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