2 * ALSA PCM device for the
3 * ALSA interface to ivtv PCM capture streams
5 * Copyright (C) 2009,2012 Andy Walls <awalls@md.metrocast.net>
6 * Copyright (C) 2009 Devin Heitmueller <dheitmueller@kernellabs.com>
8 * Portions of this work were sponsored by ONELAN Limited for the cx18 driver
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.
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.
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
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/vmalloc.h>
30 #include <media/v4l2-device.h>
32 #include <sound/core.h>
33 #include <sound/pcm.h>
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"
42 static unsigned int pcm_debug;
43 module_param(pcm_debug, int, 0644);
44 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
46 #define dprintk(fmt, arg...) \
49 pr_info("ivtv-alsa-pcm %s: " fmt, __func__, ##arg); \
52 static struct snd_pcm_hardware snd_ivtv_hw_capture = {
53 .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
55 SNDRV_PCM_INFO_INTERLEAVED |
56 SNDRV_PCM_INFO_MMAP_VALID,
58 .formats = SNDRV_PCM_FMTBIT_S16_LE,
60 .rates = SNDRV_PCM_RATE_48000,
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,
70 .periods_max = 98, /* 12544, */
73 static void ivtv_alsa_announce_pcm_data(struct snd_ivtv_card *itvsc,
77 struct snd_pcm_substream *substream;
78 struct snd_pcm_runtime *runtime;
81 int period_elapsed = 0;
84 dprintk("ivtv alsa announce ptr=%p data=%p num_bytes=%zd\n", itvsc,
87 substream = itvsc->capture_pcm_substream;
88 if (substream == NULL) {
89 dprintk("substream was NULL\n");
93 runtime = substream->runtime;
94 if (runtime == NULL) {
95 dprintk("runtime was NULL\n");
99 stride = runtime->frame_bits >> 3;
101 dprintk("stride is zero\n");
105 length = num_bytes / stride;
107 dprintk("%s: length was zero\n", __func__);
111 if (runtime->dma_area == NULL) {
112 dprintk("dma area was NULL - ignoring\n");
116 oldptr = itvsc->hwptr_done_capture;
117 if (oldptr + length >= runtime->buffer_size) {
119 runtime->buffer_size - oldptr;
120 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
122 memcpy(runtime->dma_area, pcm_data + cnt * stride,
123 length * stride - cnt * stride);
125 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
128 snd_pcm_stream_lock(substream);
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;
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;
144 snd_pcm_stream_unlock(substream);
147 snd_pcm_period_elapsed(substream);
150 static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream)
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;
160 /* Instruct the CX2341[56] to start sending packets */
161 snd_ivtv_lock(itvsc);
162 s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
164 v4l2_fh_init(&item.fh, s->vdev);
168 /* See if the stream is available */
169 if (ivtv_claim_stream(&item, item.type)) {
170 /* No, it's already in use */
171 snd_ivtv_unlock(itvsc);
175 if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) ||
176 test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
177 /* We're already streaming. No additional action required */
178 snd_ivtv_unlock(itvsc);
183 runtime->hw = snd_ivtv_hw_capture;
184 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
185 itvsc->capture_pcm_substream = substream;
186 runtime->private_data = itv;
188 itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data;
190 /* Not currently streaming, so start it up */
191 set_bit(IVTV_F_S_STREAMING, &s->s_flags);
192 ret = ivtv_start_v4l2_encode_stream(s);
193 snd_ivtv_unlock(itvsc);
198 static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream)
200 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
201 struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
202 struct ivtv *itv = to_ivtv(v4l2_dev);
203 struct ivtv_stream *s;
205 /* Instruct the ivtv to stop sending packets */
206 snd_ivtv_lock(itvsc);
207 s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
208 ivtv_stop_v4l2_encode_stream(s, 0);
209 clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
211 ivtv_release_stream(s);
213 itv->pcm_announce_callback = NULL;
214 snd_ivtv_unlock(itvsc);
219 static int snd_ivtv_pcm_ioctl(struct snd_pcm_substream *substream,
220 unsigned int cmd, void *arg)
222 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
225 snd_ivtv_lock(itvsc);
226 ret = snd_pcm_lib_ioctl(substream, cmd, arg);
227 snd_ivtv_unlock(itvsc);
232 static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
235 struct snd_pcm_runtime *runtime = subs->runtime;
237 dprintk("Allocating vbuffer\n");
238 if (runtime->dma_area) {
239 if (runtime->dma_bytes > size)
242 vfree(runtime->dma_area);
244 runtime->dma_area = vmalloc(size);
245 if (!runtime->dma_area)
248 runtime->dma_bytes = size;
253 static int snd_ivtv_pcm_hw_params(struct snd_pcm_substream *substream,
254 struct snd_pcm_hw_params *params)
256 dprintk("%s called\n", __func__);
258 return snd_pcm_alloc_vmalloc_buffer(substream,
259 params_buffer_bytes(params));
262 static int snd_ivtv_pcm_hw_free(struct snd_pcm_substream *substream)
264 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
267 spin_lock_irqsave(&itvsc->slock, flags);
268 if (substream->runtime->dma_area) {
269 dprintk("freeing pcm capture region\n");
270 vfree(substream->runtime->dma_area);
271 substream->runtime->dma_area = NULL;
273 spin_unlock_irqrestore(&itvsc->slock, flags);
278 static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream)
280 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
282 itvsc->hwptr_done_capture = 0;
283 itvsc->capture_transfer_done = 0;
288 static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
294 snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream)
297 snd_pcm_uframes_t hwptr_done;
298 struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
300 spin_lock_irqsave(&itvsc->slock, flags);
301 hwptr_done = itvsc->hwptr_done_capture;
302 spin_unlock_irqrestore(&itvsc->slock, flags);
307 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
308 unsigned long offset)
310 void *pageptr = subs->runtime->dma_area + offset;
312 return vmalloc_to_page(pageptr);
315 static struct snd_pcm_ops snd_ivtv_pcm_capture_ops = {
316 .open = snd_ivtv_pcm_capture_open,
317 .close = snd_ivtv_pcm_capture_close,
318 .ioctl = snd_ivtv_pcm_ioctl,
319 .hw_params = snd_ivtv_pcm_hw_params,
320 .hw_free = snd_ivtv_pcm_hw_free,
321 .prepare = snd_ivtv_pcm_prepare,
322 .trigger = snd_ivtv_pcm_trigger,
323 .pointer = snd_ivtv_pcm_pointer,
324 .page = snd_pcm_get_vmalloc_page,
327 int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc)
330 struct snd_card *sc = itvsc->sc;
331 struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
332 struct ivtv *itv = to_ivtv(v4l2_dev);
335 ret = snd_pcm_new(sc, "CX2341[56] PCM",
336 0, /* PCM device 0, the only one for this card */
337 0, /* 0 playback substreams */
338 1, /* 1 capture substream */
341 IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
346 spin_lock_init(&itvsc->slock);
348 snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
349 &snd_ivtv_pcm_capture_ops);
351 sp->private_data = itvsc;
352 strlcpy(sp->name, itv->card_name, sizeof(sp->name));