->dma_rx = dma_request_chan(&master->dev,
 991                                              mcspi_dma->dma_rx_ch_name);
 992         if (IS_ERR(mcspi_dma->dma_rx)) {
 993                 ret = PTR_ERR(mcspi_dma->dma_rx);
 994                 mcspi_dma->dma_rx = NULL;
 995                 goto no_dma;
 996         }
 997
 998         mcspi_dma->dma_tx = dma_request_chan(&master->dev,
 999                                              mcspi_dma->dma_tx_ch_name);
1000         if (IS_ERR(mcspi_dma->dma_tx)) {
1001                 ret = PTR_ERR(mcspi_dma->dma_tx);
1002                 mcspi_dma->dma_tx = NULL;
1003                 dma_release_channel(mcspi_dma->dma_rx);
1004                 mcspi_dma->dma_rx = NULL;
1005         }
1006
1007 no_dma:
1008         return ret;
1009 }
1010
1011 static int omap2_mcspi_setup(struct spi_device *spi)
1012 {
1013         int                     ret;
1014         struct omap2_mcspi      *mcspi = spi_master_get_devdata(spi->master);
1015         struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1016         struct omap2_mcspi_dma  *mcspi_dma;
1017         struct omap2_mcspi_cs   *cs = spi->controller_state;
1018
1019         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1020
1021         if (!cs) {
1022                 cs = kzalloc(sizeof *cs, GFP_KERNEL);
1023                 if (!cs)
1024                         return -ENOMEM;
1025                 cs->base = mcspi->base + spi->chip_select * 0x14;
1026                 cs->phys = mcspi->phys + spi->chip_select * 0x14;
1027                 cs->mode = 0;
1028                 cs->chconf0 = 0;
1029                 cs->chctrl0 = 0;
1030                 spi->controller_state = cs;
1031                 /* Link this to context save list */
1032                 list_add_tail(&cs->node, &ctx->cs);
1033
1034                 if (gpio_is_valid(spi->cs_gpio)) {
1035                         ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
1036                         if (ret) {
1037                                 dev_err(&spi->dev, "failed to request gpio\n");
1038                                 return ret;
1039                         }
1040                         gpio_direction_output(spi->cs_gpio,
1041                                          !(spi->mode & SPI_CS_HIGH));
1042                 }
1043         }
1044
1045         if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1046                 ret = omap2_mcspi_request_dma(spi);
1047                 if (ret)
1048                         dev_warn(&spi->dev, "not using DMA for McSPI (%d)\n",
1049                                  ret);
1050         }
1051
1052         ret = pm_runtime_get_sync(mcspi->dev);
1053         if (ret < 0) {
1054                 pm_runtime_put_noidle(mcspi->dev);
1055
1056                 return ret;
1057         }
1058
1059         ret = omap2_mcspi_setup_transfer(spi, NULL);
1060         pm_runtime_mark_last_busy(mcspi->dev);
1061         pm_runtime_put_autosuspend(mcspi->dev);
1062
1063         return ret;
1064 }
1065
1066 static void omap2_mcspi_cleanup(struct spi_device *spi)
1067 {
1068         struct omap2_mcspi      *mcspi;
1069         struct omap2_mcspi_dma  *mcspi_dma;
1070         struct omap2_mcspi_cs   *cs;
1071
1072         mcspi = spi_master_get_devdata(spi->master);
1073
1074         if (spi->controller_state) {
1075                 /* Unlink controller state from context save list */
1076                 cs = spi->controller_state;
1077                 list_del(&cs->node);
1078
1079                 kfree(cs);
1080         }
1081
1082         if (spi->chip_select < spi->master->num_chipselect) {
1083                 mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1084
1085                 if (mcspi_dma->dma_rx) {
1086                         dma_release_channel(mcspi_dma->dma_rx);
1087                         mcspi_dma->dma_rx = NULL;
1088                 }
1089                 if (mcspi_dma->dma_tx) {
1090                         dma_release_channel(mcspi_dma->dma_tx);
1091                         mcspi_dma->dma_tx = NULL;
1092                 }
1093         }
1094
1095         if (gpio_is_valid(spi->cs_gpio))
1096                 gpio_free(spi->cs_gpio);
1097 }
1098
1099 static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data)
1100 {
1101         struct omap2_mcspi *mcspi = data;
1102         u32 irqstat;
1103
1104         irqstat = mcspi_read_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS);
1105         if (!irqstat)
1106                 return IRQ_NONE;
1107
1108         /* Disable IRQ and wakeup slave xfer task */
1109         mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQENABLE, 0);
1110         if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW)
1111                 complete(&mcspi->txdone);
1112
1113         return IRQ_HANDLED;
1114 }
1115
1116 static int omap2_mcspi_slave_abort(struct spi_master *master)
1117 {
1118         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1119         struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels;
1120
1121         mcspi->slave_aborted = true;
1122         complete(&mcspi_dma->dma_rx_completion);
1123         complete(&mcspi_dma->dma_tx_completion);
1124         complete(&mcspi->txdone);
1125
1126         return 0;
1127 }
1128
1129 static int omap2_mcspi_transfer_one(struct spi_master *master,
1130                                     struct spi_device *spi,
1131                                     struct spi_transfer *t)
1132 {
1133
1134         /* We only enable one channel at a time -- the one whose message is
1135          * -- although this controller would gladly
1136          * arbitrate among multiple channels.  This corresponds to "single
1137          * channel" master mode.  As a side effect, we need to manage the
1138          * chipselect with the FORCE bit ... CS != channel enable.
1139          */
1140
1141         struct omap2_mcspi              *mcspi;
1142         struct omap2_mcspi_dma          *mcspi_dma;
1143         struct omap2_mcspi_cs           *cs;
1144         struct omap2_mcspi_device_config *cd;
1145         int                             par_override = 0;
1146         int                             status = 0;
1147         u32                             chconf;
1148
1149         mcspi = spi_master_get_devdata(master);
1150         mcspi_dma = mcspi->dma_channels + spi->chip_select;
1151         cs = spi->controller_state;
1152         cd = spi->controller_data;
1153
1154         /*
1155          * The slave driver could have changed spi->mode in which case
1156          * it will be different from cs->mode (the current hardware setup).
1157          * If so, set par_override (even though its not a parity issue) so
1158          * omap2_mcspi_setup_transfer will be called to configure the hardware
1159          * with the correct mode on the first iteration of the loop below.
1160          */
1161         if (spi->mode != cs->mode)
1162                 par_override = 1;
1163
1164         omap2_mcspi_set_enable(spi, 0);
1165
1166         if (gpio_is_valid(spi->cs_gpio))
1167                 omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1168
1169         if (par_override ||
1170             (t->speed_hz != spi->max_speed_hz) ||
1171             (t->bits_per_word != spi->bits_per_word)) {
1172                 par_override = 1;
1173                 status = omap2_mcspi_setup_transfer(spi, t);
1174                 if (status < 0)
1175                         goto out;
1176                 if (t->speed_hz == spi->max_speed_hz &&
1177                     t->bits_per_word == spi->bits_per_word)
1178                         par_override = 0;
1179         }
1180         if (cd && cd->cs_per_word) {
1181                 chconf = mcspi->ctx.modulctrl;
1182                 chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1183                 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1184                 mcspi->ctx.modulctrl =
1185                         mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1186         }
1187
1188         chconf = mcspi_cached_chconf0(spi);
1189         chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1190         chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1191
1192         if (t->tx_buf == NULL)
1193                 chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1194         else if (t->rx_buf == NULL)
1195                 chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1196
1197         if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1198                 /* Turbo mode is for more than one word */
1199                 if (t->len > ((cs->word_len + 7) >> 3))
1200                         chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1201         }
1202
1203         mcspi_write_chconf0(spi, chconf);
1204
1205         if (t->len) {
1206                 unsigned        count;
1207
1208                 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1209                     master->cur_msg_mapped &&
1210                     master->can_dma(master, spi, t))
1211                         omap2_mcspi_set_fifo(spi, t, 1);
1212
1213                 omap2_mcspi_set_enable(spi, 1);
1214
1215                 /* RX_ONLY mode needs dummy data in TX reg */
1216                 if (t->tx_buf == NULL)
1217                         writel_relaxed(0, cs->base
1218                                         + OMAP2_MCSPI_TX0);
1219
1220                 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1221                     master->cur_msg_mapped &&
1222                     master->can_dma(master, spi, t))
1223                         count = omap2_mcspi_txrx_dma(spi, t);
1224                 else
1225                         count = omap2_mcspi_txrx_pio(spi, t);
1226
1227                 if (count != t->len) {
1228                         status = -EIO;
1229                         goto out;
1230                 }
1231         }
1232
1233         omap2_mcspi_set_enable(spi, 0);
1234
1235         if (mcspi->fifo_depth > 0)
1236                 omap2_mcspi_set_fifo(spi, t, 0);
1237
1238 out:
1239         /* Restore defaults if they were overriden */
1240         if (par_override) {
1241                 par_override = 0;
1242                 status = omap2_mcspi_setup_transfer(spi, NULL);
1243         }
1244
1245         if (cd && cd->cs_per_word) {
1246                 chconf = mcspi->ctx.modulctrl;
1247                 chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1248                 mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1249                 mcspi->ctx.modulctrl =
1250                         mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1251         }
1252
1253         omap2_mcspi_set_enable(spi, 0);
1254
1255         if (gpio_is_valid(spi->cs_gpio))
1256                 omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1257
1258         if (mcspi->fifo_depth > 0 && t)
1259                 omap2_mcspi_set_fifo(spi, t, 0);
1260
1261         return status;
1262 }
1263
1264 static int omap2_mcspi_prepare_message(struct spi_master *master,
1265                                        struct spi_message *msg)
1266 {
1267         struct omap2_mcspi      *mcspi = spi_master_get_devdata(master);
1268         struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1269         struct omap2_mcspi_cs   *cs;
1270
1271         /* Only a single channel can have the FORCE bit enabled
1272          * in its chconf0 register.
1273          * Scan all channels and disable them except the current one.
1274          * A FORCE can remain from a last transfer having cs_change enabled
1275          */
1276         list_for_each_entry(cs, &ctx->cs, node) {
1277                 if (msg->spi->controller_state == cs)
1278                         continue;
1279
1280                 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1281                         cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1282                         writel_relaxed(cs->chconf0,
1283                                         cs->base + OMAP2_MCSPI_CHCONF0);
1284                         readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1285                 }
1286         }
1287
1288         return 0;
1289 }
1290
1291 static bool omap2_mcspi_can_dma(struct spi_master *master,
1292                                 struct spi_device *spi,
1293                                 struct spi_transfer *xfer)
1294 {
1295         struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1296         struct omap2_mcspi_dma *mcspi_dma =
1297                 &mcspi->dma_channels[spi->chip_select];
1298
1299         if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx)
1300                 return false;
1301
1302         if (spi_controller_is_slave(master))
1303                 return true;
1304
1305         return (xfer->len >= DMA_MIN_BYTES);
1306 }
1307
1308 static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi)
1309 {
1310         struct spi_master       *master = mcspi->master;
1311         struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1312         int                     ret = 0;
1313
1314         ret = pm_runtime_get_sync(mcspi->dev);
1315         if (ret < 0) {
1316                 pm_runtime_put_noidle(mcspi->dev);
1317
1318                 return ret;
1319         }
1320
1321         mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1322                         OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1323         ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1324
1325         omap2_mcspi_set_mode(master);
1326         pm_runtime_mark_last_busy(mcspi->dev);
1327         pm_runtime_put_autosuspend(mcspi->dev);
1328         return 0;
1329 }
1330
1331 /*
1332  * When SPI wake up from off-mode, CS is in activate state. If it was in
1333  * inactive state when driver was suspend, then force it to inactive state at
1334  * wake up.
1335  */
1336 static int omap_mcspi_runtime_resume(struct device *dev)
1337 {
1338         struct spi_master *master = dev_get_drvdata(dev);
1339         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1340         struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1341         struct omap2_mcspi_cs *cs;
1342
1343         /* McSPI: context restore */
1344         mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
1345         mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
1346
1347         list_for_each_entry(cs, &ctx->cs, node) {
1348                 /*
1349                  * We need to toggle CS state for OMAP take this
1350                  * change in account.
1351                  */
1352                 if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1353                         cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1354                         writel_relaxed(cs->chconf0,
1355                                        cs->base + OMAP2_MCSPI_CHCONF0);
1356                         cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1357                         writel_relaxed(cs->chconf0,
1358                                        cs->base + OMAP2_MCSPI_CHCONF0);
1359                 } else {
1360                         writel_relaxed(cs->chconf0,
1361                                        cs->base + OMAP2_MCSPI_CHCONF0);
1362                 }
1363         }
1364
1365         return 0;
1366 }
1367
1368 static struct omap2_mcspi_platform_config omap2_pdata = {
1369         .regs_offset = 0,
1370 };
1371
1372 static struct omap2_mcspi_platform_config omap4_pdata = {
1373         .regs_offset = OMAP4_MCSPI_REG_OFFSET,
1374 };
1375
1376 static const struct of_device_id omap_mcspi_of_match[] = {
1377         {
1378                 .compatible = "ti,omap2-mcspi",
1379                 .data = &omap2_pdata,
1380         },
1381         {
1382                 .compatible = "ti,omap4-mcspi",
1383                 .data = &omap4_pdata,
1384         },
1385         { },
1386 };
1387 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1388
1389 static int omap2_mcspi_probe(struct platform_device *pdev)
1390 {
1391         struct spi_master       *master;
1392         const struct omap2_mcspi_platform_config *pdata;
1393         struct omap2_mcspi      *mcspi;
1394         struct resource         *r;
1395         int                     status = 0, i;
1396         u32                     regs_offset = 0;
1397         struct device_node      *node = pdev->dev.of_node;
1398         const struct of_device_id *match;
1399
1400         if (of_property_read_bool(node, "spi-slave"))
1401                 master = spi_alloc_slave(&pdev->dev, sizeof(*mcspi));
1402         else
1403                 master = spi_alloc_master(&pdev->dev, sizeof(*mcspi));
1404         if (!master)
1405                 return -ENOMEM;
1406
1407         /* the spi->mode bits understood by this driver: */
1408         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1409         master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1410         master->setup = omap2_mcspi_setup;
1411         master->auto_runtime_pm = true;
1412         master->prepare_message = omap2_mcspi_prepare_message;
1413         master->can_dma = omap2_mcspi_can_dma;
1414         master->transfer_one = omap2_mcspi_transfer_one;
1415         master->set_cs = omap2_mcspi_set_cs;
1416         master->cleanup = omap2_mcspi_cleanup;
1417         master->slave_abort = omap2_mcspi_slave_abort;
1418         master->dev.of_node = node;
1419         master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1420         master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1421
1422         platform_set_drvdata(pdev, master);
1423
1424         mcspi = spi_master_get_devdata(master);
1425         mcspi->master = master;
1426
1427         match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1428         if (match) {
1429                 u32 num_cs = 1; /* default number of chipselect */
1430                 pdata = match->data;
1431
1432                 of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1433                 master->num_chipselect = num_cs;
1434                 if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1435                         mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1436         } else {
1437                 pdata = dev_get_platdata(&pdev->dev);
1438                 master->num_chipselect = pdata->num_cs;
1439                 mcspi->pin_dir = pdata->pin_dir;
1440         }
1441         regs_offset = pdata->regs_offset;
1442
1443         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1444         mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1445         if (IS_ERR(mcspi->base)) {
1446                 status = PTR_ERR(mcspi->base);
1447                 goto free_master;
1448         }
1449         mcspi->phys = r->start + regs_offset;
1450         mcspi->base += regs_offset;
1451
1452         mcspi->dev = &pdev->dev;
1453
1454         INIT_LIST_HEAD(&mcspi->ctx.cs);
1455
1456         mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1457                                            sizeof(struct omap2_mcspi_dma),
1458                                            GFP_KERNEL);
1459         if (mcspi->dma_channels == NULL) {
1460                 status = -ENOMEM;
1461                 goto free_master;
1462         }
1463
1464         for (i = 0; i < master->num_chipselect; i++) {
1465                 sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
1466                 sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
1467         }
1468
1469         status = platform_get_irq(pdev, 0);
1470         if (status == -EPROBE_DEFER)
1471                 goto free_master;
1472         if (status < 0) {
1473                 dev_err(&pdev->dev, "no irq resource found\n");
1474                 goto free_master;
1475         }
1476         init_completion(&mcspi->txdone);
1477         status = devm_request_irq(&pdev->dev, status,
1478                                   omap2_mcspi_irq_handler, 0, pdev->name,
1479                                   mcspi);
1480         if (status) {
1481                 dev_err(&pdev->dev, "Cannot request IRQ");
1482                 goto free_master;
1483         }
1484
1485         pm_runtime_use_autosuspend(&pdev->dev);
1486         pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1487         pm_runtime_enable(&pdev->dev);
1488
1489         status = omap2_mcspi_controller_setup(mcspi);
1490         if (status < 0)
1491                 goto disable_pm;
1492
1493         status = devm_spi_register_controller(&pdev->dev, master);
1494         if (status < 0)
1495                 goto disable_pm;
1496
1497         return status;
1498
1499 disable_pm:
1500         pm_runtime_dont_use_autosuspend(&pdev->dev);
1501         pm_runtime_put_sync(&pdev->dev);
1502         pm_runtime_disable(&pdev->dev);
1503 free_master:
1504         spi_master_put(master);
1505         return status;
1506 }
1507
1508 static int omap2_mcspi_remove(struct platform_device *pdev)
1509 {
1510         struct spi_master *master = platform_get_drvdata(pdev);
1511         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1512
1513         pm_runtime_dont_use_autosuspend(mcspi->dev);
1514         pm_runtime_put_sync(mcspi->dev);
1515         pm_runtime_disable(&pdev->dev);
1516
1517         return 0;
1518 }
1519
1520 /* work with hotplug and coldplug */
1521 MODULE_ALIAS("platform:omap2_mcspi");
1522
1523 static int __maybe_unused omap2_mcspi_suspend(struct device *dev)
1524 {
1525         struct spi_master *master = dev_get_drvdata(dev);
1526         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1527         int error;
1528
1529         error = pinctrl_pm_select_sleep_state(dev);
1530         if (error)
1531                 dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1532                          __func__, error);
1533
1534         error = spi_master_suspend(master);
1535         if (error)
1536                 dev_warn(mcspi->dev, "%s: master suspend failed: %i\n",
1537                          __func__, error);
1538
1539         return pm_runtime_force_suspend(dev);
1540 }
1541
1542 static int __maybe_unused omap2_mcspi_resume(struct device *dev)
1543 {
1544         struct spi_master *master = dev_get_drvdata(dev);
1545         struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1546         int error;
1547
1548         error = pinctrl_pm_select_default_state(dev);
1549         if (error)
1550                 dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1551                          __func__, error);
1552
1553         error = spi_master_resume(master);
1554         if (error)
1555                 dev_warn(mcspi->dev, "%s: master resume failed: %i\n",
1556                          __func__, error);
1557
1558         return pm_runtime_force_resume(dev);
1559 }
1560
1561 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1562         SET_SYSTEM_SLEEP_PM_OPS(omap2_mcspi_suspend,
1563                                 omap2_mcspi_resume)
1564         .runtime_resume = omap_mcspi_runtime_resume,
1565 };
1566
1567 static struct platform_driver omap2_mcspi_driver = {
1568         .driver = {
1569                 .name =         "omap2_mcspi",
1570                 .pm =           &omap2_mcspi_pm_ops,
1571                 .of_match_table = omap_mcspi_of_match,
1572         },
1573         .probe =        omap2_mcspi_probe,
1574         .remove =       omap2_mcspi_remove,
1575 };
1576
1577 module_platform_driver(omap2_mcspi_driver);
1578 MODULE_LICENSE("GPL");