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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 
31 struct dmaengine_pcm_runtime_data {
32 	struct dma_chan *dma_chan;
33 	dma_cookie_t cookie;
34 
35 	unsigned int pos;
36 };
37 
substream_to_prtd(const struct snd_pcm_substream * substream)38 static 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 
snd_dmaengine_pcm_get_chan(struct snd_pcm_substream * substream)44 struct 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 }
50 EXPORT_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  */
snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream * substream,const struct snd_pcm_hw_params * params,struct dma_slave_config * slave_config)61 int 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 
67 	switch (params_format(params)) {
68 	case SNDRV_PCM_FORMAT_S8:
69 		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
70 		break;
71 	case SNDRV_PCM_FORMAT_S16_LE:
72 		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
73 		break;
74 	case SNDRV_PCM_FORMAT_S18_3LE:
75 	case SNDRV_PCM_FORMAT_S20_3LE:
76 	case SNDRV_PCM_FORMAT_S24_LE:
77 	case SNDRV_PCM_FORMAT_S32_LE:
78 		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
79 		break;
80 	default:
81 		return -EINVAL;
82 	}
83 
84 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
85 		slave_config->direction = DMA_MEM_TO_DEV;
86 		slave_config->dst_addr_width = buswidth;
87 	} else {
88 		slave_config->direction = DMA_DEV_TO_MEM;
89 		slave_config->src_addr_width = buswidth;
90 	}
91 
92 	slave_config->device_fc = false;
93 
94 	return 0;
95 }
96 EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);
97 
98 /**
99  * snd_dmaengine_pcm_set_config_from_dai_data() - Initializes a dma slave config
100  *  using DAI DMA data.
101  * @substream: PCM substream
102  * @dma_data: DAI DMA data
103  * @slave_config: DMA slave configuration
104  *
105  * Initializes the {dst,src}_addr, {dst,src}_maxburst, {dst,src}_addr_width and
106  * slave_id fields of the DMA slave config from the same fields of the DAI DMA
107  * data struct. The src and dst fields will be initialized depending on the
108  * direction of the substream. If the substream is a playback stream the dst
109  * fields will be initialized, if it is a capture stream the src fields will be
110  * initialized. The {dst,src}_addr_width field will only be initialized if the
111  * addr_width field of the DAI DMA data struct is not equal to
112  * DMA_SLAVE_BUSWIDTH_UNDEFINED.
113  */
snd_dmaengine_pcm_set_config_from_dai_data(const struct snd_pcm_substream * substream,const struct snd_dmaengine_dai_dma_data * dma_data,struct dma_slave_config * slave_config)114 void snd_dmaengine_pcm_set_config_from_dai_data(
115 	const struct snd_pcm_substream *substream,
116 	const struct snd_dmaengine_dai_dma_data *dma_data,
117 	struct dma_slave_config *slave_config)
118 {
119 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
120 		slave_config->dst_addr = dma_data->addr;
121 		slave_config->dst_maxburst = dma_data->maxburst;
122 		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
123 			slave_config->dst_addr_width = dma_data->addr_width;
124 	} else {
125 		slave_config->src_addr = dma_data->addr;
126 		slave_config->src_maxburst = dma_data->maxburst;
127 		if (dma_data->addr_width != DMA_SLAVE_BUSWIDTH_UNDEFINED)
128 			slave_config->src_addr_width = dma_data->addr_width;
129 	}
130 
131 	slave_config->slave_id = dma_data->slave_id;
132 }
133 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_config_from_dai_data);
134 
dmaengine_pcm_dma_complete(void * arg)135 static void dmaengine_pcm_dma_complete(void *arg)
136 {
137 	struct snd_pcm_substream *substream = arg;
138 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
139 
140 	prtd->pos += snd_pcm_lib_period_bytes(substream);
141 	if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
142 		prtd->pos = 0;
143 
144 	snd_pcm_period_elapsed(substream);
145 }
146 
dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream * substream)147 static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
148 {
149 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
150 	struct dma_chan *chan = prtd->dma_chan;
151 	struct dma_async_tx_descriptor *desc;
152 	enum dma_transfer_direction direction;
153 	unsigned long flags = DMA_CTRL_ACK;
154 
155 	direction = snd_pcm_substream_to_dma_direction(substream);
156 
157 	if (!substream->runtime->no_period_wakeup)
158 		flags |= DMA_PREP_INTERRUPT;
159 
160 	prtd->pos = 0;
161 	desc = dmaengine_prep_dma_cyclic(chan,
162 		substream->runtime->dma_addr,
163 		snd_pcm_lib_buffer_bytes(substream),
164 		snd_pcm_lib_period_bytes(substream), direction, flags);
165 
166 	if (!desc)
167 		return -ENOMEM;
168 
169 	desc->callback = dmaengine_pcm_dma_complete;
170 	desc->callback_param = substream;
171 	prtd->cookie = dmaengine_submit(desc);
172 
173 	return 0;
174 }
175 
176 /**
177  * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
178  * @substream: PCM substream
179  * @cmd: Trigger command
180  *
181  * Returns 0 on success, a negative error code otherwise.
182  *
183  * This function can be used as the PCM trigger callback for dmaengine based PCM
184  * driver implementations.
185  */
snd_dmaengine_pcm_trigger(struct snd_pcm_substream * substream,int cmd)186 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
187 {
188 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
189 	int ret;
190 
191 	switch (cmd) {
192 	case SNDRV_PCM_TRIGGER_START:
193 		ret = dmaengine_pcm_prepare_and_submit(substream);
194 		if (ret)
195 			return ret;
196 		dma_async_issue_pending(prtd->dma_chan);
197 		break;
198 	case SNDRV_PCM_TRIGGER_RESUME:
199 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
200 		dmaengine_resume(prtd->dma_chan);
201 		break;
202 	case SNDRV_PCM_TRIGGER_SUSPEND:
203 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
204 		dmaengine_pause(prtd->dma_chan);
205 		break;
206 	case SNDRV_PCM_TRIGGER_STOP:
207 		dmaengine_terminate_all(prtd->dma_chan);
208 		break;
209 	default:
210 		return -EINVAL;
211 	}
212 
213 	return 0;
214 }
215 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);
216 
217 /**
218  * snd_dmaengine_pcm_pointer_no_residue - dmaengine based PCM pointer implementation
219  * @substream: PCM substream
220  *
221  * This function is deprecated and should not be used by new drivers, as its
222  * results may be unreliable.
223  */
snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream * substream)224 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream)
225 {
226 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
227 	return bytes_to_frames(substream->runtime, prtd->pos);
228 }
229 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer_no_residue);
230 
231 /**
232  * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
233  * @substream: PCM substream
234  *
235  * This function can be used as the PCM pointer callback for dmaengine based PCM
236  * driver implementations.
237  */
snd_dmaengine_pcm_pointer(struct snd_pcm_substream * substream)238 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
239 {
240 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
241 	struct dma_tx_state state;
242 	enum dma_status status;
243 	unsigned int buf_size;
244 	unsigned int pos = 0;
245 
246 	status = dmaengine_tx_status(prtd->dma_chan, prtd->cookie, &state);
247 	if (status == DMA_IN_PROGRESS || status == DMA_PAUSED) {
248 		buf_size = snd_pcm_lib_buffer_bytes(substream);
249 		if (state.residue > 0 && state.residue <= buf_size)
250 			pos = buf_size - state.residue;
251 	}
252 
253 	return bytes_to_frames(substream->runtime, pos);
254 }
255 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);
256 
257 /**
258  * snd_dmaengine_pcm_request_channel - Request channel for the dmaengine PCM
259  * @filter_fn: Filter function used to request the DMA channel
260  * @filter_data: Data passed to the DMA filter function
261  *
262  * Returns NULL or the requested DMA channel.
263  *
264  * This function request a DMA channel for usage with dmaengine PCM.
265  */
snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,void * filter_data)266 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
267 	void *filter_data)
268 {
269 	dma_cap_mask_t mask;
270 
271 	dma_cap_zero(mask);
272 	dma_cap_set(DMA_SLAVE, mask);
273 	dma_cap_set(DMA_CYCLIC, mask);
274 
275 	return dma_request_channel(mask, filter_fn, filter_data);
276 }
277 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_request_channel);
278 
279 /**
280  * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
281  * @substream: PCM substream
282  * @chan: DMA channel to use for data transfers
283  *
284  * Returns 0 on success, a negative error code otherwise.
285  *
286  * The function should usually be called from the pcm open callback. Note that
287  * this function will use private_data field of the substream's runtime. So it
288  * is not availabe to your pcm driver implementation.
289  */
snd_dmaengine_pcm_open(struct snd_pcm_substream * substream,struct dma_chan * chan)290 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
291 	struct dma_chan *chan)
292 {
293 	struct dmaengine_pcm_runtime_data *prtd;
294 	int ret;
295 
296 	if (!chan)
297 		return -ENXIO;
298 
299 	ret = snd_pcm_hw_constraint_integer(substream->runtime,
300 					    SNDRV_PCM_HW_PARAM_PERIODS);
301 	if (ret < 0)
302 		return ret;
303 
304 	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
305 	if (!prtd)
306 		return -ENOMEM;
307 
308 	prtd->dma_chan = chan;
309 
310 	substream->runtime->private_data = prtd;
311 
312 	return 0;
313 }
314 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);
315 
316 /**
317  * snd_dmaengine_pcm_open_request_chan - Open a dmaengine based PCM substream and request channel
318  * @substream: PCM substream
319  * @filter_fn: Filter function used to request the DMA channel
320  * @filter_data: Data passed to the DMA filter function
321  *
322  * Returns 0 on success, a negative error code otherwise.
323  *
324  * This function will request a DMA channel using the passed filter function and
325  * data. The function should usually be called from the pcm open callback. Note
326  * that this function will use private_data field of the substream's runtime. So
327  * it is not availabe to your pcm driver implementation.
328  */
snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream * substream,dma_filter_fn filter_fn,void * filter_data)329 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
330 	dma_filter_fn filter_fn, void *filter_data)
331 {
332 	return snd_dmaengine_pcm_open(substream,
333 		    snd_dmaengine_pcm_request_channel(filter_fn, filter_data));
334 }
335 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open_request_chan);
336 
337 /**
338  * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
339  * @substream: PCM substream
340  */
snd_dmaengine_pcm_close(struct snd_pcm_substream * substream)341 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
342 {
343 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
344 
345 	kfree(prtd);
346 
347 	return 0;
348 }
349 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);
350 
351 /**
352  * snd_dmaengine_pcm_release_chan_close - Close a dmaengine based PCM substream and release channel
353  * @substream: PCM substream
354  *
355  * Releases the DMA channel associated with the PCM substream.
356  */
snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream * substream)357 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream)
358 {
359 	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
360 
361 	dma_release_channel(prtd->dma_chan);
362 
363 	return snd_dmaengine_pcm_close(substream);
364 }
365 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close_release_chan);
366 
367 MODULE_LICENSE("GPL");
368