sound/soc/stm/stm32_adfsdm.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * This file is part of STM32 DFSDM ASoC DAI driver
   4  *
   5  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
   6  * Authors: Arnaud Pouliquen <arnaud.pouliquen@st.com>
   7  *          Olivier Moysan <olivier.moysan@st.com>
   8  */
   9
  10 #include <linux/clk.h>
  11 #include <linux/module.h>
  12 #include <linux/mutex.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/slab.h>
  15
  16 #include <linux/iio/iio.h>
  17 #include <linux/iio/consumer.h>
  18 #include <linux/iio/adc/stm32-dfsdm-adc.h>
  19
  20 #include <sound/pcm.h>
  21 #include <sound/soc.h>
  22
  23 #define STM32_ADFSDM_DRV_NAME "stm32-adfsdm"
  24
  25 #define DFSDM_MAX_PERIOD_SIZE   (PAGE_SIZE / 2)
  26 #define DFSDM_MAX_PERIODS       6
  27
  28 struct stm32_adfsdm_priv {
  29         struct snd_soc_dai_driver dai_drv;
  30         struct snd_pcm_substream *substream;
  31         struct device *dev;
  32
  33         /* IIO */
  34         struct iio_channel *iio_ch;
  35         struct iio_cb_buffer *iio_cb;
  36         bool iio_active;
  37
  38         /* PCM buffer */
  39         unsigned char *pcm_buff;
  40         unsigned int pos;
  41
  42         struct mutex lock; /* protect against race condition on iio state */
  43 };
  44
  45 static const struct snd_pcm_hardware stm32_adfsdm_pcm_hw = {
  46         .info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
  47                 SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_PAUSE,
  48         .formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S32_LE,
  49
  50         .channels_min = 1,
  51         .channels_max = 1,
  52
  53         .periods_min = 2,
  54         .periods_max = DFSDM_MAX_PERIODS,
  55
  56         .period_bytes_max = DFSDM_MAX_PERIOD_SIZE,
  57         .buffer_bytes_max = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE
  58 };
  59
  60 static void stm32_adfsdm_shutdown(struct snd_pcm_substream *substream,
  61                                   struct snd_soc_dai *dai)
  62 {
  63         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
  64
  65         mutex_lock(&priv->lock);
  66         if (priv->iio_active) {
  67                 iio_channel_stop_all_cb(priv->iio_cb);
  68                 priv->iio_active = false;
  69         }
  70         mutex_unlock(&priv->lock);
  71 }
  72
  73 static int stm32_adfsdm_dai_prepare(struct snd_pcm_substream *substream,
  74                                     struct snd_soc_dai *dai)
  75 {
  76         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
  77         int ret;
  78
  79         mutex_lock(&priv->lock);
  80         if (priv->iio_active) {
  81                 iio_channel_stop_all_cb(priv->iio_cb);
  82                 priv->iio_active = false;
  83         }
  84
  85         ret = iio_write_channel_attribute(priv->iio_ch,
  86                                           substream->runtime->rate, 0,
  87                                           IIO_CHAN_INFO_SAMP_FREQ);
  88         if (ret < 0) {
  89                 dev_err(dai->dev, "%s: Failed to set %d sampling rate\n",
  90                         __func__, substream->runtime->rate);
  91                 goto out;
  92         }
  93
  94         if (!priv->iio_active) {
  95                 ret = iio_channel_start_all_cb(priv->iio_cb);
  96                 if (!ret)
  97                         priv->iio_active = true;
  98                 else
  99                         dev_err(dai->dev, "%s: IIO channel start failed (%d)\n",
 100                                 __func__, ret);
 101         }
 102
 103 out:
 104         mutex_unlock(&priv->lock);
 105
 106         return ret;
 107 }
 108
 109 static int stm32_adfsdm_set_sysclk(struct snd_soc_dai *dai, int clk_id,
 110                                    unsigned int freq, int dir)
 111 {
 112         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
 113         ssize_t size;
 114         char str_freq[10];
 115
 116         dev_dbg(dai->dev, "%s: Enter for freq %d\n", __func__, freq);
 117
 118         /* Set IIO frequency if CODEC is master as clock comes from SPI_IN */
 119
 120         snprintf(str_freq, sizeof(str_freq), "%d\n", freq);
 121         size = iio_write_channel_ext_info(priv->iio_ch, "spi_clk_freq",
 122                                           str_freq, sizeof(str_freq));
 123         if (size != sizeof(str_freq)) {
 124                 dev_err(dai->dev, "%s: Failed to set SPI clock\n",
 125                         __func__);
 126                 return -EINVAL;
 127         }
 128         return 0;
 129 }
 130
 131 static const struct snd_soc_dai_ops stm32_adfsdm_dai_ops = {
 132         .shutdown = stm32_adfsdm_shutdown,
 133         .prepare = stm32_adfsdm_dai_prepare,
 134         .set_sysclk = stm32_adfsdm_set_sysclk,
 135 };
 136
 137 static const struct snd_soc_dai_driver stm32_adfsdm_dai = {
 138         .capture = {
 139                     .channels_min = 1,
 140                     .channels_max = 1,
 141                     .formats = SNDRV_PCM_FMTBIT_S16_LE |
 142                                SNDRV_PCM_FMTBIT_S32_LE,
 143                     .rates = SNDRV_PCM_RATE_CONTINUOUS,
 144                     .rate_min = 8000,
 145                     .rate_max = 48000,
 146                     },
 147         .ops = &stm32_adfsdm_dai_ops,
 148 };
 149
 150 static const struct snd_soc_component_driver stm32_adfsdm_dai_component = {
 151         .name = "stm32_dfsdm_audio",
 152 };
 153
 154 static void stm32_memcpy_32to16(void *dest, const void *src, size_t n)
 155 {
 156         unsigned int i = 0;
 157         u16 *d = (u16 *)dest, *s = (u16 *)src;
 158
 159         s++;
 160         for (i = n >> 1; i > 0; i--) {
 161                 *d++ = *s++;
 162                 s++;
 163         }
 164 }
 165
 166 static int stm32_afsdm_pcm_cb(const void *data, size_t size, void *private)
 167 {
 168         struct stm32_adfsdm_priv *priv = private;
 169         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(priv->substream);
 170         u8 *pcm_buff = priv->pcm_buff;
 171         u8 *src_buff = (u8 *)data;
 172         unsigned int old_pos = priv->pos;
 173         size_t buff_size = snd_pcm_lib_buffer_bytes(priv->substream);
 174         size_t period_size = snd_pcm_lib_period_bytes(priv->substream);
 175         size_t cur_size, src_size = size;
 176         snd_pcm_format_t format = priv->substream->runtime->format;
 177
 178         if (format == SNDRV_PCM_FORMAT_S16_LE)
 179                 src_size >>= 1;
 180         cur_size = src_size;
 181
 182         dev_dbg(rtd->dev, "%s: buff_add :%pK, pos = %d, size = %zu\n",
 183                 __func__, &pcm_buff[priv->pos], priv->pos, src_size);
 184
 185         if ((priv->pos + src_size) > buff_size) {
 186                 if (format == SNDRV_PCM_FORMAT_S16_LE)
 187                         stm32_memcpy_32to16(&pcm_buff[priv->pos], src_buff,
 188                                             buff_size - priv->pos);
 189                 else
 190                         memcpy(&pcm_buff[priv->pos], src_buff,
 191                                buff_size - priv->pos);
 192                 cur_size -= buff_size - priv->pos;
 193                 priv->pos = 0;
 194         }
 195
 196         if (format == SNDRV_PCM_FORMAT_S16_LE)
 197                 stm32_memcpy_32to16(&pcm_buff[priv->pos],
 198                                     &src_buff[src_size - cur_size], cur_size);
 199         else
 200                 memcpy(&pcm_buff[priv->pos], &src_buff[src_size - cur_size],
 201                        cur_size);
 202
 203         priv->pos = (priv->pos + cur_size) % buff_size;
 204
 205         if (cur_size != src_size || (old_pos && (old_pos % period_size < size)))
 206                 snd_pcm_period_elapsed(priv->substream);
 207
 208         return 0;
 209 }
 210
 211 static int stm32_adfsdm_trigger(struct snd_soc_component *component,
 212                                 struct snd_pcm_substream *substream, int cmd)
 213 {
 214         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 215         struct stm32_adfsdm_priv *priv =
 216                 snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
 217
 218         switch (cmd) {
 219         case SNDRV_PCM_TRIGGER_START:
 220         case SNDRV_PCM_TRIGGER_RESUME:
 221                 priv->pos = 0;
 222                 return stm32_dfsdm_get_buff_cb(priv->iio_ch->indio_dev,
 223                                                stm32_afsdm_pcm_cb, priv);
 224         case SNDRV_PCM_TRIGGER_SUSPEND:
 225         case SNDRV_PCM_TRIGGER_STOP:
 226                 return stm32_dfsdm_release_buff_cb(priv->iio_ch->indio_dev);
 227         }
 228
 229         return -EINVAL;
 230 }
 231
 232 static int stm32_adfsdm_pcm_open(struct snd_soc_component *component,
 233                                  struct snd_pcm_substream *substream)
 234 {
 235         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 236         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
 237         int ret;
 238
 239         ret =  snd_soc_set_runtime_hwparams(substream, &stm32_adfsdm_pcm_hw);
 240         if (!ret)
 241                 priv->substream = substream;
 242
 243         return ret;
 244 }
 245
 246 static int stm32_adfsdm_pcm_close(struct snd_soc_component *component,
 247                                   struct snd_pcm_substream *substream)
 248 {
 249         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 250         struct stm32_adfsdm_priv *priv =
 251                 snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
 252
 253         priv->substream = NULL;
 254
 255         return 0;
 256 }
 257
 258 static snd_pcm_uframes_t stm32_adfsdm_pcm_pointer(
 259                                             struct snd_soc_component *component,
 260                                             struct snd_pcm_substream *substream)
 261 {
 262         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 263         struct stm32_adfsdm_priv *priv =
 264                 snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
 265
 266         return bytes_to_frames(substream->runtime, priv->pos);
 267 }
 268
 269 static int stm32_adfsdm_pcm_hw_params(struct snd_soc_component *component,
 270                                       struct snd_pcm_substream *substream,
 271                                       struct snd_pcm_hw_params *params)
 272 {
 273         struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 274         struct stm32_adfsdm_priv *priv =
 275                 snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
 276
 277         priv->pcm_buff = substream->runtime->dma_area;
 278
 279         return iio_channel_cb_set_buffer_watermark(priv->iio_cb,
 280                                                    params_period_size(params));
 281 }
 282
 283 static int stm32_adfsdm_pcm_new(struct snd_soc_component *component,
 284                                 struct snd_soc_pcm_runtime *rtd)
 285 {
 286         struct snd_pcm *pcm = rtd->pcm;
 287         struct stm32_adfsdm_priv *priv =
 288                 snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
 289         unsigned int size = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE;
 290
 291         snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
 292                                        priv->dev, size, size);
 293         return 0;
 294 }
 295
 296 static int stm32_adfsdm_dummy_cb(const void *data, void *private)
 297 {
 298         /*
 299          * This dummmy callback is requested by iio_channel_get_all_cb() API,
 300          * but the stm32_dfsdm_get_buff_cb() API is used instead, to optimize
 301          * DMA transfers.
 302          */
 303         return 0;
 304 }
 305
 306 static struct snd_soc_component_driver stm32_adfsdm_soc_platform = {
 307         .open           = stm32_adfsdm_pcm_open,
 308         .close          = stm32_adfsdm_pcm_close,
 309         .hw_params      = stm32_adfsdm_pcm_hw_params,
 310         .trigger        = stm32_adfsdm_trigger,
 311         .pointer        = stm32_adfsdm_pcm_pointer,
 312         .pcm_construct  = stm32_adfsdm_pcm_new,
 313 };
 314
 315 static const struct of_device_id stm32_adfsdm_of_match[] = {
 316         {.compatible = "st,stm32h7-dfsdm-dai"},
 317         {}
 318 };
 319 MODULE_DEVICE_TABLE(of, stm32_adfsdm_of_match);
 320
 321 static int stm32_adfsdm_probe(struct platform_device *pdev)
 322 {
 323         struct stm32_adfsdm_priv *priv;
 324         struct snd_soc_component *component;
 325         int ret;
 326
 327         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 328         if (!priv)
 329                 return -ENOMEM;
 330
 331         priv->dev = &pdev->dev;
 332         priv->dai_drv = stm32_adfsdm_dai;
 333         mutex_init(&priv->lock);
 334
 335         dev_set_drvdata(&pdev->dev, priv);
 336
 337         ret = devm_snd_soc_register_component(&pdev->dev,
 338                                               &stm32_adfsdm_dai_component,
 339                                               &priv->dai_drv, 1);
 340         if (ret < 0)
 341                 return ret;
 342
 343         /* Associate iio channel */
 344         priv->iio_ch  = devm_iio_channel_get_all(&pdev->dev);
 345         if (IS_ERR(priv->iio_ch))
 346                 return PTR_ERR(priv->iio_ch);
 347
 348         priv->iio_cb = iio_channel_get_all_cb(&pdev->dev, &stm32_adfsdm_dummy_cb, NULL);
 349         if (IS_ERR(priv->iio_cb))
 350                 return PTR_ERR(priv->iio_cb);
 351
 352         component = devm_kzalloc(&pdev->dev, sizeof(*component), GFP_KERNEL);
 353         if (!component)
 354                 return -ENOMEM;
 355
 356         ret = snd_soc_component_initialize(component,
 357                                            &stm32_adfsdm_soc_platform,
 358                                            &pdev->dev);
 359         if (ret < 0)
 360                 return ret;
 361 #ifdef CONFIG_DEBUG_FS
 362         component->debugfs_prefix = "pcm";
 363 #endif
 364
 365         ret = snd_soc_add_component(component, NULL, 0);
 366         if (ret < 0)
 367                 dev_err(&pdev->dev, "%s: Failed to register PCM platform\n",
 368                         __func__);
 369
 370         return ret;
 371 }
 372
 373 static int stm32_adfsdm_remove(struct platform_device *pdev)
 374 {
 375         snd_soc_unregister_component(&pdev->dev);
 376
 377         return 0;
 378 }
 379
 380 static struct platform_driver stm32_adfsdm_driver = {
 381         .driver = {
 382                    .name = STM32_ADFSDM_DRV_NAME,
 383                    .of_match_table = stm32_adfsdm_of_match,
 384                    },
 385         .probe = stm32_adfsdm_probe,
 386         .remove = stm32_adfsdm_remove,
 387 };
 388
 389 module_platform_driver(stm32_adfsdm_driver);
 390
 391 MODULE_DESCRIPTION("stm32 DFSDM DAI driver");
 392 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
 393 MODULE_LICENSE("GPL v2");
 394 MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);