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1/*
2 *  ALSA PCM device for the
3 *  ALSA interface to ivtv PCM capture streams
4 *
5 *  Copyright (C) 2009,2012  Andy Walls <awalls@md.metrocast.net>
6 *  Copyright (C) 2009  Devin Heitmueller <dheitmueller@kernellabs.com>
7 *
8 *  Portions of this work were sponsored by ONELAN Limited for the cx18 driver
9 *
10 *  This program is free software; you can redistribute it and/or modify
11 *  it under the terms of the GNU General Public License as published by
12 *  the Free Software Foundation; either version 2 of the License, or
13 *  (at your option) any later version.
14 *
15 *  This program is distributed in the hope that it will be useful,
16 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
17 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 *  GNU General Public License for more details.
19 *
20 *  You should have received a copy of the GNU General Public License
21 *  along with this program; if not, write to the Free Software
22 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 *  02111-1307  USA
24 */
25
26#include <linux/init.h>
27#include <linux/kernel.h>
28#include <linux/vmalloc.h>
29
30#include <media/v4l2-device.h>
31
32#include <sound/core.h>
33#include <sound/pcm.h>
34
35#include "ivtv-driver.h"
36#include "ivtv-queue.h"
37#include "ivtv-streams.h"
38#include "ivtv-fileops.h"
39#include "ivtv-alsa.h"
40#include "ivtv-alsa-pcm.h"
41
42static unsigned int pcm_debug;
43module_param(pcm_debug, int, 0644);
44MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
45
46#define dprintk(fmt, arg...) \
47	do { \
48		if (pcm_debug) \
49			pr_info("ivtv-alsa-pcm %s: " fmt, __func__, ##arg); \
50	} while (0)
51
52static struct snd_pcm_hardware snd_ivtv_hw_capture = {
53	.info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
54		SNDRV_PCM_INFO_MMAP           |
55		SNDRV_PCM_INFO_INTERLEAVED    |
56		SNDRV_PCM_INFO_MMAP_VALID,
57
58	.formats = SNDRV_PCM_FMTBIT_S16_LE,
59
60	.rates = SNDRV_PCM_RATE_48000,
61
62	.rate_min = 48000,
63	.rate_max = 48000,
64	.channels_min = 2,
65	.channels_max = 2,
66	.buffer_bytes_max = 62720 * 8,	/* just about the value in usbaudio.c */
67	.period_bytes_min = 64,		/* 12544/2, */
68	.period_bytes_max = 12544,
69	.periods_min = 2,
70	.periods_max = 98,		/* 12544, */
71};
72
73static void ivtv_alsa_announce_pcm_data(struct snd_ivtv_card *itvsc,
74					u8 *pcm_data,
75					size_t num_bytes)
76{
77	struct snd_pcm_substream *substream;
78	struct snd_pcm_runtime *runtime;
79	unsigned int oldptr;
80	unsigned int stride;
81	int period_elapsed = 0;
82	int length;
83
84	dprintk("ivtv alsa announce ptr=%p data=%p num_bytes=%zu\n", itvsc,
85		pcm_data, num_bytes);
86
87	substream = itvsc->capture_pcm_substream;
88	if (substream == NULL) {
89		dprintk("substream was NULL\n");
90		return;
91	}
92
93	runtime = substream->runtime;
94	if (runtime == NULL) {
95		dprintk("runtime was NULL\n");
96		return;
97	}
98
99	stride = runtime->frame_bits >> 3;
100	if (stride == 0) {
101		dprintk("stride is zero\n");
102		return;
103	}
104
105	length = num_bytes / stride;
106	if (length == 0) {
107		dprintk("%s: length was zero\n", __func__);
108		return;
109	}
110
111	if (runtime->dma_area == NULL) {
112		dprintk("dma area was NULL - ignoring\n");
113		return;
114	}
115
116	oldptr = itvsc->hwptr_done_capture;
117	if (oldptr + length >= runtime->buffer_size) {
118		unsigned int cnt =
119			runtime->buffer_size - oldptr;
120		memcpy(runtime->dma_area + oldptr * stride, pcm_data,
121		       cnt * stride);
122		memcpy(runtime->dma_area, pcm_data + cnt * stride,
123		       length * stride - cnt * stride);
124	} else {
125		memcpy(runtime->dma_area + oldptr * stride, pcm_data,
126		       length * stride);
127	}
128	snd_pcm_stream_lock(substream);
129
130	itvsc->hwptr_done_capture += length;
131	if (itvsc->hwptr_done_capture >=
132	    runtime->buffer_size)
133		itvsc->hwptr_done_capture -=
134			runtime->buffer_size;
135
136	itvsc->capture_transfer_done += length;
137	if (itvsc->capture_transfer_done >=
138	    runtime->period_size) {
139		itvsc->capture_transfer_done -=
140			runtime->period_size;
141		period_elapsed = 1;
142	}
143
144	snd_pcm_stream_unlock(substream);
145
146	if (period_elapsed)
147		snd_pcm_period_elapsed(substream);
148}
149
150static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream)
151{
152	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
153	struct snd_pcm_runtime *runtime = substream->runtime;
154	struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
155	struct ivtv *itv = to_ivtv(v4l2_dev);
156	struct ivtv_stream *s;
157	struct ivtv_open_id item;
158	int ret;
159
160	/* Instruct the CX2341[56] to start sending packets */
161	snd_ivtv_lock(itvsc);
162
163	if (ivtv_init_on_first_open(itv)) {
164		snd_ivtv_unlock(itvsc);
165		return -ENXIO;
166	}
167
168	s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
169
170	v4l2_fh_init(&item.fh, s->vdev);
171	item.itv = itv;
172	item.type = s->type;
173
174	/* See if the stream is available */
175	if (ivtv_claim_stream(&item, item.type)) {
176		/* No, it's already in use */
177		snd_ivtv_unlock(itvsc);
178		return -EBUSY;
179	}
180
181	if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) ||
182	    test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
183		/* We're already streaming.  No additional action required */
184		snd_ivtv_unlock(itvsc);
185		return 0;
186	}
187
188
189	runtime->hw = snd_ivtv_hw_capture;
190	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
191	itvsc->capture_pcm_substream = substream;
192	runtime->private_data = itv;
193
194	itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data;
195
196	/* Not currently streaming, so start it up */
197	set_bit(IVTV_F_S_STREAMING, &s->s_flags);
198	ret = ivtv_start_v4l2_encode_stream(s);
199	snd_ivtv_unlock(itvsc);
200
201	return ret;
202}
203
204static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream)
205{
206	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
207	struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
208	struct ivtv *itv = to_ivtv(v4l2_dev);
209	struct ivtv_stream *s;
210
211	/* Instruct the ivtv to stop sending packets */
212	snd_ivtv_lock(itvsc);
213	s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
214	ivtv_stop_v4l2_encode_stream(s, 0);
215	clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
216
217	ivtv_release_stream(s);
218
219	itv->pcm_announce_callback = NULL;
220	snd_ivtv_unlock(itvsc);
221
222	return 0;
223}
224
225static int snd_ivtv_pcm_ioctl(struct snd_pcm_substream *substream,
226		     unsigned int cmd, void *arg)
227{
228	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
229	int ret;
230
231	snd_ivtv_lock(itvsc);
232	ret = snd_pcm_lib_ioctl(substream, cmd, arg);
233	snd_ivtv_unlock(itvsc);
234	return ret;
235}
236
237
238static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
239					size_t size)
240{
241	struct snd_pcm_runtime *runtime = subs->runtime;
242
243	dprintk("Allocating vbuffer\n");
244	if (runtime->dma_area) {
245		if (runtime->dma_bytes > size)
246			return 0;
247
248		vfree(runtime->dma_area);
249	}
250	runtime->dma_area = vmalloc(size);
251	if (!runtime->dma_area)
252		return -ENOMEM;
253
254	runtime->dma_bytes = size;
255
256	return 0;
257}
258
259static int snd_ivtv_pcm_hw_params(struct snd_pcm_substream *substream,
260			 struct snd_pcm_hw_params *params)
261{
262	dprintk("%s called\n", __func__);
263
264	return snd_pcm_alloc_vmalloc_buffer(substream,
265					   params_buffer_bytes(params));
266}
267
268static int snd_ivtv_pcm_hw_free(struct snd_pcm_substream *substream)
269{
270	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
271	unsigned long flags;
272
273	spin_lock_irqsave(&itvsc->slock, flags);
274	if (substream->runtime->dma_area) {
275		dprintk("freeing pcm capture region\n");
276		vfree(substream->runtime->dma_area);
277		substream->runtime->dma_area = NULL;
278	}
279	spin_unlock_irqrestore(&itvsc->slock, flags);
280
281	return 0;
282}
283
284static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream)
285{
286	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
287
288	itvsc->hwptr_done_capture = 0;
289	itvsc->capture_transfer_done = 0;
290
291	return 0;
292}
293
294static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
295{
296	return 0;
297}
298
299static
300snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream)
301{
302	unsigned long flags;
303	snd_pcm_uframes_t hwptr_done;
304	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
305
306	spin_lock_irqsave(&itvsc->slock, flags);
307	hwptr_done = itvsc->hwptr_done_capture;
308	spin_unlock_irqrestore(&itvsc->slock, flags);
309
310	return hwptr_done;
311}
312
313static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
314					     unsigned long offset)
315{
316	void *pageptr = subs->runtime->dma_area + offset;
317
318	return vmalloc_to_page(pageptr);
319}
320
321static struct snd_pcm_ops snd_ivtv_pcm_capture_ops = {
322	.open		= snd_ivtv_pcm_capture_open,
323	.close		= snd_ivtv_pcm_capture_close,
324	.ioctl		= snd_ivtv_pcm_ioctl,
325	.hw_params	= snd_ivtv_pcm_hw_params,
326	.hw_free	= snd_ivtv_pcm_hw_free,
327	.prepare	= snd_ivtv_pcm_prepare,
328	.trigger	= snd_ivtv_pcm_trigger,
329	.pointer	= snd_ivtv_pcm_pointer,
330	.page		= snd_pcm_get_vmalloc_page,
331};
332
333int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc)
334{
335	struct snd_pcm *sp;
336	struct snd_card *sc = itvsc->sc;
337	struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
338	struct ivtv *itv = to_ivtv(v4l2_dev);
339	int ret;
340
341	ret = snd_pcm_new(sc, "CX2341[56] PCM",
342			  0, /* PCM device 0, the only one for this card */
343			  0, /* 0 playback substreams */
344			  1, /* 1 capture substream */
345			  &sp);
346	if (ret) {
347		IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
348			      __func__, ret);
349		goto err_exit;
350	}
351
352	spin_lock_init(&itvsc->slock);
353
354	snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
355			&snd_ivtv_pcm_capture_ops);
356	sp->info_flags = 0;
357	sp->private_data = itvsc;
358	strlcpy(sp->name, itv->card_name, sizeof(sp->name));
359
360	return 0;
361
362err_exit:
363	return ret;
364}
365