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
41 static unsigned int pcm_debug;
42 module_param(pcm_debug, int, 0644);
43 MODULE_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
51 static 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
cx18_alsa_announce_pcm_data(struct snd_cx18_card * cxsc,u8 * pcm_data,size_t num_bytes)72 void 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
snd_cx18_pcm_capture_open(struct snd_pcm_substream * substream)148 static 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 0;
194 }
195
snd_cx18_pcm_capture_close(struct snd_pcm_substream * substream)196 static 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 int ret;
203
204 /* Instruct the cx18 to stop sending packets */
205 snd_cx18_lock(cxsc);
206 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
207 ret = cx18_stop_v4l2_encode_stream(s, 0);
208 clear_bit(CX18_F_S_STREAMING, &s->s_flags);
209
210 cx18_release_stream(s);
211
212 cx->pcm_announce_callback = NULL;
213 snd_cx18_unlock(cxsc);
214
215 return 0;
216 }
217
snd_cx18_pcm_ioctl(struct snd_pcm_substream * substream,unsigned int cmd,void * arg)218 static int snd_cx18_pcm_ioctl(struct snd_pcm_substream *substream,
219 unsigned int cmd, void *arg)
220 {
221 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
222 int ret;
223
224 snd_cx18_lock(cxsc);
225 ret = snd_pcm_lib_ioctl(substream, cmd, arg);
226 snd_cx18_unlock(cxsc);
227 return ret;
228 }
229
230
snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream * subs,size_t size)231 static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
232 size_t size)
233 {
234 struct snd_pcm_runtime *runtime = subs->runtime;
235
236 dprintk("Allocating vbuffer\n");
237 if (runtime->dma_area) {
238 if (runtime->dma_bytes > size)
239 return 0;
240
241 vfree(runtime->dma_area);
242 }
243 runtime->dma_area = vmalloc(size);
244 if (!runtime->dma_area)
245 return -ENOMEM;
246
247 runtime->dma_bytes = size;
248
249 return 0;
250 }
251
snd_cx18_pcm_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params)252 static int snd_cx18_pcm_hw_params(struct snd_pcm_substream *substream,
253 struct snd_pcm_hw_params *params)
254 {
255 int ret;
256
257 dprintk("%s called\n", __func__);
258
259 ret = snd_pcm_alloc_vmalloc_buffer(substream,
260 params_buffer_bytes(params));
261 return 0;
262 }
263
snd_cx18_pcm_hw_free(struct snd_pcm_substream * substream)264 static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
265 {
266 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
267 unsigned long flags;
268
269 spin_lock_irqsave(&cxsc->slock, flags);
270 if (substream->runtime->dma_area) {
271 dprintk("freeing pcm capture region\n");
272 vfree(substream->runtime->dma_area);
273 substream->runtime->dma_area = NULL;
274 }
275 spin_unlock_irqrestore(&cxsc->slock, flags);
276
277 return 0;
278 }
279
snd_cx18_pcm_prepare(struct snd_pcm_substream * substream)280 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
281 {
282 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
283
284 cxsc->hwptr_done_capture = 0;
285 cxsc->capture_transfer_done = 0;
286
287 return 0;
288 }
289
snd_cx18_pcm_trigger(struct snd_pcm_substream * substream,int cmd)290 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
291 {
292 return 0;
293 }
294
295 static
snd_cx18_pcm_pointer(struct snd_pcm_substream * substream)296 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
297 {
298 unsigned long flags;
299 snd_pcm_uframes_t hwptr_done;
300 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
301
302 spin_lock_irqsave(&cxsc->slock, flags);
303 hwptr_done = cxsc->hwptr_done_capture;
304 spin_unlock_irqrestore(&cxsc->slock, flags);
305
306 return hwptr_done;
307 }
308
snd_pcm_get_vmalloc_page(struct snd_pcm_substream * subs,unsigned long offset)309 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
310 unsigned long offset)
311 {
312 void *pageptr = subs->runtime->dma_area + offset;
313
314 return vmalloc_to_page(pageptr);
315 }
316
317 static struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
318 .open = snd_cx18_pcm_capture_open,
319 .close = snd_cx18_pcm_capture_close,
320 .ioctl = snd_cx18_pcm_ioctl,
321 .hw_params = snd_cx18_pcm_hw_params,
322 .hw_free = snd_cx18_pcm_hw_free,
323 .prepare = snd_cx18_pcm_prepare,
324 .trigger = snd_cx18_pcm_trigger,
325 .pointer = snd_cx18_pcm_pointer,
326 .page = snd_pcm_get_vmalloc_page,
327 };
328
snd_cx18_pcm_create(struct snd_cx18_card * cxsc)329 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
330 {
331 struct snd_pcm *sp;
332 struct snd_card *sc = cxsc->sc;
333 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
334 struct cx18 *cx = to_cx18(v4l2_dev);
335 int ret;
336
337 ret = snd_pcm_new(sc, "CX23418 PCM",
338 0, /* PCM device 0, the only one for this card */
339 0, /* 0 playback substreams */
340 1, /* 1 capture substream */
341 &sp);
342 if (ret) {
343 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
344 __func__, ret);
345 goto err_exit;
346 }
347
348 spin_lock_init(&cxsc->slock);
349
350 snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
351 &snd_cx18_pcm_capture_ops);
352 sp->info_flags = 0;
353 sp->private_data = cxsc;
354 strlcpy(sp->name, cx->card_name, sizeof(sp->name));
355
356 return 0;
357
358 err_exit:
359 return ret;
360 }
361