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 slave_config->dst_port_window_size = dma_data->port_window_size; 115 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK) 116 slave_config->dst_addr_width = 117 DMA_SLAVE_BUSWIDTH_UNDEFINED; 118 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 119 slave_config->dst_addr_width = dma_data->addr_width; 120 } else { 121 slave_config->src_addr = dma_data->addr; 122 slave_config->src_maxburst = dma_data->maxburst; 123 slave_config->src_port_window_size = dma_data->port_window_size; 124 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK) 125 slave_config->src_addr_width = 126 DMA_SLAVE_BUSWIDTH_UNDEFINED; 127 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 128 slave_config->src_addr_width = dma_data->addr_width; 129 } 130 131 slave_config->peripheral_config = dma_data->peripheral_config; 132 slave_config->peripheral_size = dma_data->peripheral_size; 133 } 134 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); 135 136 static void dmaengine_pcm_dma_complete(void *arg) 137 { 138 unsigned int new_pos; 139 struct snd_pcm_substream *substream = arg; 140 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 141 142 new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream); 143 if (new_pos >= snd_pcm_lib_buffer_bytes(substream)) 144 new_pos = 0; 145 prtd->pos = new_pos; 146 147 snd_pcm_period_elapsed(substream); 148 } 149 150 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream) 151 { 152 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 153 struct dma_chan *chan = prtd->dma_chan; 154 struct dma_async_tx_descriptor *desc; 155 enum dma_transfer_direction direction; 156 unsigned long flags = DMA_CTRL_ACK; 157 158 direction = snd_pcm_substream_to_dma_direction(substream); 159 160 if (!substream->runtime->no_period_wakeup) 161 flags |= DMA_PREP_INTERRUPT; 162 163 prtd->pos = 0; 164 desc = dmaengine_prep_dma_cyclic(chan, 165 substream->runtime->dma_addr, 166 snd_pcm_lib_buffer_bytes(substream), 167 snd_pcm_lib_period_bytes(substream), direction, flags); 168 169 if (!desc) 170 return -ENOMEM; 171 172 desc->callback = dmaengine_pcm_dma_complete; 173 desc->callback_param = substream; 174 prtd->cookie = dmaengine_submit(desc); 175 176 return 0; 177 } 178 179 /** 180 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation 181 * @substream: PCM substream 182 * @cmd: Trigger command 183 * 184 * This function can be used as the PCM trigger callback for dmaengine based PCM 185 * driver implementations. 186 * 187 * Return: 0 on success, a negative error code otherwise 188 */ 189 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 190 { 191 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 192 struct snd_pcm_runtime *runtime = substream->runtime; 193 int ret; 194 195 switch (cmd) { 196 case SNDRV_PCM_TRIGGER_START: 197 ret = dmaengine_pcm_prepare_and_submit(substream); 198 if (ret) 199 return ret; 200 dma_async_issue_pending(prtd->dma_chan); 201 break; 202 case SNDRV_PCM_TRIGGER_RESUME: 203 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 204 dmaengine_resume(prtd->dma_chan); 205 break; 206 case SNDRV_PCM_TRIGGER_SUSPEND: 207 if (runtime->info & SNDRV_PCM_INFO_PAUSE) 208 dmaengine_pause(prtd->dma_chan); 209 else 210 dmaengine_terminate_async(prtd->dma_chan); 211 break; 212 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 213 dmaengine_pause(prtd->dma_chan); 214 break; 215 case SNDRV_PCM_TRIGGER_STOP: 216 dmaengine_terminate_async(prtd->dma_chan); 217 break; 218 default: 219 return -EINVAL; 220 } 221 222 return 0; 223 } 224 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); 225 226 /** 227 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation 228 * @substream: PCM substream 229 * 230 * This function is deprecated and should not be used by new drivers, as its 231 * results may be unreliable. 232 * 233 * Return: PCM position in frames 234 */ 235 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream) 236 { 237 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 238 return bytes_to_frames(substream->runtime, prtd->pos); 239 } 240 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue); 241 242 /** 243 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation 244 * @substream: PCM substream 245 * 246 * This function can be used as the PCM pointer callback for dmaengine based PCM 247 * driver implementations. 248 * 249 * Return: PCM position in frames 250 */ 251 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream) 252 { 253 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 254 struct snd_pcm_runtime *runtime = substream->runtime; 255 struct dma_tx_state state; 256 enum dma_status status; 257 unsigned int buf_size; 258 unsigned int pos = 0; 259 260 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state); 261 if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) { 262 buf_size = snd_pcm_lib_buffer_bytes(substream); 263 if (state.residue > 0 && state.residue <= buf_size) 264 pos = buf_size - state.residue; 265 266 runtime->delay = bytes_to_frames(runtime, 267 state.in_flight_bytes); 268 } 269 270 return bytes_to_frames(runtime, pos); 271 } 272 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer); 273 274 /** 275 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM 276 * @filter_fn: Filter function used to request the DMA channel 277 * @filter_data: Data passed to the DMA filter function 278 * 279 * This function request a DMA channel for usage with dmaengine PCM. 280 * 281 * Return: NULL or the requested DMA channel 282 */ 283 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn, 284 void *filter_data) 285 { 286 dma_cap_mask_t mask; 287 288 dma_cap_zero(mask); 289 dma_cap_set(DMA_SLAVE, mask); 290 dma_cap_set(DMA_CYCLIC, mask); 291 292 return dma_request_channel(mask, filter_fn, filter_data); 293 } 294 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel); 295 296 /** 297 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream 298 * @substream: PCM substream 299 * @chan: DMA channel to use for data transfers 300 * 301 * The function should usually be called from the pcm open callback. Note that 302 * this function will use private_data field of the substream's runtime. So it 303 * is not available to your pcm driver implementation. 304 * 305 * Return: 0 on success, a negative error code otherwise 306 */ 307 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream, 308 struct dma_chan *chan) 309 { 310 struct dmaengine_pcm_runtime_data *prtd; 311 int ret; 312 313 if (!chan) 314 return -ENXIO; 315 316 ret = snd_pcm_hw_constraint_integer(substream->runtime, 317 SNDRV_PCM_HW_PARAM_PERIODS); 318 if (ret < 0) 319 return ret; 320 321 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL); 322 if (!prtd) 323 return -ENOMEM; 324 325 prtd->dma_chan = chan; 326 327 substream->runtime->private_data = prtd; 328 329 return 0; 330 } 331 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open); 332 333 int snd_dmaengine_pcm_sync_stop(struct snd_pcm_substream *substream) 334 { 335 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 336 struct dma_tx_state state; 337 enum dma_status status; 338 339 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state); 340 if (status != DMA_PAUSED) 341 dmaengine_synchronize(prtd->dma_chan); 342 343 return 0; 344 } 345 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_sync_stop); 346 347 static void __snd_dmaengine_pcm_close(struct snd_pcm_substream *substream, 348 bool release_channel) 349 { 350 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 351 struct dma_tx_state state; 352 enum dma_status status; 353 354 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state); 355 if (status == DMA_PAUSED) 356 dmaengine_terminate_async(prtd->dma_chan); 357 358 dmaengine_synchronize(prtd->dma_chan); 359 if (release_channel) 360 dma_release_channel(prtd->dma_chan); 361 kfree(prtd); 362 } 363 364 /** 365 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream 366 * @substream: PCM substream 367 * 368 * Return: 0 on success, a negative error code otherwise 369 */ 370 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream) 371 { 372 __snd_dmaengine_pcm_close(substream, false); 373 return 0; 374 } 375 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close); 376 377 /** 378 * snd_dmaengine_pcm_close_release_chan - Close a dmaengine based PCM 379 * substream and release channel 380 * @substream: PCM substream 381 * 382 * Releases the DMA channel associated with the PCM substream. 383 * 384 * Return: zero if successful, or a negative error code 385 */ 386 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream) 387 { 388 __snd_dmaengine_pcm_close(substream, true); 389 return 0; 390 } 391 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan); 392 393 /** 394 * snd_dmaengine_pcm_refine_runtime_hwparams - Refine runtime hw params 395 * @substream: PCM substream 396 * @dma_data: DAI DMA data 397 * @hw: PCM hw params 398 * @chan: DMA channel to use for data transfers 399 * 400 * This function will query DMA capability, then refine the pcm hardware 401 * parameters. 402 * 403 * Return: 0 on success, a negative error code otherwise 404 */ 405 int snd_dmaengine_pcm_refine_runtime_hwparams( 406 struct snd_pcm_substream *substream, 407 struct snd_dmaengine_dai_dma_data *dma_data, 408 struct snd_pcm_hardware *hw, 409 struct dma_chan *chan) 410 { 411 struct dma_slave_caps dma_caps; 412 u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | 413 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | 414 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 415 snd_pcm_format_t i; 416 int ret = 0; 417 418 if (!hw || !chan || !dma_data) 419 return -EINVAL; 420 421 ret = dma_get_slave_caps(chan, &dma_caps); 422 if (ret == 0) { 423 if (dma_caps.cmd_pause && dma_caps.cmd_resume) 424 hw->info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME; 425 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT) 426 hw->info |= SNDRV_PCM_INFO_BATCH; 427 428 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) 429 addr_widths = dma_caps.dst_addr_widths; 430 else 431 addr_widths = dma_caps.src_addr_widths; 432 } 433 434 /* 435 * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep 436 * hw.formats set to 0, meaning no restrictions are in place. 437 * In this case it's the responsibility of the DAI driver to 438 * provide the supported format information. 439 */ 440 if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)) 441 /* 442 * Prepare formats mask for valid/allowed sample types. If the 443 * dma does not have support for the given physical word size, 444 * it needs to be masked out so user space can not use the 445 * format which produces corrupted audio. 446 * In case the dma driver does not implement the slave_caps the 447 * default assumption is that it supports 1, 2 and 4 bytes 448 * widths. 449 */ 450 pcm_for_each_format(i) { 451 int bits = snd_pcm_format_physical_width(i); 452 453 /* 454 * Enable only samples with DMA supported physical 455 * widths 456 */ 457 switch (bits) { 458 case 8: 459 case 16: 460 case 24: 461 case 32: 462 case 64: 463 if (addr_widths & (1 << (bits / 8))) 464 hw->formats |= pcm_format_to_bits(i); 465 break; 466 default: 467 /* Unsupported types */ 468 break; 469 } 470 } 471 472 return ret; 473 } 474 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_refine_runtime_hwparams); 475 476 MODULE_DESCRIPTION("PCM dmaengine helper APIs"); 477 MODULE_LICENSE("GPL"); 478