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 /*
28 * The platforms dmaengine driver does not support reporting the amount of
29 * bytes that are still left to transfer.
30 */
31 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
32
33 struct dmaengine_pcm {
34 struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
35 const struct snd_dmaengine_pcm_config *config;
36 struct snd_soc_platform platform;
37 unsigned int flags;
38 };
39
soc_platform_to_pcm(struct snd_soc_platform * p)40 static struct dmaengine_pcm *soc_platform_to_pcm(struct snd_soc_platform *p)
41 {
42 return container_of(p, struct dmaengine_pcm, platform);
43 }
44
dmaengine_dma_dev(struct dmaengine_pcm * pcm,struct snd_pcm_substream * substream)45 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
46 struct snd_pcm_substream *substream)
47 {
48 if (!pcm->chan[substream->stream])
49 return NULL;
50
51 return pcm->chan[substream->stream]->device->dev;
52 }
53
54 /**
55 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
56 * @substream: PCM substream
57 * @params: hw_params
58 * @slave_config: DMA slave config to prepare
59 *
60 * This function can be used as a generic prepare_slave_config callback for
61 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
62 * DAI DMA data. Internally the function will first call
63 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
64 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
65 * remaining fields based on the DAI DMA data.
66 */
snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params,struct dma_slave_config * slave_config)67 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
68 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
69 {
70 struct snd_soc_pcm_runtime *rtd = substream->private_data;
71 struct snd_dmaengine_dai_dma_data *dma_data;
72 int ret;
73
74 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
75
76 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
77 if (ret)
78 return ret;
79
80 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
81 slave_config);
82
83 return 0;
84 }
85 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
86
dmaengine_pcm_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)87 static int dmaengine_pcm_hw_params(struct snd_pcm_substream *substream,
88 struct snd_pcm_hw_params *params)
89 {
90 struct snd_soc_pcm_runtime *rtd = substream->private_data;
91 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
92 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
93 int (*prepare_slave_config)(struct snd_pcm_substream *substream,
94 struct snd_pcm_hw_params *params,
95 struct dma_slave_config *slave_config);
96 struct dma_slave_config slave_config;
97 int ret;
98
99 memset(&slave_config, 0, sizeof(slave_config));
100
101 if (!pcm->config)
102 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
103 else
104 prepare_slave_config = pcm->config->prepare_slave_config;
105
106 if (prepare_slave_config) {
107 ret = prepare_slave_config(substream, params, &slave_config);
108 if (ret)
109 return ret;
110
111 ret = dmaengine_slave_config(chan, &slave_config);
112 if (ret)
113 return ret;
114 }
115
116 return snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
117 }
118
dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream * substream)119 static int dmaengine_pcm_set_runtime_hwparams(struct snd_pcm_substream *substream)
120 {
121 struct snd_soc_pcm_runtime *rtd = substream->private_data;
122 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
123 struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
124 struct dma_chan *chan = pcm->chan[substream->stream];
125 struct snd_dmaengine_dai_dma_data *dma_data;
126 struct dma_slave_caps dma_caps;
127 struct snd_pcm_hardware hw;
128 u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
129 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
130 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
131 int i, ret;
132
133 if (pcm->config && pcm->config->pcm_hardware)
134 return snd_soc_set_runtime_hwparams(substream,
135 pcm->config->pcm_hardware);
136
137 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
138
139 memset(&hw, 0, sizeof(hw));
140 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
141 SNDRV_PCM_INFO_INTERLEAVED;
142 hw.periods_min = 2;
143 hw.periods_max = UINT_MAX;
144 hw.period_bytes_min = 256;
145 hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
146 hw.buffer_bytes_max = SIZE_MAX;
147 hw.fifo_size = dma_data->fifo_size;
148
149 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
150 hw.info |= SNDRV_PCM_INFO_BATCH;
151
152 ret = dma_get_slave_caps(chan, &dma_caps);
153 if (ret == 0) {
154 if (dma_caps.cmd_pause)
155 hw.info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
156 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
157 hw.info |= SNDRV_PCM_INFO_BATCH;
158
159 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
160 addr_widths = dma_caps.dst_addr_widths;
161 else
162 addr_widths = dma_caps.src_addr_widths;
163 }
164
165 /*
166 * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
167 * hw.formats set to 0, meaning no restrictions are in place.
168 * In this case it's the responsibility of the DAI driver to
169 * provide the supported format information.
170 */
171 if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
172 /*
173 * Prepare formats mask for valid/allowed sample types. If the
174 * dma does not have support for the given physical word size,
175 * it needs to be masked out so user space can not use the
176 * format which produces corrupted audio.
177 * In case the dma driver does not implement the slave_caps the
178 * default assumption is that it supports 1, 2 and 4 bytes
179 * widths.
180 */
181 for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) {
182 int bits = snd_pcm_format_physical_width(i);
183
184 /*
185 * Enable only samples with DMA supported physical
186 * widths
187 */
188 switch (bits) {
189 case 8:
190 case 16:
191 case 24:
192 case 32:
193 case 64:
194 if (addr_widths & (1 << (bits / 8)))
195 hw.formats |= (1LL << i);
196 break;
197 default:
198 /* Unsupported types */
199 break;
200 }
201 }
202
203 return snd_soc_set_runtime_hwparams(substream, &hw);
204 }
205
dmaengine_pcm_open(struct snd_pcm_substream * substream)206 static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
207 {
208 struct snd_soc_pcm_runtime *rtd = substream->private_data;
209 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
210 struct dma_chan *chan = pcm->chan[substream->stream];
211 int ret;
212
213 ret = dmaengine_pcm_set_runtime_hwparams(substream);
214 if (ret)
215 return ret;
216
217 return snd_dmaengine_pcm_open(substream, chan);
218 }
219
dmaengine_pcm_compat_request_channel(struct snd_soc_pcm_runtime * rtd,struct snd_pcm_substream * substream)220 static struct dma_chan *dmaengine_pcm_compat_request_channel(
221 struct snd_soc_pcm_runtime *rtd,
222 struct snd_pcm_substream *substream)
223 {
224 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
225 struct snd_dmaengine_dai_dma_data *dma_data;
226 dma_filter_fn fn = NULL;
227
228 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
229
230 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
231 return pcm->chan[0];
232
233 if (pcm->config && pcm->config->compat_request_channel)
234 return pcm->config->compat_request_channel(rtd, substream);
235
236 if (pcm->config)
237 fn = pcm->config->compat_filter_fn;
238
239 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
240 }
241
dmaengine_pcm_can_report_residue(struct device * dev,struct dma_chan * chan)242 static bool dmaengine_pcm_can_report_residue(struct device *dev,
243 struct dma_chan *chan)
244 {
245 struct dma_slave_caps dma_caps;
246 int ret;
247
248 ret = dma_get_slave_caps(chan, &dma_caps);
249 if (ret != 0) {
250 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
251 ret);
252 return false;
253 }
254
255 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
256 return false;
257
258 return true;
259 }
260
dmaengine_pcm_new(struct snd_soc_pcm_runtime * rtd)261 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
262 {
263 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
264 const struct snd_dmaengine_pcm_config *config = pcm->config;
265 struct device *dev = rtd->platform->dev;
266 struct snd_dmaengine_dai_dma_data *dma_data;
267 struct snd_pcm_substream *substream;
268 size_t prealloc_buffer_size;
269 size_t max_buffer_size;
270 unsigned int i;
271 int ret;
272
273 if (config && config->prealloc_buffer_size) {
274 prealloc_buffer_size = config->prealloc_buffer_size;
275 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
276 } else {
277 prealloc_buffer_size = 512 * 1024;
278 max_buffer_size = SIZE_MAX;
279 }
280
281 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
282 substream = rtd->pcm->streams[i].substream;
283 if (!substream)
284 continue;
285
286 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
287
288 if (!pcm->chan[i] &&
289 (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME))
290 pcm->chan[i] = dma_request_slave_channel(dev,
291 dma_data->chan_name);
292
293 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
294 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
295 substream);
296 }
297
298 if (!pcm->chan[i]) {
299 dev_err(rtd->platform->dev,
300 "Missing dma channel for stream: %d\n", i);
301 return -EINVAL;
302 }
303
304 ret = snd_pcm_lib_preallocate_pages(substream,
305 SNDRV_DMA_TYPE_DEV_IRAM,
306 dmaengine_dma_dev(pcm, substream),
307 prealloc_buffer_size,
308 max_buffer_size);
309 if (ret)
310 return ret;
311
312 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
313 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
314
315 if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
316 strncpy(rtd->pcm->streams[i].pcm->name,
317 rtd->pcm->streams[i].pcm->id,
318 sizeof(rtd->pcm->streams[i].pcm->name));
319 }
320 }
321
322 return 0;
323 }
324
dmaengine_pcm_pointer(struct snd_pcm_substream * substream)325 static snd_pcm_uframes_t dmaengine_pcm_pointer(
326 struct snd_pcm_substream *substream)
327 {
328 struct snd_soc_pcm_runtime *rtd = substream->private_data;
329 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
330
331 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
332 return snd_dmaengine_pcm_pointer_no_residue(substream);
333 else
334 return snd_dmaengine_pcm_pointer(substream);
335 }
336
337 static const struct snd_pcm_ops dmaengine_pcm_ops = {
338 .open = dmaengine_pcm_open,
339 .close = snd_dmaengine_pcm_close,
340 .ioctl = snd_pcm_lib_ioctl,
341 .hw_params = dmaengine_pcm_hw_params,
342 .hw_free = snd_pcm_lib_free_pages,
343 .trigger = snd_dmaengine_pcm_trigger,
344 .pointer = dmaengine_pcm_pointer,
345 };
346
347 static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
348 .component_driver = {
349 .probe_order = SND_SOC_COMP_ORDER_LATE,
350 },
351 .ops = &dmaengine_pcm_ops,
352 .pcm_new = dmaengine_pcm_new,
353 };
354
355 static const char * const dmaengine_pcm_dma_channel_names[] = {
356 [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
357 [SNDRV_PCM_STREAM_CAPTURE] = "rx",
358 };
359
dmaengine_pcm_request_chan_of(struct dmaengine_pcm * pcm,struct device * dev,const struct snd_dmaengine_pcm_config * config)360 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
361 struct device *dev, const struct snd_dmaengine_pcm_config *config)
362 {
363 unsigned int i;
364 const char *name;
365 struct dma_chan *chan;
366
367 if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT |
368 SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) ||
369 !dev->of_node)
370 return 0;
371
372 if (config && config->dma_dev) {
373 /*
374 * If this warning is seen, it probably means that your Linux
375 * device structure does not match your HW device structure.
376 * It would be best to refactor the Linux device structure to
377 * correctly match the HW structure.
378 */
379 dev_warn(dev, "DMA channels sourced from device %s",
380 dev_name(config->dma_dev));
381 dev = config->dma_dev;
382 }
383
384 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
385 i++) {
386 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
387 name = "rx-tx";
388 else
389 name = dmaengine_pcm_dma_channel_names[i];
390 if (config && config->chan_names[i])
391 name = config->chan_names[i];
392 chan = dma_request_slave_channel_reason(dev, name);
393 if (IS_ERR(chan)) {
394 if (PTR_ERR(chan) == -EPROBE_DEFER)
395 return -EPROBE_DEFER;
396 pcm->chan[i] = NULL;
397 } else {
398 pcm->chan[i] = chan;
399 }
400 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
401 break;
402 }
403
404 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
405 pcm->chan[1] = pcm->chan[0];
406
407 return 0;
408 }
409
dmaengine_pcm_release_chan(struct dmaengine_pcm * pcm)410 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
411 {
412 unsigned int i;
413
414 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
415 i++) {
416 if (!pcm->chan[i])
417 continue;
418 dma_release_channel(pcm->chan[i]);
419 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
420 break;
421 }
422 }
423
424 /**
425 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
426 * @dev: The parent device for the PCM device
427 * @config: Platform specific PCM configuration
428 * @flags: Platform specific quirks
429 */
snd_dmaengine_pcm_register(struct device * dev,const struct snd_dmaengine_pcm_config * config,unsigned int flags)430 int snd_dmaengine_pcm_register(struct device *dev,
431 const struct snd_dmaengine_pcm_config *config, unsigned int flags)
432 {
433 struct dmaengine_pcm *pcm;
434 int ret;
435
436 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
437 if (!pcm)
438 return -ENOMEM;
439
440 pcm->config = config;
441 pcm->flags = flags;
442
443 ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
444 if (ret)
445 goto err_free_dma;
446
447 ret = snd_soc_add_platform(dev, &pcm->platform,
448 &dmaengine_pcm_platform);
449 if (ret)
450 goto err_free_dma;
451
452 return 0;
453
454 err_free_dma:
455 dmaengine_pcm_release_chan(pcm);
456 kfree(pcm);
457 return ret;
458 }
459 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
460
461 /**
462 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
463 * @dev: Parent device the PCM was register with
464 *
465 * Removes a dmaengine based PCM device previously registered with
466 * snd_dmaengine_pcm_register.
467 */
snd_dmaengine_pcm_unregister(struct device * dev)468 void snd_dmaengine_pcm_unregister(struct device *dev)
469 {
470 struct snd_soc_platform *platform;
471 struct dmaengine_pcm *pcm;
472
473 platform = snd_soc_lookup_platform(dev);
474 if (!platform)
475 return;
476
477 pcm = soc_platform_to_pcm(platform);
478
479 snd_soc_remove_platform(platform);
480 dmaengine_pcm_release_chan(pcm);
481 kfree(pcm);
482 }
483 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
484
485 MODULE_LICENSE("GPL");
486