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6#include <linux/module.h>
7#include <linux/init.h>
8#include <linux/dmaengine.h>
9#include <linux/slab.h>
10#include <sound/pcm.h>
11#include <sound/pcm_params.h>
12#include <sound/soc.h>
13#include <linux/dma-mapping.h>
14#include <linux/of.h>
15
16#include <sound/dmaengine_pcm.h>
17
18static unsigned int prealloc_buffer_size_kbytes = 512;
19module_param(prealloc_buffer_size_kbytes, uint, 0444);
20MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB).");
21
22
23
24
25
26#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
27
28static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
29 struct snd_pcm_substream *substream)
30{
31 if (!pcm->chan[substream->stream])
32 return NULL;
33
34 return pcm->chan[substream->stream]->device->dev;
35}
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
51 struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
52{
53 struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
54 struct snd_dmaengine_dai_dma_data *dma_data;
55 int ret;
56
57 if (rtd->num_cpus > 1) {
58 dev_err(rtd->dev,
59 "%s doesn't support Multi CPU yet\n", __func__);
60 return -EINVAL;
61 }
62
63 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
64
65 ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
66 if (ret)
67 return ret;
68
69 snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
70 slave_config);
71
72 return 0;
73}
74EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
75
76static int dmaengine_pcm_hw_params(struct snd_soc_component *component,
77 struct snd_pcm_substream *substream,
78 struct snd_pcm_hw_params *params)
79{
80 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
81 struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
82 int (*prepare_slave_config)(struct snd_pcm_substream *substream,
83 struct snd_pcm_hw_params *params,
84 struct dma_slave_config *slave_config);
85 struct dma_slave_config slave_config;
86
87 memset(&slave_config, 0, sizeof(slave_config));
88
89 if (!pcm->config)
90 prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
91 else
92 prepare_slave_config = pcm->config->prepare_slave_config;
93
94 if (prepare_slave_config) {
95 int ret = prepare_slave_config(substream, params, &slave_config);
96 if (ret)
97 return ret;
98
99 ret = dmaengine_slave_config(chan, &slave_config);
100 if (ret)
101 return ret;
102 }
103
104 return 0;
105}
106
107static int
108dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
109 struct snd_pcm_substream *substream)
110{
111 struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
112 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
113 struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
114 struct dma_chan *chan = pcm->chan[substream->stream];
115 struct snd_dmaengine_dai_dma_data *dma_data;
116 struct snd_pcm_hardware hw;
117
118 if (rtd->num_cpus > 1) {
119 dev_err(rtd->dev,
120 "%s doesn't support Multi CPU yet\n", __func__);
121 return -EINVAL;
122 }
123
124 if (pcm->config && pcm->config->pcm_hardware)
125 return snd_soc_set_runtime_hwparams(substream,
126 pcm->config->pcm_hardware);
127
128 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
129
130 memset(&hw, 0, sizeof(hw));
131 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
132 SNDRV_PCM_INFO_INTERLEAVED;
133 hw.periods_min = 2;
134 hw.periods_max = UINT_MAX;
135 hw.period_bytes_min = 256;
136 hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
137 hw.buffer_bytes_max = SIZE_MAX;
138 hw.fifo_size = dma_data->fifo_size;
139
140 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
141 hw.info |= SNDRV_PCM_INFO_BATCH;
142
143
144
145
146
147
148 snd_dmaengine_pcm_refine_runtime_hwparams(substream,
149 dma_data,
150 &hw,
151 chan);
152
153 return snd_soc_set_runtime_hwparams(substream, &hw);
154}
155
156static int dmaengine_pcm_open(struct snd_soc_component *component,
157 struct snd_pcm_substream *substream)
158{
159 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
160 struct dma_chan *chan = pcm->chan[substream->stream];
161 int ret;
162
163 ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
164 if (ret)
165 return ret;
166
167 return snd_dmaengine_pcm_open(substream, chan);
168}
169
170static int dmaengine_pcm_close(struct snd_soc_component *component,
171 struct snd_pcm_substream *substream)
172{
173 return snd_dmaengine_pcm_close(substream);
174}
175
176static int dmaengine_pcm_trigger(struct snd_soc_component *component,
177 struct snd_pcm_substream *substream, int cmd)
178{
179 return snd_dmaengine_pcm_trigger(substream, cmd);
180}
181
182static struct dma_chan *dmaengine_pcm_compat_request_channel(
183 struct snd_soc_component *component,
184 struct snd_soc_pcm_runtime *rtd,
185 struct snd_pcm_substream *substream)
186{
187 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
188 struct snd_dmaengine_dai_dma_data *dma_data;
189 dma_filter_fn fn = NULL;
190
191 if (rtd->num_cpus > 1) {
192 dev_err(rtd->dev,
193 "%s doesn't support Multi CPU yet\n", __func__);
194 return NULL;
195 }
196
197 dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
198
199 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
200 return pcm->chan[0];
201
202 if (pcm->config && pcm->config->compat_request_channel)
203 return pcm->config->compat_request_channel(rtd, substream);
204
205 if (pcm->config)
206 fn = pcm->config->compat_filter_fn;
207
208 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
209}
210
211static bool dmaengine_pcm_can_report_residue(struct device *dev,
212 struct dma_chan *chan)
213{
214 struct dma_slave_caps dma_caps;
215 int ret;
216
217 ret = dma_get_slave_caps(chan, &dma_caps);
218 if (ret != 0) {
219 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
220 ret);
221 return false;
222 }
223
224 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
225 return false;
226
227 return true;
228}
229
230static int dmaengine_pcm_new(struct snd_soc_component *component,
231 struct snd_soc_pcm_runtime *rtd)
232{
233 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
234 const struct snd_dmaengine_pcm_config *config = pcm->config;
235 struct device *dev = component->dev;
236 size_t prealloc_buffer_size;
237 size_t max_buffer_size;
238 unsigned int i;
239
240 if (config && config->prealloc_buffer_size) {
241 prealloc_buffer_size = config->prealloc_buffer_size;
242 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
243 } else {
244 prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024;
245 max_buffer_size = SIZE_MAX;
246 }
247
248 for_each_pcm_streams(i) {
249 struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream;
250 if (!substream)
251 continue;
252
253 if (!pcm->chan[i] && config && config->chan_names[i])
254 pcm->chan[i] = dma_request_slave_channel(dev,
255 config->chan_names[i]);
256
257 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
258 pcm->chan[i] = dmaengine_pcm_compat_request_channel(
259 component, rtd, substream);
260 }
261
262 if (!pcm->chan[i]) {
263 dev_err(component->dev,
264 "Missing dma channel for stream: %d\n", i);
265 return -EINVAL;
266 }
267
268 snd_pcm_set_managed_buffer(substream,
269 SNDRV_DMA_TYPE_DEV_IRAM,
270 dmaengine_dma_dev(pcm, substream),
271 prealloc_buffer_size,
272 max_buffer_size);
273
274 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
275 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
276
277 if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
278 strscpy_pad(rtd->pcm->streams[i].pcm->name,
279 rtd->pcm->streams[i].pcm->id,
280 sizeof(rtd->pcm->streams[i].pcm->name));
281 }
282 }
283
284 return 0;
285}
286
287static snd_pcm_uframes_t dmaengine_pcm_pointer(
288 struct snd_soc_component *component,
289 struct snd_pcm_substream *substream)
290{
291 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
292
293 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
294 return snd_dmaengine_pcm_pointer_no_residue(substream);
295 else
296 return snd_dmaengine_pcm_pointer(substream);
297}
298
299static int dmaengine_copy_user(struct snd_soc_component *component,
300 struct snd_pcm_substream *substream,
301 int channel, unsigned long hwoff,
302 void __user *buf, unsigned long bytes)
303{
304 struct snd_pcm_runtime *runtime = substream->runtime;
305 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
306 int (*process)(struct snd_pcm_substream *substream,
307 int channel, unsigned long hwoff,
308 void *buf, unsigned long bytes) = pcm->config->process;
309 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
310 void *dma_ptr = runtime->dma_area + hwoff +
311 channel * (runtime->dma_bytes / runtime->channels);
312
313 if (is_playback)
314 if (copy_from_user(dma_ptr, buf, bytes))
315 return -EFAULT;
316
317 if (process) {
318 int ret = process(substream, channel, hwoff, (__force void *)buf, bytes);
319 if (ret < 0)
320 return ret;
321 }
322
323 if (!is_playback)
324 if (copy_to_user(buf, dma_ptr, bytes))
325 return -EFAULT;
326
327 return 0;
328}
329
330static const struct snd_soc_component_driver dmaengine_pcm_component = {
331 .name = SND_DMAENGINE_PCM_DRV_NAME,
332 .probe_order = SND_SOC_COMP_ORDER_LATE,
333 .open = dmaengine_pcm_open,
334 .close = dmaengine_pcm_close,
335 .hw_params = dmaengine_pcm_hw_params,
336 .trigger = dmaengine_pcm_trigger,
337 .pointer = dmaengine_pcm_pointer,
338 .pcm_construct = dmaengine_pcm_new,
339};
340
341static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
342 .name = SND_DMAENGINE_PCM_DRV_NAME,
343 .probe_order = SND_SOC_COMP_ORDER_LATE,
344 .open = dmaengine_pcm_open,
345 .close = dmaengine_pcm_close,
346 .hw_params = dmaengine_pcm_hw_params,
347 .trigger = dmaengine_pcm_trigger,
348 .pointer = dmaengine_pcm_pointer,
349 .copy_user = dmaengine_copy_user,
350 .pcm_construct = dmaengine_pcm_new,
351};
352
353static const char * const dmaengine_pcm_dma_channel_names[] = {
354 [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
355 [SNDRV_PCM_STREAM_CAPTURE] = "rx",
356};
357
358static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
359 struct device *dev, const struct snd_dmaengine_pcm_config *config)
360{
361 unsigned int i;
362 const char *name;
363 struct dma_chan *chan;
364
365 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node &&
366 !(config && config->dma_dev && config->dma_dev->of_node)))
367 return 0;
368
369 if (config && config->dma_dev) {
370
371
372
373
374
375
376 dev_warn(dev, "DMA channels sourced from device %s",
377 dev_name(config->dma_dev));
378 dev = config->dma_dev;
379 }
380
381 for_each_pcm_streams(i) {
382 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
383 name = "rx-tx";
384 else
385 name = dmaengine_pcm_dma_channel_names[i];
386 if (config && config->chan_names[i])
387 name = config->chan_names[i];
388 chan = dma_request_chan(dev, name);
389 if (IS_ERR(chan)) {
390
391
392
393
394
395 if (PTR_ERR(chan) == -EPROBE_DEFER)
396 return -EPROBE_DEFER;
397 pcm->chan[i] = NULL;
398 } else {
399 pcm->chan[i] = chan;
400 }
401 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
402 break;
403 }
404
405 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
406 pcm->chan[1] = pcm->chan[0];
407
408 return 0;
409}
410
411static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
412{
413 unsigned int i;
414
415 for_each_pcm_streams(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
426
427
428
429
430int snd_dmaengine_pcm_register(struct device *dev,
431 const struct snd_dmaengine_pcm_config *config, unsigned int flags)
432{
433 const struct snd_soc_component_driver *driver;
434 struct dmaengine_pcm *pcm;
435 int ret;
436
437 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
438 if (!pcm)
439 return -ENOMEM;
440
441#ifdef CONFIG_DEBUG_FS
442 pcm->component.debugfs_prefix = "dma";
443#endif
444 pcm->config = config;
445 pcm->flags = flags;
446
447 ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
448 if (ret)
449 goto err_free_dma;
450
451 if (config && config->process)
452 driver = &dmaengine_pcm_component_process;
453 else
454 driver = &dmaengine_pcm_component;
455
456 ret = snd_soc_component_initialize(&pcm->component, driver, dev);
457 if (ret)
458 goto err_free_dma;
459
460 ret = snd_soc_add_component(&pcm->component, NULL, 0);
461 if (ret)
462 goto err_free_dma;
463
464 return 0;
465
466err_free_dma:
467 dmaengine_pcm_release_chan(pcm);
468 kfree(pcm);
469 return ret;
470}
471EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
472
473
474
475
476
477
478
479
480void snd_dmaengine_pcm_unregister(struct device *dev)
481{
482 struct snd_soc_component *component;
483 struct dmaengine_pcm *pcm;
484
485 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
486 if (!component)
487 return;
488
489 pcm = soc_component_to_pcm(component);
490
491 snd_soc_unregister_component_by_driver(dev, component->driver);
492 dmaengine_pcm_release_chan(pcm);
493 kfree(pcm);
494}
495EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
496
497MODULE_LICENSE("GPL");
498
