drivers/spi/spi-tegra114.c

   1 /*
   2  * SPI driver for NVIDIA's Tegra114 SPI Controller.
   3  *
   4  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/clk.h>
  20 #include <linux/completion.h>
  21 #include <linux/delay.h>
  22 #include <linux/dmaengine.h>
  23 #include <linux/dma-mapping.h>
  24 #include <linux/dmapool.h>
  25 #include <linux/err.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/io.h>
  28 #include <linux/kernel.h>
  29 #include <linux/kthread.h>
  30 #include <linux/module.h>
  31 #include <linux/platform_device.h>
  32 #include <linux/pm_runtime.h>
  33 #include <linux/of.h>
  34 #include <linux/of_device.h>
  35 #include <linux/reset.h>
  36 #include <linux/spi/spi.h>
  37
  38 #define SPI_COMMAND1                            0x000
  39 #define SPI_BIT_LENGTH(x)                       (((x) & 0x1f) << 0)
  40 #define SPI_PACKED                              (1 << 5)
  41 #define SPI_TX_EN                               (1 << 11)
  42 #define SPI_RX_EN                               (1 << 12)
  43 #define SPI_BOTH_EN_BYTE                        (1 << 13)
  44 #define SPI_BOTH_EN_BIT                         (1 << 14)
  45 #define SPI_LSBYTE_FE                           (1 << 15)
  46 #define SPI_LSBIT_FE                            (1 << 16)
  47 #define SPI_BIDIROE                             (1 << 17)
  48 #define SPI_IDLE_SDA_DRIVE_LOW                  (0 << 18)
  49 #define SPI_IDLE_SDA_DRIVE_HIGH                 (1 << 18)
  50 #define SPI_IDLE_SDA_PULL_LOW                   (2 << 18)
  51 #define SPI_IDLE_SDA_PULL_HIGH                  (3 << 18)
  52 #define SPI_IDLE_SDA_MASK                       (3 << 18)
  53 #define SPI_CS_SW_VAL                           (1 << 20)
  54 #define SPI_CS_SW_HW                            (1 << 21)
  55 /* SPI_CS_POL_INACTIVE bits are default high */
  56                                                 /* n from 0 to 3 */
  57 #define SPI_CS_POL_INACTIVE(n)                  (1 << (22 + (n)))
  58 #define SPI_CS_POL_INACTIVE_MASK                (0xF << 22)
  59
  60 #define SPI_CS_SEL_0                            (0 << 26)
  61 #define SPI_CS_SEL_1                            (1 << 26)
  62 #define SPI_CS_SEL_2                            (2 << 26)
  63 #define SPI_CS_SEL_3                            (3 << 26)
  64 #define SPI_CS_SEL_MASK                         (3 << 26)
  65 #define SPI_CS_SEL(x)                           (((x) & 0x3) << 26)
  66 #define SPI_CONTROL_MODE_0                      (0 << 28)
  67 #define SPI_CONTROL_MODE_1                      (1 << 28)
  68 #define SPI_CONTROL_MODE_2                      (2 << 28)
  69 #define SPI_CONTROL_MODE_3                      (3 << 28)
  70 #define SPI_CONTROL_MODE_MASK                   (3 << 28)
  71 #define SPI_MODE_SEL(x)                         (((x) & 0x3) << 28)
  72 #define SPI_M_S                                 (1 << 30)
  73 #define SPI_PIO                                 (1 << 31)
  74
  75 #define SPI_COMMAND2                            0x004
  76 #define SPI_TX_TAP_DELAY(x)                     (((x) & 0x3F) << 6)
  77 #define SPI_RX_TAP_DELAY(x)                     (((x) & 0x3F) << 0)
  78
  79 #define SPI_CS_TIMING1                          0x008
  80 #define SPI_SETUP_HOLD(setup, hold)             (((setup) << 4) | (hold))
  81 #define SPI_CS_SETUP_HOLD(reg, cs, val)                 \
  82                 ((((val) & 0xFFu) << ((cs) * 8)) |      \
  83                 ((reg) & ~(0xFFu << ((cs) * 8))))
  84
  85 #define SPI_CS_TIMING2                          0x00C
  86 #define CYCLES_BETWEEN_PACKETS_0(x)             (((x) & 0x1F) << 0)
  87 #define CS_ACTIVE_BETWEEN_PACKETS_0             (1 << 5)
  88 #define CYCLES_BETWEEN_PACKETS_1(x)             (((x) & 0x1F) << 8)
  89 #define CS_ACTIVE_BETWEEN_PACKETS_1             (1 << 13)
  90 #define CYCLES_BETWEEN_PACKETS_2(x)             (((x) & 0x1F) << 16)
  91 #define CS_ACTIVE_BETWEEN_PACKETS_2             (1 << 21)
  92 #define CYCLES_BETWEEN_PACKETS_3(x)             (((x) & 0x1F) << 24)
  93 #define CS_ACTIVE_BETWEEN_PACKETS_3             (1 << 29)
  94 #define SPI_SET_CS_ACTIVE_BETWEEN_PACKETS(reg, cs, val)         \
  95                 (reg = (((val) & 0x1) << ((cs) * 8 + 5)) |      \
  96                         ((reg) & ~(1 << ((cs) * 8 + 5))))
  97 #define SPI_SET_CYCLES_BETWEEN_PACKETS(reg, cs, val)            \
  98                 (reg = (((val) & 0xF) << ((cs) * 8)) |          \
  99                         ((reg) & ~(0xF << ((cs) * 8))))
 100
 101 #define SPI_TRANS_STATUS                        0x010
 102 #define SPI_BLK_CNT(val)                        (((val) >> 0) & 0xFFFF)
 103 #define SPI_SLV_IDLE_COUNT(val)                 (((val) >> 16) & 0xFF)
 104 #define SPI_RDY                                 (1 << 30)
 105
 106 #define SPI_FIFO_STATUS                         0x014
 107 #define SPI_RX_FIFO_EMPTY                       (1 << 0)
 108 #define SPI_RX_FIFO_FULL                        (1 << 1)
 109 #define SPI_TX_FIFO_EMPTY                       (1 << 2)
 110 #define SPI_TX_FIFO_FULL                        (1 << 3)
 111 #define SPI_RX_FIFO_UNF                         (1 << 4)
 112 #define SPI_RX_FIFO_OVF                         (1 << 5)
 113 #define SPI_TX_FIFO_UNF                         (1 << 6)
 114 #define SPI_TX_FIFO_OVF                         (1 << 7)
 115 #define SPI_ERR                                 (1 << 8)
 116 #define SPI_TX_FIFO_FLUSH                       (1 << 14)
 117 #define SPI_RX_FIFO_FLUSH                       (1 << 15)
 118 #define SPI_TX_FIFO_EMPTY_COUNT(val)            (((val) >> 16) & 0x7F)
 119 #define SPI_RX_FIFO_FULL_COUNT(val)             (((val) >> 23) & 0x7F)
 120 #define SPI_FRAME_END                           (1 << 30)
 121 #define SPI_CS_INACTIVE                         (1 << 31)
 122
 123 #define SPI_FIFO_ERROR                          (SPI_RX_FIFO_UNF | \
 124                         SPI_RX_FIFO_OVF | SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF)
 125 #define SPI_FIFO_EMPTY                  (SPI_RX_FIFO_EMPTY | SPI_TX_FIFO_EMPTY)
 126
 127 #define SPI_TX_DATA                             0x018
 128 #define SPI_RX_DATA                             0x01C
 129
 130 #define SPI_DMA_CTL                             0x020
 131 #define SPI_TX_TRIG_1                           (0 << 15)
 132 #define SPI_TX_TRIG_4                           (1 << 15)
 133 #define SPI_TX_TRIG_8                           (2 << 15)
 134 #define SPI_TX_TRIG_16                          (3 << 15)
 135 #define SPI_TX_TRIG_MASK                        (3 << 15)
 136 #define SPI_RX_TRIG_1                           (0 << 19)
 137 #define SPI_RX_TRIG_4                           (1 << 19)
 138 #define SPI_RX_TRIG_8                           (2 << 19)
 139 #define SPI_RX_TRIG_16                          (3 << 19)
 140 #define SPI_RX_TRIG_MASK                        (3 << 19)
 141 #define SPI_IE_TX                               (1 << 28)
 142 #define SPI_IE_RX                               (1 << 29)
 143 #define SPI_CONT                                (1 << 30)
 144 #define SPI_DMA                                 (1 << 31)
 145 #define SPI_DMA_EN                              SPI_DMA
 146
 147 #define SPI_DMA_BLK                             0x024
 148 #define SPI_DMA_BLK_SET(x)                      (((x) & 0xFFFF) << 0)
 149
 150 #define SPI_TX_FIFO                             0x108
 151 #define SPI_RX_FIFO                             0x188
 152 #define MAX_CHIP_SELECT                         4
 153 #define SPI_FIFO_DEPTH                          64
 154 #define DATA_DIR_TX                             (1 << 0)
 155 #define DATA_DIR_RX                             (1 << 1)
 156
 157 #define SPI_DMA_TIMEOUT                         (msecs_to_jiffies(1000))
 158 #define DEFAULT_SPI_DMA_BUF_LEN                 (16*1024)
 159 #define TX_FIFO_EMPTY_COUNT_MAX                 SPI_TX_FIFO_EMPTY_COUNT(0x40)
 160 #define RX_FIFO_FULL_COUNT_ZERO                 SPI_RX_FIFO_FULL_COUNT(0)
 161 #define MAX_HOLD_CYCLES                         16
 162 #define SPI_DEFAULT_SPEED                       25000000
 163
 164 struct tegra_spi_data {
 165         struct device                           *dev;
 166         struct spi_master                       *master;
 167         spinlock_t                              lock;
 168
 169         struct clk                              *clk;
 170         struct reset_control                    *rst;
 171         void __iomem                            *base;
 172         phys_addr_t                             phys;
 173         unsigned                                irq;
 174         u32                                     cur_speed;
 175
 176         struct spi_device                       *cur_spi;
 177         struct spi_device                       *cs_control;
 178         unsigned                                cur_pos;
 179         unsigned                                words_per_32bit;
 180         unsigned                                bytes_per_word;
 181         unsigned                                curr_dma_words;
 182         unsigned                                cur_direction;
 183
 184         unsigned                                cur_rx_pos;
 185         unsigned                                cur_tx_pos;
 186
 187         unsigned                                dma_buf_size;
 188         unsigned                                max_buf_size;
 189         bool                                    is_curr_dma_xfer;
 190
 191         struct completion                       rx_dma_complete;
 192         struct completion                       tx_dma_complete;
 193
 194         u32                                     tx_status;
 195         u32                                     rx_status;
 196         u32                                     status_reg;
 197         bool                                    is_packed;
 198
 199         u32                                     command1_reg;
 200         u32                                     dma_control_reg;
 201         u32                                     def_command1_reg;
 202
 203         struct completion                       xfer_completion;
 204         struct spi_transfer                     *curr_xfer;
 205         struct dma_chan                         *rx_dma_chan;
 206         u32                                     *rx_dma_buf;
 207         dma_addr_t                              rx_dma_phys;
 208         struct dma_async_tx_descriptor          *rx_dma_desc;
 209
 210         struct dma_chan                         *tx_dma_chan;
 211         u32                                     *tx_dma_buf;
 212         dma_addr_t                              tx_dma_phys;
 213         struct dma_async_tx_descriptor          *tx_dma_desc;
 214 };
 215
 216 static int tegra_spi_runtime_suspend(struct device *dev);
 217 static int tegra_spi_runtime_resume(struct device *dev);
 218
 219 static inline u32 tegra_spi_readl(struct tegra_spi_data *tspi,
 220                 unsigned long reg)
 221 {
 222         return readl(tspi->base + reg);
 223 }
 224
 225 static inline void tegra_spi_writel(struct tegra_spi_data *tspi,
 226                 u32 val, unsigned long reg)
 227 {
 228         writel(val, tspi->base + reg);
 229
 230         /* Read back register to make sure that register writes completed */
 231         if (reg != SPI_TX_FIFO)
 232                 readl(tspi->base + SPI_COMMAND1);
 233 }
 234
 235 static void tegra_spi_clear_status(struct tegra_spi_data *tspi)
 236 {
 237         u32 val;
 238
 239         /* Write 1 to clear status register */
 240         val = tegra_spi_readl(tspi, SPI_TRANS_STATUS);
 241         tegra_spi_writel(tspi, val, SPI_TRANS_STATUS);
 242
 243         /* Clear fifo status error if any */
 244         val = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
 245         if (val & SPI_ERR)
 246                 tegra_spi_writel(tspi, SPI_ERR | SPI_FIFO_ERROR,
 247                                 SPI_FIFO_STATUS);
 248 }
 249
 250 static unsigned tegra_spi_calculate_curr_xfer_param(
 251         struct spi_device *spi, struct tegra_spi_data *tspi,
 252         struct spi_transfer *t)
 253 {
 254         unsigned remain_len = t->len - tspi->cur_pos;
 255         unsigned max_word;
 256         unsigned bits_per_word = t->bits_per_word;
 257         unsigned max_len;
 258         unsigned total_fifo_words;
 259
 260         tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
 261
 262         if (bits_per_word == 8 || bits_per_word == 16 || bits_per_word == 32) {
 263                 tspi->is_packed = 1;
 264                 tspi->words_per_32bit = 32/bits_per_word;
 265         } else {
 266                 tspi->is_packed = 0;
 267                 tspi->words_per_32bit = 1;
 268         }
 269
 270         if (tspi->is_packed) {
 271                 max_len = min(remain_len, tspi->max_buf_size);
 272                 tspi->curr_dma_words = max_len/tspi->bytes_per_word;
 273                 total_fifo_words = (max_len + 3) / 4;
 274         } else {
 275                 max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
 276                 max_word = min(max_word, tspi->max_buf_size/4);
 277                 tspi->curr_dma_words = max_word;
 278                 total_fifo_words = max_word;
 279         }
 280         return total_fifo_words;
 281 }
 282
 283 static unsigned tegra_spi_fill_tx_fifo_from_client_txbuf(
 284         struct tegra_spi_data *tspi, struct spi_transfer *t)
 285 {
 286         unsigned nbytes;
 287         unsigned tx_empty_count;
 288         u32 fifo_status;
 289         unsigned max_n_32bit;
 290         unsigned i, count;
 291         unsigned int written_words;
 292         unsigned fifo_words_left;
 293         u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
 294
 295         fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
 296         tx_empty_count = SPI_TX_FIFO_EMPTY_COUNT(fifo_status);
 297
 298         if (tspi->is_packed) {
 299                 fifo_words_left = tx_empty_count * tspi->words_per_32bit;
 300                 written_words = min(fifo_words_left, tspi->curr_dma_words);
 301                 nbytes = written_words * tspi->bytes_per_word;
 302                 max_n_32bit = DIV_ROUND_UP(nbytes, 4);
 303                 for (count = 0; count < max_n_32bit; count++) {
 304                         u32 x = 0;
 305
 306                         for (i = 0; (i < 4) && nbytes; i++, nbytes--)
 307                                 x |= (u32)(*tx_buf++) << (i * 8);
 308                         tegra_spi_writel(tspi, x, SPI_TX_FIFO);
 309                 }
 310
 311                 tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
 312         } else {
 313                 unsigned int write_bytes;
 314                 max_n_32bit = min(tspi->curr_dma_words,  tx_empty_count);
 315                 written_words = max_n_32bit;
 316                 nbytes = written_words * tspi->bytes_per_word;
 317                 if (nbytes > t->len - tspi->cur_pos)
 318                         nbytes = t->len - tspi->cur_pos;
 319                 write_bytes = nbytes;
 320                 for (count = 0; count < max_n_32bit; count++) {
 321                         u32 x = 0;
 322
 323                         for (i = 0; nbytes && (i < tspi->bytes_per_word);
 324                                                         i++, nbytes--)
 325                                 x |= (u32)(*tx_buf++) << (i * 8);
 326                         tegra_spi_writel(tspi, x, SPI_TX_FIFO);
 327                 }
 328
 329                 tspi->cur_tx_pos += write_bytes;
 330         }
 331
 332         return written_words;
 333 }
 334
 335 static unsigned int tegra_spi_read_rx_fifo_to_client_rxbuf(
 336                 struct tegra_spi_data *tspi, struct spi_transfer *t)
 337 {
 338         unsigned rx_full_count;
 339         u32 fifo_status;
 340         unsigned i, count;
 341         unsigned int read_words = 0;
 342         unsigned len;
 343         u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
 344
 345         fifo_status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
 346         rx_full_count = SPI_RX_FIFO_FULL_COUNT(fifo_status);
 347         if (tspi->is_packed) {
 348                 len = tspi->curr_dma_words * tspi->bytes_per_word;
 349                 for (count = 0; count < rx_full_count; count++) {
 350                         u32 x = tegra_spi_readl(tspi, SPI_RX_FIFO);
 351
 352                         for (i = 0; len && (i < 4); i++, len--)
 353                                 *rx_buf++ = (x >> i*8) & 0xFF;
 354                 }
 355                 read_words += tspi->curr_dma_words;
 356                 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
 357         } else {
 358                 u32 rx_mask = ((u32)1 << t->bits_per_word) - 1;
 359                 u8 bytes_per_word = tspi->bytes_per_word;
 360                 unsigned int read_bytes;
 361
 362                 len = rx_full_count * bytes_per_word;
 363                 if (len > t->len - tspi->cur_pos)
 364                         len = t->len - tspi->cur_pos;
 365                 read_bytes = len;
 366                 for (count = 0; count < rx_full_count; count++) {
 367                         u32 x = tegra_spi_readl(tspi, SPI_RX_FIFO) & rx_mask;
 368
 369                         for (i = 0; len && (i < bytes_per_word); i++, len--)
 370                                 *rx_buf++ = (x >> (i*8)) & 0xFF;
 371                 }
 372                 read_words += rx_full_count;
 373                 tspi->cur_rx_pos += read_bytes;
 374         }
 375
 376         return read_words;
 377 }
 378
 379 static void tegra_spi_copy_client_txbuf_to_spi_txbuf(
 380                 struct tegra_spi_data *tspi, struct spi_transfer *t)
 381 {
 382         /* Make the dma buffer to read by cpu */
 383         dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
 384                                 tspi->dma_buf_size, DMA_TO_DEVICE);
 385
 386         if (tspi->is_packed) {
 387                 unsigned len = tspi->curr_dma_words * tspi->bytes_per_word;
 388
 389                 memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
 390                 tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
 391         } else {
 392                 unsigned int i;
 393                 unsigned int count;
 394                 u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
 395                 unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
 396                 unsigned int write_bytes;
 397
 398                 if (consume > t->len - tspi->cur_pos)
 399                         consume = t->len - tspi->cur_pos;
 400                 write_bytes = consume;
 401                 for (count = 0; count < tspi->curr_dma_words; count++) {
 402                         u32 x = 0;
 403
 404                         for (i = 0; consume && (i < tspi->bytes_per_word);
 405                                                         i++, consume--)
 406                                 x |= (u32)(*tx_buf++) << (i * 8);
 407                         tspi->tx_dma_buf[count] = x;
 408                 }
 409
 410                 tspi->cur_tx_pos += write_bytes;
 411         }
 412
 413         /* Make the dma buffer to read by dma */
 414         dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
 415                                 tspi->dma_buf_size, DMA_TO_DEVICE);
 416 }
 417
 418 static void tegra_spi_copy_spi_rxbuf_to_client_rxbuf(
 419                 struct tegra_spi_data *tspi, struct spi_transfer *t)
 420 {
 421         /* Make the dma buffer to read by cpu */
 422         dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
 423                 tspi->dma_buf_size, DMA_FROM_DEVICE);
 424
 425         if (tspi->is_packed) {
 426                 unsigned len = tspi->curr_dma_words * tspi->bytes_per_word;
 427
 428                 memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
 429                 tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
 430         } else {
 431                 unsigned int i;
 432                 unsigned int count;
 433                 unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
 434                 u32 rx_mask = ((u32)1 << t->bits_per_word) - 1;
 435                 unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
 436                 unsigned int read_bytes;
 437
 438                 if (consume > t->len - tspi->cur_pos)
 439                         consume = t->len - tspi->cur_pos;
 440                 read_bytes = consume;
 441                 for (count = 0; count < tspi->curr_dma_words; count++) {
 442                         u32 x = tspi->rx_dma_buf[count] & rx_mask;
 443
 444                         for (i = 0; consume && (i < tspi->bytes_per_word);
 445                                                         i++, consume--)
 446                                 *rx_buf++ = (x >> (i*8)) & 0xFF;
 447                 }
 448
 449                 tspi->cur_rx_pos += read_bytes;
 450         }
 451
 452         /* Make the dma buffer to read by dma */
 453         dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
 454                 tspi->dma_buf_size, DMA_FROM_DEVICE);
 455 }
 456
 457 static void tegra_spi_dma_complete(void *args)
 458 {
 459         struct completion *dma_complete = args;
 460
 461         complete(dma_complete);
 462 }
 463
 464 static int tegra_spi_start_tx_dma(struct tegra_spi_data *tspi, int len)
 465 {
 466         reinit_completion(&tspi->tx_dma_complete);
 467         tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
 468                                 tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
 469                                 DMA_PREP_INTERRUPT |  DMA_CTRL_ACK);
 470         if (!tspi->tx_dma_desc) {
 471                 dev_err(tspi->dev, "Not able to get desc for Tx\n");
 472                 return -EIO;
 473         }
 474
 475         tspi->tx_dma_desc->callback = tegra_spi_dma_complete;
 476         tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
 477
 478         dmaengine_submit(tspi->tx_dma_desc);
 479         dma_async_issue_pending(tspi->tx_dma_chan);
 480         return 0;
 481 }
 482
 483 static int tegra_spi_start_rx_dma(struct tegra_spi_data *tspi, int len)
 484 {
 485         reinit_completion(&tspi->rx_dma_complete);
 486         tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
 487                                 tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
 488                                 DMA_PREP_INTERRUPT |  DMA_CTRL_ACK);
 489         if (!tspi->rx_dma_desc) {
 490                 dev_err(tspi->dev, "Not able to get desc for Rx\n");
 491                 return -EIO;
 492         }
 493
 494         tspi->rx_dma_desc->callback = tegra_spi_dma_complete;
 495         tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
 496
 497         dmaengine_submit(tspi->rx_dma_desc);
 498         dma_async_issue_pending(tspi->rx_dma_chan);
 499         return 0;
 500 }
 501
 502 static int tegra_spi_flush_fifos(struct tegra_spi_data *tspi)
 503 {
 504         unsigned long timeout = jiffies + HZ;
 505         u32 status;
 506
 507         status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
 508         if ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
 509                 status |= SPI_RX_FIFO_FLUSH | SPI_TX_FIFO_FLUSH;
 510                 tegra_spi_writel(tspi, status, SPI_FIFO_STATUS);
 511                 while ((status & SPI_FIFO_EMPTY) != SPI_FIFO_EMPTY) {
 512                         status = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
 513                         if (time_after(jiffies, timeout)) {
 514                                 dev_err(tspi->dev,
 515                                         "timeout waiting for fifo flush\n");
 516                                 return -EIO;
 517                         }
 518
 519                         udelay(1);
 520                 }
 521         }
 522
 523         return 0;
 524 }
 525
 526 static int tegra_spi_start_dma_based_transfer(
 527                 struct tegra_spi_data *tspi, struct spi_transfer *t)
 528 {
 529         u32 val;
 530         unsigned int len;
 531         int ret = 0;
 532         u8 dma_burst;
 533         struct dma_slave_config dma_sconfig = {0};
 534
 535         val = SPI_DMA_BLK_SET(tspi->curr_dma_words - 1);
 536         tegra_spi_writel(tspi, val, SPI_DMA_BLK);
 537
 538         if (tspi->is_packed)
 539                 len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
 540                                         4) * 4;
 541         else
 542                 len = tspi->curr_dma_words * 4;
 543
 544         /* Set attention level based on length of transfer */
 545         if (len & 0xF) {
 546                 val |= SPI_TX_TRIG_1 | SPI_RX_TRIG_1;
 547                 dma_burst = 1;
 548         } else if (((len) >> 4) & 0x1) {
 549                 val |= SPI_TX_TRIG_4 | SPI_RX_TRIG_4;
 550                 dma_burst = 4;
 551         } else {
 552                 val |= SPI_TX_TRIG_8 | SPI_RX_TRIG_8;
 553                 dma_burst = 8;
 554         }
 555
 556         if (tspi->cur_direction & DATA_DIR_TX)
 557                 val |= SPI_IE_TX;
 558
 559         if (tspi->cur_direction & DATA_DIR_RX)
 560                 val |= SPI_IE_RX;
 561
 562         tegra_spi_writel(tspi, val, SPI_DMA_CTL);
 563         tspi->dma_control_reg = val;
 564
 565         dma_sconfig.device_fc = true;
 566         if (tspi->cur_direction & DATA_DIR_TX) {
 567                 dma_sconfig.dst_addr = tspi->phys + SPI_TX_FIFO;
 568                 dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 569                 dma_sconfig.dst_maxburst = dma_burst;
 570                 ret = dmaengine_slave_config(tspi->tx_dma_chan, &dma_sconfig);
 571                 if (ret < 0) {
 572                         dev_err(tspi->dev,
 573                                 "DMA slave config failed: %d\n", ret);
 574                         return ret;
 575                 }
 576
 577                 tegra_spi_copy_client_txbuf_to_spi_txbuf(tspi, t);
 578                 ret = tegra_spi_start_tx_dma(tspi, len);
 579                 if (ret < 0) {
 580                         dev_err(tspi->dev,
 581                                 "Starting tx dma failed, err %d\n", ret);
 582                         return ret;
 583                 }
 584         }
 585
 586         if (tspi->cur_direction & DATA_DIR_RX) {
 587                 dma_sconfig.src_addr = tspi->phys + SPI_RX_FIFO;
 588                 dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 589                 dma_sconfig.src_maxburst = dma_burst;
 590                 ret = dmaengine_slave_config(tspi->rx_dma_chan, &dma_sconfig);
 591                 if (ret < 0) {
 592                         dev_err(tspi->dev,
 593                                 "DMA slave config failed: %d\n", ret);
 594                         return ret;
 595                 }
 596
 597                 /* Make the dma buffer to read by dma */
 598                 dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
 599                                 tspi->dma_buf_size, DMA_FROM_DEVICE);
 600
 601                 ret = tegra_spi_start_rx_dma(tspi, len);
 602                 if (ret < 0) {
 603                         dev_err(tspi->dev,
 604                                 "Starting rx dma failed, err %d\n", ret);
 605                         if (tspi->cur_direction & DATA_DIR_TX)
 606                                 dmaengine_terminate_all(tspi->tx_dma_chan);
 607                         return ret;
 608                 }
 609         }
 610         tspi->is_curr_dma_xfer = true;
 611         tspi->dma_control_reg = val;
 612
 613         val |= SPI_DMA_EN;
 614         tegra_spi_writel(tspi, val, SPI_DMA_CTL);
 615         return ret;
 616 }
 617
 618 static int tegra_spi_start_cpu_based_transfer(
 619                 struct tegra_spi_data *tspi, struct spi_transfer *t)
 620 {
 621         u32 val;
 622         unsigned cur_words;
 623
 624         if (tspi->cur_direction & DATA_DIR_TX)
 625                 cur_words = tegra_spi_fill_tx_fifo_from_client_txbuf(tspi, t);
 626         else
 627                 cur_words = tspi->curr_dma_words;
 628
 629         val = SPI_DMA_BLK_SET(cur_words - 1);
 630         tegra_spi_writel(tspi, val, SPI_DMA_BLK);
 631
 632         val = 0;
 633         if (tspi->cur_direction & DATA_DIR_TX)
 634                 val |= SPI_IE_TX;
 635
 636         if (tspi->cur_direction & DATA_DIR_RX)
 637                 val |= SPI_IE_RX;
 638
 639         tegra_spi_writel(tspi, val, SPI_DMA_CTL);
 640         tspi->dma_control_reg = val;
 641
 642         tspi->is_curr_dma_xfer = false;
 643
 644         val |= SPI_DMA_EN;
 645         tegra_spi_writel(tspi, val, SPI_DMA_CTL);
 646         return 0;
 647 }
 648
 649 static int tegra_spi_init_dma_param(struct tegra_spi_data *tspi,
 650                         bool dma_to_memory)
 651 {
 652         struct dma_chan *dma_chan;
 653         u32 *dma_buf;
 654         dma_addr_t dma_phys;
 655         int ret;
 656
 657         dma_chan = dma_request_slave_channel_reason(tspi->dev,
 658                                         dma_to_memory ? "rx" : "tx");
 659         if (IS_ERR(dma_chan)) {
 660                 ret = PTR_ERR(dma_chan);
 661                 if (ret != -EPROBE_DEFER)
 662                         dev_err(tspi->dev,
 663                                 "Dma channel is not available: %d\n", ret);
 664                 return ret;
 665         }
 666
 667         dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
 668                                 &dma_phys, GFP_KERNEL);
 669         if (!dma_buf) {
 670                 dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
 671                 dma_release_channel(dma_chan);
 672                 return -ENOMEM;
 673         }
 674
 675         if (dma_to_memory) {
 676                 tspi->rx_dma_chan = dma_chan;
 677                 tspi->rx_dma_buf = dma_buf;
 678                 tspi->rx_dma_phys = dma_phys;
 679         } else {
 680                 tspi->tx_dma_chan = dma_chan;
 681                 tspi->tx_dma_buf = dma_buf;
 682                 tspi->tx_dma_phys = dma_phys;
 683         }
 684         return 0;
 685 }
 686
 687 static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi,
 688         bool dma_to_memory)
 689 {
 690         u32 *dma_buf;
 691         dma_addr_t dma_phys;
 692         struct dma_chan *dma_chan;
 693
 694         if (dma_to_memory) {
 695                 dma_buf = tspi->rx_dma_buf;
 696                 dma_chan = tspi->rx_dma_chan;
 697                 dma_phys = tspi->rx_dma_phys;
 698                 tspi->rx_dma_chan = NULL;
 699                 tspi->rx_dma_buf = NULL;
 700         } else {
 701                 dma_buf = tspi->tx_dma_buf;
 702                 dma_chan = tspi->tx_dma_chan;
 703                 dma_phys = tspi->tx_dma_phys;
 704                 tspi->tx_dma_buf = NULL;
 705                 tspi->tx_dma_chan = NULL;
 706         }
 707         if (!dma_chan)
 708                 return;
 709
 710         dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
 711         dma_release_channel(dma_chan);
 712 }
 713
 714 static u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
 715                 struct spi_transfer *t, bool is_first_of_msg)
 716 {
 717         struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
 718         u32 speed = t->speed_hz;
 719         u8 bits_per_word = t->bits_per_word;
 720         u32 command1;
 721         int req_mode;
 722
 723         if (speed != tspi->cur_speed) {
 724                 clk_set_rate(tspi->clk, speed);
 725                 tspi->cur_speed = speed;
 726         }
 727
 728         tspi->cur_spi = spi;
 729         tspi->cur_pos = 0;
 730         tspi->cur_rx_pos = 0;
 731         tspi->cur_tx_pos = 0;
 732         tspi->curr_xfer = t;
 733
 734         if (is_first_of_msg) {
 735                 tegra_spi_clear_status(tspi);
 736
 737                 command1 = tspi->def_command1_reg;
 738                 command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
 739
 740                 command1 &= ~SPI_CONTROL_MODE_MASK;
 741                 req_mode = spi->mode & 0x3;
 742                 if (req_mode == SPI_MODE_0)
 743                         command1 |= SPI_CONTROL_MODE_0;
 744                 else if (req_mode == SPI_MODE_1)
 745                         command1 |= SPI_CONTROL_MODE_1;
 746                 else if (req_mode == SPI_MODE_2)
 747                         command1 |= SPI_CONTROL_MODE_2;
 748                 else if (req_mode == SPI_MODE_3)
 749                         command1 |= SPI_CONTROL_MODE_3;
 750
 751                 if (spi->mode & SPI_LSB_FIRST)
 752                         command1 |= SPI_LSBIT_FE;
 753                 else
 754                         command1 &= ~SPI_LSBIT_FE;
 755
 756                 if (tspi->cs_control) {
 757                         if (tspi->cs_control != spi)
 758                                 tegra_spi_writel(tspi, command1, SPI_COMMAND1);
 759                         tspi->cs_control = NULL;
 760                 } else
 761                         tegra_spi_writel(tspi, command1, SPI_COMMAND1);
 762
 763                 command1 |= SPI_CS_SW_HW;
 764                 if (spi->mode & SPI_CS_HIGH)
 765                         command1 |= SPI_CS_SW_VAL;
 766                 else
 767                         command1 &= ~SPI_CS_SW_VAL;
 768
 769                 tegra_spi_writel(tspi, 0, SPI_COMMAND2);
 770         } else {
 771                 command1 = tspi->command1_reg;
 772                 command1 &= ~SPI_BIT_LENGTH(~0);
 773                 command1 |= SPI_BIT_LENGTH(bits_per_word - 1);
 774         }
 775
 776         return command1;
 777 }
 778
 779 static int tegra_spi_start_transfer_one(struct spi_device *spi,
 780                 struct spi_transfer *t, u32 command1)
 781 {
 782         struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
 783         unsigned total_fifo_words;
 784         int ret;
 785
 786         total_fifo_words = tegra_spi_calculate_curr_xfer_param(spi, tspi, t);
 787
 788         if (tspi->is_packed)
 789                 command1 |= SPI_PACKED;
 790         else
 791                 command1 &= ~SPI_PACKED;
 792
 793         command1 &= ~(SPI_CS_SEL_MASK | SPI_TX_EN | SPI_RX_EN);
 794         tspi->cur_direction = 0;
 795         if (t->rx_buf) {
 796                 command1 |= SPI_RX_EN;
 797                 tspi->cur_direction |= DATA_DIR_RX;
 798         }
 799         if (t->tx_buf) {
 800                 command1 |= SPI_TX_EN;
 801                 tspi->cur_direction |= DATA_DIR_TX;
 802         }
 803         command1 |= SPI_CS_SEL(spi->chip_select);
 804         tegra_spi_writel(tspi, command1, SPI_COMMAND1);
 805         tspi->command1_reg = command1;
 806
 807         dev_dbg(tspi->dev, "The def 0x%x and written 0x%x\n",
 808                 tspi->def_command1_reg, (unsigned)command1);
 809
 810         ret = tegra_spi_flush_fifos(tspi);
 811         if (ret < 0)
 812                 return ret;
 813         if (total_fifo_words > SPI_FIFO_DEPTH)
 814                 ret = tegra_spi_start_dma_based_transfer(tspi, t);
 815         else
 816                 ret = tegra_spi_start_cpu_based_transfer(tspi, t);
 817         return ret;
 818 }
 819
 820 static int tegra_spi_setup(struct spi_device *spi)
 821 {
 822         struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
 823         u32 val;
 824         unsigned long flags;
 825         int ret;
 826
 827         dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
 828                 spi->bits_per_word,
 829                 spi->mode & SPI_CPOL ? "" : "~",
 830                 spi->mode & SPI_CPHA ? "" : "~",
 831                 spi->max_speed_hz);
 832
 833         ret = pm_runtime_get_sync(tspi->dev);
 834         if (ret < 0) {
 835                 dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
 836                 return ret;
 837         }
 838
 839         spin_lock_irqsave(&tspi->lock, flags);
 840         val = tspi->def_command1_reg;
 841         if (spi->mode & SPI_CS_HIGH)
 842                 val &= ~SPI_CS_POL_INACTIVE(spi->chip_select);
 843         else
 844                 val |= SPI_CS_POL_INACTIVE(spi->chip_select);
 845         tspi->def_command1_reg = val;
 846         tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
 847         spin_unlock_irqrestore(&tspi->lock, flags);
 848
 849         pm_runtime_put(tspi->dev);
 850         return 0;
 851 }
 852
 853 static void tegra_spi_transfer_delay(int delay)
 854 {
 855         if (!delay)
 856                 return;
 857
 858         if (delay >= 1000)
 859                 mdelay(delay / 1000);
 860
 861         udelay(delay % 1000);
 862 }
 863
 864 static void tegra_spi_transfer_end(struct spi_device *spi)
 865 {
 866         struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
 867         int cs_val = (spi->mode & SPI_CS_HIGH) ? 0 : 1;
 868
 869         if (cs_val)
 870                 tspi->command1_reg |= SPI_CS_SW_VAL;
 871         else
 872                 tspi->command1_reg &= ~SPI_CS_SW_VAL;
 873         tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
 874         tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
 875 }
 876
 877 static int tegra_spi_transfer_one_message(struct spi_master *master,
 878                         struct spi_message *msg)
 879 {
 880         bool is_first_msg = true;
 881         struct tegra_spi_data *tspi = spi_master_get_devdata(master);
 882         struct spi_transfer *xfer;
 883         struct spi_device *spi = msg->spi;
 884         int ret;
 885         bool skip = false;
 886
 887         msg->status = 0;
 888         msg->actual_length = 0;
 889
 890         list_for_each_entry(xfer, &msg->transfers, transfer_list) {
 891                 u32 cmd1;
 892
 893                 reinit_completion(&tspi->xfer_completion);
 894
 895                 cmd1 = tegra_spi_setup_transfer_one(spi, xfer, is_first_msg);
 896
 897                 if (!xfer->len) {
 898                         ret = 0;
 899                         skip = true;
 900                         goto complete_xfer;
 901                 }
 902
 903                 ret = tegra_spi_start_transfer_one(spi, xfer, cmd1);
 904                 if (ret < 0) {
 905                         dev_err(tspi->dev,
 906                                 "spi can not start transfer, err %d\n", ret);
 907                         goto complete_xfer;
 908                 }
 909
 910                 is_first_msg = false;
 911                 ret = wait_for_completion_timeout(&tspi->xfer_completion,
 912                                                 SPI_DMA_TIMEOUT);
 913                 if (WARN_ON(ret == 0)) {
 914                         dev_err(tspi->dev,
 915                                 "spi transfer timeout, err %d\n", ret);
 916                         if (tspi->is_curr_dma_xfer &&
 917                             (tspi->cur_direction & DATA_DIR_TX))
 918                                 dmaengine_terminate_all(tspi->tx_dma_chan);
 919                         if (tspi->is_curr_dma_xfer &&
 920                             (tspi->cur_direction & DATA_DIR_RX))
 921                                 dmaengine_terminate_all(tspi->rx_dma_chan);
 922                         ret = -EIO;
 923                         tegra_spi_flush_fifos(tspi);
 924                         reset_control_assert(tspi->rst);
 925                         udelay(2);
 926                         reset_control_deassert(tspi->rst);
 927                         goto complete_xfer;
 928                 }
 929
 930                 if (tspi->tx_status ||  tspi->rx_status) {
 931                         dev_err(tspi->dev, "Error in Transfer\n");
 932                         ret = -EIO;
 933                         goto complete_xfer;
 934                 }
 935                 msg->actual_length += xfer->len;
 936
 937 complete_xfer:
 938                 if (ret < 0 || skip) {
 939                         tegra_spi_transfer_end(spi);
 940                         tegra_spi_transfer_delay(xfer->delay_usecs);
 941                         goto exit;
 942                 } else if (list_is_last(&xfer->transfer_list,
 943                                         &msg->transfers)) {
 944                         if (xfer->cs_change)
 945                                 tspi->cs_control = spi;
 946                         else {
 947                                 tegra_spi_transfer_end(spi);
 948                                 tegra_spi_transfer_delay(xfer->delay_usecs);
 949                         }
 950                 } else if (xfer->cs_change) {
 951                         tegra_spi_transfer_end(spi);
 952                         tegra_spi_transfer_delay(xfer->delay_usecs);
 953                 }
 954
 955         }
 956         ret = 0;
 957 exit:
 958         msg->status = ret;
 959         spi_finalize_current_message(master);
 960         return ret;
 961 }
 962
 963 static irqreturn_t handle_cpu_based_xfer(struct tegra_spi_data *tspi)
 964 {
 965         struct spi_transfer *t = tspi->curr_xfer;
 966         unsigned long flags;
 967
 968         spin_lock_irqsave(&tspi->lock, flags);
 969         if (tspi->tx_status ||  tspi->rx_status) {
 970                 dev_err(tspi->dev, "CpuXfer ERROR bit set 0x%x\n",
 971                         tspi->status_reg);
 972                 dev_err(tspi->dev, "CpuXfer 0x%08x:0x%08x\n",
 973                         tspi->command1_reg, tspi->dma_control_reg);
 974                 tegra_spi_flush_fifos(tspi);
 975                 complete(&tspi->xfer_completion);
 976                 spin_unlock_irqrestore(&tspi->lock, flags);
 977                 reset_control_assert(tspi->rst);
 978                 udelay(2);
 979                 reset_control_deassert(tspi->rst);
 980                 return IRQ_HANDLED;
 981         }
 982
 983         if (tspi->cur_direction & DATA_DIR_RX)
 984                 tegra_spi_read_rx_fifo_to_client_rxbuf(tspi, t);
 985
 986         if (tspi->cur_direction & DATA_DIR_TX)
 987                 tspi->cur_pos = tspi->cur_tx_pos;
 988         else
 989                 tspi->cur_pos = tspi->cur_rx_pos;
 990
 991         if (tspi->cur_pos == t->len) {
 992                 complete(&tspi->xfer_completion);
 993                 goto exit;
 994         }
 995
 996         tegra_spi_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
 997         tegra_spi_start_cpu_based_transfer(tspi, t);
 998 exit:
 999         spin_unlock_irqrestore(&tspi->lock, flags);
1000         return IRQ_HANDLED;
1001 }
1002
1003 static irqreturn_t handle_dma_based_xfer(struct tegra_spi_data *tspi)
1004 {
1005         struct spi_transfer *t = tspi->curr_xfer;
1006         long wait_status;
1007         int err = 0;
1008         unsigned total_fifo_words;
1009         unsigned long flags;
1010
1011         /* Abort dmas if any error */
1012         if (tspi->cur_direction & DATA_DIR_TX) {
1013                 if (tspi->tx_status) {
1014                         dmaengine_terminate_all(tspi->tx_dma_chan);
1015                         err += 1;
1016                 } else {
1017                         wait_status = wait_for_completion_interruptible_timeout(
1018                                 &tspi->tx_dma_complete, SPI_DMA_TIMEOUT);
1019                         if (wait_status <= 0) {
1020                                 dmaengine_terminate_all(tspi->tx_dma_chan);
1021                                 dev_err(tspi->dev, "TxDma Xfer failed\n");
1022                                 err += 1;
1023                         }
1024                 }
1025         }
1026
1027         if (tspi->cur_direction & DATA_DIR_RX) {
1028                 if (tspi->rx_status) {
1029                         dmaengine_terminate_all(tspi->rx_dma_chan);
1030                         err += 2;
1031                 } else {
1032                         wait_status = wait_for_completion_interruptible_timeout(
1033                                 &tspi->rx_dma_complete, SPI_DMA_TIMEOUT);
1034                         if (wait_status <= 0) {
1035                                 dmaengine_terminate_all(tspi->rx_dma_chan);
1036                                 dev_err(tspi->dev, "RxDma Xfer failed\n");
1037                                 err += 2;
1038                         }
1039                 }
1040         }
1041
1042         spin_lock_irqsave(&tspi->lock, flags);
1043         if (err) {
1044                 dev_err(tspi->dev, "DmaXfer: ERROR bit set 0x%x\n",
1045                         tspi->status_reg);
1046                 dev_err(tspi->dev, "DmaXfer 0x%08x:0x%08x\n",
1047                         tspi->command1_reg, tspi->dma_control_reg);
1048                 tegra_spi_flush_fifos(tspi);
1049                 complete(&tspi->xfer_completion);
1050                 spin_unlock_irqrestore(&tspi->lock, flags);
1051                 reset_control_assert(tspi->rst);
1052                 udelay(2);
1053                 reset_control_deassert(tspi->rst);
1054                 return IRQ_HANDLED;
1055         }
1056
1057         if (tspi->cur_direction & DATA_DIR_RX)
1058                 tegra_spi_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
1059
1060         if (tspi->cur_direction & DATA_DIR_TX)
1061                 tspi->cur_pos = tspi->cur_tx_pos;
1062         else
1063                 tspi->cur_pos = tspi->cur_rx_pos;
1064
1065         if (tspi->cur_pos == t->len) {
1066                 complete(&tspi->xfer_completion);
1067                 goto exit;
1068         }
1069
1070         /* Continue transfer in current message */
1071         total_fifo_words = tegra_spi_calculate_curr_xfer_param(tspi->cur_spi,
1072                                                         tspi, t);
1073         if (total_fifo_words > SPI_FIFO_DEPTH)
1074                 err = tegra_spi_start_dma_based_transfer(tspi, t);
1075         else
1076                 err = tegra_spi_start_cpu_based_transfer(tspi, t);
1077
1078 exit:
1079         spin_unlock_irqrestore(&tspi->lock, flags);
1080         return IRQ_HANDLED;
1081 }
1082
1083 static irqreturn_t tegra_spi_isr_thread(int irq, void *context_data)
1084 {
1085         struct tegra_spi_data *tspi = context_data;
1086
1087         if (!tspi->is_curr_dma_xfer)
1088                 return handle_cpu_based_xfer(tspi);
1089         return handle_dma_based_xfer(tspi);
1090 }
1091
1092 static irqreturn_t tegra_spi_isr(int irq, void *context_data)
1093 {
1094         struct tegra_spi_data *tspi = context_data;
1095
1096         tspi->status_reg = tegra_spi_readl(tspi, SPI_FIFO_STATUS);
1097         if (tspi->cur_direction & DATA_DIR_TX)
1098                 tspi->tx_status = tspi->status_reg &
1099                                         (SPI_TX_FIFO_UNF | SPI_TX_FIFO_OVF);
1100
1101         if (tspi->cur_direction & DATA_DIR_RX)
1102                 tspi->rx_status = tspi->status_reg &
1103                                         (SPI_RX_FIFO_OVF | SPI_RX_FIFO_UNF);
1104         tegra_spi_clear_status(tspi);
1105
1106         return IRQ_WAKE_THREAD;
1107 }
1108
1109 static const struct of_device_id tegra_spi_of_match[] = {
1110         { .compatible = "nvidia,tegra114-spi", },
1111         {}
1112 };
1113 MODULE_DEVICE_TABLE(of, tegra_spi_of_match);
1114
1115 static int tegra_spi_probe(struct platform_device *pdev)
1116 {
1117         struct spi_master       *master;
1118         struct tegra_spi_data   *tspi;
1119         struct resource         *r;
1120         int ret, spi_irq;
1121
1122         master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
1123         if (!master) {
1124                 dev_err(&pdev->dev, "master allocation failed\n");
1125                 return -ENOMEM;
1126         }
1127         platform_set_drvdata(pdev, master);
1128         tspi = spi_master_get_devdata(master);
1129
1130         if (of_property_read_u32(pdev->dev.of_node, "spi-max-frequency",
1131                                  &master->max_speed_hz))
1132                 master->max_speed_hz = 25000000; /* 25MHz */
1133
1134         /* the spi->mode bits understood by this driver: */
1135         master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
1136         master->setup = tegra_spi_setup;
1137         master->transfer_one_message = tegra_spi_transfer_one_message;
1138         master->num_chipselect = MAX_CHIP_SELECT;
1139         master->auto_runtime_pm = true;
1140
1141         tspi->master = master;
1142         tspi->dev = &pdev->dev;
1143         spin_lock_init(&tspi->lock);
1144
1145         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1146         tspi->base = devm_ioremap_resource(&pdev->dev, r);
1147         if (IS_ERR(tspi->base)) {
1148                 ret = PTR_ERR(tspi->base);
1149                 goto exit_free_master;
1150         }
1151         tspi->phys = r->start;
1152
1153         spi_irq = platform_get_irq(pdev, 0);
1154         tspi->irq = spi_irq;
1155
1156         tspi->clk = devm_clk_get(&pdev->dev, "spi");
1157         if (IS_ERR(tspi->clk)) {
1158                 dev_err(&pdev->dev, "can not get clock\n");
1159                 ret = PTR_ERR(tspi->clk);
1160                 goto exit_free_master;
1161         }
1162
1163         tspi->rst = devm_reset_control_get_exclusive(&pdev->dev, "spi");
1164         if (IS_ERR(tspi->rst)) {
1165                 dev_err(&pdev->dev, "can not get reset\n");
1166                 ret = PTR_ERR(tspi->rst);
1167                 goto exit_free_master;
1168         }
1169
1170         tspi->max_buf_size = SPI_FIFO_DEPTH << 2;
1171         tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
1172
1173         ret = tegra_spi_init_dma_param(tspi, true);
1174         if (ret < 0)
1175                 goto exit_free_master;
1176         ret = tegra_spi_init_dma_param(tspi, false);
1177         if (ret < 0)
1178                 goto exit_rx_dma_free;
1179         tspi->max_buf_size = tspi->dma_buf_size;
1180         init_completion(&tspi->tx_dma_complete);
1181         init_completion(&tspi->rx_dma_complete);
1182
1183         init_completion(&tspi->xfer_completion);
1184
1185         pm_runtime_enable(&pdev->dev);
1186         if (!pm_runtime_enabled(&pdev->dev)) {
1187                 ret = tegra_spi_runtime_resume(&pdev->dev);
1188                 if (ret)
1189                         goto exit_pm_disable;
1190         }
1191
1192         ret = pm_runtime_get_sync(&pdev->dev);
1193         if (ret < 0) {
1194                 dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
1195                 goto exit_pm_disable;
1196         }
1197
1198         reset_control_assert(tspi->rst);
1199         udelay(2);
1200         reset_control_deassert(tspi->rst);
1201         tspi->def_command1_reg  = SPI_M_S;
1202         tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1);
1203         pm_runtime_put(&pdev->dev);
1204         ret = request_threaded_irq(tspi->irq, tegra_spi_isr,
1205                                    tegra_spi_isr_thread, IRQF_ONESHOT,
1206                                    dev_name(&pdev->dev), tspi);
1207         if (ret < 0) {
1208                 dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
1209                         tspi->irq);
1210                 goto exit_pm_disable;
1211         }
1212
1213         master->dev.of_node = pdev->dev.of_node;
1214         ret = devm_spi_register_master(&pdev->dev, master);
1215         if (ret < 0) {
1216                 dev_err(&pdev->dev, "can not register to master err %d\n", ret);
1217                 goto exit_free_irq;
1218         }
1219         return ret;
1220
1221 exit_free_irq:
1222         free_irq(spi_irq, tspi);
1223 exit_pm_disable:
1224         pm_runtime_disable(&pdev->dev);
1225         if (!pm_runtime_status_suspended(&pdev->dev))
1226                 tegra_spi_runtime_suspend(&pdev->dev);
1227         tegra_spi_deinit_dma_param(tspi, false);
1228 exit_rx_dma_free:
1229         tegra_spi_deinit_dma_param(tspi, true);
1230 exit_free_master:
1231         spi_master_put(master);
1232         return ret;
1233 }
1234
1235 static int tegra_spi_remove(struct platform_device *pdev)
1236 {
1237         struct spi_master *master = platform_get_drvdata(pdev);
1238         struct tegra_spi_data   *tspi = spi_master_get_devdata(master);
1239
1240         free_irq(tspi->irq, tspi);
1241
1242         if (tspi->tx_dma_chan)
1243                 tegra_spi_deinit_dma_param(tspi, false);
1244
1245         if (tspi->rx_dma_chan)
1246                 tegra_spi_deinit_dma_param(tspi, true);
1247
1248         pm_runtime_disable(&pdev->dev);
1249         if (!pm_runtime_status_suspended(&pdev->dev))
1250                 tegra_spi_runtime_suspend(&pdev->dev);
1251
1252         return 0;
1253 }
1254
1255 #ifdef CONFIG_PM_SLEEP
1256 static int tegra_spi_suspend(struct device *dev)
1257 {
1258         struct spi_master *master = dev_get_drvdata(dev);
1259
1260         return spi_master_suspend(master);
1261 }
1262
1263 static int tegra_spi_resume(struct device *dev)
1264 {
1265         struct spi_master *master = dev_get_drvdata(dev);
1266         struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1267         int ret;
1268
1269         ret = pm_runtime_get_sync(dev);
1270         if (ret < 0) {
1271                 dev_err(dev, "pm runtime failed, e = %d\n", ret);
1272                 return ret;
1273         }
1274         tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
1275         pm_runtime_put(dev);
1276
1277         return spi_master_resume(master);
1278 }
1279 #endif
1280
1281 static int tegra_spi_runtime_suspend(struct device *dev)
1282 {
1283         struct spi_master *master = dev_get_drvdata(dev);
1284         struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1285
1286         /* Flush all write which are in PPSB queue by reading back */
1287         tegra_spi_readl(tspi, SPI_COMMAND1);
1288
1289         clk_disable_unprepare(tspi->clk);
1290         return 0;
1291 }
1292
1293 static int tegra_spi_runtime_resume(struct device *dev)
1294 {
1295         struct spi_master *master = dev_get_drvdata(dev);
1296         struct tegra_spi_data *tspi = spi_master_get_devdata(master);
1297         int ret;
1298
1299         ret = clk_prepare_enable(tspi->clk);
1300         if (ret < 0) {
1301                 dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
1302                 return ret;
1303         }
1304         return 0;
1305 }
1306
1307 static const struct dev_pm_ops tegra_spi_pm_ops = {
1308         SET_RUNTIME_PM_OPS(tegra_spi_runtime_suspend,
1309                 tegra_spi_runtime_resume, NULL)
1310         SET_SYSTEM_SLEEP_PM_OPS(tegra_spi_suspend, tegra_spi_resume)
1311 };
1312 static struct platform_driver tegra_spi_driver = {
1313         .driver = {
1314                 .name           = "spi-tegra114",
1315                 .pm             = &tegra_spi_pm_ops,
1316                 .of_match_table = tegra_spi_of_match,
1317         },
1318         .probe =        tegra_spi_probe,
1319         .remove =       tegra_spi_remove,
1320 };
1321 module_platform_driver(tegra_spi_driver);
1322
1323 MODULE_ALIAS("platform:spi-tegra114");
1324 MODULE_DESCRIPTION("NVIDIA Tegra114 SPI Controller Driver");
1325 MODULE_AUTHOR("Laxman Dewangan <[email protected]>");
1326 MODULE_LICENSE("GPL v2");