sound/soc/xtensa/xtfpga-i2s.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Xtfpga I2S controller driver
   4  *
   5  * Copyright (c) 2014 Cadence Design Systems Inc.
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/io.h>
  10 #include <linux/module.h>
  11 #include <linux/of.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/pm_runtime.h>
  14 #include <sound/pcm_params.h>
  15 #include <sound/soc.h>
  16
  17 #define DRV_NAME        "xtfpga-i2s"
  18
  19 #define XTFPGA_I2S_VERSION      0x00
  20 #define XTFPGA_I2S_CONFIG       0x04
  21 #define XTFPGA_I2S_INT_MASK     0x08
  22 #define XTFPGA_I2S_INT_STATUS   0x0c
  23 #define XTFPGA_I2S_CHAN0_DATA   0x10
  24 #define XTFPGA_I2S_CHAN1_DATA   0x14
  25 #define XTFPGA_I2S_CHAN2_DATA   0x18
  26 #define XTFPGA_I2S_CHAN3_DATA   0x1c
  27
  28 #define XTFPGA_I2S_CONFIG_TX_ENABLE     0x1
  29 #define XTFPGA_I2S_CONFIG_INT_ENABLE    0x2
  30 #define XTFPGA_I2S_CONFIG_LEFT          0x4
  31 #define XTFPGA_I2S_CONFIG_RATIO_BASE    8
  32 #define XTFPGA_I2S_CONFIG_RATIO_MASK    0x0000ff00
  33 #define XTFPGA_I2S_CONFIG_RES_BASE      16
  34 #define XTFPGA_I2S_CONFIG_RES_MASK      0x003f0000
  35 #define XTFPGA_I2S_CONFIG_LEVEL_BASE    24
  36 #define XTFPGA_I2S_CONFIG_LEVEL_MASK    0x0f000000
  37 #define XTFPGA_I2S_CONFIG_CHANNEL_BASE  28
  38
  39 #define XTFPGA_I2S_INT_UNDERRUN         0x1
  40 #define XTFPGA_I2S_INT_LEVEL            0x2
  41 #define XTFPGA_I2S_INT_VALID            0x3
  42
  43 #define XTFPGA_I2S_FIFO_SIZE            8192
  44
  45 /*
  46  * I2S controller operation:
  47  *
  48  * Enabling TX: output 1 period of zeros (starting with left channel)
  49  * and then queued data.
  50  *
  51  * Level status and interrupt: whenever FIFO level is below FIFO trigger,
  52  * level status is 1 and an IRQ is asserted (if enabled).
  53  *
  54  * Underrun status and interrupt: whenever FIFO is empty, underrun status
  55  * is 1 and an IRQ is asserted (if enabled).
  56  */
  57 struct xtfpga_i2s {
  58         struct device *dev;
  59         struct clk *clk;
  60         struct regmap *regmap;
  61         void __iomem *regs;
  62
  63         /* current playback substream. NULL if not playing.
  64          *
  65          * Access to that field is synchronized between the interrupt handler
  66          * and userspace through RCU.
  67          *
  68          * Interrupt handler (threaded part) does PIO on substream data in RCU
  69          * read-side critical section. Trigger callback sets and clears the
  70          * pointer when the playback is started and stopped with
  71          * rcu_assign_pointer. When userspace is about to free the playback
  72          * stream in the pcm_close callback it synchronizes with the interrupt
  73          * handler by means of synchronize_rcu call.
  74          */
  75         struct snd_pcm_substream __rcu *tx_substream;
  76         unsigned (*tx_fn)(struct xtfpga_i2s *i2s,
  77                           struct snd_pcm_runtime *runtime,
  78                           unsigned tx_ptr);
  79         unsigned tx_ptr; /* next frame index in the sample buffer */
  80
  81         /* current fifo level estimate.
  82          * Doesn't have to be perfectly accurate, but must be not less than
  83          * the actual FIFO level in order to avoid stall on push attempt.
  84          */
  85         unsigned tx_fifo_level;
  86
  87         /* FIFO level at which level interrupt occurs */
  88         unsigned tx_fifo_low;
  89
  90         /* maximal FIFO level */
  91         unsigned tx_fifo_high;
  92 };
  93
  94 static bool xtfpga_i2s_wr_reg(struct device *dev, unsigned int reg)
  95 {
  96         return reg >= XTFPGA_I2S_CONFIG;
  97 }
  98
  99 static bool xtfpga_i2s_rd_reg(struct device *dev, unsigned int reg)
 100 {
 101         return reg < XTFPGA_I2S_CHAN0_DATA;
 102 }
 103
 104 static bool xtfpga_i2s_volatile_reg(struct device *dev, unsigned int reg)
 105 {
 106         return reg == XTFPGA_I2S_INT_STATUS;
 107 }
 108
 109 static const struct regmap_config xtfpga_i2s_regmap_config = {
 110         .reg_bits = 32,
 111         .reg_stride = 4,
 112         .val_bits = 32,
 113         .max_register = XTFPGA_I2S_CHAN3_DATA,
 114         .writeable_reg = xtfpga_i2s_wr_reg,
 115         .readable_reg = xtfpga_i2s_rd_reg,
 116         .volatile_reg = xtfpga_i2s_volatile_reg,
 117         .cache_type = REGCACHE_FLAT,
 118 };
 119
 120 /* Generate functions that do PIO from TX DMA area to FIFO for all supported
 121  * stream formats.
 122  * Functions will be called xtfpga_pcm_tx_<channels>x<sample bits>, e.g.
 123  * xtfpga_pcm_tx_2x16 for 16-bit stereo.
 124  *
 125  * FIFO consists of 32-bit words, one word per channel, always 2 channels.
 126  * If I2S interface is configured with smaller sample resolution, only
 127  * the LSB of each word is used.
 128  */
 129 #define xtfpga_pcm_tx_fn(channels, sample_bits) \
 130 static unsigned xtfpga_pcm_tx_##channels##x##sample_bits( \
 131         struct xtfpga_i2s *i2s, struct snd_pcm_runtime *runtime, \
 132         unsigned tx_ptr) \
 133 { \
 134         const u##sample_bits (*p)[channels] = \
 135                 (void *)runtime->dma_area; \
 136 \
 137         for (; i2s->tx_fifo_level < i2s->tx_fifo_high; \
 138              i2s->tx_fifo_level += 2) { \
 139                 iowrite32(p[tx_ptr][0], \
 140                           i2s->regs + XTFPGA_I2S_CHAN0_DATA); \
 141                 iowrite32(p[tx_ptr][channels - 1], \
 142                           i2s->regs + XTFPGA_I2S_CHAN0_DATA); \
 143                 if (++tx_ptr >= runtime->buffer_size) \
 144                         tx_ptr = 0; \
 145         } \
 146         return tx_ptr; \
 147 }
 148
 149 xtfpga_pcm_tx_fn(1, 16)
 150 xtfpga_pcm_tx_fn(2, 16)
 151 xtfpga_pcm_tx_fn(1, 32)
 152 xtfpga_pcm_tx_fn(2, 32)
 153
 154 #undef xtfpga_pcm_tx_fn
 155
 156 static bool xtfpga_pcm_push_tx(struct xtfpga_i2s *i2s)
 157 {
 158         struct snd_pcm_substream *tx_substream;
 159         bool tx_active;
 160
 161         rcu_read_lock();
 162         tx_substream = rcu_dereference(i2s->tx_substream);
 163         tx_active = tx_substream && snd_pcm_running(tx_substream);
 164         if (tx_active) {
 165                 unsigned tx_ptr = READ_ONCE(i2s->tx_ptr);
 166                 unsigned new_tx_ptr = i2s->tx_fn(i2s, tx_substream->runtime,
 167                                                  tx_ptr);
 168
 169                 cmpxchg(&i2s->tx_ptr, tx_ptr, new_tx_ptr);
 170         }
 171         rcu_read_unlock();
 172
 173         return tx_active;
 174 }
 175
 176 static void xtfpga_pcm_refill_fifo(struct xtfpga_i2s *i2s)
 177 {
 178         unsigned int_status;
 179         unsigned i;
 180
 181         regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS,
 182                     &int_status);
 183
 184         for (i = 0; i < 2; ++i) {
 185                 bool tx_active = xtfpga_pcm_push_tx(i2s);
 186
 187                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS,
 188                              XTFPGA_I2S_INT_VALID);
 189                 if (tx_active)
 190                         regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS,
 191                                     &int_status);
 192
 193                 if (!tx_active ||
 194                     !(int_status & XTFPGA_I2S_INT_LEVEL))
 195                         break;
 196
 197                 /* After the push the level IRQ is still asserted,
 198                  * means FIFO level is below tx_fifo_low. Estimate
 199                  * it as tx_fifo_low.
 200                  */
 201                 i2s->tx_fifo_level = i2s->tx_fifo_low;
 202         }
 203
 204         if (!(int_status & XTFPGA_I2S_INT_LEVEL))
 205                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK,
 206                              XTFPGA_I2S_INT_VALID);
 207         else if (!(int_status & XTFPGA_I2S_INT_UNDERRUN))
 208                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK,
 209                              XTFPGA_I2S_INT_UNDERRUN);
 210
 211         if (!(int_status & XTFPGA_I2S_INT_UNDERRUN))
 212                 regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 213                                    XTFPGA_I2S_CONFIG_INT_ENABLE |
 214                                    XTFPGA_I2S_CONFIG_TX_ENABLE,
 215                                    XTFPGA_I2S_CONFIG_INT_ENABLE |
 216                                    XTFPGA_I2S_CONFIG_TX_ENABLE);
 217         else
 218                 regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 219                                    XTFPGA_I2S_CONFIG_INT_ENABLE |
 220                                    XTFPGA_I2S_CONFIG_TX_ENABLE, 0);
 221 }
 222
 223 static irqreturn_t xtfpga_i2s_threaded_irq_handler(int irq, void *dev_id)
 224 {
 225         struct xtfpga_i2s *i2s = dev_id;
 226         struct snd_pcm_substream *tx_substream;
 227         unsigned config, int_status, int_mask;
 228
 229         regmap_read(i2s->regmap, XTFPGA_I2S_CONFIG, &config);
 230         regmap_read(i2s->regmap, XTFPGA_I2S_INT_MASK, &int_mask);
 231         regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS, &int_status);
 232
 233         if (!(config & XTFPGA_I2S_CONFIG_INT_ENABLE) ||
 234             !(int_status & int_mask & XTFPGA_I2S_INT_VALID))
 235                 return IRQ_NONE;
 236
 237         /* Update FIFO level estimate in accordance with interrupt status
 238          * register.
 239          */
 240         if (int_status & XTFPGA_I2S_INT_UNDERRUN) {
 241                 i2s->tx_fifo_level = 0;
 242                 regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 243                                    XTFPGA_I2S_CONFIG_TX_ENABLE, 0);
 244         } else {
 245                 /* The FIFO isn't empty, but is below tx_fifo_low. Estimate
 246                  * it as tx_fifo_low.
 247                  */
 248                 i2s->tx_fifo_level = i2s->tx_fifo_low;
 249         }
 250
 251         rcu_read_lock();
 252         tx_substream = rcu_dereference(i2s->tx_substream);
 253
 254         if (tx_substream && snd_pcm_running(tx_substream)) {
 255                 snd_pcm_period_elapsed(tx_substream);
 256                 if (int_status & XTFPGA_I2S_INT_UNDERRUN)
 257                         dev_dbg_ratelimited(i2s->dev, "%s: underrun\n",
 258                                             __func__);
 259         }
 260         rcu_read_unlock();
 261
 262         /* Refill FIFO, update allowed IRQ reasons, enable IRQ if FIFO is
 263          * not empty.
 264          */
 265         xtfpga_pcm_refill_fifo(i2s);
 266
 267         return IRQ_HANDLED;
 268 }
 269
 270 static int xtfpga_i2s_startup(struct snd_pcm_substream *substream,
 271                               struct snd_soc_dai *dai)
 272 {
 273         struct xtfpga_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 274
 275         snd_soc_dai_set_dma_data(dai, substream, i2s);
 276         return 0;
 277 }
 278
 279 static int xtfpga_i2s_hw_params(struct snd_pcm_substream *substream,
 280                                 struct snd_pcm_hw_params *params,
 281                                 struct snd_soc_dai *dai)
 282 {
 283         struct xtfpga_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 284         unsigned srate = params_rate(params);
 285         unsigned channels = params_channels(params);
 286         unsigned period_size = params_period_size(params);
 287         unsigned sample_size = snd_pcm_format_width(params_format(params));
 288         unsigned freq, ratio, level;
 289         int err;
 290
 291         regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 292                            XTFPGA_I2S_CONFIG_RES_MASK,
 293                            sample_size << XTFPGA_I2S_CONFIG_RES_BASE);
 294
 295         freq = 256 * srate;
 296         err = clk_set_rate(i2s->clk, freq);
 297         if (err < 0)
 298                 return err;
 299
 300         /* ratio field of the config register controls MCLK->I2S clock
 301          * derivation: I2S clock = MCLK / (2 * (ratio + 2)).
 302          *
 303          * So with MCLK = 256 * sample rate ratio is 0 for 32 bit stereo
 304          * and 2 for 16 bit stereo.
 305          */
 306         ratio = (freq - (srate * sample_size * 8)) /
 307                 (srate * sample_size * 4);
 308
 309         regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 310                            XTFPGA_I2S_CONFIG_RATIO_MASK,
 311                            ratio << XTFPGA_I2S_CONFIG_RATIO_BASE);
 312
 313         i2s->tx_fifo_low = XTFPGA_I2S_FIFO_SIZE / 2;
 314
 315         /* period_size * 2: FIFO always gets 2 samples per frame */
 316         for (level = 1;
 317              i2s->tx_fifo_low / 2 >= period_size * 2 &&
 318              level < (XTFPGA_I2S_CONFIG_LEVEL_MASK >>
 319                       XTFPGA_I2S_CONFIG_LEVEL_BASE); ++level)
 320                 i2s->tx_fifo_low /= 2;
 321
 322         i2s->tx_fifo_high = 2 * i2s->tx_fifo_low;
 323
 324         regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 325                            XTFPGA_I2S_CONFIG_LEVEL_MASK,
 326                            level << XTFPGA_I2S_CONFIG_LEVEL_BASE);
 327
 328         dev_dbg(i2s->dev,
 329                 "%s srate: %u, channels: %u, sample_size: %u, period_size: %u\n",
 330                 __func__, srate, channels, sample_size, period_size);
 331         dev_dbg(i2s->dev, "%s freq: %u, ratio: %u, level: %u\n",
 332                 __func__, freq, ratio, level);
 333
 334         return 0;
 335 }
 336
 337 static int xtfpga_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
 338                               unsigned int fmt)
 339 {
 340         if ((fmt & SND_SOC_DAIFMT_INV_MASK) != SND_SOC_DAIFMT_NB_NF)
 341                 return -EINVAL;
 342         if ((fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) != SND_SOC_DAIFMT_BP_FP)
 343                 return -EINVAL;
 344         if ((fmt & SND_SOC_DAIFMT_FORMAT_MASK) != SND_SOC_DAIFMT_I2S)
 345                 return -EINVAL;
 346
 347         return 0;
 348 }
 349
 350 /* PCM */
 351
 352 static const struct snd_pcm_hardware xtfpga_pcm_hardware = {
 353         .info = SNDRV_PCM_INFO_INTERLEAVED |
 354                 SNDRV_PCM_INFO_MMAP_VALID |
 355                 SNDRV_PCM_INFO_BLOCK_TRANSFER,
 356         .formats                = SNDRV_PCM_FMTBIT_S16_LE |
 357                                   SNDRV_PCM_FMTBIT_S32_LE,
 358         .channels_min           = 1,
 359         .channels_max           = 2,
 360         .period_bytes_min       = 2,
 361         .period_bytes_max       = XTFPGA_I2S_FIFO_SIZE / 2 * 8,
 362         .periods_min            = 2,
 363         .periods_max            = XTFPGA_I2S_FIFO_SIZE * 8 / 2,
 364         .buffer_bytes_max       = XTFPGA_I2S_FIFO_SIZE * 8,
 365         .fifo_size              = 16,
 366 };
 367
 368 static int xtfpga_pcm_open(struct snd_soc_component *component,
 369                            struct snd_pcm_substream *substream)
 370 {
 371         struct snd_pcm_runtime *runtime = substream->runtime;
 372         struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 373         void *p;
 374
 375         snd_soc_set_runtime_hwparams(substream, &xtfpga_pcm_hardware);
 376         p = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
 377         runtime->private_data = p;
 378
 379         return 0;
 380 }
 381
 382 static int xtfpga_pcm_close(struct snd_soc_component *component,
 383                             struct snd_pcm_substream *substream)
 384 {
 385         synchronize_rcu();
 386         return 0;
 387 }
 388
 389 static int xtfpga_pcm_hw_params(struct snd_soc_component *component,
 390                                 struct snd_pcm_substream *substream,
 391                                 struct snd_pcm_hw_params *hw_params)
 392 {
 393         struct snd_pcm_runtime *runtime = substream->runtime;
 394         struct xtfpga_i2s *i2s = runtime->private_data;
 395         unsigned channels = params_channels(hw_params);
 396
 397         switch (channels) {
 398         case 1:
 399         case 2:
 400                 break;
 401
 402         default:
 403                 return -EINVAL;
 404
 405         }
 406
 407         switch (params_format(hw_params)) {
 408         case SNDRV_PCM_FORMAT_S16_LE:
 409                 i2s->tx_fn = (channels == 1) ?
 410                         xtfpga_pcm_tx_1x16 :
 411                         xtfpga_pcm_tx_2x16;
 412                 break;
 413
 414         case SNDRV_PCM_FORMAT_S32_LE:
 415                 i2s->tx_fn = (channels == 1) ?
 416                         xtfpga_pcm_tx_1x32 :
 417                         xtfpga_pcm_tx_2x32;
 418                 break;
 419
 420         default:
 421                 return -EINVAL;
 422         }
 423
 424         return 0;
 425 }
 426
 427 static int xtfpga_pcm_trigger(struct snd_soc_component *component,
 428                               struct snd_pcm_substream *substream, int cmd)
 429 {
 430         int ret = 0;
 431         struct snd_pcm_runtime *runtime = substream->runtime;
 432         struct xtfpga_i2s *i2s = runtime->private_data;
 433
 434         switch (cmd) {
 435         case SNDRV_PCM_TRIGGER_START:
 436         case SNDRV_PCM_TRIGGER_RESUME:
 437         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 438                 WRITE_ONCE(i2s->tx_ptr, 0);
 439                 rcu_assign_pointer(i2s->tx_substream, substream);
 440                 xtfpga_pcm_refill_fifo(i2s);
 441                 break;
 442
 443         case SNDRV_PCM_TRIGGER_STOP:
 444         case SNDRV_PCM_TRIGGER_SUSPEND:
 445         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 446                 rcu_assign_pointer(i2s->tx_substream, NULL);
 447                 break;
 448
 449         default:
 450                 ret = -EINVAL;
 451                 break;
 452         }
 453         return ret;
 454 }
 455
 456 static snd_pcm_uframes_t xtfpga_pcm_pointer(struct snd_soc_component *component,
 457                                             struct snd_pcm_substream *substream)
 458 {
 459         struct snd_pcm_runtime *runtime = substream->runtime;
 460         struct xtfpga_i2s *i2s = runtime->private_data;
 461         snd_pcm_uframes_t pos = READ_ONCE(i2s->tx_ptr);
 462
 463         return pos < runtime->buffer_size ? pos : 0;
 464 }
 465
 466 static int xtfpga_pcm_new(struct snd_soc_component *component,
 467                           struct snd_soc_pcm_runtime *rtd)
 468 {
 469         struct snd_card *card = rtd->card->snd_card;
 470         size_t size = xtfpga_pcm_hardware.buffer_bytes_max;
 471
 472         snd_pcm_set_managed_buffer_all(rtd->pcm, SNDRV_DMA_TYPE_DEV,
 473                                        card->dev, size, size);
 474         return 0;
 475 }
 476
 477 static const struct snd_soc_component_driver xtfpga_i2s_component = {
 478         .name                   = DRV_NAME,
 479         .open                   = xtfpga_pcm_open,
 480         .close                  = xtfpga_pcm_close,
 481         .hw_params              = xtfpga_pcm_hw_params,
 482         .trigger                = xtfpga_pcm_trigger,
 483         .pointer                = xtfpga_pcm_pointer,
 484         .pcm_construct          = xtfpga_pcm_new,
 485         .legacy_dai_naming      = 1,
 486 };
 487
 488 static const struct snd_soc_dai_ops xtfpga_i2s_dai_ops = {
 489         .startup        = xtfpga_i2s_startup,
 490         .hw_params      = xtfpga_i2s_hw_params,
 491         .set_fmt        = xtfpga_i2s_set_fmt,
 492 };
 493
 494 static struct snd_soc_dai_driver xtfpga_i2s_dai[] = {
 495         {
 496                 .name = "xtfpga-i2s",
 497                 .id = 0,
 498                 .playback = {
 499                         .channels_min = 1,
 500                         .channels_max = 2,
 501                         .rates = SNDRV_PCM_RATE_8000_96000,
 502                         .formats = SNDRV_PCM_FMTBIT_S16_LE |
 503                                    SNDRV_PCM_FMTBIT_S32_LE,
 504                 },
 505                 .ops = &xtfpga_i2s_dai_ops,
 506         },
 507 };
 508
 509 static int xtfpga_i2s_runtime_suspend(struct device *dev)
 510 {
 511         struct xtfpga_i2s *i2s = dev_get_drvdata(dev);
 512
 513         clk_disable_unprepare(i2s->clk);
 514         return 0;
 515 }
 516
 517 static int xtfpga_i2s_runtime_resume(struct device *dev)
 518 {
 519         struct xtfpga_i2s *i2s = dev_get_drvdata(dev);
 520         int ret;
 521
 522         ret = clk_prepare_enable(i2s->clk);
 523         if (ret) {
 524                 dev_err(dev, "clk_prepare_enable failed: %d\n", ret);
 525                 return ret;
 526         }
 527         return 0;
 528 }
 529
 530 static int xtfpga_i2s_probe(struct platform_device *pdev)
 531 {
 532         struct xtfpga_i2s *i2s;
 533         int err, irq;
 534
 535         i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
 536         if (!i2s) {
 537                 err = -ENOMEM;
 538                 goto err;
 539         }
 540         platform_set_drvdata(pdev, i2s);
 541         i2s->dev = &pdev->dev;
 542         dev_dbg(&pdev->dev, "dev: %p, i2s: %p\n", &pdev->dev, i2s);
 543
 544         i2s->regs = devm_platform_ioremap_resource(pdev, 0);
 545         if (IS_ERR(i2s->regs)) {
 546                 err = PTR_ERR(i2s->regs);
 547                 goto err;
 548         }
 549
 550         i2s->regmap = devm_regmap_init_mmio(&pdev->dev, i2s->regs,
 551                                             &xtfpga_i2s_regmap_config);
 552         if (IS_ERR(i2s->regmap)) {
 553                 dev_err(&pdev->dev, "regmap init failed\n");
 554                 err = PTR_ERR(i2s->regmap);
 555                 goto err;
 556         }
 557
 558         i2s->clk = devm_clk_get(&pdev->dev, NULL);
 559         if (IS_ERR(i2s->clk)) {
 560                 dev_err(&pdev->dev, "couldn't get clock\n");
 561                 err = PTR_ERR(i2s->clk);
 562                 goto err;
 563         }
 564
 565         regmap_write(i2s->regmap, XTFPGA_I2S_CONFIG,
 566                      (0x1 << XTFPGA_I2S_CONFIG_CHANNEL_BASE));
 567         regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS, XTFPGA_I2S_INT_VALID);
 568         regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK, XTFPGA_I2S_INT_UNDERRUN);
 569
 570         irq = platform_get_irq(pdev, 0);
 571         if (irq < 0) {
 572                 err = irq;
 573                 goto err;
 574         }
 575         err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 576                                         xtfpga_i2s_threaded_irq_handler,
 577                                         IRQF_SHARED | IRQF_ONESHOT,
 578                                         pdev->name, i2s);
 579         if (err < 0) {
 580                 dev_err(&pdev->dev, "request_irq failed\n");
 581                 goto err;
 582         }
 583
 584         err = devm_snd_soc_register_component(&pdev->dev,
 585                                               &xtfpga_i2s_component,
 586                                               xtfpga_i2s_dai,
 587                                               ARRAY_SIZE(xtfpga_i2s_dai));
 588         if (err < 0) {
 589                 dev_err(&pdev->dev, "couldn't register component\n");
 590                 goto err;
 591         }
 592
 593         pm_runtime_enable(&pdev->dev);
 594         if (!pm_runtime_enabled(&pdev->dev)) {
 595                 err = xtfpga_i2s_runtime_resume(&pdev->dev);
 596                 if (err)
 597                         goto err_pm_disable;
 598         }
 599         return 0;
 600
 601 err_pm_disable:
 602         pm_runtime_disable(&pdev->dev);
 603 err:
 604         dev_err(&pdev->dev, "%s: err = %d\n", __func__, err);
 605         return err;
 606 }
 607
 608 static void xtfpga_i2s_remove(struct platform_device *pdev)
 609 {
 610         struct xtfpga_i2s *i2s = dev_get_drvdata(&pdev->dev);
 611
 612         if (i2s->regmap && !IS_ERR(i2s->regmap)) {
 613                 regmap_write(i2s->regmap, XTFPGA_I2S_CONFIG, 0);
 614                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK, 0);
 615                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS,
 616                              XTFPGA_I2S_INT_VALID);
 617         }
 618         pm_runtime_disable(&pdev->dev);
 619         if (!pm_runtime_status_suspended(&pdev->dev))
 620                 xtfpga_i2s_runtime_suspend(&pdev->dev);
 621 }
 622
 623 #ifdef CONFIG_OF
 624 static const struct of_device_id xtfpga_i2s_of_match[] = {
 625         { .compatible = "cdns,xtfpga-i2s", },
 626         {},
 627 };
 628 MODULE_DEVICE_TABLE(of, xtfpga_i2s_of_match);
 629 #endif
 630
 631 static const struct dev_pm_ops xtfpga_i2s_pm_ops = {
 632         SET_RUNTIME_PM_OPS(xtfpga_i2s_runtime_suspend,
 633                            xtfpga_i2s_runtime_resume, NULL)
 634 };
 635
 636 static struct platform_driver xtfpga_i2s_driver = {
 637         .probe   = xtfpga_i2s_probe,
 638         .remove = xtfpga_i2s_remove,
 639         .driver  = {
 640                 .name = "xtfpga-i2s",
 641                 .of_match_table = of_match_ptr(xtfpga_i2s_of_match),
 642                 .pm = &xtfpga_i2s_pm_ops,
 643         },
 644 };
 645
 646 module_platform_driver(xtfpga_i2s_driver);
 647
 648 MODULE_AUTHOR("Max Filippov <jcmvbkbc@gmail.com>");
 649 MODULE_DESCRIPTION("xtfpga I2S controller driver");
 650 MODULE_LICENSE("GPL v2");