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 | config: 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(p: 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, config: &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(p: 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 | hw: 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(dev: 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: &hw, |
143 | chan); |
144 | |
145 | return snd_soc_set_runtime_hwparams(substream, hw: &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(p: 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(p: 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(filter_fn: pcm->config->compat_filter_fn, |
197 | filter_data: 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, caps: &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(p: 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 | name: 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 | data: dmaengine_dma_dev(pcm, substream), |
262 | size: prealloc_buffer_size, |
263 | max: max_buffer_size); |
264 | |
265 | if (!dmaengine_pcm_can_report_residue(dev, chan: 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(dest: rtd->pcm->streams[i].pcm->name, |
270 | src: rtd->pcm->streams[i].pcm->id, |
271 | count: 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(p: 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(p: 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(addr: dma_ptr, bytes, i: 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(addr: dma_ptr, bytes, i: iter) != bytes) |
316 | return -EFAULT; |
317 | |
318 | return 0; |
319 | } |
320 | |
321 | static const struct snd_soc_component_driver dmaengine_pcm_component = { |
322 | .name = SND_DMAENGINE_PCM_DRV_NAME, |
323 | .probe_order = SND_SOC_COMP_ORDER_LATE, |
324 | .open = dmaengine_pcm_open, |
325 | .close = dmaengine_pcm_close, |
326 | .hw_params = dmaengine_pcm_hw_params, |
327 | .trigger = dmaengine_pcm_trigger, |
328 | .pointer = dmaengine_pcm_pointer, |
329 | .pcm_construct = dmaengine_pcm_new, |
330 | }; |
331 | |
332 | static const struct snd_soc_component_driver dmaengine_pcm_component_process = { |
333 | .name = SND_DMAENGINE_PCM_DRV_NAME, |
334 | .probe_order = SND_SOC_COMP_ORDER_LATE, |
335 | .open = dmaengine_pcm_open, |
336 | .close = dmaengine_pcm_close, |
337 | .hw_params = dmaengine_pcm_hw_params, |
338 | .trigger = dmaengine_pcm_trigger, |
339 | .pointer = dmaengine_pcm_pointer, |
340 | .copy = dmaengine_copy, |
341 | .pcm_construct = dmaengine_pcm_new, |
342 | }; |
343 | |
344 | static const char * const dmaengine_pcm_dma_channel_names[] = { |
345 | [SNDRV_PCM_STREAM_PLAYBACK] = "tx" , |
346 | [SNDRV_PCM_STREAM_CAPTURE] = "rx" , |
347 | }; |
348 | |
349 | static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, |
350 | struct device *dev, const struct snd_dmaengine_pcm_config *config) |
351 | { |
352 | unsigned int i; |
353 | const char *name; |
354 | struct dma_chan *chan; |
355 | |
356 | if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && |
357 | !(config->dma_dev && config->dma_dev->of_node))) |
358 | return 0; |
359 | |
360 | if (config->dma_dev) { |
361 | /* |
362 | * If this warning is seen, it probably means that your Linux |
363 | * device structure does not match your HW device structure. |
364 | * It would be best to refactor the Linux device structure to |
365 | * correctly match the HW structure. |
366 | */ |
367 | dev_warn(dev, "DMA channels sourced from device %s" , |
368 | dev_name(config->dma_dev)); |
369 | dev = config->dma_dev; |
370 | } |
371 | |
372 | for_each_pcm_streams(i) { |
373 | if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) |
374 | name = "rx-tx" ; |
375 | else |
376 | name = dmaengine_pcm_dma_channel_names[i]; |
377 | if (config->chan_names[i]) |
378 | name = config->chan_names[i]; |
379 | chan = dma_request_chan(dev, name); |
380 | if (IS_ERR(ptr: chan)) { |
381 | /* |
382 | * Only report probe deferral errors, channels |
383 | * might not be present for devices that |
384 | * support only TX or only RX. |
385 | */ |
386 | if (PTR_ERR(ptr: chan) == -EPROBE_DEFER) |
387 | return -EPROBE_DEFER; |
388 | pcm->chan[i] = NULL; |
389 | } else { |
390 | pcm->chan[i] = chan; |
391 | } |
392 | if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) |
393 | break; |
394 | } |
395 | |
396 | if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) |
397 | pcm->chan[1] = pcm->chan[0]; |
398 | |
399 | return 0; |
400 | } |
401 | |
402 | static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) |
403 | { |
404 | unsigned int i; |
405 | |
406 | for_each_pcm_streams(i) { |
407 | if (!pcm->chan[i]) |
408 | continue; |
409 | dma_release_channel(chan: pcm->chan[i]); |
410 | if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) |
411 | break; |
412 | } |
413 | } |
414 | |
415 | static const struct snd_dmaengine_pcm_config snd_dmaengine_pcm_default_config = { |
416 | .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config, |
417 | }; |
418 | |
419 | /** |
420 | * snd_dmaengine_pcm_register - Register a dmaengine based PCM device |
421 | * @dev: The parent device for the PCM device |
422 | * @config: Platform specific PCM configuration |
423 | * @flags: Platform specific quirks |
424 | */ |
425 | int snd_dmaengine_pcm_register(struct device *dev, |
426 | const struct snd_dmaengine_pcm_config *config, unsigned int flags) |
427 | { |
428 | const struct snd_soc_component_driver *driver; |
429 | struct dmaengine_pcm *pcm; |
430 | int ret; |
431 | |
432 | pcm = kzalloc(size: sizeof(*pcm), GFP_KERNEL); |
433 | if (!pcm) |
434 | return -ENOMEM; |
435 | |
436 | #ifdef CONFIG_DEBUG_FS |
437 | pcm->component.debugfs_prefix = "dma" ; |
438 | #endif |
439 | if (!config) |
440 | config = &snd_dmaengine_pcm_default_config; |
441 | pcm->config = config; |
442 | pcm->flags = flags; |
443 | |
444 | ret = dmaengine_pcm_request_chan_of(pcm, dev, config); |
445 | if (ret) |
446 | goto err_free_dma; |
447 | |
448 | if (config->process) |
449 | driver = &dmaengine_pcm_component_process; |
450 | else |
451 | driver = &dmaengine_pcm_component; |
452 | |
453 | ret = snd_soc_component_initialize(component: &pcm->component, driver, dev); |
454 | if (ret) |
455 | goto err_free_dma; |
456 | |
457 | ret = snd_soc_add_component(component: &pcm->component, NULL, num_dai: 0); |
458 | if (ret) |
459 | goto err_free_dma; |
460 | |
461 | return 0; |
462 | |
463 | err_free_dma: |
464 | dmaengine_pcm_release_chan(pcm); |
465 | kfree(objp: pcm); |
466 | return ret; |
467 | } |
468 | EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); |
469 | |
470 | /** |
471 | * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device |
472 | * @dev: Parent device the PCM was register with |
473 | * |
474 | * Removes a dmaengine based PCM device previously registered with |
475 | * snd_dmaengine_pcm_register. |
476 | */ |
477 | void snd_dmaengine_pcm_unregister(struct device *dev) |
478 | { |
479 | struct snd_soc_component *component; |
480 | struct dmaengine_pcm *pcm; |
481 | |
482 | component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); |
483 | if (!component) |
484 | return; |
485 | |
486 | pcm = soc_component_to_pcm(p: component); |
487 | |
488 | snd_soc_unregister_component_by_driver(dev, component_driver: component->driver); |
489 | dmaengine_pcm_release_chan(pcm); |
490 | kfree(objp: pcm); |
491 | } |
492 | EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); |
493 | |
494 | MODULE_LICENSE("GPL" ); |
495 | |