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/*
19 * The platforms dmaengine driver does not support reporting the amount of
20 * bytes that are still left to transfer.
21 */
22#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
23
24static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
25	struct snd_pcm_substream *substream)
26{
27	if (!pcm->chan[substream->stream])
28		return NULL;
29
30	return pcm->chan[substream->stream]->device->dev;
31}
32
33/**
34 * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
35 * @substream: PCM substream
36 * @params: hw_params
37 * @slave_config: DMA slave config to prepare
38 *
39 * This function can be used as a generic prepare_slave_config callback for
40 * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
41 * DAI DMA data. Internally the function will first call
42 * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
43 * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
44 * remaining fields based on the DAI DMA data.
45 */
46int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
47	struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
48{
49	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
50	struct snd_dmaengine_dai_dma_data *dma_data;
51	int ret;
52
53	if (rtd->num_cpus > 1) {
54		dev_err(rtd->dev,
55			"%s doesn't support Multi CPU yet\n", __func__);
56		return -EINVAL;
57	}
58
59	dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), 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}
70EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
71
72static int dmaengine_pcm_hw_params(struct snd_soc_component *component,
73				   struct snd_pcm_substream *substream,
74				   struct snd_pcm_hw_params *params)
75{
76	struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
77	struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
78	int (*prepare_slave_config)(struct snd_pcm_substream *substream,
79			struct snd_pcm_hw_params *params,
80			struct dma_slave_config *slave_config);
81	struct dma_slave_config slave_config;
82	int ret;
83
84	memset(&slave_config, 0, sizeof(slave_config));
85
86	if (!pcm->config)
87		prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config;
88	else
89		prepare_slave_config = pcm->config->prepare_slave_config;
90
91	if (prepare_slave_config) {
92		ret = prepare_slave_config(substream, params, &slave_config);
93		if (ret)
94			return ret;
95
96		ret = dmaengine_slave_config(chan, &slave_config);
97		if (ret)
98			return ret;
99	}
100
101	return 0;
102}
103
104static int
105dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
106				   struct snd_pcm_substream *substream)
107{
108	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
109	struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
110	struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
111	struct dma_chan *chan = pcm->chan[substream->stream];
112	struct snd_dmaengine_dai_dma_data *dma_data;
113	struct snd_pcm_hardware hw;
114
115	if (rtd->num_cpus > 1) {
116		dev_err(rtd->dev,
117			"%s doesn't support Multi CPU yet\n", __func__);
118		return -EINVAL;
119	}
120
121	if (pcm->config && pcm->config->pcm_hardware)
122		return snd_soc_set_runtime_hwparams(substream,
123				pcm->config->pcm_hardware);
124
125	dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
126
127	memset(&hw, 0, sizeof(hw));
128	hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
129			SNDRV_PCM_INFO_INTERLEAVED;
130	hw.periods_min = 2;
131	hw.periods_max = UINT_MAX;
132	hw.period_bytes_min = 256;
133	hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
134	hw.buffer_bytes_max = SIZE_MAX;
135	hw.fifo_size = dma_data->fifo_size;
136
137	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
138		hw.info |= SNDRV_PCM_INFO_BATCH;
139
140	/**
141	 * FIXME: Remove the return value check to align with the code
142	 * before adding snd_dmaengine_pcm_refine_runtime_hwparams
143	 * function.
144	 */
145	snd_dmaengine_pcm_refine_runtime_hwparams(substream,
146						  dma_data,
147						  &hw,
148						  chan);
149
150	return snd_soc_set_runtime_hwparams(substream, &hw);
151}
152
153static int dmaengine_pcm_open(struct snd_soc_component *component,
154			      struct snd_pcm_substream *substream)
155{
156	struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
157	struct dma_chan *chan = pcm->chan[substream->stream];
158	int ret;
159
160	ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
161	if (ret)
162		return ret;
163
164	return snd_dmaengine_pcm_open(substream, chan);
165}
166
167static int dmaengine_pcm_close(struct snd_soc_component *component,
168			       struct snd_pcm_substream *substream)
169{
170	return snd_dmaengine_pcm_close(substream);
171}
172
173static int dmaengine_pcm_trigger(struct snd_soc_component *component,
174				 struct snd_pcm_substream *substream, int cmd)
175{
176	return snd_dmaengine_pcm_trigger(substream, cmd);
177}
178
179static struct dma_chan *dmaengine_pcm_compat_request_channel(
180	struct snd_soc_component *component,
181	struct snd_soc_pcm_runtime *rtd,
182	struct snd_pcm_substream *substream)
183{
184	struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
185	struct snd_dmaengine_dai_dma_data *dma_data;
186	dma_filter_fn fn = NULL;
187
188	if (rtd->num_cpus > 1) {
189		dev_err(rtd->dev,
190			"%s doesn't support Multi CPU yet\n", __func__);
191		return NULL;
192	}
193
194	dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
195
196	if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
197		return pcm->chan[0];
198
199	if (pcm->config && pcm->config->compat_request_channel)
200		return pcm->config->compat_request_channel(rtd, substream);
201
202	if (pcm->config)
203		fn = pcm->config->compat_filter_fn;
204
205	return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
206}
207
208static bool dmaengine_pcm_can_report_residue(struct device *dev,
209	struct dma_chan *chan)
210{
211	struct dma_slave_caps dma_caps;
212	int ret;
213
214	ret = dma_get_slave_caps(chan, &dma_caps);
215	if (ret != 0) {
216		dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
217			 ret);
218		return false;
219	}
220
221	if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
222		return false;
223
224	return true;
225}
226
227static int dmaengine_pcm_new(struct snd_soc_component *component,
228			     struct snd_soc_pcm_runtime *rtd)
229{
230	struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
231	const struct snd_dmaengine_pcm_config *config = pcm->config;
232	struct device *dev = component->dev;
233	struct snd_pcm_substream *substream;
234	size_t prealloc_buffer_size;
235	size_t max_buffer_size;
236	unsigned int i;
237
238	if (config && config->prealloc_buffer_size) {
239		prealloc_buffer_size = config->prealloc_buffer_size;
240		max_buffer_size = config->pcm_hardware->buffer_bytes_max;
241	} else {
242		prealloc_buffer_size = 512 * 1024;
243		max_buffer_size = SIZE_MAX;
244	}
245
246	for_each_pcm_streams(i) {
247		substream = rtd->pcm->streams[i].substream;
248		if (!substream)
249			continue;
250
251		if (!pcm->chan[i] && config && config->chan_names[i])
252			pcm->chan[i] = dma_request_slave_channel(dev,
253				config->chan_names[i]);
254
255		if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
256			pcm->chan[i] = dmaengine_pcm_compat_request_channel(
257				component, rtd, substream);
258		}
259
260		if (!pcm->chan[i]) {
261			dev_err(component->dev,
262				"Missing dma channel for stream: %d\n", i);
263			return -EINVAL;
264		}
265
266		snd_pcm_set_managed_buffer(substream,
267				SNDRV_DMA_TYPE_DEV_IRAM,
268				dmaengine_dma_dev(pcm, substream),
269				prealloc_buffer_size,
270				max_buffer_size);
271
272		if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
273			pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
274
275		if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
276			strscpy_pad(rtd->pcm->streams[i].pcm->name,
277				    rtd->pcm->streams[i].pcm->id,
278				    sizeof(rtd->pcm->streams[i].pcm->name));
279		}
280	}
281
282	return 0;
283}
284
285static snd_pcm_uframes_t dmaengine_pcm_pointer(
286	struct snd_soc_component *component,
287	struct snd_pcm_substream *substream)
288{
289	struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
290
291	if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
292		return snd_dmaengine_pcm_pointer_no_residue(substream);
293	else
294		return snd_dmaengine_pcm_pointer(substream);
295}
296
297static int dmaengine_copy_user(struct snd_soc_component *component,
298			       struct snd_pcm_substream *substream,
299			       int channel, unsigned long hwoff,
300			       void __user *buf, unsigned long bytes)
301{
302	struct snd_pcm_runtime *runtime = substream->runtime;
303	struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
304	int (*process)(struct snd_pcm_substream *substream,
305		       int channel, unsigned long hwoff,
306		       void *buf, unsigned long bytes) = pcm->config->process;
307	bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
308	void *dma_ptr = runtime->dma_area + hwoff +
309			channel * (runtime->dma_bytes / runtime->channels);
310	int ret;
311
312	if (is_playback)
313		if (copy_from_user(dma_ptr, buf, bytes))
314			return -EFAULT;
315
316	if (process) {
317		ret = process(substream, channel, hwoff, (__force void *)buf, bytes);
318		if (ret < 0)
319			return ret;
320	}
321
322	if (!is_playback)
323		if (copy_to_user(buf, dma_ptr, bytes))
324			return -EFAULT;
325
326	return 0;
327}
328
329static const struct snd_soc_component_driver dmaengine_pcm_component = {
330	.name		= SND_DMAENGINE_PCM_DRV_NAME,
331	.probe_order	= SND_SOC_COMP_ORDER_LATE,
332	.open		= dmaengine_pcm_open,
333	.close		= dmaengine_pcm_close,
334	.hw_params	= dmaengine_pcm_hw_params,
335	.trigger	= dmaengine_pcm_trigger,
336	.pointer	= dmaengine_pcm_pointer,
337	.pcm_construct	= dmaengine_pcm_new,
338};
339
340static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
341	.name		= SND_DMAENGINE_PCM_DRV_NAME,
342	.probe_order	= SND_SOC_COMP_ORDER_LATE,
343	.open		= dmaengine_pcm_open,
344	.close		= dmaengine_pcm_close,
345	.hw_params	= dmaengine_pcm_hw_params,
346	.trigger	= dmaengine_pcm_trigger,
347	.pointer	= dmaengine_pcm_pointer,
348	.copy_user	= dmaengine_copy_user,
349	.pcm_construct	= dmaengine_pcm_new,
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 && config->dma_dev && config->dma_dev->of_node)))
366		return 0;
367
368	if (config && 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 && 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
423/**
424 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
425 * @dev: The parent device for the PCM device
426 * @config: Platform specific PCM configuration
427 * @flags: Platform specific quirks
428 */
429int snd_dmaengine_pcm_register(struct device *dev,
430	const struct snd_dmaengine_pcm_config *config, unsigned int flags)
431{
432	const struct snd_soc_component_driver *driver;
433	struct dmaengine_pcm *pcm;
434	int ret;
435
436	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
437	if (!pcm)
438		return -ENOMEM;
439
440#ifdef CONFIG_DEBUG_FS
441	pcm->component.debugfs_prefix = "dma";
442#endif
443	pcm->config = config;
444	pcm->flags = flags;
445
446	ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
447	if (ret)
448		goto err_free_dma;
449
450	if (config && config->process)
451		driver = &dmaengine_pcm_component_process;
452	else
453		driver = &dmaengine_pcm_component;
454
455	ret = snd_soc_component_initialize(&pcm->component, driver, dev);
456	if (ret)
457		goto err_free_dma;
458
459	ret = snd_soc_add_component(&pcm->component, NULL, 0);
460	if (ret)
461		goto err_free_dma;
462
463	return 0;
464
465err_free_dma:
466	dmaengine_pcm_release_chan(pcm);
467	kfree(pcm);
468	return ret;
469}
470EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
471
472/**
473 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
474 * @dev: Parent device the PCM was register with
475 *
476 * Removes a dmaengine based PCM device previously registered with
477 * snd_dmaengine_pcm_register.
478 */
479void snd_dmaengine_pcm_unregister(struct device *dev)
480{
481	struct snd_soc_component *component;
482	struct dmaengine_pcm *pcm;
483
484	component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
485	if (!component)
486		return;
487
488	pcm = soc_component_to_pcm(component);
489
490	snd_soc_unregister_component_by_driver(dev, component->driver);
491	dmaengine_pcm_release_chan(pcm);
492	kfree(pcm);
493}
494EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
495
496MODULE_LICENSE("GPL");
497