1 /* 2 * Copyright (C) 2013, Analog Devices Inc. 3 * Author: Lars-Peter Clausen <lars@metafoo.de> 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License as published by the 7 * Free Software Foundation; either version 2 of the License, or (at your 8 * option) any later version. 9 * 10 * You should have received a copy of the GNU General Public License along 11 * with this program; if not, write to the Free Software Foundation, Inc., 12 * 675 Mass Ave, Cambridge, MA 02139, USA. 13 * 14 */ 15 #include <linux/module.h> 16 #include <linux/init.h> 17 #include <linux/dmaengine.h> 18 #include <linux/slab.h> 19 #include <sound/pcm.h> 20 #include <sound/pcm_params.h> 21 #include <sound/soc.h> 22 #include <linux/dma-mapping.h> 23 #include <linux/of.h> 24 25 #include <sound/dmaengine_pcm.h> 26 27 struct dmaengine_pcm { 28 struct dma_chan *chan[SNDRV_PCM_STREAM_CAPTURE + 1]; 29 const struct snd_dmaengine_pcm_config *config; 30 struct snd_soc_platform platform; 31 unsigned int flags; 32 }; 33 34 static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p) 35 { 36 return container_of(p, struct dmaengine_pcm, platform); 37 } 38 39 /** 40 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback 41 * @substream: PCM substream 42 * @params: hw_params 43 * @slave_config: DMA slave config to prepare 44 * 45 * This function can be used as a generic prepare_slave_config callback for 46 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their 47 * DAI DMA data. Internally the function will first call 48 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the 49 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the 50 * remaining fields based on the DAI DMA data. 51 */ 52 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, 53 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) 54 { 55 struct snd_soc_pcm_runtime *rtd = substream->private_data; 56 struct snd_dmaengine_dai_dma_data *dma_data; 57 int ret; 58 59 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 60 61 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); 62 if (ret) 63 return ret; 64 65 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, 66 slave_config); 67 68 return 0; 69 } 70 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); 71 72 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream, 73 struct snd_pcm_hw_params *params) 74 { 75 struct snd_soc_pcm_runtime *rtd = substream->private_data; 76 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 77 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); 78 struct dma_slave_config slave_config; 79 int ret; 80 81 if (pcm->config->prepare_slave_config) { 82 ret = pcm->config->prepare_slave_config(substream, params, 83 &slave_config); 84 if (ret) 85 return ret; 86 87 ret = dmaengine_slave_config(chan, &slave_config); 88 if (ret) 89 return ret; 90 } 91 92 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params)); 93 } 94 95 static int dmaengine_pcm_open(struct snd_pcm_substream *substream) 96 { 97 struct snd_soc_pcm_runtime *rtd = substream->private_data; 98 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 99 struct dma_chan *chan = pcm->chan[substream->stream]; 100 int ret; 101 102 ret = snd_soc_set_runtime_hwparams(substream, 103 pcm->config->pcm_hardware); 104 if (ret) 105 return ret; 106 107 return snd_dmaengine_pcm_open(substream, chan); 108 } 109 110 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, 111 struct snd_pcm_substream *substream) 112 { 113 if (!pcm->chan[substream->stream]) 114 return NULL; 115 116 return pcm->chan[substream->stream]->device->dev; 117 } 118 119 static void dmaengine_pcm_free(struct snd_pcm *pcm) 120 { 121 snd_pcm_lib_preallocate_free_for_all(pcm); 122 } 123 124 static struct dma_chan *dmaengine_pcm_compat_request_channel( 125 struct snd_soc_pcm_runtime *rtd, 126 struct snd_pcm_substream *substream) 127 { 128 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 129 130 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) 131 return pcm->chan[0]; 132 133 if (pcm->config->compat_request_channel) 134 return pcm->config->compat_request_channel(rtd, substream); 135 136 return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn, 137 snd_soc_dai_get_dma_data(rtd->cpu_dai, substream)); 138 } 139 140 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd) 141 { 142 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform); 143 const struct snd_dmaengine_pcm_config *config = pcm->config; 144 struct snd_pcm_substream *substream; 145 unsigned int i; 146 int ret; 147 148 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 149 substream = rtd->pcm->streams[i].substream; 150 if (!substream) 151 continue; 152 153 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { 154 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd, 155 substream); 156 } 157 158 if (!pcm->chan[i]) { 159 dev_err(rtd->platform->dev, 160 "Missing dma channel for stream: %d\n", i); 161 ret = -EINVAL; 162 goto err_free; 163 } 164 165 ret = snd_pcm_lib_preallocate_pages(substream, 166 SNDRV_DMA_TYPE_DEV, 167 dmaengine_dma_dev(pcm, substream), 168 config->prealloc_buffer_size, 169 config->pcm_hardware->buffer_bytes_max); 170 if (ret) 171 goto err_free; 172 } 173 174 return 0; 175 176 err_free: 177 dmaengine_pcm_free(rtd->pcm); 178 return ret; 179 } 180 181 static const struct snd_pcm_ops dmaengine_pcm_ops = { 182 .open = dmaengine_pcm_open, 183 .close = snd_dmaengine_pcm_close, 184 .ioctl = snd_pcm_lib_ioctl, 185 .hw_params = dmaengine_pcm_hw_params, 186 .hw_free = snd_pcm_lib_free_pages, 187 .trigger = snd_dmaengine_pcm_trigger, 188 .pointer = snd_dmaengine_pcm_pointer, 189 }; 190 191 static const struct snd_soc_platform_driver dmaengine_pcm_platform = { 192 .ops = &dmaengine_pcm_ops, 193 .pcm_new = dmaengine_pcm_new, 194 .pcm_free = dmaengine_pcm_free, 195 .probe_order = SND_SOC_COMP_ORDER_LATE, 196 }; 197 198 static const struct snd_pcm_ops dmaengine_no_residue_pcm_ops = { 199 .open = dmaengine_pcm_open, 200 .close = snd_dmaengine_pcm_close, 201 .ioctl = snd_pcm_lib_ioctl, 202 .hw_params = dmaengine_pcm_hw_params, 203 .hw_free = snd_pcm_lib_free_pages, 204 .trigger = snd_dmaengine_pcm_trigger, 205 .pointer = snd_dmaengine_pcm_pointer_no_residue, 206 }; 207 208 static const struct snd_soc_platform_driver dmaengine_no_residue_pcm_platform = { 209 .ops = &dmaengine_no_residue_pcm_ops, 210 .pcm_new = dmaengine_pcm_new, 211 .pcm_free = dmaengine_pcm_free, 212 .probe_order = SND_SOC_COMP_ORDER_LATE, 213 }; 214 215 static const char * const dmaengine_pcm_dma_channel_names[] = { 216 [SNDRV_PCM_STREAM_PLAYBACK] = "tx", 217 [SNDRV_PCM_STREAM_CAPTURE] = "rx", 218 }; 219 220 static void dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, 221 struct device *dev) 222 { 223 unsigned int i; 224 225 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || !dev->of_node) 226 return; 227 228 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) { 229 pcm->chan[0] = dma_request_slave_channel(dev, "rx-tx"); 230 pcm->chan[1] = pcm->chan[0]; 231 } else { 232 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 233 pcm->chan[i] = dma_request_slave_channel(dev, 234 dmaengine_pcm_dma_channel_names[i]); 235 } 236 } 237 } 238 239 /** 240 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device 241 * @dev: The parent device for the PCM device 242 * @config: Platform specific PCM configuration 243 * @flags: Platform specific quirks 244 */ 245 int snd_dmaengine_pcm_register(struct device *dev, 246 const struct snd_dmaengine_pcm_config *config, unsigned int flags) 247 { 248 struct dmaengine_pcm *pcm; 249 250 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); 251 if (!pcm) 252 return -ENOMEM; 253 254 pcm->config = config; 255 pcm->flags = flags; 256 257 dmaengine_pcm_request_chan_of(pcm, dev); 258 259 if (flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) 260 return snd_soc_add_platform(dev, &pcm->platform, 261 &dmaengine_no_residue_pcm_platform); 262 else 263 return snd_soc_add_platform(dev, &pcm->platform, 264 &dmaengine_pcm_platform); 265 } 266 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); 267 268 /** 269 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device 270 * @dev: Parent device the PCM was register with 271 * 272 * Removes a dmaengine based PCM device previously registered with 273 * snd_dmaengine_pcm_register. 274 */ 275 void snd_dmaengine_pcm_unregister(struct device *dev) 276 { 277 struct snd_soc_platform *platform; 278 struct dmaengine_pcm *pcm; 279 unsigned int i; 280 281 platform = snd_soc_lookup_platform(dev); 282 if (!platform) 283 return; 284 285 pcm = soc_platform_to_pcm(platform); 286 287 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) { 288 if (pcm->chan[i]) { 289 dma_release_channel(pcm->chan[i]); 290 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) 291 break; 292 } 293 } 294 295 snd_soc_remove_platform(platform); 296 kfree(pcm); 297 } 298 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); 299 300 MODULE_LICENSE("GPL"); 301