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 67 switch (params_format(params)) { 68 case SNDRV_PCM_FORMAT_S8: 69 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; 70 break; 71 case SNDRV_PCM_FORMAT_S16_LE: 72 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; 73 break; 74 case SNDRV_PCM_FORMAT_S18_3LE: 75 case SNDRV_PCM_FORMAT_S20_3LE: 76 case SNDRV_PCM_FORMAT_S24_LE: 77 case SNDRV_PCM_FORMAT_S32_LE: 78 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; 79 break; 80 default: 81 return -EINVAL; 82 } 83 84 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 85 slave_config->direction = DMA_MEM_TO_DEV; 86 slave_config->dst_addr_width = buswidth; 87 } else { 88 slave_config->direction = DMA_DEV_TO_MEM; 89 slave_config->src_addr_width = buswidth; 90 } 91 92 slave_config->device_fc = false; 93 94 return 0; 95 } 96 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config); 97 98 /** 99 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config 100 * using DAI DMA data. 101 * @substream: PCM substream 102 * @dma_data: DAI DMA data 103 * @slave_config: DMA slave configuration 104 * 105 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and 106 * slave_id fields of the DMA slave config from the same fields of the DAI DMA 107 * data struct. The src and dst fields will be initialized depending on the 108 * direction of the substream. If the substream is a playback stream the dst 109 * fields will be initialized, if it is a capture stream the src fields will be 110 * initialized. The {dst,src}_addr_width field will only be initialized if the 111 * addr_width field of the DAI DMA data struct is not equal to 112 * DMA_SLAVE_BUSWIDTH_UNDEFINED. 113 */ 114 void snd_dmaengine_pcm_set_config_from_dai_data( 115 const struct snd_pcm_substream *substream, 116 const struct snd_dmaengine_dai_dma_data *dma_data, 117 struct dma_slave_config *slave_config) 118 { 119 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 120 slave_config->dst_addr = dma_data->addr; 121 slave_config->dst_maxburst = dma_data->maxburst; 122 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 123 slave_config->dst_addr_width = dma_data->addr_width; 124 } else { 125 slave_config->src_addr = dma_data->addr; 126 slave_config->src_maxburst = dma_data->maxburst; 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->slave_id = dma_data->slave_id; 132 } 133 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); 134 135 static void dmaengine_pcm_dma_complete(void *arg) 136 { 137 struct snd_pcm_substream *substream = arg; 138 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 139 140 prtd->pos += snd_pcm_lib_period_bytes(substream); 141 if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream)) 142 prtd->pos = 0; 143 144 snd_pcm_period_elapsed(substream); 145 } 146 147 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream) 148 { 149 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 150 struct dma_chan *chan = prtd->dma_chan; 151 struct dma_async_tx_descriptor *desc; 152 enum dma_transfer_direction direction; 153 unsigned long flags = DMA_CTRL_ACK; 154 155 direction = snd_pcm_substream_to_dma_direction(substream); 156 157 if (!substream->runtime->no_period_wakeup) 158 flags |= DMA_PREP_INTERRUPT; 159 160 prtd->pos = 0; 161 desc = dmaengine_prep_dma_cyclic(chan, 162 substream->runtime->dma_addr, 163 snd_pcm_lib_buffer_bytes(substream), 164 snd_pcm_lib_period_bytes(substream), direction, flags); 165 166 if (!desc) 167 return -ENOMEM; 168 169 desc->callback = dmaengine_pcm_dma_complete; 170 desc->callback_param = substream; 171 prtd->cookie = dmaengine_submit(desc); 172 173 return 0; 174 } 175 176 /** 177 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation 178 * @substream: PCM substream 179 * @cmd: Trigger command 180 * 181 * Returns 0 on success, a negative error code otherwise. 182 * 183 * This function can be used as the PCM trigger callback for dmaengine based PCM 184 * driver implementations. 185 */ 186 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 187 { 188 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 189 int ret; 190 191 switch (cmd) { 192 case SNDRV_PCM_TRIGGER_START: 193 ret = dmaengine_pcm_prepare_and_submit(substream); 194 if (ret) 195 return ret; 196 dma_async_issue_pending(prtd->dma_chan); 197 break; 198 case SNDRV_PCM_TRIGGER_RESUME: 199 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 200 dmaengine_resume(prtd->dma_chan); 201 break; 202 case SNDRV_PCM_TRIGGER_SUSPEND: 203 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 204 dmaengine_pause(prtd->dma_chan); 205 break; 206 case SNDRV_PCM_TRIGGER_STOP: 207 dmaengine_terminate_all(prtd->dma_chan); 208 break; 209 default: 210 return -EINVAL; 211 } 212 213 return 0; 214 } 215 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); 216 217 /** 218 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation 219 * @substream: PCM substream 220 * 221 * This function is deprecated and should not be used by new drivers, as its 222 * results may be unreliable. 223 */ 224 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream) 225 { 226 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 227 return bytes_to_frames(substream->runtime, prtd->pos); 228 } 229 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue); 230 231 /** 232 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation 233 * @substream: PCM substream 234 * 235 * This function can be used as the PCM pointer callback for dmaengine based PCM 236 * driver implementations. 237 */ 238 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream) 239 { 240 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 241 struct dma_tx_state state; 242 enum dma_status status; 243 unsigned int buf_size; 244 unsigned int pos = 0; 245 246 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state); 247 if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) { 248 buf_size = snd_pcm_lib_buffer_bytes(substream); 249 if (state.residue > 0 && state.residue <= buf_size) 250 pos = buf_size - state.residue; 251 } 252 253 return bytes_to_frames(substream->runtime, pos); 254 } 255 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer); 256 257 /** 258 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM 259 * @filter_fn: Filter function used to request the DMA channel 260 * @filter_data: Data passed to the DMA filter function 261 * 262 * Returns NULL or the requested DMA channel. 263 * 264 * This function request a DMA channel for usage with dmaengine PCM. 265 */ 266 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn, 267 void *filter_data) 268 { 269 dma_cap_mask_t mask; 270 271 dma_cap_zero(mask); 272 dma_cap_set(DMA_SLAVE, mask); 273 dma_cap_set(DMA_CYCLIC, mask); 274 275 return dma_request_channel(mask, filter_fn, filter_data); 276 } 277 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel); 278 279 /** 280 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream 281 * @substream: PCM substream 282 * @chan: DMA channel to use for data transfers 283 * 284 * Returns 0 on success, a negative error code otherwise. 285 * 286 * The function should usually be called from the pcm open callback. Note that 287 * this function will use private_data field of the substream's runtime. So it 288 * is not availabe to your pcm driver implementation. 289 */ 290 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream, 291 struct dma_chan *chan) 292 { 293 struct dmaengine_pcm_runtime_data *prtd; 294 int ret; 295 296 if (!chan) 297 return -ENXIO; 298 299 ret = snd_pcm_hw_constraint_integer(substream->runtime, 300 SNDRV_PCM_HW_PARAM_PERIODS); 301 if (ret < 0) 302 return ret; 303 304 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL); 305 if (!prtd) 306 return -ENOMEM; 307 308 prtd->dma_chan = chan; 309 310 substream->runtime->private_data = prtd; 311 312 return 0; 313 } 314 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open); 315 316 /** 317 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel 318 * @substream: PCM substream 319 * @filter_fn: Filter function used to request the DMA channel 320 * @filter_data: Data passed to the DMA filter function 321 * 322 * Returns 0 on success, a negative error code otherwise. 323 * 324 * This function will request a DMA channel using the passed filter function and 325 * data. The function should usually be called from the pcm open callback. Note 326 * that this function will use private_data field of the substream's runtime. So 327 * it is not availabe to your pcm driver implementation. 328 */ 329 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream, 330 dma_filter_fn filter_fn, void *filter_data) 331 { 332 return snd_dmaengine_pcm_open(substream, 333 snd_dmaengine_pcm_request_channel(filter_fn, filter_data)); 334 } 335 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan); 336 337 /** 338 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream 339 * @substream: PCM substream 340 */ 341 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream) 342 { 343 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 344 345 kfree(prtd); 346 347 return 0; 348 } 349 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close); 350 351 /** 352 * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel 353 * @substream: PCM substream 354 * 355 * Releases the DMA channel associated with the PCM substream. 356 */ 357 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream) 358 { 359 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 360 361 dma_release_channel(prtd->dma_chan); 362 363 return snd_dmaengine_pcm_close(substream); 364 } 365 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan); 366 367 MODULE_LICENSE("GPL"); 368