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 * addr_width field of the DAI DMA data struct is not equal to 110 * DMA_SLAVE_BUSWIDTH_UNDEFINED. 111 */ 112 void snd_dmaengine_pcm_set_config_from_dai_data( 113 const struct snd_pcm_substream *substream, 114 const struct snd_dmaengine_dai_dma_data *dma_data, 115 struct dma_slave_config *slave_config) 116 { 117 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 118 slave_config->dst_addr = dma_data->addr; 119 slave_config->dst_maxburst = dma_data->maxburst; 120 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 121 slave_config->dst_addr_width = dma_data->addr_width; 122 } else { 123 slave_config->src_addr = dma_data->addr; 124 slave_config->src_maxburst = dma_data->maxburst; 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->slave_id = dma_data->slave_id; 130 } 131 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); 132 133 static void dmaengine_pcm_dma_complete(void *arg) 134 { 135 struct snd_pcm_substream *substream = arg; 136 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 137 138 prtd->pos += snd_pcm_lib_period_bytes(substream); 139 if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream)) 140 prtd->pos = 0; 141 142 snd_pcm_period_elapsed(substream); 143 } 144 145 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream) 146 { 147 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 148 struct dma_chan *chan = prtd->dma_chan; 149 struct dma_async_tx_descriptor *desc; 150 enum dma_transfer_direction direction; 151 unsigned long flags = DMA_CTRL_ACK; 152 153 direction = snd_pcm_substream_to_dma_direction(substream); 154 155 if (!substream->runtime->no_period_wakeup) 156 flags |= DMA_PREP_INTERRUPT; 157 158 prtd->pos = 0; 159 desc = dmaengine_prep_dma_cyclic(chan, 160 substream->runtime->dma_addr, 161 snd_pcm_lib_buffer_bytes(substream), 162 snd_pcm_lib_period_bytes(substream), direction, flags); 163 164 if (!desc) 165 return -ENOMEM; 166 167 desc->callback = dmaengine_pcm_dma_complete; 168 desc->callback_param = substream; 169 prtd->cookie = dmaengine_submit(desc); 170 171 return 0; 172 } 173 174 /** 175 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation 176 * @substream: PCM substream 177 * @cmd: Trigger command 178 * 179 * Returns 0 on success, a negative error code otherwise. 180 * 181 * This function can be used as the PCM trigger callback for dmaengine based PCM 182 * driver implementations. 183 */ 184 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 185 { 186 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 187 struct snd_pcm_runtime *runtime = substream->runtime; 188 int ret; 189 190 switch (cmd) { 191 case SNDRV_PCM_TRIGGER_START: 192 ret = dmaengine_pcm_prepare_and_submit(substream); 193 if (ret) 194 return ret; 195 dma_async_issue_pending(prtd->dma_chan); 196 break; 197 case SNDRV_PCM_TRIGGER_RESUME: 198 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 199 dmaengine_resume(prtd->dma_chan); 200 break; 201 case SNDRV_PCM_TRIGGER_SUSPEND: 202 if (runtime->info & SNDRV_PCM_INFO_PAUSE) 203 dmaengine_pause(prtd->dma_chan); 204 else 205 dmaengine_terminate_all(prtd->dma_chan); 206 break; 207 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 208 dmaengine_pause(prtd->dma_chan); 209 break; 210 case SNDRV_PCM_TRIGGER_STOP: 211 dmaengine_terminate_all(prtd->dma_chan); 212 break; 213 default: 214 return -EINVAL; 215 } 216 217 return 0; 218 } 219 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); 220 221 /** 222 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation 223 * @substream: PCM substream 224 * 225 * This function is deprecated and should not be used by new drivers, as its 226 * results may be unreliable. 227 */ 228 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream) 229 { 230 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 231 return bytes_to_frames(substream->runtime, prtd->pos); 232 } 233 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue); 234 235 /** 236 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation 237 * @substream: PCM substream 238 * 239 * This function can be used as the PCM pointer callback for dmaengine based PCM 240 * driver implementations. 241 */ 242 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream) 243 { 244 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 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 } 256 257 return bytes_to_frames(substream->runtime, pos); 258 } 259 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer); 260 261 /** 262 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM 263 * @filter_fn: Filter function used to request the DMA channel 264 * @filter_data: Data passed to the DMA filter function 265 * 266 * Returns NULL or the requested DMA channel. 267 * 268 * This function request a DMA channel for usage with dmaengine PCM. 269 */ 270 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn, 271 void *filter_data) 272 { 273 dma_cap_mask_t mask; 274 275 dma_cap_zero(mask); 276 dma_cap_set(DMA_SLAVE, mask); 277 dma_cap_set(DMA_CYCLIC, mask); 278 279 return dma_request_channel(mask, filter_fn, filter_data); 280 } 281 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel); 282 283 /** 284 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream 285 * @substream: PCM substream 286 * @chan: DMA channel to use for data transfers 287 * 288 * Returns 0 on success, a negative error code otherwise. 289 * 290 * The function should usually be called from the pcm open callback. Note that 291 * this function will use private_data field of the substream's runtime. So it 292 * is not availabe to your pcm driver implementation. 293 */ 294 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream, 295 struct dma_chan *chan) 296 { 297 struct dmaengine_pcm_runtime_data *prtd; 298 int ret; 299 300 if (!chan) 301 return -ENXIO; 302 303 ret = snd_pcm_hw_constraint_integer(substream->runtime, 304 SNDRV_PCM_HW_PARAM_PERIODS); 305 if (ret < 0) 306 return ret; 307 308 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL); 309 if (!prtd) 310 return -ENOMEM; 311 312 prtd->dma_chan = chan; 313 314 substream->runtime->private_data = prtd; 315 316 return 0; 317 } 318 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open); 319 320 /** 321 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel 322 * @substream: PCM substream 323 * @filter_fn: Filter function used to request the DMA channel 324 * @filter_data: Data passed to the DMA filter function 325 * 326 * Returns 0 on success, a negative error code otherwise. 327 * 328 * This function will request a DMA channel using the passed filter function and 329 * data. The function should usually be called from the pcm open callback. Note 330 * that this function will use private_data field of the substream's runtime. So 331 * it is not availabe to your pcm driver implementation. 332 */ 333 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream, 334 dma_filter_fn filter_fn, void *filter_data) 335 { 336 return snd_dmaengine_pcm_open(substream, 337 snd_dmaengine_pcm_request_channel(filter_fn, filter_data)); 338 } 339 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan); 340 341 /** 342 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream 343 * @substream: PCM substream 344 */ 345 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream) 346 { 347 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 348 349 kfree(prtd); 350 351 return 0; 352 } 353 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close); 354 355 /** 356 * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel 357 * @substream: PCM substream 358 * 359 * Releases the DMA channel associated with the PCM substream. 360 */ 361 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream) 362 { 363 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 364 365 dma_release_channel(prtd->dma_chan); 366 367 return snd_dmaengine_pcm_close(substream); 368 } 369 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan); 370 371 MODULE_LICENSE("GPL"); 372