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         .rate_min = 8000,
  51         .rate_max = 32000,
  52
  53         .channels_min = 1,
  54         .channels_max = 1,
  55
  56         .periods_min = 2,
  57         .periods_max = DFSDM_MAX_PERIODS,
  58
  59         .period_bytes_max = DFSDM_MAX_PERIOD_SIZE,
  60         .buffer_bytes_max = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE
  61 };
  62
  63 static void stm32_adfsdm_shutdown(struct snd_pcm_substream *substream,
  64                                   struct snd_soc_dai *dai)
  65 {
  66         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
  67
  68         mutex_lock(&priv->lock);
  69         if (priv->iio_active) {
  70                 iio_channel_stop_all_cb(priv->iio_cb);
  71                 priv->iio_active = false;
  72         }
  73         mutex_unlock(&priv->lock);
  74 }
  75
  76 static int stm32_adfsdm_dai_prepare(struct snd_pcm_substream *substream,
  77                                     struct snd_soc_dai *dai)
  78 {
  79         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
  80         int ret;
  81
  82         mutex_lock(&priv->lock);
  83         if (priv->iio_active) {
  84                 iio_channel_stop_all_cb(priv->iio_cb);
  85                 priv->iio_active = false;
  86         }
  87
  88         ret = iio_write_channel_attribute(priv->iio_ch,
  89                                           substream->runtime->rate, 0,
  90                                           IIO_CHAN_INFO_SAMP_FREQ);
  91         if (ret < 0) {
  92                 dev_err(dai->dev, "%s: Failed to set %d sampling rate\n",
  93                         __func__, substream->runtime->rate);
  94                 goto out;
  95         }
  96
  97         if (!priv->iio_active) {
  98                 ret = iio_channel_start_all_cb(priv->iio_cb);
  99                 if (!ret)
 100                         priv->iio_active = true;
 101                 else
 102                         dev_err(dai->dev, "%s: IIO channel start failed (%d)\n",
 103                                 __func__, ret);
 104         }
 105
 106 out:
 107         mutex_unlock(&priv->lock);
 108
 109         return ret;
 110 }
 111
 112 static int stm32_adfsdm_set_sysclk(struct snd_soc_dai *dai, int clk_id,
 113                                    unsigned int freq, int dir)
 114 {
 115         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
 116         ssize_t size;
 117         char str_freq[10];
 118
 119         dev_dbg(dai->dev, "%s: Enter for freq %d\n", __func__, freq);
 120
 121         /* Set IIO frequency if CODEC is master as clock comes from SPI_IN */
 122
 123         snprintf(str_freq, sizeof(str_freq), "%d\n", freq);
 124         size = iio_write_channel_ext_info(priv->iio_ch, "spi_clk_freq",
 125                                           str_freq, sizeof(str_freq));
 126         if (size != sizeof(str_freq)) {
 127                 dev_err(dai->dev, "%s: Failed to set SPI clock\n",
 128                         __func__);
 129                 return -EINVAL;
 130         }
 131         return 0;
 132 }
 133
 134 static const struct snd_soc_dai_ops stm32_adfsdm_dai_ops = {
 135         .shutdown = stm32_adfsdm_shutdown,
 136         .prepare = stm32_adfsdm_dai_prepare,
 137         .set_sysclk = stm32_adfsdm_set_sysclk,
 138 };
 139
 140 static const struct snd_soc_dai_driver stm32_adfsdm_dai = {
 141         .capture = {
 142                     .channels_min = 1,
 143                     .channels_max = 1,
 144                     .formats = SNDRV_PCM_FMTBIT_S16_LE |
 145                                SNDRV_PCM_FMTBIT_S32_LE,
 146                     .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
 147                               SNDRV_PCM_RATE_32000),
 148                     },
 149         .ops = &stm32_adfsdm_dai_ops,
 150 };
 151
 152 static const struct snd_soc_component_driver stm32_adfsdm_dai_component = {
 153         .name = "stm32_dfsdm_audio",
 154 };
 155
 156 static void stm32_memcpy_32to16(void *dest, const void *src, size_t n)
 157 {
 158         unsigned int i = 0;
 159         u16 *d = (u16 *)dest, *s = (u16 *)src;
 160
 161         s++;
 162         for (i = n >> 1; i > 0; i--) {
 163                 *d++ = *s++;
 164                 s++;
 165         }
 166 }
 167
 168 static int stm32_afsdm_pcm_cb(const void *data, size_t size, void *private)
 169 {
 170         struct stm32_adfsdm_priv *priv = private;
 171         struct snd_soc_pcm_runtime *rtd = priv->substream->private_data;
 172         u8 *pcm_buff = priv->pcm_buff;
 173         u8 *src_buff = (u8 *)data;
 174         unsigned int old_pos = priv->pos;
 175         size_t buff_size = snd_pcm_lib_buffer_bytes(priv->substream);
 176         size_t period_size = snd_pcm_lib_period_bytes(priv->substream);
 177         size_t cur_size, src_size = size;
 178         snd_pcm_format_t format = priv->substream->runtime->format;
 179
 180         if (format == SNDRV_PCM_FORMAT_S16_LE)
 181                 src_size >>= 1;
 182         cur_size = src_size;
 183
 184         dev_dbg(rtd->dev, "%s: buff_add :%pK, pos = %d, size = %zu\n",
 185                 __func__, &pcm_buff[priv->pos], priv->pos, src_size);
 186
 187         if ((priv->pos + src_size) > buff_size) {
 188                 if (format == SNDRV_PCM_FORMAT_S16_LE)
 189                         stm32_memcpy_32to16(&pcm_buff[priv->pos], src_buff,
 190                                             buff_size - priv->pos);
 191                 else
 192                         memcpy(&pcm_buff[priv->pos], src_buff,
 193                                buff_size - priv->pos);
 194                 cur_size -= buff_size - priv->pos;
 195                 priv->pos = 0;
 196         }
 197
 198         if (format == SNDRV_PCM_FORMAT_S16_LE)
 199                 stm32_memcpy_32to16(&pcm_buff[priv->pos],
 200                                     &src_buff[src_size - cur_size], cur_size);
 201         else
 202                 memcpy(&pcm_buff[priv->pos], &src_buff[src_size - cur_size],
 203                        cur_size);
 204
 205         priv->pos = (priv->pos + cur_size) % buff_size;
 206
 207         if (cur_size != src_size || (old_pos && (old_pos % period_size < size)))
 208                 snd_pcm_period_elapsed(priv->substream);
 209
 210         return 0;
 211 }
 212
 213 static int stm32_adfsdm_trigger(struct snd_soc_component *component,
 214                                 struct snd_pcm_substream *substream, int cmd)
 215 {
 216         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 217         struct stm32_adfsdm_priv *priv =
 218                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 219
 220         switch (cmd) {
 221         case SNDRV_PCM_TRIGGER_START:
 222         case SNDRV_PCM_TRIGGER_RESUME:
 223                 priv->pos = 0;
 224                 return stm32_dfsdm_get_buff_cb(priv->iio_ch->indio_dev,
 225                                                stm32_afsdm_pcm_cb, priv);
 226         case SNDRV_PCM_TRIGGER_SUSPEND:
 227         case SNDRV_PCM_TRIGGER_STOP:
 228                 return stm32_dfsdm_release_buff_cb(priv->iio_ch->indio_dev);
 229         }
 230
 231         return -EINVAL;
 232 }
 233
 234 static int stm32_adfsdm_pcm_open(struct snd_soc_component *component,
 235                                  struct snd_pcm_substream *substream)
 236 {
 237         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 238         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(rtd->cpu_dai);
 239         int ret;
 240
 241         ret =  snd_soc_set_runtime_hwparams(substream, &stm32_adfsdm_pcm_hw);
 242         if (!ret)
 243                 priv->substream = substream;
 244
 245         return ret;
 246 }
 247
 248 static int stm32_adfsdm_pcm_close(struct snd_soc_component *component,
 249                                   struct snd_pcm_substream *substream)
 250 {
 251         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 252         struct stm32_adfsdm_priv *priv =
 253                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 254
 255         priv->substream = NULL;
 256
 257         return 0;
 258 }
 259
 260 static snd_pcm_uframes_t stm32_adfsdm_pcm_pointer(
 261                                             struct snd_soc_component *component,
 262                                             struct snd_pcm_substream *substream)
 263 {
 264         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 265         struct stm32_adfsdm_priv *priv =
 266                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 267
 268         return bytes_to_frames(substream->runtime, priv->pos);
 269 }
 270
 271 static int stm32_adfsdm_pcm_hw_params(struct snd_soc_component *component,
 272                                       struct snd_pcm_substream *substream,
 273                                       struct snd_pcm_hw_params *params)
 274 {
 275         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 276         struct stm32_adfsdm_priv *priv =
 277                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 278
 279         priv->pcm_buff = substream->runtime->dma_area;
 280
 281         return iio_channel_cb_set_buffer_watermark(priv->iio_cb,
 282                                                    params_period_size(params));
 283 }
 284
 285 static int stm32_adfsdm_pcm_new(struct snd_soc_component *component,
 286                                 struct snd_soc_pcm_runtime *rtd)
 287 {
 288         struct snd_pcm *pcm = rtd->pcm;
 289         struct stm32_adfsdm_priv *priv =
 290                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 291         unsigned int size = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE;
 292
 293         snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
 294                                        priv->dev, size, size);
 295         return 0;
 296 }
 297
 298 static struct snd_soc_component_driver stm32_adfsdm_soc_platform = {
 299         .open           = stm32_adfsdm_pcm_open,
 300         .close          = stm32_adfsdm_pcm_close,
 301         .hw_params      = stm32_adfsdm_pcm_hw_params,
 302         .trigger        = stm32_adfsdm_trigger,
 303         .pointer        = stm32_adfsdm_pcm_pointer,
 304         .pcm_construct  = stm32_adfsdm_pcm_new,
 305 };
 306
 307 static const struct of_device_id stm32_adfsdm_of_match[] = {
 308         {.compatible = "st,stm32h7-dfsdm-dai"},
 309         {}
 310 };
 311 MODULE_DEVICE_TABLE(of, stm32_adfsdm_of_match);
 312
 313 static int stm32_adfsdm_probe(struct platform_device *pdev)
 314 {
 315         struct stm32_adfsdm_priv *priv;
 316         struct snd_soc_component *component;
 317         int ret;
 318
 319         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 320         if (!priv)
 321                 return -ENOMEM;
 322
 323         priv->dev = &pdev->dev;
 324         priv->dai_drv = stm32_adfsdm_dai;
 325         mutex_init(&priv->lock);
 326
 327         dev_set_drvdata(&pdev->dev, priv);
 328
 329         ret = devm_snd_soc_register_component(&pdev->dev,
 330                                               &stm32_adfsdm_dai_component,
 331                                               &priv->dai_drv, 1);
 332         if (ret < 0)
 333                 return ret;
 334
 335         /* Associate iio channel */
 336         priv->iio_ch  = devm_iio_channel_get_all(&pdev->dev);
 337         if (IS_ERR(priv->iio_ch))
 338                 return PTR_ERR(priv->iio_ch);
 339
 340         priv->iio_cb = iio_channel_get_all_cb(&pdev->dev, NULL, NULL);
 341         if (IS_ERR(priv->iio_cb))
 342                 return PTR_ERR(priv->iio_cb);
 343
 344         component = devm_kzalloc(&pdev->dev, sizeof(*component), GFP_KERNEL);
 345         if (!component)
 346                 return -ENOMEM;
 347 #ifdef CONFIG_DEBUG_FS
 348         component->debugfs_prefix = "pcm";
 349 #endif
 350
 351         ret = snd_soc_add_component(&pdev->dev, component,
 352                                     &stm32_adfsdm_soc_platform, NULL, 0);
 353         if (ret < 0)
 354                 dev_err(&pdev->dev, "%s: Failed to register PCM platform\n",
 355                         __func__);
 356
 357         return ret;
 358 }
 359
 360 static int stm32_adfsdm_remove(struct platform_device *pdev)
 361 {
 362         snd_soc_unregister_component(&pdev->dev);
 363
 364         return 0;
 365 }
 366
 367 static struct platform_driver stm32_adfsdm_driver = {
 368         .driver = {
 369                    .name = STM32_ADFSDM_DRV_NAME,
 370                    .of_match_table = stm32_adfsdm_of_match,
 371                    },
 372         .probe = stm32_adfsdm_probe,
 373         .remove = stm32_adfsdm_remove,
 374 };
 375
 376 module_platform_driver(stm32_adfsdm_driver);
 377
 378 MODULE_DESCRIPTION("stm32 DFSDM DAI driver");
 379 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
 380 MODULE_LICENSE("GPL v2");
 381 MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);