soc-generic-dmaengine-pcm.c

  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
 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 * 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
 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 * 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 */
 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 = 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}
 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	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
 97static int
 98dmaengine_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
148static 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
162static 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
168static 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
174static 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
200static 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
219static 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
278static 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
290static 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
321static 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
327static 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
339static 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
352static const char * const dmaengine_pcm_dma_channel_names[] = {
353	[SNDRV_PCM_STREAM_PLAYBACK] = "tx",
354	[SNDRV_PCM_STREAM_CAPTURE] = "rx",
355};
356
357static 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
410static 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
423static 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 */
433int 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
474err_free_dma:
475	dmaengine_pcm_release_chan(pcm);
476	kfree(pcm);
477	return ret;
478}
479EXPORT_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 */
488void 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}
503EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
504
505MODULE_DESCRIPTION("ASoC helpers for generic PCM dmaengine API");
506MODULE_LICENSE("GPL");