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_PAUSE,
  48         .formats = 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_S32_LE,
 145                     .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
 146                               SNDRV_PCM_RATE_32000),
 147                     },
 148         .ops = &stm32_adfsdm_dai_ops,
 149 };
 150
 151 static const struct snd_soc_component_driver stm32_adfsdm_dai_component = {
 152         .name = "stm32_dfsdm_audio",
 153 };
 154
 155 static int stm32_afsdm_pcm_cb(const void *data, size_t size, void *private)
 156 {
 157         struct stm32_adfsdm_priv *priv = private;
 158         struct snd_soc_pcm_runtime *rtd = priv->substream->private_data;
 159         u8 *pcm_buff = priv->pcm_buff;
 160         u8 *src_buff = (u8 *)data;
 161         unsigned int buff_size = snd_pcm_lib_buffer_bytes(priv->substream);
 162         unsigned int period_size = snd_pcm_lib_period_bytes(priv->substream);
 163         unsigned int old_pos = priv->pos;
 164         unsigned int cur_size = size;
 165
 166         dev_dbg(rtd->dev, "%s: buff_add :%pK, pos = %d, size = %zu\n",
 167                 __func__, &pcm_buff[priv->pos], priv->pos, size);
 168
 169         if ((priv->pos + size) > buff_size) {
 170                 memcpy(&pcm_buff[priv->pos], src_buff, buff_size - priv->pos);
 171                 cur_size -= buff_size - priv->pos;
 172                 priv->pos = 0;
 173         }
 174
 175         memcpy(&pcm_buff[priv->pos], &src_buff[size - cur_size], cur_size);
 176         priv->pos = (priv->pos + cur_size) % buff_size;
 177
 178         if (cur_size != size || (old_pos && (old_pos % period_size < size)))
 179                 snd_pcm_period_elapsed(priv->substream);
 180
 181         return 0;
 182 }
 183
 184 static int stm32_adfsdm_trigger(struct snd_pcm_substream *substream, int cmd)
 185 {
 186         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 187         struct stm32_adfsdm_priv *priv =
 188                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 189
 190         switch (cmd) {
 191         case SNDRV_PCM_TRIGGER_START:
 192         case SNDRV_PCM_TRIGGER_RESUME:
 193                 priv->pos = 0;
 194                 return stm32_dfsdm_get_buff_cb(priv->iio_ch->indio_dev,
 195                                                stm32_afsdm_pcm_cb, priv);
 196         case SNDRV_PCM_TRIGGER_SUSPEND:
 197         case SNDRV_PCM_TRIGGER_STOP:
 198                 return stm32_dfsdm_release_buff_cb(priv->iio_ch->indio_dev);
 199         }
 200
 201         return -EINVAL;
 202 }
 203
 204 static int stm32_adfsdm_pcm_open(struct snd_pcm_substream *substream)
 205 {
 206         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 207         struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(rtd->cpu_dai);
 208         int ret;
 209
 210         ret =  snd_soc_set_runtime_hwparams(substream, &stm32_adfsdm_pcm_hw);
 211         if (!ret)
 212                 priv->substream = substream;
 213
 214         return ret;
 215 }
 216
 217 static int stm32_adfsdm_pcm_close(struct snd_pcm_substream *substream)
 218 {
 219         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 220         struct stm32_adfsdm_priv *priv =
 221                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 222
 223         snd_pcm_lib_free_pages(substream);
 224         priv->substream = NULL;
 225
 226         return 0;
 227 }
 228
 229 static snd_pcm_uframes_t stm32_adfsdm_pcm_pointer(
 230                                             struct snd_pcm_substream *substream)
 231 {
 232         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 233         struct stm32_adfsdm_priv *priv =
 234                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 235
 236         return bytes_to_frames(substream->runtime, priv->pos);
 237 }
 238
 239 static int stm32_adfsdm_pcm_hw_params(struct snd_pcm_substream *substream,
 240                                       struct snd_pcm_hw_params *params)
 241 {
 242         struct snd_soc_pcm_runtime *rtd = substream->private_data;
 243         struct stm32_adfsdm_priv *priv =
 244                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 245         int ret;
 246
 247         ret =  snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
 248         if (ret < 0)
 249                 return ret;
 250         priv->pcm_buff = substream->runtime->dma_area;
 251
 252         return iio_channel_cb_set_buffer_watermark(priv->iio_cb,
 253                                                    params_period_size(params));
 254 }
 255
 256 static int stm32_adfsdm_pcm_hw_free(struct snd_pcm_substream *substream)
 257 {
 258         snd_pcm_lib_free_pages(substream);
 259
 260         return 0;
 261 }
 262
 263 static struct snd_pcm_ops stm32_adfsdm_pcm_ops = {
 264         .open           = stm32_adfsdm_pcm_open,
 265         .close          = stm32_adfsdm_pcm_close,
 266         .hw_params      = stm32_adfsdm_pcm_hw_params,
 267         .hw_free        = stm32_adfsdm_pcm_hw_free,
 268         .trigger        = stm32_adfsdm_trigger,
 269         .pointer        = stm32_adfsdm_pcm_pointer,
 270 };
 271
 272 static int stm32_adfsdm_pcm_new(struct snd_soc_pcm_runtime *rtd)
 273 {
 274         struct snd_pcm *pcm = rtd->pcm;
 275         struct stm32_adfsdm_priv *priv =
 276                 snd_soc_dai_get_drvdata(rtd->cpu_dai);
 277         unsigned int size = DFSDM_MAX_PERIODS * DFSDM_MAX_PERIOD_SIZE;
 278
 279         snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
 280                                               priv->dev, size, size);
 281         return 0;
 282 }
 283
 284 static void stm32_adfsdm_pcm_free(struct snd_pcm *pcm)
 285 {
 286         struct snd_pcm_substream *substream;
 287
 288         substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
 289         if (substream)
 290                 snd_pcm_lib_preallocate_free_for_all(pcm);
 291 }
 292
 293 static struct snd_soc_component_driver stm32_adfsdm_soc_platform = {
 294         .ops            = &stm32_adfsdm_pcm_ops,
 295         .pcm_new        = stm32_adfsdm_pcm_new,
 296         .pcm_free       = stm32_adfsdm_pcm_free,
 297 };
 298
 299 static const struct of_device_id stm32_adfsdm_of_match[] = {
 300         {.compatible = "st,stm32h7-dfsdm-dai"},
 301         {}
 302 };
 303 MODULE_DEVICE_TABLE(of, stm32_adfsdm_of_match);
 304
 305 static int stm32_adfsdm_probe(struct platform_device *pdev)
 306 {
 307         struct stm32_adfsdm_priv *priv;
 308         struct snd_soc_component *component;
 309         int ret;
 310
 311         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 312         if (!priv)
 313                 return -ENOMEM;
 314
 315         priv->dev = &pdev->dev;
 316         priv->dai_drv = stm32_adfsdm_dai;
 317         mutex_init(&priv->lock);
 318
 319         dev_set_drvdata(&pdev->dev, priv);
 320
 321         ret = devm_snd_soc_register_component(&pdev->dev,
 322                                               &stm32_adfsdm_dai_component,
 323                                               &priv->dai_drv, 1);
 324         if (ret < 0)
 325                 return ret;
 326
 327         /* Associate iio channel */
 328         priv->iio_ch  = devm_iio_channel_get_all(&pdev->dev);
 329         if (IS_ERR(priv->iio_ch))
 330                 return PTR_ERR(priv->iio_ch);
 331
 332         priv->iio_cb = iio_channel_get_all_cb(&pdev->dev, NULL, NULL);
 333         if (IS_ERR(priv->iio_cb))
 334                 return PTR_ERR(priv->iio_cb);
 335
 336         component = devm_kzalloc(&pdev->dev, sizeof(*component), GFP_KERNEL);
 337         if (!component)
 338                 return -ENOMEM;
 339 #ifdef CONFIG_DEBUG_FS
 340         component->debugfs_prefix = "pcm";
 341 #endif
 342
 343         ret = snd_soc_add_component(&pdev->dev, component,
 344                                     &stm32_adfsdm_soc_platform, NULL, 0);
 345         if (ret < 0)
 346                 dev_err(&pdev->dev, "%s: Failed to register PCM platform\n",
 347                         __func__);
 348
 349         return ret;
 350 }
 351
 352 static int stm32_adfsdm_remove(struct platform_device *pdev)
 353 {
 354         snd_soc_unregister_component(&pdev->dev);
 355
 356         return 0;
 357 }
 358
 359 static struct platform_driver stm32_adfsdm_driver = {
 360         .driver = {
 361                    .name = STM32_ADFSDM_DRV_NAME,
 362                    .of_match_table = stm32_adfsdm_of_match,
 363                    },
 364         .probe = stm32_adfsdm_probe,
 365         .remove = stm32_adfsdm_remove,
 366 };
 367
 368 module_platform_driver(stm32_adfsdm_driver);
 369
 370 MODULE_DESCRIPTION("stm32 DFSDM DAI driver");
 371 MODULE_AUTHOR("Arnaud Pouliquen <arnaud.pouliquen@st.com>");
 372 MODULE_LICENSE("GPL v2");
 373 MODULE_ALIAS("platform:" STM32_ADFSDM_DRV_NAME);