1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2012, Analog Devices Inc. 4 * Author: Lars-Peter Clausen <lars@metafoo.de> 5 * 6 * Based on: 7 * imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de> 8 * mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc. 9 * ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org> 10 * Copyright (C) 2006 Applied Data Systems 11 */ 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/dmaengine.h> 15 #include <linux/slab.h> 16 #include <sound/pcm.h> 17 #include <sound/pcm_params.h> 18 #include <sound/soc.h> 19 20 #include <sound/dmaengine_pcm.h> 21 22 struct dmaengine_pcm_runtime_data { 23 struct dma_chan *dma_chan; 24 dma_cookie_t cookie; 25 26 unsigned int pos; 27 }; 28 29 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd( 30 const struct snd_pcm_substream *substream) 31 { 32 return substream->runtime->private_data; 33 } 34 35 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream) 36 { 37 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 38 39 return prtd->dma_chan; 40 } 41 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan); 42 43 /** 44 * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config 45 * @substream: PCM substream 46 * @params: hw_params 47 * @slave_config: DMA slave config 48 * 49 * This function can be used to initialize a dma_slave_config from a substream 50 * and hw_params in a dmaengine based PCM driver implementation. 51 * 52 * Return: zero if successful, or a negative error code 53 */ 54 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream, 55 const struct snd_pcm_hw_params *params, 56 struct dma_slave_config *slave_config) 57 { 58 enum dma_slave_buswidth buswidth; 59 int bits; 60 61 bits = params_physical_width(params); 62 if (bits < 8 || bits > 64) 63 return -EINVAL; 64 else if (bits == 8) 65 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; 66 else if (bits == 16) 67 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; 68 else if (bits == 24) 69 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES; 70 else if (bits <= 32) 71 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; 72 else 73 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES; 74 75 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 76 slave_config->direction = DMA_MEM_TO_DEV; 77 slave_config->dst_addr_width = buswidth; 78 } else { 79 slave_config->direction = DMA_DEV_TO_MEM; 80 slave_config->src_addr_width = buswidth; 81 } 82 83 slave_config->device_fc = false; 84 85 return 0; 86 } 87 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config); 88 89 /** 90 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config 91 * using DAI DMA data. 92 * @substream: PCM substream 93 * @dma_data: DAI DMA data 94 * @slave_config: DMA slave configuration 95 * 96 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width 97 * fields of the DMA slave config from the same fields of the DAI DMA 98 * data struct. The src and dst fields will be initialized depending on the 99 * direction of the substream. If the substream is a playback stream the dst 100 * fields will be initialized, if it is a capture stream the src fields will be 101 * initialized. The {dst,src}_addr_width field will only be initialized if the 102 * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of 103 * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If 104 * both conditions are met the latter takes priority. 105 */ 106 void snd_dmaengine_pcm_set_config_from_dai_data( 107 const struct snd_pcm_substream *substream, 108 const struct snd_dmaengine_dai_dma_data *dma_data, 109 struct dma_slave_config *slave_config) 110 { 111 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 112 slave_config->dst_addr = dma_data->addr; 113 slave_config->dst_maxburst = dma_data->maxburst; 114 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK) 115 slave_config->dst_addr_width = 116 DMA_SLAVE_BUSWIDTH_UNDEFINED; 117 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 118 slave_config->dst_addr_width = dma_data->addr_width; 119 } else { 120 slave_config->src_addr = dma_data->addr; 121 slave_config->src_maxburst = dma_data->maxburst; 122 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK) 123 slave_config->src_addr_width = 124 DMA_SLAVE_BUSWIDTH_UNDEFINED; 125 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 126 slave_config->src_addr_width = dma_data->addr_width; 127 } 128 129 slave_config->peripheral_config = dma_data->peripheral_config; 130 slave_config->peripheral_size = dma_data->peripheral_size; 131 } 132 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); 133 134 static void dmaengine_pcm_dma_complete(void *arg) 135 { 136 unsigned int new_pos; 137 struct snd_pcm_substream *substream = arg; 138 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 139 140 new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream); 141 if (new_pos >= snd_pcm_lib_buffer_bytes(substream)) 142 new_pos = 0; 143 prtd->pos = new_pos; 144 145 snd_pcm_period_elapsed(substream); 146 } 147 148 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream) 149 { 150 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 151 struct dma_chan *chan = prtd->dma_chan; 152 struct dma_async_tx_descriptor *desc; 153 enum dma_transfer_direction direction; 154 unsigned long flags = DMA_CTRL_ACK; 155 156 direction = snd_pcm_substream_to_dma_direction(substream); 157 158 if (!substream->runtime->no_period_wakeup) 159 flags |= DMA_PREP_INTERRUPT; 160 161 prtd->pos = 0; 162 desc = dmaengine_prep_dma_cyclic(chan, 163 substream->runtime->dma_addr, 164 snd_pcm_lib_buffer_bytes(substream), 165 snd_pcm_lib_period_bytes(substream), direction, flags); 166 167 if (!desc) 168 return -ENOMEM; 169 170 desc->callback = dmaengine_pcm_dma_complete; 171 desc->callback_param = substream; 172 prtd->cookie = dmaengine_submit(desc); 173 174 return 0; 175 } 176 177 /** 178 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation 179 * @substream: PCM substream 180 * @cmd: Trigger command 181 * 182 * This function can be used as the PCM trigger callback for dmaengine based PCM 183 * driver implementations. 184 * 185 * Return: 0 on success, a negative error code otherwise 186 */ 187 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 188 { 189 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 190 struct snd_pcm_runtime *runtime = substream->runtime; 191 int ret; 192 193 switch (cmd) { 194 case SNDRV_PCM_TRIGGER_START: 195 ret = dmaengine_pcm_prepare_and_submit(substream); 196 if (ret) 197 return ret; 198 dma_async_issue_pending(prtd->dma_chan); 199 break; 200 case SNDRV_PCM_TRIGGER_RESUME: 201 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 202 dmaengine_resume(prtd->dma_chan); 203 break; 204 case SNDRV_PCM_TRIGGER_SUSPEND: 205 if (runtime->info & SNDRV_PCM_INFO_PAUSE) 206 dmaengine_pause(prtd->dma_chan); 207 else 208 dmaengine_terminate_async(prtd->dma_chan); 209 break; 210 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 211 dmaengine_pause(prtd->dma_chan); 212 break; 213 case SNDRV_PCM_TRIGGER_STOP: 214 dmaengine_terminate_async(prtd->dma_chan); 215 break; 216 default: 217 return -EINVAL; 218 } 219 220 return 0; 221 } 222 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); 223 224 /** 225 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation 226 * @substream: PCM substream 227 * 228 * This function is deprecated and should not be used by new drivers, as its 229 * results may be unreliable. 230 * 231 * Return: PCM position in frames 232 */ 233 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream) 234 { 235 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 236 return bytes_to_frames(substream->runtime, prtd->pos); 237 } 238 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue); 239 240 /** 241 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation 242 * @substream: PCM substream 243 * 244 * This function can be used as the PCM pointer callback for dmaengine based PCM 245 * driver implementations. 246 * 247 * Return: PCM position in frames 248 */ 249 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream) 250 { 251 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 252 struct snd_pcm_runtime *runtime = substream->runtime; 253 struct dma_tx_state state; 254 enum dma_status status; 255 unsigned int buf_size; 256 unsigned int pos = 0; 257 258 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state); 259 if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) { 260 buf_size = snd_pcm_lib_buffer_bytes(substream); 261 if (state.residue > 0 && state.residue <= buf_size) 262 pos = buf_size - state.residue; 263 264 runtime->delay = bytes_to_frames(runtime, 265 state.in_flight_bytes); 266 } 267 268 return bytes_to_frames(runtime, pos); 269 } 270 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer); 271 272 /** 273 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM 274 * @filter_fn: Filter function used to request the DMA channel 275 * @filter_data: Data passed to the DMA filter function 276 * 277 * This function request a DMA channel for usage with dmaengine PCM. 278 * 279 * Return: NULL or the requested DMA channel 280 */ 281 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn, 282 void *filter_data) 283 { 284 dma_cap_mask_t mask; 285 286 dma_cap_zero(mask); 287 dma_cap_set(DMA_SLAVE, mask); 288 dma_cap_set(DMA_CYCLIC, mask); 289 290 return dma_request_channel(mask, filter_fn, filter_data); 291 } 292 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel); 293 294 /** 295 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream 296 * @substream: PCM substream 297 * @chan: DMA channel to use for data transfers 298 * 299 * The function should usually be called from the pcm open callback. Note that 300 * this function will use private_data field of the substream's runtime. So it 301 * is not available to your pcm driver implementation. 302 * 303 * Return: 0 on success, a negative error code otherwise 304 */ 305 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream, 306 struct dma_chan *chan) 307 { 308 struct dmaengine_pcm_runtime_data *prtd; 309 int ret; 310 311 if (!chan) 312 return -ENXIO; 313 314 ret = snd_pcm_hw_constraint_integer(substream->runtime, 315 SNDRV_PCM_HW_PARAM_PERIODS); 316 if (ret < 0) 317 return ret; 318 319 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL); 320 if (!prtd) 321 return -ENOMEM; 322 323 prtd->dma_chan = chan; 324 325 substream->runtime->private_data = prtd; 326 327 return 0; 328 } 329 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open); 330 331 /** 332 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel 333 * @substream: PCM substream 334 * @filter_fn: Filter function used to request the DMA channel 335 * @filter_data: Data passed to the DMA filter function 336 * 337 * This function will request a DMA channel using the passed filter function and 338 * data. The function should usually be called from the pcm open callback. Note 339 * that this function will use private_data field of the substream's runtime. So 340 * it is not available to your pcm driver implementation. 341 * 342 * Return: 0 on success, a negative error code otherwise 343 */ 344 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream, 345 dma_filter_fn filter_fn, void *filter_data) 346 { 347 return snd_dmaengine_pcm_open(substream, 348 snd_dmaengine_pcm_request_channel(filter_fn, filter_data)); 349 } 350 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan); 351 352 /** 353 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream 354 * @substream: PCM substream 355 * 356 * Return: 0 on success, a negative error code otherwise 357 */ 358 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream) 359 { 360 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 361 362 dmaengine_synchronize(prtd->dma_chan); 363 kfree(prtd); 364 365 return 0; 366 } 367 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close); 368 369 /** 370 * snd_dmaengine_pcm_close_release_chan - Close a dmaengine based PCM 371 * substream and release channel 372 * @substream: PCM substream 373 * 374 * Releases the DMA channel associated with the PCM substream. 375 * 376 * Return: zero if successful, or a negative error code 377 */ 378 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream) 379 { 380 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 381 382 dmaengine_synchronize(prtd->dma_chan); 383 dma_release_channel(prtd->dma_chan); 384 kfree(prtd); 385 386 return 0; 387 } 388 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan); 389 390 /** 391 * snd_dmaengine_pcm_refine_runtime_hwparams - Refine runtime hw params 392 * @substream: PCM substream 393 * @dma_data: DAI DMA data 394 * @hw: PCM hw params 395 * @chan: DMA channel to use for data transfers 396 * 397 * This function will query DMA capability, then refine the pcm hardware 398 * parameters. 399 * 400 * Return: 0 on success, a negative error code otherwise 401 */ 402 int snd_dmaengine_pcm_refine_runtime_hwparams( 403 struct snd_pcm_substream *substream, 404 struct snd_dmaengine_dai_dma_data *dma_data, 405 struct snd_pcm_hardware *hw, 406 struct dma_chan *chan) 407 { 408 struct dma_slave_caps dma_caps; 409 u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | 410 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | 411 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 412 snd_pcm_format_t i; 413 int ret = 0; 414 415 if (!hw || !chan || !dma_data) 416 return -EINVAL; 417 418 ret = dma_get_slave_caps(chan, &dma_caps); 419 if (ret == 0) { 420 if (dma_caps.cmd_pause && dma_caps.cmd_resume) 421 hw->info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME; 422 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT) 423 hw->info |= SNDRV_PCM_INFO_BATCH; 424 425 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 426 addr_widths = dma_caps.dst_addr_widths; 427 else 428 addr_widths = dma_caps.src_addr_widths; 429 } 430 431 /* 432 * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep 433 * hw.formats set to 0, meaning no restrictions are in place. 434 * In this case it's the responsibility of the DAI driver to 435 * provide the supported format information. 436 */ 437 if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)) 438 /* 439 * Prepare formats mask for valid/allowed sample types. If the 440 * dma does not have support for the given physical word size, 441 * it needs to be masked out so user space can not use the 442 * format which produces corrupted audio. 443 * In case the dma driver does not implement the slave_caps the 444 * default assumption is that it supports 1, 2 and 4 bytes 445 * widths. 446 */ 447 pcm_for_each_format(i) { 448 int bits = snd_pcm_format_physical_width(i); 449 450 /* 451 * Enable only samples with DMA supported physical 452 * widths 453 */ 454 switch (bits) { 455 case 8: 456 case 16: 457 case 24: 458 case 32: 459 case 64: 460 if (addr_widths & (1 << (bits / 8))) 461 hw->formats |= pcm_format_to_bits(i); 462 break; 463 default: 464 /* Unsupported types */ 465 break; 466 } 467 } 468 469 return ret; 470 } 471 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_refine_runtime_hwparams); 472 473 MODULE_DESCRIPTION("PCM dmaengine helper APIs"); 474 MODULE_LICENSE("GPL"); 475