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 * Prepare formats mask for valid/allowed sample types. If the dma does
167 * not have support for the given physical word size, it needs to be
168 * masked out so user space can not use the format which produces
169 * corrupted audio.
170 * In case the dma driver does not implement the slave_caps the default
171 * assumption is that it supports 1, 2 and 4 bytes widths.
172 */
173 for (i = 0; i <= SNDRV_PCM_FORMAT_LAST; i++) {
174 int bits = snd_pcm_format_physical_width(i);
175
176 /* Enable only samples with DMA supported physical widths */
177 switch (bits) {
178 case 8:
179 case 16:
180 case 24:
181 case 32:
182 case 64:
183 if (addr_widths & (1 << (bits / 8)))
184 hw.formats |= (1LL << i);
185 break;
186 default:
187 /* Unsupported types */
188 break;
189 }
190 }
191
192 return snd_soc_set_runtime_hwparams(substream, &hw);
193 }
194
dmaengine_pcm_open(struct snd_pcm_substream * substream)195 static int dmaengine_pcm_open(struct snd_pcm_substream *substream)
196 {
197 struct snd_soc_pcm_runtime *rtd = substream->private_data;
198 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
199 struct dma_chan *chan = pcm->chan[substream->stream];
200 int ret;
201
202 ret = dmaengine_pcm_set_runtime_hwparams(substream);
203 if (ret)
204 return ret;
205
206 return snd_dmaengine_pcm_open(substream, chan);
207 }
208
dmaengine_pcm_compat_request_channel(struct snd_soc_pcm_runtime * rtd,struct snd_pcm_substream * substream)209 static struct dma_chan *dmaengine_pcm_compat_request_channel(
210 struct snd_soc_pcm_runtime *rtd,
211 struct snd_pcm_substream *substream)
212 {
213 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
214 struct snd_dmaengine_dai_dma_data *dma_data;
215 dma_filter_fn fn = NULL;
216
217 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
218
219 if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
220 return pcm->chan[0];
221
222 if (pcm->config && pcm->config->compat_request_channel)
223 return pcm->config->compat_request_channel(rtd, substream);
224
225 if (pcm->config)
226 fn = pcm->config->compat_filter_fn;
227
228 return snd_dmaengine_pcm_request_channel(fn, dma_data->filter_data);
229 }
230
dmaengine_pcm_can_report_residue(struct device * dev,struct dma_chan * chan)231 static bool dmaengine_pcm_can_report_residue(struct device *dev,
232 struct dma_chan *chan)
233 {
234 struct dma_slave_caps dma_caps;
235 int ret;
236
237 ret = dma_get_slave_caps(chan, &dma_caps);
238 if (ret != 0) {
239 dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
240 ret);
241 return false;
242 }
243
244 if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
245 return false;
246
247 return true;
248 }
249
dmaengine_pcm_new(struct snd_soc_pcm_runtime * rtd)250 static int dmaengine_pcm_new(struct snd_soc_pcm_runtime *rtd)
251 {
252 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
253 const struct snd_dmaengine_pcm_config *config = pcm->config;
254 struct device *dev = rtd->platform->dev;
255 struct snd_dmaengine_dai_dma_data *dma_data;
256 struct snd_pcm_substream *substream;
257 size_t prealloc_buffer_size;
258 size_t max_buffer_size;
259 unsigned int i;
260 int ret;
261
262 if (config && config->prealloc_buffer_size) {
263 prealloc_buffer_size = config->prealloc_buffer_size;
264 max_buffer_size = config->pcm_hardware->buffer_bytes_max;
265 } else {
266 prealloc_buffer_size = 512 * 1024;
267 max_buffer_size = SIZE_MAX;
268 }
269
270
271 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE; i++) {
272 substream = rtd->pcm->streams[i].substream;
273 if (!substream)
274 continue;
275
276 dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
277
278 if (!pcm->chan[i] &&
279 (pcm->flags & SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME))
280 pcm->chan[i] = dma_request_slave_channel(dev,
281 dma_data->chan_name);
282
283 if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
284 pcm->chan[i] = dmaengine_pcm_compat_request_channel(rtd,
285 substream);
286 }
287
288 if (!pcm->chan[i]) {
289 dev_err(rtd->platform->dev,
290 "Missing dma channel for stream: %d\n", i);
291 return -EINVAL;
292 }
293
294 ret = snd_pcm_lib_preallocate_pages(substream,
295 SNDRV_DMA_TYPE_DEV_IRAM,
296 dmaengine_dma_dev(pcm, substream),
297 prealloc_buffer_size,
298 max_buffer_size);
299 if (ret)
300 return ret;
301
302 if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
303 pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
304
305 if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
306 strncpy(rtd->pcm->streams[i].pcm->name,
307 rtd->pcm->streams[i].pcm->id,
308 sizeof(rtd->pcm->streams[i].pcm->name));
309 }
310 }
311
312 return 0;
313 }
314
dmaengine_pcm_pointer(struct snd_pcm_substream * substream)315 static snd_pcm_uframes_t dmaengine_pcm_pointer(
316 struct snd_pcm_substream *substream)
317 {
318 struct snd_soc_pcm_runtime *rtd = substream->private_data;
319 struct dmaengine_pcm *pcm = soc_platform_to_pcm(rtd->platform);
320
321 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
322 return snd_dmaengine_pcm_pointer_no_residue(substream);
323 else
324 return snd_dmaengine_pcm_pointer(substream);
325 }
326
327 static const struct snd_pcm_ops dmaengine_pcm_ops = {
328 .open = dmaengine_pcm_open,
329 .close = snd_dmaengine_pcm_close,
330 .ioctl = snd_pcm_lib_ioctl,
331 .hw_params = dmaengine_pcm_hw_params,
332 .hw_free = snd_pcm_lib_free_pages,
333 .trigger = snd_dmaengine_pcm_trigger,
334 .pointer = dmaengine_pcm_pointer,
335 };
336
337 static const struct snd_soc_platform_driver dmaengine_pcm_platform = {
338 .component_driver = {
339 .probe_order = SND_SOC_COMP_ORDER_LATE,
340 },
341 .ops = &dmaengine_pcm_ops,
342 .pcm_new = dmaengine_pcm_new,
343 };
344
345 static const char * const dmaengine_pcm_dma_channel_names[] = {
346 [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
347 [SNDRV_PCM_STREAM_CAPTURE] = "rx",
348 };
349
dmaengine_pcm_request_chan_of(struct dmaengine_pcm * pcm,struct device * dev,const struct snd_dmaengine_pcm_config * config)350 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
351 struct device *dev, const struct snd_dmaengine_pcm_config *config)
352 {
353 unsigned int i;
354 const char *name;
355 struct dma_chan *chan;
356
357 if ((pcm->flags & (SND_DMAENGINE_PCM_FLAG_NO_DT |
358 SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME)) ||
359 !dev->of_node)
360 return 0;
361
362 if (config && config->dma_dev) {
363 /*
364 * If this warning is seen, it probably means that your Linux
365 * device structure does not match your HW device structure.
366 * It would be best to refactor the Linux device structure to
367 * correctly match the HW structure.
368 */
369 dev_warn(dev, "DMA channels sourced from device %s",
370 dev_name(config->dma_dev));
371 dev = config->dma_dev;
372 }
373
374 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
375 i++) {
376 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
377 name = "rx-tx";
378 else
379 name = dmaengine_pcm_dma_channel_names[i];
380 if (config && config->chan_names[i])
381 name = config->chan_names[i];
382 chan = dma_request_slave_channel_reason(dev, name);
383 if (IS_ERR(chan)) {
384 if (PTR_ERR(chan) == -EPROBE_DEFER)
385 return -EPROBE_DEFER;
386 pcm->chan[i] = NULL;
387 } else {
388 pcm->chan[i] = chan;
389 }
390 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
391 break;
392 }
393
394 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
395 pcm->chan[1] = pcm->chan[0];
396
397 return 0;
398 }
399
dmaengine_pcm_release_chan(struct dmaengine_pcm * pcm)400 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
401 {
402 unsigned int i;
403
404 for (i = SNDRV_PCM_STREAM_PLAYBACK; i <= SNDRV_PCM_STREAM_CAPTURE;
405 i++) {
406 if (!pcm->chan[i])
407 continue;
408 dma_release_channel(pcm->chan[i]);
409 if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
410 break;
411 }
412 }
413
414 /**
415 * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
416 * @dev: The parent device for the PCM device
417 * @config: Platform specific PCM configuration
418 * @flags: Platform specific quirks
419 */
snd_dmaengine_pcm_register(struct device * dev,const struct snd_dmaengine_pcm_config * config,unsigned int flags)420 int snd_dmaengine_pcm_register(struct device *dev,
421 const struct snd_dmaengine_pcm_config *config, unsigned int flags)
422 {
423 struct dmaengine_pcm *pcm;
424 int ret;
425
426 pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
427 if (!pcm)
428 return -ENOMEM;
429
430 pcm->config = config;
431 pcm->flags = flags;
432
433 ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
434 if (ret)
435 goto err_free_dma;
436
437 ret = snd_soc_add_platform(dev, &pcm->platform,
438 &dmaengine_pcm_platform);
439 if (ret)
440 goto err_free_dma;
441
442 return 0;
443
444 err_free_dma:
445 dmaengine_pcm_release_chan(pcm);
446 kfree(pcm);
447 return ret;
448 }
449 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
450
451 /**
452 * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
453 * @dev: Parent device the PCM was register with
454 *
455 * Removes a dmaengine based PCM device previously registered with
456 * snd_dmaengine_pcm_register.
457 */
snd_dmaengine_pcm_unregister(struct device * dev)458 void snd_dmaengine_pcm_unregister(struct device *dev)
459 {
460 struct snd_soc_platform *platform;
461 struct dmaengine_pcm *pcm;
462
463 platform = snd_soc_lookup_platform(dev);
464 if (!platform)
465 return;
466
467 pcm = soc_platform_to_pcm(platform);
468
469 snd_soc_remove_platform(platform);
470 dmaengine_pcm_release_chan(pcm);
471 kfree(pcm);
472 }
473 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
474
475 MODULE_LICENSE("GPL");
476