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1/*
2 * Copyright (C) 2012, Analog Devices Inc.
3 * Author: Lars-Peter Clausen <lars@metafoo.de>
4 *
5 * Based on:
6 * imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
7 * mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
8 * ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
9 * Copyright (C) 2006 Applied Data Systems
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 */
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/dmaengine.h>
24#include <linux/slab.h>
25#include <sound/pcm.h>
26#include <sound/pcm_params.h>
27#include <sound/soc.h>
28
29#include <sound/dmaengine_pcm.h>
30
31struct dmaengine_pcm_runtime_data {
32 struct dma_chan *dma_chan;
33 dma_cookie_t cookie;
34
35 unsigned int pos;
36};
37
38static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
39 const struct snd_pcm_substream *substream)
40{
41 return substream->runtime->private_data;
42}
43
44struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
45{
46 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
47
48 return prtd->dma_chan;
49}
50EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
51
52/**
53 * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
54 * @substream: PCM substream
55 * @params: hw_params
56 * @slave_config: DMA slave config
57 *
58 * This function can be used to initialize a dma_slave_config from a substream
59 * and hw_params in a dmaengine based PCM driver implementation.
60 */
61int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
62 const struct snd_pcm_hw_params *params,
63 struct dma_slave_config *slave_config)
64{
65 enum dma_slave_buswidth buswidth;
66 int bits;
67
68 bits = snd_pcm_format_physical_width(params_format(params));
69 if (bits < 8 || bits > 64)
70 return -EINVAL;
71 else if (bits == 8)
72 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
73 else if (bits == 16)
74 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
75 else if (bits <= 32)
76 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
77 else
78 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
79
80 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
81 slave_config->direction = DMA_MEM_TO_DEV;
82 slave_config->dst_addr_width = buswidth;
83 } else {
84 slave_config->direction = DMA_DEV_TO_MEM;
85 slave_config->src_addr_width = buswidth;
86 }
87
88 slave_config->device_fc = false;
89
90 return 0;
91}
92EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
93
94/**
95 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
96 * using DAI DMA data.
97 * @substream: PCM substream
98 * @dma_data: DAI DMA data
99 * @slave_config: DMA slave configuration
100 *
101 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
102 * slave_id fields of the DMA slave config from the same fields of the DAI DMA
103 * data struct. The src and dst fields will be initialized depending on the
104 * direction of the substream. If the substream is a playback stream the dst
105 * fields will be initialized, if it is a capture stream the src fields will be
106 * initialized. The {dst,src}_addr_width field will only be initialized if the
107 * addr_width field of the DAI DMA data struct is not equal to
108 * DMA_SLAVE_BUSWIDTH_UNDEFINED.
109 */
110void snd_dmaengine_pcm_set_config_from_dai_data(
111 const struct snd_pcm_substream *substream,
112 const struct snd_dmaengine_dai_dma_data *dma_data,
113 struct dma_slave_config *slave_config)
114{
115 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
116 slave_config->dst_addr = dma_data->addr;
117 slave_config->dst_maxburst = dma_data->maxburst;
118 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
119 slave_config->dst_addr_width = dma_data->addr_width;
120 } else {
121 slave_config->src_addr = dma_data->addr;
122 slave_config->src_maxburst = dma_data->maxburst;
123 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
124 slave_config->src_addr_width = dma_data->addr_width;
125 }
126
127 slave_config->slave_id = dma_data->slave_id;
128}
129EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
130
131static void dmaengine_pcm_dma_complete(void *arg)
132{
133 struct snd_pcm_substream *substream = arg;
134 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
135
136 prtd->pos += snd_pcm_lib_period_bytes(substream);
137 if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
138 prtd->pos = 0;
139
140 snd_pcm_period_elapsed(substream);
141}
142
143static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
144{
145 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
146 struct dma_chan *chan = prtd->dma_chan;
147 struct dma_async_tx_descriptor *desc;
148 enum dma_transfer_direction direction;
149 unsigned long flags = DMA_CTRL_ACK;
150
151 direction = snd_pcm_substream_to_dma_direction(substream);
152
153 if (!substream->runtime->no_period_wakeup)
154 flags |= DMA_PREP_INTERRUPT;
155
156 prtd->pos = 0;
157 desc = dmaengine_prep_dma_cyclic(chan,
158 substream->runtime->dma_addr,
159 snd_pcm_lib_buffer_bytes(substream),
160 snd_pcm_lib_period_bytes(substream), direction, flags);
161
162 if (!desc)
163 return -ENOMEM;
164
165 desc->callback = dmaengine_pcm_dma_complete;
166 desc->callback_param = substream;
167 prtd->cookie = dmaengine_submit(desc);
168
169 return 0;
170}
171
172/**
173 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
174 * @substream: PCM substream
175 * @cmd: Trigger command
176 *
177 * Returns 0 on success, a negative error code otherwise.
178 *
179 * This function can be used as the PCM trigger callback for dmaengine based PCM
180 * driver implementations.
181 */
182int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
183{
184 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
185 struct snd_pcm_runtime *runtime = substream->runtime;
186 int ret;
187
188 switch (cmd) {
189 case SNDRV_PCM_TRIGGER_START:
190 ret = dmaengine_pcm_prepare_and_submit(substream);
191 if (ret)
192 return ret;
193 dma_async_issue_pending(prtd->dma_chan);
194 break;
195 case SNDRV_PCM_TRIGGER_RESUME:
196 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
197 dmaengine_resume(prtd->dma_chan);
198 break;
199 case SNDRV_PCM_TRIGGER_SUSPEND:
200 if (runtime->info & SNDRV_PCM_INFO_PAUSE)
201 dmaengine_pause(prtd->dma_chan);
202 else
203 dmaengine_terminate_all(prtd->dma_chan);
204 break;
205 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
206 dmaengine_pause(prtd->dma_chan);
207 break;
208 case SNDRV_PCM_TRIGGER_STOP:
209 dmaengine_terminate_all(prtd->dma_chan);
210 break;
211 default:
212 return -EINVAL;
213 }
214
215 return 0;
216}
217EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
218
219/**
220 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
221 * @substream: PCM substream
222 *
223 * This function is deprecated and should not be used by new drivers, as its
224 * results may be unreliable.
225 */
226snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
227{
228 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
229 return bytes_to_frames(substream->runtime, prtd->pos);
230}
231EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
232
233/**
234 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
235 * @substream: PCM substream
236 *
237 * This function can be used as the PCM pointer callback for dmaengine based PCM
238 * driver implementations.
239 */
240snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
241{
242 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
243 struct dma_tx_state state;
244 enum dma_status status;
245 unsigned int buf_size;
246 unsigned int pos = 0;
247
248 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
249 if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
250 buf_size = snd_pcm_lib_buffer_bytes(substream);
251 if (state.residue > 0 && state.residue <= buf_size)
252 pos = buf_size - state.residue;
253 }
254
255 return bytes_to_frames(substream->runtime, pos);
256}
257EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
258
259/**
260 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
261 * @filter_fn: Filter function used to request the DMA channel
262 * @filter_data: Data passed to the DMA filter function
263 *
264 * Returns NULL or the requested DMA channel.
265 *
266 * This function request a DMA channel for usage with dmaengine PCM.
267 */
268struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
269 void *filter_data)
270{
271 dma_cap_mask_t mask;
272
273 dma_cap_zero(mask);
274 dma_cap_set(DMA_SLAVE, mask);
275 dma_cap_set(DMA_CYCLIC, mask);
276
277 return dma_request_channel(mask, filter_fn, filter_data);
278}
279EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
280
281/**
282 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
283 * @substream: PCM substream
284 * @chan: DMA channel to use for data transfers
285 *
286 * Returns 0 on success, a negative error code otherwise.
287 *
288 * The function should usually be called from the pcm open callback. Note that
289 * this function will use private_data field of the substream's runtime. So it
290 * is not availabe to your pcm driver implementation.
291 */
292int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
293 struct dma_chan *chan)
294{
295 struct dmaengine_pcm_runtime_data *prtd;
296 int ret;
297
298 if (!chan)
299 return -ENXIO;
300
301 ret = snd_pcm_hw_constraint_integer(substream->runtime,
302 SNDRV_PCM_HW_PARAM_PERIODS);
303 if (ret < 0)
304 return ret;
305
306 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
307 if (!prtd)
308 return -ENOMEM;
309
310 prtd->dma_chan = chan;
311
312 substream->runtime->private_data = prtd;
313
314 return 0;
315}
316EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
317
318/**
319 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
320 * @substream: PCM substream
321 * @filter_fn: Filter function used to request the DMA channel
322 * @filter_data: Data passed to the DMA filter function
323 *
324 * Returns 0 on success, a negative error code otherwise.
325 *
326 * This function will request a DMA channel using the passed filter function and
327 * data. The function should usually be called from the pcm open callback. Note
328 * that this function will use private_data field of the substream's runtime. So
329 * it is not availabe to your pcm driver implementation.
330 */
331int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
332 dma_filter_fn filter_fn, void *filter_data)
333{
334 return snd_dmaengine_pcm_open(substream,
335 snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
336}
337EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
338
339/**
340 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
341 * @substream: PCM substream
342 */
343int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
344{
345 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
346
347 kfree(prtd);
348
349 return 0;
350}
351EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
352
353/**
354 * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
355 * @substream: PCM substream
356 *
357 * Releases the DMA channel associated with the PCM substream.
358 */
359int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
360{
361 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
362
363 dma_release_channel(prtd->dma_chan);
364
365 return snd_dmaengine_pcm_close(substream);
366}
367EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
368
369MODULE_LICENSE("GPL");
1/*
2 * Copyright (C) 2012, Analog Devices Inc.
3 * Author: Lars-Peter Clausen <lars@metafoo.de>
4 *
5 * Based on:
6 * imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
7 * mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
8 * ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
9 * Copyright (C) 2006 Applied Data Systems
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the License, or (at your
14 * option) any later version.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 */
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/dmaengine.h>
24#include <linux/slab.h>
25#include <sound/pcm.h>
26#include <sound/pcm_params.h>
27#include <sound/soc.h>
28
29#include <sound/dmaengine_pcm.h>
30
31struct dmaengine_pcm_runtime_data {
32 struct dma_chan *dma_chan;
33 dma_cookie_t cookie;
34
35 unsigned int pos;
36};
37
38static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
39 const struct snd_pcm_substream *substream)
40{
41 return substream->runtime->private_data;
42}
43
44struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
45{
46 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
47
48 return prtd->dma_chan;
49}
50EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);
51
52/**
53 * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
54 * @substream: PCM substream
55 * @params: hw_params
56 * @slave_config: DMA slave config
57 *
58 * This function can be used to initialize a dma_slave_config from a substream
59 * and hw_params in a dmaengine based PCM driver implementation.
60 */
61int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
62 const struct snd_pcm_hw_params *params,
63 struct dma_slave_config *slave_config)
64{
65 enum dma_slave_buswidth buswidth;
66 int bits;
67
68 bits = params_physical_width(params);
69 if (bits < 8 || bits > 64)
70 return -EINVAL;
71 else if (bits == 8)
72 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
73 else if (bits == 16)
74 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
75 else if (bits == 24)
76 buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
77 else if (bits <= 32)
78 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
79 else
80 buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;
81
82 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
83 slave_config->direction = DMA_MEM_TO_DEV;
84 slave_config->dst_addr_width = buswidth;
85 } else {
86 slave_config->direction = DMA_DEV_TO_MEM;
87 slave_config->src_addr_width = buswidth;
88 }
89
90 slave_config->device_fc = false;
91
92 return 0;
93}
94EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
95
96/**
97 * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
98 * using DAI DMA data.
99 * @substream: PCM substream
100 * @dma_data: DAI DMA data
101 * @slave_config: DMA slave configuration
102 *
103 * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
104 * slave_id fields of the DMA slave config from the same fields of the DAI DMA
105 * data struct. The src and dst fields will be initialized depending on the
106 * direction of the substream. If the substream is a playback stream the dst
107 * fields will be initialized, if it is a capture stream the src fields will be
108 * initialized. The {dst,src}_addr_width field will only be initialized if the
109 * SND_DMAENGINE_PCM_DAI_FLAG_PACK flag is set or if the addr_width field of
110 * the DAI DMA data struct is not equal to DMA_SLAVE_BUSWIDTH_UNDEFINED. If
111 * both conditions are met the latter takes priority.
112 */
113void snd_dmaengine_pcm_set_config_from_dai_data(
114 const struct snd_pcm_substream *substream,
115 const struct snd_dmaengine_dai_dma_data *dma_data,
116 struct dma_slave_config *slave_config)
117{
118 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
119 slave_config->dst_addr = dma_data->addr;
120 slave_config->dst_maxburst = dma_data->maxburst;
121 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
122 slave_config->dst_addr_width =
123 DMA_SLAVE_BUSWIDTH_UNDEFINED;
124 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
125 slave_config->dst_addr_width = dma_data->addr_width;
126 } else {
127 slave_config->src_addr = dma_data->addr;
128 slave_config->src_maxburst = dma_data->maxburst;
129 if (dma_data->flags & SND_DMAENGINE_PCM_DAI_FLAG_PACK)
130 slave_config->src_addr_width =
131 DMA_SLAVE_BUSWIDTH_UNDEFINED;
132 if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
133 slave_config->src_addr_width = dma_data->addr_width;
134 }
135
136 slave_config->slave_id = dma_data->slave_id;
137}
138EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
139
140static void dmaengine_pcm_dma_complete(void *arg)
141{
142 struct snd_pcm_substream *substream = arg;
143 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
144
145 prtd->pos += snd_pcm_lib_period_bytes(substream);
146 if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
147 prtd->pos = 0;
148
149 snd_pcm_period_elapsed(substream);
150}
151
152static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
153{
154 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
155 struct dma_chan *chan = prtd->dma_chan;
156 struct dma_async_tx_descriptor *desc;
157 enum dma_transfer_direction direction;
158 unsigned long flags = DMA_CTRL_ACK;
159
160 direction = snd_pcm_substream_to_dma_direction(substream);
161
162 if (!substream->runtime->no_period_wakeup)
163 flags |= DMA_PREP_INTERRUPT;
164
165 prtd->pos = 0;
166 desc = dmaengine_prep_dma_cyclic(chan,
167 substream->runtime->dma_addr,
168 snd_pcm_lib_buffer_bytes(substream),
169 snd_pcm_lib_period_bytes(substream), direction, flags);
170
171 if (!desc)
172 return -ENOMEM;
173
174 desc->callback = dmaengine_pcm_dma_complete;
175 desc->callback_param = substream;
176 prtd->cookie = dmaengine_submit(desc);
177
178 return 0;
179}
180
181/**
182 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
183 * @substream: PCM substream
184 * @cmd: Trigger command
185 *
186 * Returns 0 on success, a negative error code otherwise.
187 *
188 * This function can be used as the PCM trigger callback for dmaengine based PCM
189 * driver implementations.
190 */
191int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
192{
193 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
194 struct snd_pcm_runtime *runtime = substream->runtime;
195 int ret;
196
197 switch (cmd) {
198 case SNDRV_PCM_TRIGGER_START:
199 ret = dmaengine_pcm_prepare_and_submit(substream);
200 if (ret)
201 return ret;
202 dma_async_issue_pending(prtd->dma_chan);
203 break;
204 case SNDRV_PCM_TRIGGER_RESUME:
205 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
206 dmaengine_resume(prtd->dma_chan);
207 break;
208 case SNDRV_PCM_TRIGGER_SUSPEND:
209 if (runtime->info & SNDRV_PCM_INFO_PAUSE)
210 dmaengine_pause(prtd->dma_chan);
211 else
212 dmaengine_terminate_async(prtd->dma_chan);
213 break;
214 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
215 dmaengine_pause(prtd->dma_chan);
216 break;
217 case SNDRV_PCM_TRIGGER_STOP:
218 dmaengine_terminate_async(prtd->dma_chan);
219 break;
220 default:
221 return -EINVAL;
222 }
223
224 return 0;
225}
226EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
227
228/**
229 * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
230 * @substream: PCM substream
231 *
232 * This function is deprecated and should not be used by new drivers, as its
233 * results may be unreliable.
234 */
235snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
236{
237 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
238 return bytes_to_frames(substream->runtime, prtd->pos);
239}
240EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
241
242/**
243 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
244 * @substream: PCM substream
245 *
246 * This function can be used as the PCM pointer callback for dmaengine based PCM
247 * driver implementations.
248 */
249snd_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 dma_tx_state state;
253 enum dma_status status;
254 unsigned int buf_size;
255 unsigned int pos = 0;
256
257 status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
258 if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
259 buf_size = snd_pcm_lib_buffer_bytes(substream);
260 if (state.residue > 0 && state.residue <= buf_size)
261 pos = buf_size - state.residue;
262 }
263
264 return bytes_to_frames(substream->runtime, pos);
265}
266EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
267
268/**
269 * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
270 * @filter_fn: Filter function used to request the DMA channel
271 * @filter_data: Data passed to the DMA filter function
272 *
273 * Returns NULL or the requested DMA channel.
274 *
275 * This function request a DMA channel for usage with dmaengine PCM.
276 */
277struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
278 void *filter_data)
279{
280 dma_cap_mask_t mask;
281
282 dma_cap_zero(mask);
283 dma_cap_set(DMA_SLAVE, mask);
284 dma_cap_set(DMA_CYCLIC, mask);
285
286 return dma_request_channel(mask, filter_fn, filter_data);
287}
288EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
289
290/**
291 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
292 * @substream: PCM substream
293 * @chan: DMA channel to use for data transfers
294 *
295 * Returns 0 on success, a negative error code otherwise.
296 *
297 * The function should usually be called from the pcm open callback. Note that
298 * this function will use private_data field of the substream's runtime. So it
299 * is not available to your pcm driver implementation.
300 */
301int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
302 struct dma_chan *chan)
303{
304 struct dmaengine_pcm_runtime_data *prtd;
305 int ret;
306
307 if (!chan)
308 return -ENXIO;
309
310 ret = snd_pcm_hw_constraint_integer(substream->runtime,
311 SNDRV_PCM_HW_PARAM_PERIODS);
312 if (ret < 0)
313 return ret;
314
315 prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
316 if (!prtd)
317 return -ENOMEM;
318
319 prtd->dma_chan = chan;
320
321 substream->runtime->private_data = prtd;
322
323 return 0;
324}
325EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
326
327/**
328 * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
329 * @substream: PCM substream
330 * @filter_fn: Filter function used to request the DMA channel
331 * @filter_data: Data passed to the DMA filter function
332 *
333 * Returns 0 on success, a negative error code otherwise.
334 *
335 * This function will request a DMA channel using the passed filter function and
336 * data. The function should usually be called from the pcm open callback. Note
337 * that this function will use private_data field of the substream's runtime. So
338 * it is not available to your pcm driver implementation.
339 */
340int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
341 dma_filter_fn filter_fn, void *filter_data)
342{
343 return snd_dmaengine_pcm_open(substream,
344 snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
345}
346EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
347
348/**
349 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
350 * @substream: PCM substream
351 */
352int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
353{
354 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
355
356 dmaengine_synchronize(prtd->dma_chan);
357 kfree(prtd);
358
359 return 0;
360}
361EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
362
363/**
364 * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
365 * @substream: PCM substream
366 *
367 * Releases the DMA channel associated with the PCM substream.
368 */
369int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
370{
371 struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
372
373 dmaengine_synchronize(prtd->dma_chan);
374 dma_release_channel(prtd->dma_chan);
375 kfree(prtd);
376
377 return 0;
378}
379EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
380
381MODULE_LICENSE("GPL");