sound/soc/xtensa/xtfpga-i2s.c

   1 /*
   2  * Xtfpga I2S controller driver
   3  *
   4  * Copyright (c) 2014 Cadence Design Systems Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/clk.h>
  12 #include <linux/io.h>
  13 #include <linux/module.h>
  14 #include <linux/of.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/pm_runtime.h>
  17 #include <sound/pcm_params.h>
  18 #include <sound/soc.h>
  19
  20 #define DRV_NAME        "xtfpga-i2s"
  21
  22 #define XTFPGA_I2S_VERSION      0x00
  23 #define XTFPGA_I2S_CONFIG       0x04
  24 #define XTFPGA_I2S_INT_MASK     0x08
  25 #define XTFPGA_I2S_INT_STATUS   0x0c
  26 #define XTFPGA_I2S_CHAN0_DATA   0x10
  27 #define XTFPGA_I2S_CHAN1_DATA   0x14
  28 #define XTFPGA_I2S_CHAN2_DATA   0x18
  29 #define XTFPGA_I2S_CHAN3_DATA   0x1c
  30
  31 #define XTFPGA_I2S_CONFIG_TX_ENABLE     0x1
  32 #define XTFPGA_I2S_CONFIG_INT_ENABLE    0x2
  33 #define XTFPGA_I2S_CONFIG_LEFT          0x4
  34 #define XTFPGA_I2S_CONFIG_RATIO_BASE    8
  35 #define XTFPGA_I2S_CONFIG_RATIO_MASK    0x0000ff00
  36 #define XTFPGA_I2S_CONFIG_RES_BASE      16
  37 #define XTFPGA_I2S_CONFIG_RES_MASK      0x003f0000
  38 #define XTFPGA_I2S_CONFIG_LEVEL_BASE    24
  39 #define XTFPGA_I2S_CONFIG_LEVEL_MASK    0x0f000000
  40 #define XTFPGA_I2S_CONFIG_CHANNEL_BASE  28
  41
  42 #define XTFPGA_I2S_INT_UNDERRUN         0x1
  43 #define XTFPGA_I2S_INT_LEVEL            0x2
  44 #define XTFPGA_I2S_INT_VALID            0x3
  45
  46 #define XTFPGA_I2S_FIFO_SIZE            8192
  47
  48 /*
  49  * I2S controller operation:
  50  *
  51  * Enabling TX: output 1 period of zeros (starting with left channel)
  52  * and then queued data.
  53  *
  54  * Level status and interrupt: whenever FIFO level is below FIFO trigger,
  55  * level status is 1 and an IRQ is asserted (if enabled).
  56  *
  57  * Underrun status and interrupt: whenever FIFO is empty, underrun status
  58  * is 1 and an IRQ is asserted (if enabled).
  59  */
  60 struct xtfpga_i2s {
  61         struct device *dev;
  62         struct clk *clk;
  63         struct regmap *regmap;
  64         void __iomem *regs;
  65
  66         /* current playback substream. NULL if not playing.
  67          *
  68          * Access to that field is synchronized between the interrupt handler
  69          * and userspace through RCU.
  70          *
  71          * Interrupt handler (threaded part) does PIO on substream data in RCU
  72          * read-side critical section. Trigger callback sets and clears the
  73          * pointer when the playback is started and stopped with
  74          * rcu_assign_pointer. When userspace is about to free the playback
  75          * stream in the pcm_close callback it synchronizes with the interrupt
  76          * handler by means of synchronize_rcu call.
  77          */
  78         struct snd_pcm_substream *tx_substream;
  79         unsigned (*tx_fn)(struct xtfpga_i2s *i2s,
  80                           struct snd_pcm_runtime *runtime,
  81                           unsigned tx_ptr);
  82         unsigned tx_ptr; /* next frame index in the sample buffer */
  83
  84         /* current fifo level estimate.
  85          * Doesn't have to be perfectly accurate, but must be not less than
  86          * the actual FIFO level in order to avoid stall on push attempt.
  87          */
  88         unsigned tx_fifo_level;
  89
  90         /* FIFO level at which level interrupt occurs */
  91         unsigned tx_fifo_low;
  92
  93         /* maximal FIFO level */
  94         unsigned tx_fifo_high;
  95 };
  96
  97 static bool xtfpga_i2s_wr_reg(struct device *dev, unsigned int reg)
  98 {
  99         return reg >= XTFPGA_I2S_CONFIG;
 100 }
 101
 102 static bool xtfpga_i2s_rd_reg(struct device *dev, unsigned int reg)
 103 {
 104         return reg < XTFPGA_I2S_CHAN0_DATA;
 105 }
 106
 107 static bool xtfpga_i2s_volatile_reg(struct device *dev, unsigned int reg)
 108 {
 109         return reg == XTFPGA_I2S_INT_STATUS;
 110 }
 111
 112 static const struct regmap_config xtfpga_i2s_regmap_config = {
 113         .reg_bits = 32,
 114         .reg_stride = 4,
 115         .val_bits = 32,
 116         .max_register = XTFPGA_I2S_CHAN3_DATA,
 117         .writeable_reg = xtfpga_i2s_wr_reg,
 118         .readable_reg = xtfpga_i2s_rd_reg,
 119         .volatile_reg = xtfpga_i2s_volatile_reg,
 120         .cache_type = REGCACHE_FLAT,
 121 };
 122
 123 /* Generate functions that do PIO from TX DMA area to FIFO for all supported
 124  * stream formats.
 125  * Functions will be called xtfpga_pcm_tx_<channels>x<sample bits>, e.g.
 126  * xtfpga_pcm_tx_2x16 for 16-bit stereo.
 127  *
 128  * FIFO consists of 32-bit words, one word per channel, always 2 channels.
 129  * If I2S interface is configured with smaller sample resolution, only
 130  * the LSB of each word is used.
 131  */
 132 #define xtfpga_pcm_tx_fn(channels, sample_bits) \
 133 static unsigned xtfpga_pcm_tx_##channels##x##sample_bits( \
 134         struct xtfpga_i2s *i2s, struct snd_pcm_runtime *runtime, \
 135         unsigned tx_ptr) \
 136 { \
 137         const u##sample_bits (*p)[channels] = \
 138                 (void *)runtime->dma_area; \
 139 \
 140         for (; i2s->tx_fifo_level < i2s->tx_fifo_high; \
 141              i2s->tx_fifo_level += 2) { \
 142                 iowrite32(p[tx_ptr][0], \
 143                           i2s->regs + XTFPGA_I2S_CHAN0_DATA); \
 144                 iowrite32(p[tx_ptr][channels - 1], \
 145                           i2s->regs + XTFPGA_I2S_CHAN0_DATA); \
 146                 if (++tx_ptr >= runtime->buffer_size) \
 147                         tx_ptr = 0; \
 148         } \
 149         return tx_ptr; \
 150 }
 151
 152 xtfpga_pcm_tx_fn(1, 16)
 153 xtfpga_pcm_tx_fn(2, 16)
 154 xtfpga_pcm_tx_fn(1, 32)
 155 xtfpga_pcm_tx_fn(2, 32)
 156
 157 #undef xtfpga_pcm_tx_fn
 158
 159 static bool xtfpga_pcm_push_tx(struct xtfpga_i2s *i2s)
 160 {
 161         struct snd_pcm_substream *tx_substream;
 162         bool tx_active;
 163
 164         rcu_read_lock();
 165         tx_substream = rcu_dereference(i2s->tx_substream);
 166         tx_active = tx_substream && snd_pcm_running(tx_substream);
 167         if (tx_active) {
 168                 unsigned tx_ptr = ACCESS_ONCE(i2s->tx_ptr);
 169                 unsigned new_tx_ptr = i2s->tx_fn(i2s, tx_substream->runtime,
 170                                                  tx_ptr);
 171
 172                 cmpxchg(&i2s->tx_ptr, tx_ptr, new_tx_ptr);
 173         }
 174         rcu_read_unlock();
 175
 176         return tx_active;
 177 }
 178
 179 static void xtfpga_pcm_refill_fifo(struct xtfpga_i2s *i2s)
 180 {
 181         unsigned int_status;
 182         unsigned i;
 183
 184         regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS,
 185                     &int_status);
 186
 187         for (i = 0; i < 2; ++i) {
 188                 bool tx_active = xtfpga_pcm_push_tx(i2s);
 189
 190                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS,
 191                              XTFPGA_I2S_INT_VALID);
 192                 if (tx_active)
 193                         regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS,
 194                                     &int_status);
 195
 196                 if (!tx_active ||
 197                     !(int_status & XTFPGA_I2S_INT_LEVEL))
 198                         break;
 199
 200                 /* After the push the level IRQ is still asserted,
 201                  * means FIFO level is below tx_fifo_low. Estimate
 202                  * it as tx_fifo_low.
 203                  */
 204                 i2s->tx_fifo_level = i2s->tx_fifo_low;
 205         }
 206
 207         if (!(int_status & XTFPGA_I2S_INT_LEVEL))
 208                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK,
 209                              XTFPGA_I2S_INT_VALID);
 210         else if (!(int_status & XTFPGA_I2S_INT_UNDERRUN))
 211                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK,
 212                              XTFPGA_I2S_INT_UNDERRUN);
 213
 214         if (!(int_status & XTFPGA_I2S_INT_UNDERRUN))
 215                 regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 216                                    XTFPGA_I2S_CONFIG_INT_ENABLE |
 217                                    XTFPGA_I2S_CONFIG_TX_ENABLE,
 218                                    XTFPGA_I2S_CONFIG_INT_ENABLE |
 219                                    XTFPGA_I2S_CONFIG_TX_ENABLE);
 220         else
 221                 regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 222                                    XTFPGA_I2S_CONFIG_INT_ENABLE |
 223                                    XTFPGA_I2S_CONFIG_TX_ENABLE, 0);
 224 }
 225
 226 static irqreturn_t xtfpga_i2s_threaded_irq_handler(int irq, void *dev_id)
 227 {
 228         struct xtfpga_i2s *i2s = dev_id;
 229         struct snd_pcm_substream *tx_substream;
 230         unsigned config, int_status, int_mask;
 231
 232         regmap_read(i2s->regmap, XTFPGA_I2S_CONFIG, &config);
 233         regmap_read(i2s->regmap, XTFPGA_I2S_INT_MASK, &int_mask);
 234         regmap_read(i2s->regmap, XTFPGA_I2S_INT_STATUS, &int_status);
 235
 236         if (!(config & XTFPGA_I2S_CONFIG_INT_ENABLE) ||
 237             !(int_status & int_mask & XTFPGA_I2S_INT_VALID))
 238                 return IRQ_NONE;
 239
 240         /* Update FIFO level estimate in accordance with interrupt status
 241          * register.
 242          */
 243         if (int_status & XTFPGA_I2S_INT_UNDERRUN) {
 244                 i2s->tx_fifo_level = 0;
 245                 regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 246                                    XTFPGA_I2S_CONFIG_TX_ENABLE, 0);
 247         } else {
 248                 /* The FIFO isn't empty, but is below tx_fifo_low. Estimate
 249                  * it as tx_fifo_low.
 250                  */
 251                 i2s->tx_fifo_level = i2s->tx_fifo_low;
 252         }
 253
 254         rcu_read_lock();
 255         tx_substream = rcu_dereference(i2s->tx_substream);
 256
 257         if (tx_substream && snd_pcm_running(tx_substream)) {
 258                 snd_pcm_period_elapsed(tx_substream);
 259                 if (int_status & XTFPGA_I2S_INT_UNDERRUN)
 260                         dev_dbg_ratelimited(i2s->dev, "%s: underrun\n",
 261                                             __func__);
 262         }
 263         rcu_read_unlock();
 264
 265         /* Refill FIFO, update allowed IRQ reasons, enable IRQ if FIFO is
 266          * not empty.
 267          */
 268         xtfpga_pcm_refill_fifo(i2s);
 269
 270         return IRQ_HANDLED;
 271 }
 272
 273 static int xtfpga_i2s_startup(struct snd_pcm_substream *substream,
 274                               struct snd_soc_dai *dai)
 275 {
 276         struct xtfpga_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 277
 278         snd_soc_dai_set_dma_data(dai, substream, i2s);
 279         return 0;
 280 }
 281
 282 static int xtfpga_i2s_hw_params(struct snd_pcm_substream *substream,
 283                                 struct snd_pcm_hw_params *params,
 284                                 struct snd_soc_dai *dai)
 285 {
 286         struct xtfpga_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 287         unsigned srate = params_rate(params);
 288         unsigned channels = params_channels(params);
 289         unsigned period_size = params_period_size(params);
 290         unsigned sample_size = snd_pcm_format_width(params_format(params));
 291         unsigned freq, ratio, level;
 292         int err;
 293
 294         regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 295                            XTFPGA_I2S_CONFIG_RES_MASK,
 296                            sample_size << XTFPGA_I2S_CONFIG_RES_BASE);
 297
 298         freq = 256 * srate;
 299         err = clk_set_rate(i2s->clk, freq);
 300         if (err < 0)
 301                 return err;
 302
 303         /* ratio field of the config register controls MCLK->I2S clock
 304          * derivation: I2S clock = MCLK / (2 * (ratio + 2)).
 305          *
 306          * So with MCLK = 256 * sample rate ratio is 0 for 32 bit stereo
 307          * and 2 for 16 bit stereo.
 308          */
 309         ratio = (freq - (srate * sample_size * 8)) /
 310                 (srate * sample_size * 4);
 311
 312         regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 313                            XTFPGA_I2S_CONFIG_RATIO_MASK,
 314                            ratio << XTFPGA_I2S_CONFIG_RATIO_BASE);
 315
 316         i2s->tx_fifo_low = XTFPGA_I2S_FIFO_SIZE / 2;
 317
 318         /* period_size * 2: FIFO always gets 2 samples per frame */
 319         for (level = 1;
 320              i2s->tx_fifo_low / 2 >= period_size * 2 &&
 321              level < (XTFPGA_I2S_CONFIG_LEVEL_MASK >>
 322                       XTFPGA_I2S_CONFIG_LEVEL_BASE); ++level)
 323                 i2s->tx_fifo_low /= 2;
 324
 325         i2s->tx_fifo_high = 2 * i2s->tx_fifo_low;
 326
 327         regmap_update_bits(i2s->regmap, XTFPGA_I2S_CONFIG,
 328                            XTFPGA_I2S_CONFIG_LEVEL_MASK,
 329                            level << XTFPGA_I2S_CONFIG_LEVEL_BASE);
 330
 331         dev_dbg(i2s->dev,
 332                 "%s srate: %u, channels: %u, sample_size: %u, period_size: %u\n",
 333                 __func__, srate, channels, sample_size, period_size);
 334         dev_dbg(i2s->dev, "%s freq: %u, ratio: %u, level: %u\n",
 335                 __func__, freq, ratio, level);
 336
 337         return 0;
 338 }
 339
 340 static int xtfpga_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
 341                               unsigned int fmt)
 342 {
 343         if ((fmt & SND_SOC_DAIFMT_INV_MASK) != SND_SOC_DAIFMT_NB_NF)
 344                 return -EINVAL;
 345         if ((fmt & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS)
 346                 return -EINVAL;
 347         if ((fmt & SND_SOC_DAIFMT_FORMAT_MASK) != SND_SOC_DAIFMT_I2S)
 348                 return -EINVAL;
 349
 350         return 0;
 351 }
 352
 353 /* PCM */
 354
 355 static const struct snd_pcm_hardware xtfpga_pcm_hardware = {
 356         .info = SNDRV_PCM_INFO_INTERLEAVED |
 357                 SNDRV_PCM_INFO_MMAP_VALID |
 358                 SNDRV_PCM_INFO_BLOCK_TRANSFER,
 359         .formats                = SNDRV_PCM_FMTBIT_S16_LE |
 360                                   SNDRV_PCM_FMTBIT_S32_LE,
 361         .channels_min           = 1,
 362         .channels_max           = 2,
 363         .period_bytes_min       = 2,
 364         .period_bytes_max       = XTFPGA_I2S_FIFO_SIZE / 2 * 8,
 365         .periods_min            = 2,
 366         .periods_max            = XTFPGA_I2S_FIFO_SIZE * 8 / 2,
 367         .buffer_bytes_max       = XTFPGA_I2S_FIFO_SIZE * 8,
 368         .fifo_size              = 16,
 369 };
 370
 371 static int xtfpga_pcm_open(struct snd_pcm_substream *substream)
 372 {
 373         struct snd_pcm_runtime *runtime = substream->runtime;
 374         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 375         void *p;
 376
 377         snd_soc_set_runtime_hwparams(substream, &xtfpga_pcm_hardware);
 378         p = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 379         runtime->private_data = p;
 380
 381         return 0;
 382 }
 383
 384 static int xtfpga_pcm_close(struct snd_pcm_substream *substream)
 385 {
 386         synchronize_rcu();
 387         return 0;
 388 }
 389
 390 static int xtfpga_pcm_hw_params(struct snd_pcm_substream *substream,
 391                                 struct snd_pcm_hw_params *hw_params)
 392 {
 393         int ret;
 394         struct snd_pcm_runtime *runtime = substream->runtime;
 395         struct xtfpga_i2s *i2s = runtime->private_data;
 396         unsigned channels = params_channels(hw_params);
 397
 398         switch (channels) {
 399         case 1:
 400         case 2:
 401                 break;
 402
 403         default:
 404                 return -EINVAL;
 405
 406         }
 407
 408         switch (params_format(hw_params)) {
 409         case SNDRV_PCM_FORMAT_S16_LE:
 410                 i2s->tx_fn = (channels == 1) ?
 411                         xtfpga_pcm_tx_1x16 :
 412                         xtfpga_pcm_tx_2x16;
 413                 break;
 414
 415         case SNDRV_PCM_FORMAT_S32_LE:
 416                 i2s->tx_fn = (channels == 1) ?
 417                         xtfpga_pcm_tx_1x32 :
 418                         xtfpga_pcm_tx_2x32;
 419                 break;
 420
 421         default:
 422                 return -EINVAL;
 423         }
 424
 425         ret = snd_pcm_lib_malloc_pages(substream,
 426                                        params_buffer_bytes(hw_params));
 427         return ret;
 428 }
 429
 430 static int xtfpga_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 431 {
 432         int ret = 0;
 433         struct snd_pcm_runtime *runtime = substream->runtime;
 434         struct xtfpga_i2s *i2s = runtime->private_data;
 435
 436         switch (cmd) {
 437         case SNDRV_PCM_TRIGGER_START:
 438         case SNDRV_PCM_TRIGGER_RESUME:
 439         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 440                 ACCESS_ONCE(i2s->tx_ptr) = 0;
 441                 rcu_assign_pointer(i2s->tx_substream, substream);
 442                 xtfpga_pcm_refill_fifo(i2s);
 443                 break;
 444
 445         case SNDRV_PCM_TRIGGER_STOP:
 446         case SNDRV_PCM_TRIGGER_SUSPEND:
 447         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 448                 rcu_assign_pointer(i2s->tx_substream, NULL);
 449                 break;
 450
 451         default:
 452                 ret = -EINVAL;
 453                 break;
 454         }
 455         return ret;
 456 }
 457
 458 static snd_pcm_uframes_t xtfpga_pcm_pointer(struct snd_pcm_substream *substream)
 459 {
 460         struct snd_pcm_runtime *runtime = substream->runtime;
 461         struct xtfpga_i2s *i2s = runtime->private_data;
 462         snd_pcm_uframes_t pos = ACCESS_ONCE(i2s->tx_ptr);
 463
 464         return pos < runtime->buffer_size ? pos : 0;
 465 }
 466
 467 static int xtfpga_pcm_new(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         return snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
 473                                                      SNDRV_DMA_TYPE_DEV,
 474                                                      card->dev, size, size);
 475 }
 476
 477 static void xtfpga_pcm_free(struct snd_pcm *pcm)
 478 {
 479         snd_pcm_lib_preallocate_free_for_all(pcm);
 480 }
 481
 482 static const struct snd_pcm_ops xtfpga_pcm_ops = {
 483         .open           = xtfpga_pcm_open,
 484         .close          = xtfpga_pcm_close,
 485         .ioctl          = snd_pcm_lib_ioctl,
 486         .hw_params      = xtfpga_pcm_hw_params,
 487         .trigger        = xtfpga_pcm_trigger,
 488         .pointer        = xtfpga_pcm_pointer,
 489 };
 490
 491 static const struct snd_soc_platform_driver xtfpga_soc_platform = {
 492         .pcm_new        = xtfpga_pcm_new,
 493         .pcm_free       = xtfpga_pcm_free,
 494         .ops            = &xtfpga_pcm_ops,
 495 };
 496
 497 static const struct snd_soc_component_driver xtfpga_i2s_component = {
 498         .name           = DRV_NAME,
 499 };
 500
 501 static const struct snd_soc_dai_ops xtfpga_i2s_dai_ops = {
 502         .startup        = xtfpga_i2s_startup,
 503         .hw_params      = xtfpga_i2s_hw_params,
 504         .set_fmt        = xtfpga_i2s_set_fmt,
 505 };
 506
 507 static struct snd_soc_dai_driver xtfpga_i2s_dai[] = {
 508         {
 509                 .name = "xtfpga-i2s",
 510                 .id = 0,
 511                 .playback = {
 512                         .channels_min = 1,
 513                         .channels_max = 2,
 514                         .rates = SNDRV_PCM_RATE_8000_96000,
 515                         .formats = SNDRV_PCM_FMTBIT_S16_LE |
 516                                    SNDRV_PCM_FMTBIT_S32_LE,
 517                 },
 518                 .ops = &xtfpga_i2s_dai_ops,
 519         },
 520 };
 521
 522 static int xtfpga_i2s_runtime_suspend(struct device *dev)
 523 {
 524         struct xtfpga_i2s *i2s = dev_get_drvdata(dev);
 525
 526         clk_disable_unprepare(i2s->clk);
 527         return 0;
 528 }
 529
 530 static int xtfpga_i2s_runtime_resume(struct device *dev)
 531 {
 532         struct xtfpga_i2s *i2s = dev_get_drvdata(dev);
 533         int ret;
 534
 535         ret = clk_prepare_enable(i2s->clk);
 536         if (ret) {
 537                 dev_err(dev, "clk_prepare_enable failed: %d\n", ret);
 538                 return ret;
 539         }
 540         return 0;
 541 }
 542
 543 static int xtfpga_i2s_probe(struct platform_device *pdev)
 544 {
 545         struct xtfpga_i2s *i2s;
 546         struct resource *mem;
 547         int err, irq;
 548
 549         i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
 550         if (!i2s) {
 551                 err = -ENOMEM;
 552                 goto err;
 553         }
 554         platform_set_drvdata(pdev, i2s);
 555         i2s->dev = &pdev->dev;
 556         dev_dbg(&pdev->dev, "dev: %p, i2s: %p\n", &pdev->dev, i2s);
 557
 558         mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 559         i2s->regs = devm_ioremap_resource(&pdev->dev, mem);
 560         if (IS_ERR(i2s->regs)) {
 561                 err = PTR_ERR(i2s->regs);
 562                 goto err;
 563         }
 564
 565         i2s->regmap = devm_regmap_init_mmio(&pdev->dev, i2s->regs,
 566                                             &xtfpga_i2s_regmap_config);
 567         if (IS_ERR(i2s->regmap)) {
 568                 dev_err(&pdev->dev, "regmap init failed\n");
 569                 err = PTR_ERR(i2s->regmap);
 570                 goto err;
 571         }
 572
 573         i2s->clk = devm_clk_get(&pdev->dev, NULL);
 574         if (IS_ERR(i2s->clk)) {
 575                 dev_err(&pdev->dev, "couldn't get clock\n");
 576                 err = PTR_ERR(i2s->clk);
 577                 goto err;
 578         }
 579
 580         regmap_write(i2s->regmap, XTFPGA_I2S_CONFIG,
 581                      (0x1 << XTFPGA_I2S_CONFIG_CHANNEL_BASE));
 582         regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS, XTFPGA_I2S_INT_VALID);
 583         regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK, XTFPGA_I2S_INT_UNDERRUN);
 584
 585         irq = platform_get_irq(pdev, 0);
 586         if (irq < 0) {
 587                 dev_err(&pdev->dev, "No IRQ resource\n");
 588                 err = irq;
 589                 goto err;
 590         }
 591         err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 592                                         xtfpga_i2s_threaded_irq_handler,
 593                                         IRQF_SHARED | IRQF_ONESHOT,
 594                                         pdev->name, i2s);
 595         if (err < 0) {
 596                 dev_err(&pdev->dev, "request_irq failed\n");
 597                 goto err;
 598         }
 599
 600         err = snd_soc_register_platform(&pdev->dev, &xtfpga_soc_platform);
 601         if (err < 0) {
 602                 dev_err(&pdev->dev, "couldn't register platform\n");
 603                 goto err;
 604         }
 605         err = devm_snd_soc_register_component(&pdev->dev,
 606                                               &xtfpga_i2s_component,
 607                                               xtfpga_i2s_dai,
 608                                               ARRAY_SIZE(xtfpga_i2s_dai));
 609         if (err < 0) {
 610                 dev_err(&pdev->dev, "couldn't register component\n");
 611                 goto err_unregister_platform;
 612         }
 613
 614         pm_runtime_enable(&pdev->dev);
 615         if (!pm_runtime_enabled(&pdev->dev)) {
 616                 err = xtfpga_i2s_runtime_resume(&pdev->dev);
 617                 if (err)
 618                         goto err_pm_disable;
 619         }
 620         return 0;
 621
 622 err_pm_disable:
 623         pm_runtime_disable(&pdev->dev);
 624 err_unregister_platform:
 625         snd_soc_unregister_platform(&pdev->dev);
 626 err:
 627         dev_err(&pdev->dev, "%s: err = %d\n", __func__, err);
 628         return err;
 629 }
 630
 631 static int xtfpga_i2s_remove(struct platform_device *pdev)
 632 {
 633         struct xtfpga_i2s *i2s = dev_get_drvdata(&pdev->dev);
 634
 635         snd_soc_unregister_platform(&pdev->dev);
 636         if (i2s->regmap && !IS_ERR(i2s->regmap)) {
 637                 regmap_write(i2s->regmap, XTFPGA_I2S_CONFIG, 0);
 638                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_MASK, 0);
 639                 regmap_write(i2s->regmap, XTFPGA_I2S_INT_STATUS,
 640                              XTFPGA_I2S_INT_VALID);
 641         }
 642         pm_runtime_disable(&pdev->dev);
 643         if (!pm_runtime_status_suspended(&pdev->dev))
 644                 xtfpga_i2s_runtime_suspend(&pdev->dev);
 645         return 0;
 646 }
 647
 648 #ifdef CONFIG_OF
 649 static const struct of_device_id xtfpga_i2s_of_match[] = {
 650         { .compatible = "cdns,xtfpga-i2s", },
 651         {},
 652 };
 653 MODULE_DEVICE_TABLE(of, xtfpga_i2s_of_match);
 654 #endif
 655
 656 static const struct dev_pm_ops xtfpga_i2s_pm_ops = {
 657         SET_RUNTIME_PM_OPS(xtfpga_i2s_runtime_suspend,
 658                            xtfpga_i2s_runtime_resume, NULL)
 659 };
 660
 661 static struct platform_driver xtfpga_i2s_driver = {
 662         .probe   = xtfpga_i2s_probe,
 663         .remove  = xtfpga_i2s_remove,
 664         .driver  = {
 665                 .name = "xtfpga-i2s",
 666                 .of_match_table = of_match_ptr(xtfpga_i2s_of_match),
 667                 .pm = &xtfpga_i2s_pm_ops,
 668         },
 669 };
 670
 671 module_platform_driver(xtfpga_i2s_driver);
 672
 673 MODULE_AUTHOR("Max Filippov <jcmvbkbc@gmail.com>");
 674 MODULE_DESCRIPTION("xtfpga I2S controller driver");
 675 MODULE_LICENSE("GPL v2");