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 = snd_pcm_format_physical_width(params_format(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 <= 32) 76 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; 77 else 78 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES; 79 80 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 81 slave_config->direction = DMA_MEM_TO_DEV; 82 slave_config->dst_addr_width = buswidth; 83 } else { 84 slave_config->direction = DMA_DEV_TO_MEM; 85 slave_config->src_addr_width = buswidth; 86 } 87 88 slave_config->device_fc = false; 89 90 return 0; 91 } 92 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config); 93 94 /** 95 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config 96 * using DAI DMA data. 97 * @substream: PCM substream 98 * @dma_data: DAI DMA data 99 * @slave_config: DMA slave configuration 100 * 101 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and 102 * slave_id fields of the DMA slave config from the same fields of the DAI DMA 103 * data struct. The src and dst fields will be initialized depending on the 104 * direction of the substream. If the substream is a playback stream the dst 105 * fields will be initialized, if it is a capture stream the src fields will be 106 * initialized. The {dst,src}_addr_width field will only be initialized if the 107 * addr_width field of the DAI DMA data struct is not equal to 108 * DMA_SLAVE_BUSWIDTH_UNDEFINED. 109 */ 110 void snd_dmaengine_pcm_set_config_from_dai_data( 111 const struct snd_pcm_substream *substream, 112 const struct snd_dmaengine_dai_dma_data *dma_data, 113 struct dma_slave_config *slave_config) 114 { 115 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 116 slave_config->dst_addr = dma_data->addr; 117 slave_config->dst_maxburst = dma_data->maxburst; 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 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED) 124 slave_config->src_addr_width = dma_data->addr_width; 125 } 126 127 slave_config->slave_id = dma_data->slave_id; 128 } 129 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data); 130 131 static void dmaengine_pcm_dma_complete(void *arg) 132 { 133 struct snd_pcm_substream *substream = arg; 134 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 135 136 prtd->pos += snd_pcm_lib_period_bytes(substream); 137 if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream)) 138 prtd->pos = 0; 139 140 snd_pcm_period_elapsed(substream); 141 } 142 143 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream) 144 { 145 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 146 struct dma_chan *chan = prtd->dma_chan; 147 struct dma_async_tx_descriptor *desc; 148 enum dma_transfer_direction direction; 149 unsigned long flags = DMA_CTRL_ACK; 150 151 direction = snd_pcm_substream_to_dma_direction(substream); 152 153 if (!substream->runtime->no_period_wakeup) 154 flags |= DMA_PREP_INTERRUPT; 155 156 prtd->pos = 0; 157 desc = dmaengine_prep_dma_cyclic(chan, 158 substream->runtime->dma_addr, 159 snd_pcm_lib_buffer_bytes(substream), 160 snd_pcm_lib_period_bytes(substream), direction, flags); 161 162 if (!desc) 163 return -ENOMEM; 164 165 desc->callback = dmaengine_pcm_dma_complete; 166 desc->callback_param = substream; 167 prtd->cookie = dmaengine_submit(desc); 168 169 return 0; 170 } 171 172 /** 173 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation 174 * @substream: PCM substream 175 * @cmd: Trigger command 176 * 177 * Returns 0 on success, a negative error code otherwise. 178 * 179 * This function can be used as the PCM trigger callback for dmaengine based PCM 180 * driver implementations. 181 */ 182 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd) 183 { 184 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 185 int ret; 186 187 switch (cmd) { 188 case SNDRV_PCM_TRIGGER_START: 189 ret = dmaengine_pcm_prepare_and_submit(substream); 190 if (ret) 191 return ret; 192 dma_async_issue_pending(prtd->dma_chan); 193 break; 194 case SNDRV_PCM_TRIGGER_RESUME: 195 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 196 dmaengine_resume(prtd->dma_chan); 197 break; 198 case SNDRV_PCM_TRIGGER_SUSPEND: 199 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 200 dmaengine_pause(prtd->dma_chan); 201 break; 202 case SNDRV_PCM_TRIGGER_STOP: 203 dmaengine_terminate_all(prtd->dma_chan); 204 break; 205 default: 206 return -EINVAL; 207 } 208 209 return 0; 210 } 211 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger); 212 213 /** 214 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation 215 * @substream: PCM substream 216 * 217 * This function is deprecated and should not be used by new drivers, as its 218 * results may be unreliable. 219 */ 220 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream) 221 { 222 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 223 return bytes_to_frames(substream->runtime, prtd->pos); 224 } 225 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue); 226 227 /** 228 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation 229 * @substream: PCM substream 230 * 231 * This function can be used as the PCM pointer callback for dmaengine based PCM 232 * driver implementations. 233 */ 234 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream) 235 { 236 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 237 struct dma_tx_state state; 238 enum dma_status status; 239 unsigned int buf_size; 240 unsigned int pos = 0; 241 242 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state); 243 if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) { 244 buf_size = snd_pcm_lib_buffer_bytes(substream); 245 if (state.residue > 0 && state.residue <= buf_size) 246 pos = buf_size - state.residue; 247 } 248 249 return bytes_to_frames(substream->runtime, pos); 250 } 251 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer); 252 253 /** 254 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM 255 * @filter_fn: Filter function used to request the DMA channel 256 * @filter_data: Data passed to the DMA filter function 257 * 258 * Returns NULL or the requested DMA channel. 259 * 260 * This function request a DMA channel for usage with dmaengine PCM. 261 */ 262 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn, 263 void *filter_data) 264 { 265 dma_cap_mask_t mask; 266 267 dma_cap_zero(mask); 268 dma_cap_set(DMA_SLAVE, mask); 269 dma_cap_set(DMA_CYCLIC, mask); 270 271 return dma_request_channel(mask, filter_fn, filter_data); 272 } 273 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel); 274 275 /** 276 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream 277 * @substream: PCM substream 278 * @chan: DMA channel to use for data transfers 279 * 280 * Returns 0 on success, a negative error code otherwise. 281 * 282 * The function should usually be called from the pcm open callback. Note that 283 * this function will use private_data field of the substream's runtime. So it 284 * is not availabe to your pcm driver implementation. 285 */ 286 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream, 287 struct dma_chan *chan) 288 { 289 struct dmaengine_pcm_runtime_data *prtd; 290 int ret; 291 292 if (!chan) 293 return -ENXIO; 294 295 ret = snd_pcm_hw_constraint_integer(substream->runtime, 296 SNDRV_PCM_HW_PARAM_PERIODS); 297 if (ret < 0) 298 return ret; 299 300 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL); 301 if (!prtd) 302 return -ENOMEM; 303 304 prtd->dma_chan = chan; 305 306 substream->runtime->private_data = prtd; 307 308 return 0; 309 } 310 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open); 311 312 /** 313 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel 314 * @substream: PCM substream 315 * @filter_fn: Filter function used to request the DMA channel 316 * @filter_data: Data passed to the DMA filter function 317 * 318 * Returns 0 on success, a negative error code otherwise. 319 * 320 * This function will request a DMA channel using the passed filter function and 321 * data. The function should usually be called from the pcm open callback. Note 322 * that this function will use private_data field of the substream's runtime. So 323 * it is not availabe to your pcm driver implementation. 324 */ 325 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream, 326 dma_filter_fn filter_fn, void *filter_data) 327 { 328 return snd_dmaengine_pcm_open(substream, 329 snd_dmaengine_pcm_request_channel(filter_fn, filter_data)); 330 } 331 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan); 332 333 /** 334 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream 335 * @substream: PCM substream 336 */ 337 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream) 338 { 339 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 340 341 kfree(prtd); 342 343 return 0; 344 } 345 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close); 346 347 /** 348 * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel 349 * @substream: PCM substream 350 * 351 * Releases the DMA channel associated with the PCM substream. 352 */ 353 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream) 354 { 355 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream); 356 357 dma_release_channel(prtd->dma_chan); 358 359 return snd_dmaengine_pcm_close(substream); 360 } 361 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan); 362 363 MODULE_LICENSE("GPL"); 364