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); 395