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1/*
2 * ALSA PCM device for the
3 * ALSA interface to cx18 PCM capture streams
4 *
5 * Copyright (C) 2009 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.
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 "cx18-driver.h"
36#include "cx18-queue.h"
37#include "cx18-streams.h"
38#include "cx18-fileops.h"
39#include "cx18-alsa.h"
40
41static unsigned int pcm_debug;
42module_param(pcm_debug, int, 0644);
43MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
44
45#define dprintk(fmt, arg...) do { \
46 if (pcm_debug) \
47 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt, \
48 __func__, ##arg); \
49 } while (0)
50
51static struct snd_pcm_hardware snd_cx18_hw_capture = {
52 .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
53 SNDRV_PCM_INFO_MMAP |
54 SNDRV_PCM_INFO_INTERLEAVED |
55 SNDRV_PCM_INFO_MMAP_VALID,
56
57 .formats = SNDRV_PCM_FMTBIT_S16_LE,
58
59 .rates = SNDRV_PCM_RATE_48000,
60
61 .rate_min = 48000,
62 .rate_max = 48000,
63 .channels_min = 2,
64 .channels_max = 2,
65 .buffer_bytes_max = 62720 * 8, /* just about the value in usbaudio.c */
66 .period_bytes_min = 64, /* 12544/2, */
67 .period_bytes_max = 12544,
68 .periods_min = 2,
69 .periods_max = 98, /* 12544, */
70};
71
72void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
73 size_t num_bytes)
74{
75 struct snd_pcm_substream *substream;
76 struct snd_pcm_runtime *runtime;
77 unsigned int oldptr;
78 unsigned int stride;
79 int period_elapsed = 0;
80 int length;
81
82 dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zd\n", cxsc,
83 pcm_data, num_bytes);
84
85 substream = cxsc->capture_pcm_substream;
86 if (substream == NULL) {
87 dprintk("substream was NULL\n");
88 return;
89 }
90
91 runtime = substream->runtime;
92 if (runtime == NULL) {
93 dprintk("runtime was NULL\n");
94 return;
95 }
96
97 stride = runtime->frame_bits >> 3;
98 if (stride == 0) {
99 dprintk("stride is zero\n");
100 return;
101 }
102
103 length = num_bytes / stride;
104 if (length == 0) {
105 dprintk("%s: length was zero\n", __func__);
106 return;
107 }
108
109 if (runtime->dma_area == NULL) {
110 dprintk("dma area was NULL - ignoring\n");
111 return;
112 }
113
114 oldptr = cxsc->hwptr_done_capture;
115 if (oldptr + length >= runtime->buffer_size) {
116 unsigned int cnt =
117 runtime->buffer_size - oldptr;
118 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
119 cnt * stride);
120 memcpy(runtime->dma_area, pcm_data + cnt * stride,
121 length * stride - cnt * stride);
122 } else {
123 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
124 length * stride);
125 }
126 snd_pcm_stream_lock(substream);
127
128 cxsc->hwptr_done_capture += length;
129 if (cxsc->hwptr_done_capture >=
130 runtime->buffer_size)
131 cxsc->hwptr_done_capture -=
132 runtime->buffer_size;
133
134 cxsc->capture_transfer_done += length;
135 if (cxsc->capture_transfer_done >=
136 runtime->period_size) {
137 cxsc->capture_transfer_done -=
138 runtime->period_size;
139 period_elapsed = 1;
140 }
141
142 snd_pcm_stream_unlock(substream);
143
144 if (period_elapsed)
145 snd_pcm_period_elapsed(substream);
146}
147
148static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
149{
150 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
151 struct snd_pcm_runtime *runtime = substream->runtime;
152 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
153 struct cx18 *cx = to_cx18(v4l2_dev);
154 struct cx18_stream *s;
155 struct cx18_open_id item;
156 int ret;
157
158 /* Instruct the cx18 to start sending packets */
159 snd_cx18_lock(cxsc);
160 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
161
162 item.cx = cx;
163 item.type = s->type;
164 item.open_id = cx->open_id++;
165
166 /* See if the stream is available */
167 if (cx18_claim_stream(&item, item.type)) {
168 /* No, it's already in use */
169 snd_cx18_unlock(cxsc);
170 return -EBUSY;
171 }
172
173 if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
174 test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
175 /* We're already streaming. No additional action required */
176 snd_cx18_unlock(cxsc);
177 return 0;
178 }
179
180
181 runtime->hw = snd_cx18_hw_capture;
182 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
183 cxsc->capture_pcm_substream = substream;
184 runtime->private_data = cx;
185
186 cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
187
188 /* Not currently streaming, so start it up */
189 set_bit(CX18_F_S_STREAMING, &s->s_flags);
190 ret = cx18_start_v4l2_encode_stream(s);
191 snd_cx18_unlock(cxsc);
192
193 return ret;
194}
195
196static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
197{
198 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
199 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
200 struct cx18 *cx = to_cx18(v4l2_dev);
201 struct cx18_stream *s;
202
203 /* Instruct the cx18 to stop sending packets */
204 snd_cx18_lock(cxsc);
205 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
206 cx18_stop_v4l2_encode_stream(s, 0);
207 clear_bit(CX18_F_S_STREAMING, &s->s_flags);
208
209 cx18_release_stream(s);
210
211 cx->pcm_announce_callback = NULL;
212 snd_cx18_unlock(cxsc);
213
214 return 0;
215}
216
217static int snd_cx18_pcm_ioctl(struct snd_pcm_substream *substream,
218 unsigned int cmd, void *arg)
219{
220 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
221 int ret;
222
223 snd_cx18_lock(cxsc);
224 ret = snd_pcm_lib_ioctl(substream, cmd, arg);
225 snd_cx18_unlock(cxsc);
226 return ret;
227}
228
229
230static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
231 size_t size)
232{
233 struct snd_pcm_runtime *runtime = subs->runtime;
234
235 dprintk("Allocating vbuffer\n");
236 if (runtime->dma_area) {
237 if (runtime->dma_bytes > size)
238 return 0;
239
240 vfree(runtime->dma_area);
241 }
242 runtime->dma_area = vmalloc(size);
243 if (!runtime->dma_area)
244 return -ENOMEM;
245
246 runtime->dma_bytes = size;
247
248 return 0;
249}
250
251static int snd_cx18_pcm_hw_params(struct snd_pcm_substream *substream,
252 struct snd_pcm_hw_params *params)
253{
254 dprintk("%s called\n", __func__);
255
256 return snd_pcm_alloc_vmalloc_buffer(substream,
257 params_buffer_bytes(params));
258}
259
260static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
261{
262 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
263 unsigned long flags;
264
265 spin_lock_irqsave(&cxsc->slock, flags);
266 if (substream->runtime->dma_area) {
267 dprintk("freeing pcm capture region\n");
268 vfree(substream->runtime->dma_area);
269 substream->runtime->dma_area = NULL;
270 }
271 spin_unlock_irqrestore(&cxsc->slock, flags);
272
273 return 0;
274}
275
276static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
277{
278 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
279
280 cxsc->hwptr_done_capture = 0;
281 cxsc->capture_transfer_done = 0;
282
283 return 0;
284}
285
286static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
287{
288 return 0;
289}
290
291static
292snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
293{
294 unsigned long flags;
295 snd_pcm_uframes_t hwptr_done;
296 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
297
298 spin_lock_irqsave(&cxsc->slock, flags);
299 hwptr_done = cxsc->hwptr_done_capture;
300 spin_unlock_irqrestore(&cxsc->slock, flags);
301
302 return hwptr_done;
303}
304
305static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
306 unsigned long offset)
307{
308 void *pageptr = subs->runtime->dma_area + offset;
309
310 return vmalloc_to_page(pageptr);
311}
312
313static struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
314 .open = snd_cx18_pcm_capture_open,
315 .close = snd_cx18_pcm_capture_close,
316 .ioctl = snd_cx18_pcm_ioctl,
317 .hw_params = snd_cx18_pcm_hw_params,
318 .hw_free = snd_cx18_pcm_hw_free,
319 .prepare = snd_cx18_pcm_prepare,
320 .trigger = snd_cx18_pcm_trigger,
321 .pointer = snd_cx18_pcm_pointer,
322 .page = snd_pcm_get_vmalloc_page,
323};
324
325int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
326{
327 struct snd_pcm *sp;
328 struct snd_card *sc = cxsc->sc;
329 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
330 struct cx18 *cx = to_cx18(v4l2_dev);
331 int ret;
332
333 ret = snd_pcm_new(sc, "CX23418 PCM",
334 0, /* PCM device 0, the only one for this card */
335 0, /* 0 playback substreams */
336 1, /* 1 capture substream */
337 &sp);
338 if (ret) {
339 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
340 __func__, ret);
341 goto err_exit;
342 }
343
344 spin_lock_init(&cxsc->slock);
345
346 snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
347 &snd_cx18_pcm_capture_ops);
348 sp->info_flags = 0;
349 sp->private_data = cxsc;
350 strlcpy(sp->name, cx->card_name, sizeof(sp->name));
351
352 return 0;
353
354err_exit:
355 return ret;
356}