1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2012, Analog Devices Inc.
4 * Author: Lars-Peter Clausen <lars@metafoo.de>
5 *
6 * Based on:
7 * imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
8 * mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
9 * ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
10 * Copyright (C) 2006 Applied Data Systems
11 */
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/dmaengine.h>
15 #include <linux/slab.h>
16 #include <sound/pcm.h>
17 #include <sound/pcm_params.h>
18 #include <sound/soc.h>
19
20 #include <sound/dmaengine_pcm.h>
21
22 struct dmaengine_pcm_runtime_data {
23 struct dma_chan *dma_chan;
24 dma_cookie_t cookie;
25
26 unsigned int pos;
27 };
28
29 static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
30 const struct snd_pcm_substream *substream)
31 {
32 return substream->runtime->private_data;
33 }
34
35 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
36 {
37 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
38
39 return prtd->dma_chan;
40 }
41 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
42
43 /**
44 * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
45 * @substream: PCM substream
46 * @params: hw_params
47 * @slave_config: DMA slave config
48 *
49 * This function can be used to initialize a dma_slave_config from a substream
50 * and hw_params in a dmaengine based PCM driver implementation.
51 *
52 * Return: zero if successful, or a negative error code
53 */
54 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
55 const struct snd_pcm_hw_params *params,
56 struct dma_slave_config *slave_config)
57 {
58 enum dma_slave_buswidth buswidth;
59 int bits;
60
61 bits = params_physical_width(params);
62 if (bits < 8 || bits > 64)
63 return -EINVAL;
64 else if (bits == 8)
65 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
66 else if (bits == 16)
67 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
68 else if (bits == 24)
69 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
70 else if (bits <= 32)
71 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
72 else
73 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
74
75 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
76 slave_config->direction = DMA_MEM_TO_DEV;
77 slave_config->dst_addr_width = buswidth;
78 } else {
79 slave_config->direction = DMA_DEV_TO_MEM;
80 slave_config->src_addr_width = buswidth;
81 }
82
83 slave_config->device_fc = false;
84
85 return 0;
86 }
87 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
88
89 /**
90 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
91 * using DAI DMA data.
92 * @substream: PCM substream
93 * @dma_data: DAI DMA data
94 * @slave_config: DMA slave configuration
95 *
96 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width
97 * fields of the DMA slave config from the same fields of the DAI DMA
98 * data struct. The src and dst fields will be initialized depending on the
99 * direction of the substream. If the substream is a playback stream the dst
100 * fields will be initialized, if it is a capture stream the src fields will be
101 * initialized. The {dst,src}_addr_width field will only be initialized if the
102 * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of
103 * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If
104 * both conditions are met the latter takes priority.
105 */
106 void snd_dmaengine_pcm_set_config_from_dai_data(
107 const struct snd_pcm_substream *substream,
108 const struct snd_dmaengine_dai_dma_data *dma_data,
109 struct dma_slave_config *slave_config)
110 {
111 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
112 slave_config->dst_addr = dma_data->addr;
113 slave_config->dst_maxburst = dma_data->maxburst;
114 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
115 slave_config->dst_addr_width =
116 DMA_SLAVE_BUSWIDTH_UNDEFINED;
117 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
118 slave_config->dst_addr_width = dma_data->addr_width;
119 } else {
120 slave_config->src_addr = dma_data->addr;
121 slave_config->src_maxburst = dma_data->maxburst;
122 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
123 slave_config->src_addr_width =
124 DMA_SLAVE_BUSWIDTH_UNDEFINED;
125 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
126 slave_config->src_addr_width = dma_data->addr_width;
127 }
128
129 slave_config->peripheral_config = dma_data->peripheral_config;
130 slave_config->peripheral_size = dma_data->peripheral_size;
131 }
132 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
133
134 static void dmaengine_pcm_dma_complete(void *arg)
135 {
136 unsigned int new_pos;
137 struct snd_pcm_substream *substream = arg;
138 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
139
140 new_pos = prtd->pos + snd_pcm_lib_period_bytes(substream);
141 if (new_pos >= snd_pcm_lib_buffer_bytes(substream))
142 new_pos = 0;
143 prtd->pos = new_pos;
144
145 snd_pcm_period_elapsed(substream);
146 }
147
148 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
149 {
150 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
151 struct dma_chan *chan = prtd->dma_chan;
152 struct dma_async_tx_descriptor *desc;
153 enum dma_transfer_direction direction;
154 unsigned long flags = DMA_CTRL_ACK;
155
156 direction = snd_pcm_substream_to_dma_direction(substream);
157
158 if (!substream->runtime->no_period_wakeup)
159 flags |= DMA_PREP_INTERRUPT;
160
161 prtd->pos = 0;
162 desc = dmaengine_prep_dma_cyclic(chan,
163 substream->runtime->dma_addr,
164 snd_pcm_lib_buffer_bytes(substream),
165 snd_pcm_lib_period_bytes(substream), direction, flags);
166
167 if (!desc)
168 return -ENOMEM;
169
170 desc->callback = dmaengine_pcm_dma_complete;
171 desc->callback_param = substream;
172 prtd->cookie = dmaengine_submit(desc);
173
174 return 0;
175 }
176
177 /**
178 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
179 * @substream: PCM substream
180 * @cmd: Trigger command
181 *
182 * This function can be used as the PCM trigger callback for dmaengine based PCM
183 * driver implementations.
184 *
185 * Return: 0 on success, a negative error code otherwise
186 */
187 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
188 {
189 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
190 struct snd_pcm_runtime *runtime = substream->runtime;
191 int ret;
192
193 switch (cmd) {
194 case SNDRV_PCM_TRIGGER_START:
195 ret = dmaengine_pcm_prepare_and_submit(substream);
196 if (ret)
197 return ret;
198 dma_async_issue_pending(prtd->dma_chan);
199 break;
200 case SNDRV_PCM_TRIGGER_RESUME:
201 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
202 dmaengine_resume(prtd->dma_chan);
203 break;
204 case SNDRV_PCM_TRIGGER_SUSPEND:
205 if (runtime->info & SNDRV_PCM_INFO_PAUSE)
206 dmaengine_pause(prtd->dma_chan);
207 else
208 dmaengine_terminate_async(prtd->dma_chan);
209 break;
210 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
211 dmaengine_pause(prtd->dma_chan);
212 break;
213 case SNDRV_PCM_TRIGGER_STOP:
214 dmaengine_terminate_async(prtd->dma_chan);
215 break;
216 default:
217 return -EINVAL;
218 }
219
220 return 0;
221 }
222 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
223
224 /**
225 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
226 * @substream: PCM substream
227 *
228 * This function is deprecated and should not be used by new drivers, as its
229 * results may be unreliable.
230 *
231 * Return: PCM position in frames
232 */
233 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
234 {
235 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
236 return bytes_to_frames(substream->runtime, prtd->pos);
237 }
238 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
239
240 /**
241 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
242 * @substream: PCM substream
243 *
244 * This function can be used as the PCM pointer callback for dmaengine based PCM
245 * driver implementations.
246 *
247 * Return: PCM position in frames
248 */
249 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
250 {
251 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
252 struct snd_pcm_runtime *runtime = substream->runtime;
253 struct dma_tx_state state;
254 enum dma_status status;
255 unsigned int buf_size;
256 unsigned int pos = 0;
257
258 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
259 if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
260 buf_size = snd_pcm_lib_buffer_bytes(substream);
261 if (state.residue > 0 && state.residue <= buf_size)
262 pos = buf_size - state.residue;
263
264 runtime->delay = bytes_to_frames(runtime,
265 state.in_flight_bytes);
266 }
267
268 return bytes_to_frames(runtime, pos);
269 }
270 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
271
272 /**
273 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
274 * @filter_fn: Filter function used to request the DMA channel
275 * @filter_data: Data passed to the DMA filter function
276 *
277 * This function request a DMA channel for usage with dmaengine PCM.
278 *
279 * Return: NULL or the requested DMA channel
280 */
281 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
282 void *filter_data)
283 {
284 dma_cap_mask_t mask;
285
286 dma_cap_zero(mask);
287 dma_cap_set(DMA_SLAVE, mask);
288 dma_cap_set(DMA_CYCLIC, mask);
289
290 return dma_request_channel(mask, filter_fn, filter_data);
291 }
292 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
293
294 /**
295 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
296 * @substream: PCM substream
297 * @chan: DMA channel to use for data transfers
298 *
299 * The function should usually be called from the pcm open callback. Note that
300 * this function will use private_data field of the substream's runtime. So it
301 * is not available to your pcm driver implementation.
302 *
303 * Return: 0 on success, a negative error code otherwise
304 */
305 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
306 struct dma_chan *chan)
307 {
308 struct dmaengine_pcm_runtime_data *prtd;
309 int ret;
310
311 if (!chan)
312 return -ENXIO;
313
314 ret = snd_pcm_hw_constraint_integer(substream->runtime,
315 SNDRV_PCM_HW_PARAM_PERIODS);
316 if (ret < 0)
317 return ret;
318
319 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
320 if (!prtd)
321 return -ENOMEM;
322
323 prtd->dma_chan = chan;
324
325 substream->runtime->private_data = prtd;
326
327 return 0;
328 }
329 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
330
331 /**
332 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
333 * @substream: PCM substream
334 * @filter_fn: Filter function used to request the DMA channel
335 * @filter_data: Data passed to the DMA filter function
336 *
337 * This function will request a DMA channel using the passed filter function and
338 * data. The function should usually be called from the pcm open callback. Note
339 * that this function will use private_data field of the substream's runtime. So
340 * it is not available to your pcm driver implementation.
341 *
342 * Return: 0 on success, a negative error code otherwise
343 */
344 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
345 dma_filter_fn filter_fn, void *filter_data)
346 {
347 return snd_dmaengine_pcm_open(substream,
348 snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
349 }
350 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
351
352 int snd_dmaengine_pcm_sync_stop(struct snd_pcm_substream *substream)
353 {
354 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
355 struct dma_tx_state state;
356 enum dma_status status;
357
358 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
359 if (status != DMA_PAUSED)
360 dmaengine_synchronize(prtd->dma_chan);
361
362 return 0;
363 }
364 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_sync_stop);
365
366 static void __snd_dmaengine_pcm_close(struct snd_pcm_substream *substream,
367 bool release_channel)
368 {
369 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
370 struct dma_tx_state state;
371 enum dma_status status;
372
373 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
374 if (status == DMA_PAUSED)
375 dmaengine_terminate_async(prtd->dma_chan);
376
377 dmaengine_synchronize(prtd->dma_chan);
378 if (release_channel)
379 dma_release_channel(prtd->dma_chan);
380 kfree(prtd);
381 }
382
383 /**
384 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
385 * @substream: PCM substream
386 *
387 * Return: 0 on success, a negative error code otherwise
388 */
389 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
390 {
391 __snd_dmaengine_pcm_close(substream, false);
392 return 0;
393 }
394 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
395
396 /**
397 * snd_dmaengine_pcm_close_release_chan - Close a dmaengine based PCM
398 * substream and release channel
399 * @substream: PCM substream
400 *
401 * Releases the DMA channel associated with the PCM substream.
402 *
403 * Return: zero if successful, or a negative error code
404 */
405 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
406 {
407 __snd_dmaengine_pcm_close(substream, true);
408 return 0;
409 }
410 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
411
412 /**
413 * snd_dmaengine_pcm_refine_runtime_hwparams - Refine runtime hw params
414 * @substream: PCM substream
415 * @dma_data: DAI DMA data
416 * @hw: PCM hw params
417 * @chan: DMA channel to use for data transfers
418 *
419 * This function will query DMA capability, then refine the pcm hardware
420 * parameters.
421 *
422 * Return: 0 on success, a negative error code otherwise
423 */
424 int snd_dmaengine_pcm_refine_runtime_hwparams(
425 struct snd_pcm_substream *substream,
426 struct snd_dmaengine_dai_dma_data *dma_data,
427 struct snd_pcm_hardware *hw,
428 struct dma_chan *chan)
429 {
430 struct dma_slave_caps dma_caps;
431 u32 addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
432 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
433 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
434 snd_pcm_format_t i;
435 int ret = 0;
436
437 if (!hw || !chan || !dma_data)
438 return -EINVAL;
439
440 ret = dma_get_slave_caps(chan, &dma_caps);
441 if (ret == 0) {
442 if (dma_caps.cmd_pause && dma_caps.cmd_resume)
443 hw->info |= SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME;
444 if (dma_caps.residue_granularity <= DMA_RESIDUE_GRANULARITY_SEGMENT)
445 hw->info |= SNDRV_PCM_INFO_BATCH;
446
447 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
448 addr_widths = dma_caps.dst_addr_widths;
449 else
450 addr_widths = dma_caps.src_addr_widths;
451 }
452
453 /*
454 * If SND_DMAENGINE_PCM_DAI_FLAG_PACK is set keep
455 * hw.formats set to 0, meaning no restrictions are in place.
456 * In this case it's the responsibility of the DAI driver to
457 * provide the supported format information.
458 */
459 if (!(dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK))
460 /*
461 * Prepare formats mask for valid/allowed sample types. If the
462 * dma does not have support for the given physical word size,
463 * it needs to be masked out so user space can not use the
464 * format which produces corrupted audio.
465 * In case the dma driver does not implement the slave_caps the
466 * default assumption is that it supports 1, 2 and 4 bytes
467 * widths.
468 */
469 pcm_for_each_format(i) {
470 int bits = snd_pcm_format_physical_width(i);
471
472 /*
473 * Enable only samples with DMA supported physical
474 * widths
475 */
476 switch (bits) {
477 case 8:
478 case 16:
479 case 24:
480 case 32:
481 case 64:
482 if (addr_widths & (1 << (bits / 8)))
483 hw->formats |= pcm_format_to_bits(i);
484 break;
485 default:
486 /* Unsupported types */
487 break;
488 }
489 }
490
491 return ret;
492 }
493 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_refine_runtime_hwparams);
494
495 MODULE_DESCRIPTION("PCM dmaengine helper APIs");
496 MODULE_LICENSE("GPL");
497
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