1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright (C) 2013, Analog Devices Inc.
4 // Author: Lars-Peter Clausen <lars@metafoo.de>
5
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
18 static unsigned int prealloc_buffer_size_kbytes = 512;
19 module_param(prealloc_buffer_size_kbytes, uint, 0444);
20 MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB).");
21
22 /*
23 * The platforms dmaengine driver does not support reporting the amount of
24 * bytes that are still left to transfer.
25 */
26 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
27
28 static 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 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
39 * @substream: PCM substream
40 * @params: hw_params
41 * @slave_config: DMA slave config to prepare
42 *
43 * This function can be used as a generic prepare_slave_config callback for
44 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
45 * DAI DMA data. Internally the function will first call
46 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
47 * hw_params, followed by snd_dmaengine_pcm_set_config_from_dai_data to fill in
48 * the remaining fields based on the DAI DMA data.
49 */
50 int 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 = snd_soc_substream_to_rtd(substream);
54 struct snd_dmaengine_dai_dma_data *dma_data;
55 int ret;
56
57 if (rtd->dai_link->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(snd_soc_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 }
74 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
75
76 static 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 struct dma_slave_config slave_config;
83 int ret;
84
85 if (!pcm->config->prepare_slave_config)
86 return 0;
87
88 memset(&slave_config, 0, sizeof(slave_config));
89
90 ret = pcm->config->prepare_slave_config(substream, params, &slave_config);
91 if (ret)
92 return ret;
93
94 return dmaengine_slave_config(chan, &slave_config);
95 }
96
97 static int
98 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
99 struct snd_pcm_substream *substream)
100 {
101 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
102 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
103 struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
104 struct dma_chan *chan = pcm->chan[substream->stream];
105 struct snd_dmaengine_dai_dma_data *dma_data;
106 struct snd_pcm_hardware hw;
107
108 if (rtd->dai_link->num_cpus > 1) {
109 dev_err(rtd->dev,
110 "%s doesn't support Multi CPU yet\n", __func__);
111 return -EINVAL;
112 }
113
114 if (pcm->config->pcm_hardware)
115 return snd_soc_set_runtime_hwparams(substream,
116 pcm->config->pcm_hardware);
117
118 dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
119
120 memset(&hw, 0, sizeof(hw));
121 hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
122 SNDRV_PCM_INFO_INTERLEAVED;
123 hw.periods_min = 2;
124 hw.periods_max = UINT_MAX;
125 hw.period_bytes_min = dma_data->maxburst * DMA_SLAVE_BUSWIDTH_8_BYTES;
126 if (!hw.period_bytes_min)
127 hw.period_bytes_min = 256;
128 hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
129 hw.buffer_bytes_max = SIZE_MAX;
130 hw.fifo_size = dma_data->fifo_size;
131
132 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
133 hw.info |= SNDRV_PCM_INFO_BATCH;
134
135 /**
136 * FIXME: Remove the return value check to align with the code
137 * before adding snd_dmaengine_pcm_refine_runtime_hwparams
138 * function.
139 */
140 snd_dmaengine_pcm_refine_runtime_hwparams(substream,
141 dma_data,
142 &hw,
143 chan);
144
145 return snd_soc_set_runtime_hwparams(substream, &hw);
146 }
147
148 static int dmaengine_pcm_open(struct snd_soc_component *component,
149 struct snd_pcm_substream *substream)
150 {
151 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
152 struct dma_chan *chan = pcm->chan[substream->stream];
153 int ret;
154
155 ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
156 if (ret)
157 return ret;
158
159 return snd_dmaengine_pcm_open(substream, chan);
160 }
161
162 static int dmaengine_pcm_close(struct snd_soc_component *component,
163 struct snd_pcm_substream *substream)
164 {
165 return snd_dmaengine_pcm_close(substream);
166 }
167
168 static int dmaengine_pcm_trigger(struct snd_soc_component *component,
169 struct snd_pcm_substream *substream, int cmd)
170 {
171 return snd_dmaengine_pcm_trigger(substream, cmd);
172 }
173
174 static struct dma_chan *dmaengine_pcm_compat_request_channel(
175 struct snd_soc_component *component,
176 struct snd_soc_pcm_runtime *rtd,
177 struct snd_pcm_substream *substream)
178 {
179 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
180 struct snd_dmaengine_dai_dma_data *dma_data;
181
182 if (rtd->dai_link->num_cpus > 1) {
183 dev_err(rtd->dev,
184 "%s doesn't support Multi CPU yet\n", __func__);
185 return NULL;
186 }
187
188 dma_data = snd_soc_dai_get_dma_data(snd_soc_rtd_to_cpu(rtd, 0), substream);
189
190 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
191 return pcm->chan[0];
192
193 if (pcm->config->compat_request_channel)
194 return pcm->config->compat_request_channel(rtd, substream);
195
196 return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn,
197 dma_data->filter_data);
198 }
199
200 static bool dmaengine_pcm_can_report_residue(struct device *dev,
201 struct dma_chan *chan)
202 {
203 struct dma_slave_caps dma_caps;
204 int ret;
205
206 ret = dma_get_slave_caps(chan, &dma_caps);
207 if (ret != 0) {
208 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
209 ret);
210 return false;
211 }
212
213 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
214 return false;
215
216 return true;
217 }
218
219 static int dmaengine_pcm_new(struct snd_soc_component *component,
220 struct snd_soc_pcm_runtime *rtd)
221 {
222 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
223 const struct snd_dmaengine_pcm_config *config = pcm->config;
224 struct device *dev = component->dev;
225 size_t prealloc_buffer_size;
226 size_t max_buffer_size;
227 unsigned int i;
228
229 if (config->prealloc_buffer_size)
230 prealloc_buffer_size = config->prealloc_buffer_size;
231 else
232 prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024;
233
234 if (config->pcm_hardware && config->pcm_hardware->buffer_bytes_max)
235 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
236 else
237 max_buffer_size = SIZE_MAX;
238
239 for_each_pcm_streams(i) {
240 struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream;
241 if (!substream)
242 continue;
243
244 if (!pcm->chan[i] && config->chan_names[i])
245 pcm->chan[i] = dma_request_slave_channel(dev,
246 config->chan_names[i]);
247
248 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
249 pcm->chan[i] = dmaengine_pcm_compat_request_channel(
250 component, rtd, substream);
251 }
252
253 if (!pcm->chan[i]) {
254 dev_err(component->dev,
255 "Missing dma channel for stream: %d\n", i);
256 return -EINVAL;
257 }
258
259 snd_pcm_set_managed_buffer(substream,
260 SNDRV_DMA_TYPE_DEV_IRAM,
261 dmaengine_dma_dev(pcm, substream),
262 prealloc_buffer_size,
263 max_buffer_size);
264
265 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
266 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
267
268 if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
269 strscpy_pad(rtd->pcm->streams[i].pcm->name,
270 rtd->pcm->streams[i].pcm->id,
271 sizeof(rtd->pcm->streams[i].pcm->name));
272 }
273 }
274
275 return 0;
276 }
277
278 static snd_pcm_uframes_t dmaengine_pcm_pointer(
279 struct snd_soc_component *component,
280 struct snd_pcm_substream *substream)
281 {
282 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
283
284 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
285 return snd_dmaengine_pcm_pointer_no_residue(substream);
286 else
287 return snd_dmaengine_pcm_pointer(substream);
288 }
289
290 static int dmaengine_copy(struct snd_soc_component *component,
291 struct snd_pcm_substream *substream,
292 int channel, unsigned long hwoff,
293 struct iov_iter *iter, unsigned long bytes)
294 {
295 struct snd_pcm_runtime *runtime = substream->runtime;
296 struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
297 int (*process)(struct snd_pcm_substream *substream,
298 int channel, unsigned long hwoff,
299 unsigned long bytes) = pcm->config->process;
300 bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
301 void *dma_ptr = runtime->dma_area + hwoff +
302 channel * (runtime->dma_bytes / runtime->channels);
303
304 if (is_playback)
305 if (copy_from_iter(dma_ptr, bytes, iter) != bytes)
306 return -EFAULT;
307
308 if (process) {
309 int ret = process(substream, channel, hwoff, bytes);
310 if (ret < 0)
311 return ret;
312 }
313
314 if (!is_playback)
315 if (copy_to_iter(dma_ptr, bytes, iter) != bytes)
316 return -EFAULT;
317
318 return 0;
319 }
320
321 static int dmaengine_pcm_sync_stop(struct snd_soc_component *component,
322 struct snd_pcm_substream *substream)
323 {
324 return snd_dmaengine_pcm_sync_stop(substream);
325 }
326
327 static const struct snd_soc_component_driver dmaengine_pcm_component = {
328 .name = SND_DMAENGINE_PCM_DRV_NAME,
329 .probe_order = SND_SOC_COMP_ORDER_LATE,
330 .open = dmaengine_pcm_open,
331 .close = dmaengine_pcm_close,
332 .hw_params = dmaengine_pcm_hw_params,
333 .trigger = dmaengine_pcm_trigger,
334 .pointer = dmaengine_pcm_pointer,
335 .pcm_construct = dmaengine_pcm_new,
336 .sync_stop = dmaengine_pcm_sync_stop,
337 };
338
339 static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
340 .name = SND_DMAENGINE_PCM_DRV_NAME,
341 .probe_order = SND_SOC_COMP_ORDER_LATE,
342 .open = dmaengine_pcm_open,
343 .close = dmaengine_pcm_close,
344 .hw_params = dmaengine_pcm_hw_params,
345 .trigger = dmaengine_pcm_trigger,
346 .pointer = dmaengine_pcm_pointer,
347 .copy = dmaengine_copy,
348 .pcm_construct = dmaengine_pcm_new,
349 .sync_stop = dmaengine_pcm_sync_stop,
350 };
351
352 static const char * const dmaengine_pcm_dma_channel_names[] = {
353 [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
354 [SNDRV_PCM_STREAM_CAPTURE] = "rx",
355 };
356
357 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
358 struct device *dev, const struct snd_dmaengine_pcm_config *config)
359 {
360 unsigned int i;
361 const char *name;
362 struct dma_chan *chan;
363
364 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node &&
365 !(config->dma_dev && config->dma_dev->of_node)))
366 return 0;
367
368 if (config->dma_dev) {
369 /*
370 * If this warning is seen, it probably means that your Linux
371 * device structure does not match your HW device structure.
372 * It would be best to refactor the Linux device structure to
373 * correctly match the HW structure.
374 */
375 dev_warn(dev, "DMA channels sourced from device %s",
376 dev_name(config->dma_dev));
377 dev = config->dma_dev;
378 }
379
380 for_each_pcm_streams(i) {
381 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
382 name = "rx-tx";
383 else
384 name = dmaengine_pcm_dma_channel_names[i];
385 if (config->chan_names[i])
386 name = config->chan_names[i];
387 chan = dma_request_chan(dev, name);
388 if (IS_ERR(chan)) {
389 /*
390 * Only report probe deferral errors, channels
391 * might not be present for devices that
392 * support only TX or only RX.
393 */
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
410 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
411 {
412 unsigned int i;
413
414 for_each_pcm_streams(i) {
415 if (!pcm->chan[i])
416 continue;
417 dma_release_channel(pcm->chan[i]);
418 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
419 break;
420 }
421 }
422
423 static const struct snd_dmaengine_pcm_config snd_dmaengine_pcm_default_config = {
424 .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
425 };
426
427 /**
428 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
429 * @dev: The parent device for the PCM device
430 * @config: Platform specific PCM configuration
431 * @flags: Platform specific quirks
432 */
433 int snd_dmaengine_pcm_register(struct device *dev,
434 const struct snd_dmaengine_pcm_config *config, unsigned int flags)
435 {
436 const struct snd_soc_component_driver *driver;
437 struct dmaengine_pcm *pcm;
438 int ret;
439
440 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
441 if (!pcm)
442 return -ENOMEM;
443
444 #ifdef CONFIG_DEBUG_FS
445 pcm->component.debugfs_prefix = "dma";
446 #endif
447 if (!config)
448 config = &snd_dmaengine_pcm_default_config;
449 pcm->config = config;
450 pcm->flags = flags;
451
452 if (config->name)
453 pcm->component.name = config->name;
454
455 ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
456 if (ret)
457 goto err_free_dma;
458
459 if (config->process)
460 driver = &dmaengine_pcm_component_process;
461 else
462 driver = &dmaengine_pcm_component;
463
464 ret = snd_soc_component_initialize(&pcm->component, driver, dev);
465 if (ret)
466 goto err_free_dma;
467
468 ret = snd_soc_add_component(&pcm->component, NULL, 0);
469 if (ret)
470 goto err_free_dma;
471
472 return 0;
473
474 err_free_dma:
475 dmaengine_pcm_release_chan(pcm);
476 kfree(pcm);
477 return ret;
478 }
479 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
480
481 /**
482 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
483 * @dev: Parent device the PCM was register with
484 *
485 * Removes a dmaengine based PCM device previously registered with
486 * snd_dmaengine_pcm_register.
487 */
488 void snd_dmaengine_pcm_unregister(struct device *dev)
489 {
490 struct snd_soc_component *component;
491 struct dmaengine_pcm *pcm;
492
493 component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
494 if (!component)
495 return;
496
497 pcm = soc_component_to_pcm(component);
498
499 snd_soc_unregister_component_by_driver(dev, component->driver);
500 dmaengine_pcm_release_chan(pcm);
501 kfree(pcm);
502 }
503 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
504
505 MODULE_DESCRIPTION("ASoC helpers for generic PCM dmaengine API");
506 MODULE_LICENSE("GPL");
507
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