1 /* 2 * Copyright (C) 2012, Analog Devices Inc. 3 * Author: Lars-Peter Clausen <lars@metafoo.de> 4 * 5 * Based on: 6 * imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de> 7 * mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc. 8 * ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org> 9 * Copyright (C) 2006 Applied Data Systems 10 * 11 * This program is free software; you can redistribute it and/or modify it 12 * under the terms of the GNU General Public License as published by the 13 * Free Software Foundation; either version 2 of the License, or (at your 14 * option) any later version. 15 * 16 * You should have received a copy of the GNU General Public License along 17 * with this program; if not, write to the Free Software Foundation, Inc., 18 * 675 Mass Ave, Cambridge, MA 02139, USA. 19 * 20 */ 21 #include <linux/module.h> 22 #include <linux/init.h> 23 #include <linux/dmaengine.h> 24 #include <linux/slab.h> 25 #include <sound/pcm.h> 26 #include <sound/pcm_params.h> 27 #include <sound/soc.h> 28 29 #include <sound/dmaengine_pcm.h> 30 31 struct dmaengine_pcm_runtime_data { 32 struct dma_chan *dma_chan; 33 dma_cookie_t cookie; 34 35 unsigned int pos; 36 }; 37 38 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd( 39 const struct snd_pcm_substream *substream) 40 { 41 return substream->runtime->private_data; 42 } 43 44 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream) 45 { 46 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 47 48 return prtd->dma_chan; 49 } 50 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan); 51 52 /** 53 * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config 54 * @substream: PCM substream 55 * @params: hw_params 56 * @slave_config: DMA slave config 57 * 58 * This function can be used to initialize a dma_slave_config from a substream 59 * and hw_params in a dmaengine based PCM driver implementation. 60 */ 61 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream, 62 const struct snd_pcm_hw_params *params, 63 struct dma_slave_config *slave_config) 64 { 65 enum dma_slave_buswidth buswidth; 66 int bits; 67 68 bits = params_physical_width(params); 69 if (bits < 8 || bits > 64) 70 return -EINVAL; 71 else if (bits == 8) 72 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; 73 else if (bits == 16) 74 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; 75 else if (bits == 24) 76 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES; 77 else if (bits <= 32) 78 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; 79 else 80 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES; 81 82 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 83 slave_config->direction = DMA_MEM_TO_DEV; 84 slave_config->dst_addr_width = buswidth; 85 } else { 86 slave_config->direction = DMA_DEV_TO_MEM; 87 slave_config->src_addr_width = buswidth; 88 } 89 90 slave_config->device_fc = false; 91 92 return 0; 93 } 94 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config); 95 96 /** 97 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config 98 * using DAI DMA data. 99 * @substream: PCM substream 100 * @dma_data: DAI DMA data 101 * @slave_config: DMA slave configuration 102 * 103 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and 104 * slave_id fields of the DMA slave config from the same fields of the DAI DMA 105 * data struct. The src and dst fields will be initialized depending on the 106 * direction of the substream. If the substream is a playback stream the dst 107 * fields will be initialized, if it is a capture stream the src fields will be 108 * initialized. The {dst,src}_addr_width field will only be initialized if the 109 * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of 110 * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If 111 * both conditions are met the latter takes priority. 112 */ 113 void snd_dmaengine_pcm_set_config_from_dai_data( 114 const struct snd_pcm_substream *substream, 115 const struct snd_dmaengine_dai_dma_data *dma_data, 116 struct dma_slave_config *slave_config) 117 { 118 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 119 slave_config->dst_addr = dma_data->addr; 120 slave_config->dst_maxburst = dma_data->maxburst; 121 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK) 122 slave_config->dst_addr_width = 123 DMA_SLAVE_BUSWIDTH_UNDEFINED; 124 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 125 slave_config->dst_addr_width = dma_data->addr_width; 126 } else { 127 slave_config->src_addr = dma_data->addr; 128 slave_config->src_maxburst = dma_data->maxburst; 129 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK) 130 slave_config->src_addr_width = 131 DMA_SLAVE_BUSWIDTH_UNDEFINED; 132 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 133 slave_config->src_addr_width = dma_data->addr_width; 134 } 135 136 slave_config->slave_id = dma_data->slave_id; 137 } 138 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); 139 140 static void dmaengine_pcm_dma_complete(void *arg) 141 { 142 struct snd_pcm_substream *substream = arg; 143 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 144 145 prtd->pos += snd_pcm_lib_period_bytes(substream); 146 if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream)) 147 prtd->pos = 0; 148 149 snd_pcm_period_elapsed(substream); 150 } 151 152 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream) 153 { 154 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 155 struct dma_chan *chan = prtd->dma_chan; 156 struct dma_async_tx_descriptor *desc; 157 enum dma_transfer_direction direction; 158 unsigned long flags = DMA_CTRL_ACK; 159 160 direction = snd_pcm_substream_to_dma_direction(substream); 161 162 if (!substream->runtime->no_period_wakeup) 163 flags |= DMA_PREP_INTERRUPT; 164 165 prtd->pos = 0; 166 desc = dmaengine_prep_dma_cyclic(chan, 167 substream->runtime->dma_addr, 168 snd_pcm_lib_buffer_bytes(substream), 169 snd_pcm_lib_period_bytes(substream), direction, flags); 170 171 if (!desc) 172 return -ENOMEM; 173 174 desc->callback = dmaengine_pcm_dma_complete; 175 desc->callback_param = substream; 176 prtd->cookie = dmaengine_submit(desc); 177 178 return 0; 179 } 180 181 /** 182 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation 183 * @substream: PCM substream 184 * @cmd: Trigger command 185 * 186 * Returns 0 on success, a negative error code otherwise. 187 * 188 * This function can be used as the PCM trigger callback for dmaengine based PCM 189 * driver implementations. 190 */ 191 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 192 { 193 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 194 struct snd_pcm_runtime *runtime = substream->runtime; 195 int ret; 196 197 switch (cmd) { 198 case SNDRV_PCM_TRIGGER_START: 199 ret = dmaengine_pcm_prepare_and_submit(substream); 200 if (ret) 201 return ret; 202 dma_async_issue_pending(prtd->dma_chan); 203 break; 204 case SNDRV_PCM_TRIGGER_RESUME: 205 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 206 dmaengine_resume(prtd->dma_chan); 207 break; 208 case SNDRV_PCM_TRIGGER_SUSPEND: 209 if (runtime->info & SNDRV_PCM_INFO_PAUSE) 210 dmaengine_pause(prtd->dma_chan); 211 else 212 dmaengine_terminate_async(prtd->dma_chan); 213 break; 214 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 215 dmaengine_pause(prtd->dma_chan); 216 break; 217 case SNDRV_PCM_TRIGGER_STOP: 218 dmaengine_terminate_async(prtd->dma_chan); 219 break; 220 default: 221 return -EINVAL; 222 } 223 224 return 0; 225 } 226 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); 227 228 /** 229 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation 230 * @substream: PCM substream 231 * 232 * This function is deprecated and should not be used by new drivers, as its 233 * results may be unreliable. 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 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 dma_tx_state state; 253 enum dma_status status; 254 unsigned int buf_size; 255 unsigned int pos = 0; 256 257 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state); 258 if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) { 259 buf_size = snd_pcm_lib_buffer_bytes(substream); 260 if (state.residue > 0 && state.residue <= buf_size) 261 pos = buf_size - state.residue; 262 } 263 264 return bytes_to_frames(substream->runtime, pos); 265 } 266 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer); 267 268 /** 269 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM 270 * @filter_fn: Filter function used to request the DMA channel 271 * @filter_data: Data passed to the DMA filter function 272 * 273 * Returns NULL or the requested DMA channel. 274 * 275 * This function request a DMA channel for usage with dmaengine PCM. 276 */ 277 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn, 278 void *filter_data) 279 { 280 dma_cap_mask_t mask; 281 282 dma_cap_zero(mask); 283 dma_cap_set(DMA_SLAVE, mask); 284 dma_cap_set(DMA_CYCLIC, mask); 285 286 return dma_request_channel(mask, filter_fn, filter_data); 287 } 288 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel); 289 290 /** 291 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream 292 * @substream: PCM substream 293 * @chan: DMA channel to use for data transfers 294 * 295 * Returns 0 on success, a negative error code otherwise. 296 * 297 * The function should usually be called from the pcm open callback. Note that 298 * this function will use private_data field of the substream's runtime. So it 299 * is not available to your pcm driver implementation. 300 */ 301 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream, 302 struct dma_chan *chan) 303 { 304 struct dmaengine_pcm_runtime_data *prtd; 305 int ret; 306 307 if (!chan) 308 return -ENXIO; 309 310 ret = snd_pcm_hw_constraint_integer(substream->runtime, 311 SNDRV_PCM_HW_PARAM_PERIODS); 312 if (ret < 0) 313 return ret; 314 315 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL); 316 if (!prtd) 317 return -ENOMEM; 318 319 prtd->dma_chan = chan; 320 321 substream->runtime->private_data = prtd; 322 323 return 0; 324 } 325 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open); 326 327 /** 328 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel 329 * @substream: PCM substream 330 * @filter_fn: Filter function used to request the DMA channel 331 * @filter_data: Data passed to the DMA filter function 332 * 333 * Returns 0 on success, a negative error code otherwise. 334 * 335 * This function will request a DMA channel using the passed filter function and 336 * data. The function should usually be called from the pcm open callback. Note 337 * that this function will use private_data field of the substream's runtime. So 338 * it is not available to your pcm driver implementation. 339 */ 340 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream, 341 dma_filter_fn filter_fn, void *filter_data) 342 { 343 return snd_dmaengine_pcm_open(substream, 344 snd_dmaengine_pcm_request_channel(filter_fn, filter_data)); 345 } 346 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan); 347 348 /** 349 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream 350 * @substream: PCM substream 351 */ 352 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream) 353 { 354 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 355 356 dmaengine_synchronize(prtd->dma_chan); 357 kfree(prtd); 358 359 return 0; 360 } 361 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close); 362 363 /** 364 * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel 365 * @substream: PCM substream 366 * 367 * Releases the DMA channel associated with the PCM substream. 368 */ 369 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream) 370 { 371 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 372 373 dmaengine_synchronize(prtd->dma_chan); 374 dma_release_channel(prtd->dma_chan); 375 kfree(prtd); 376 377 return 0; 378 } 379 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan); 380 381 MODULE_LICENSE("GPL"); 382