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 #include "cx18-alsa-pcm.h"
41
42 static unsigned int pcm_debug;
43 module_param(pcm_debug, int, 0644);
44 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
45
46 #define dprintk(fmt, arg...) do { \
47 if (pcm_debug) \
48 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt, \
49 __func__, ##arg); \
50 } while (0)
51
52 static struct snd_pcm_hardware snd_cx18_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
cx18_alsa_announce_pcm_data(struct snd_cx18_card * cxsc,u8 * pcm_data,size_t num_bytes)73 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
74 size_t num_bytes)
75 {
76 struct snd_pcm_substream *substream;
77 struct snd_pcm_runtime *runtime;
78 unsigned int oldptr;
79 unsigned int stride;
80 int period_elapsed = 0;
81 int length;
82
83 dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zd\n", cxsc,
84 pcm_data, num_bytes);
85
86 substream = cxsc->capture_pcm_substream;
87 if (substream == NULL) {
88 dprintk("substream was NULL\n");
89 return;
90 }
91
92 runtime = substream->runtime;
93 if (runtime == NULL) {
94 dprintk("runtime was NULL\n");
95 return;
96 }
97
98 stride = runtime->frame_bits >> 3;
99 if (stride == 0) {
100 dprintk("stride is zero\n");
101 return;
102 }
103
104 length = num_bytes / stride;
105 if (length == 0) {
106 dprintk("%s: length was zero\n", __func__);
107 return;
108 }
109
110 if (runtime->dma_area == NULL) {
111 dprintk("dma area was NULL - ignoring\n");
112 return;
113 }
114
115 oldptr = cxsc->hwptr_done_capture;
116 if (oldptr + length >= runtime->buffer_size) {
117 unsigned int cnt =
118 runtime->buffer_size - oldptr;
119 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
120 cnt * stride);
121 memcpy(runtime->dma_area, pcm_data + cnt * stride,
122 length * stride - cnt * stride);
123 } else {
124 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
125 length * stride);
126 }
127 snd_pcm_stream_lock(substream);
128
129 cxsc->hwptr_done_capture += length;
130 if (cxsc->hwptr_done_capture >=
131 runtime->buffer_size)
132 cxsc->hwptr_done_capture -=
133 runtime->buffer_size;
134
135 cxsc->capture_transfer_done += length;
136 if (cxsc->capture_transfer_done >=
137 runtime->period_size) {
138 cxsc->capture_transfer_done -=
139 runtime->period_size;
140 period_elapsed = 1;
141 }
142
143 snd_pcm_stream_unlock(substream);
144
145 if (period_elapsed)
146 snd_pcm_period_elapsed(substream);
147 }
148
snd_cx18_pcm_capture_open(struct snd_pcm_substream * substream)149 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
150 {
151 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
152 struct snd_pcm_runtime *runtime = substream->runtime;
153 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
154 struct cx18 *cx = to_cx18(v4l2_dev);
155 struct cx18_stream *s;
156 struct cx18_open_id item;
157 int ret;
158
159 /* Instruct the cx18 to start sending packets */
160 snd_cx18_lock(cxsc);
161 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
162
163 item.cx = cx;
164 item.type = s->type;
165 item.open_id = cx->open_id++;
166
167 /* See if the stream is available */
168 if (cx18_claim_stream(&item, item.type)) {
169 /* No, it's already in use */
170 snd_cx18_unlock(cxsc);
171 return -EBUSY;
172 }
173
174 if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
175 test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
176 /* We're already streaming. No additional action required */
177 snd_cx18_unlock(cxsc);
178 return 0;
179 }
180
181
182 runtime->hw = snd_cx18_hw_capture;
183 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
184 cxsc->capture_pcm_substream = substream;
185 runtime->private_data = cx;
186
187 cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
188
189 /* Not currently streaming, so start it up */
190 set_bit(CX18_F_S_STREAMING, &s->s_flags);
191 ret = cx18_start_v4l2_encode_stream(s);
192 snd_cx18_unlock(cxsc);
193
194 return ret;
195 }
196
snd_cx18_pcm_capture_close(struct snd_pcm_substream * substream)197 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
198 {
199 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
200 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
201 struct cx18 *cx = to_cx18(v4l2_dev);
202 struct cx18_stream *s;
203
204 /* Instruct the cx18 to stop sending packets */
205 snd_cx18_lock(cxsc);
206 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
207 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 dprintk("%s called\n", __func__);
256
257 return snd_pcm_alloc_vmalloc_buffer(substream,
258 params_buffer_bytes(params));
259 }
260
snd_cx18_pcm_hw_free(struct snd_pcm_substream * substream)261 static int snd_cx18_pcm_hw_free(struct snd_pcm_substream *substream)
262 {
263 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
264 unsigned long flags;
265
266 spin_lock_irqsave(&cxsc->slock, flags);
267 if (substream->runtime->dma_area) {
268 dprintk("freeing pcm capture region\n");
269 vfree(substream->runtime->dma_area);
270 substream->runtime->dma_area = NULL;
271 }
272 spin_unlock_irqrestore(&cxsc->slock, flags);
273
274 return 0;
275 }
276
snd_cx18_pcm_prepare(struct snd_pcm_substream * substream)277 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
278 {
279 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
280
281 cxsc->hwptr_done_capture = 0;
282 cxsc->capture_transfer_done = 0;
283
284 return 0;
285 }
286
snd_cx18_pcm_trigger(struct snd_pcm_substream * substream,int cmd)287 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
288 {
289 return 0;
290 }
291
292 static
snd_cx18_pcm_pointer(struct snd_pcm_substream * substream)293 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
294 {
295 unsigned long flags;
296 snd_pcm_uframes_t hwptr_done;
297 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
298
299 spin_lock_irqsave(&cxsc->slock, flags);
300 hwptr_done = cxsc->hwptr_done_capture;
301 spin_unlock_irqrestore(&cxsc->slock, flags);
302
303 return hwptr_done;
304 }
305
snd_pcm_get_vmalloc_page(struct snd_pcm_substream * subs,unsigned long offset)306 static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
307 unsigned long offset)
308 {
309 void *pageptr = subs->runtime->dma_area + offset;
310
311 return vmalloc_to_page(pageptr);
312 }
313
314 static struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
315 .open = snd_cx18_pcm_capture_open,
316 .close = snd_cx18_pcm_capture_close,
317 .ioctl = snd_cx18_pcm_ioctl,
318 .hw_params = snd_cx18_pcm_hw_params,
319 .hw_free = snd_cx18_pcm_hw_free,
320 .prepare = snd_cx18_pcm_prepare,
321 .trigger = snd_cx18_pcm_trigger,
322 .pointer = snd_cx18_pcm_pointer,
323 .page = snd_pcm_get_vmalloc_page,
324 };
325
snd_cx18_pcm_create(struct snd_cx18_card * cxsc)326 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
327 {
328 struct snd_pcm *sp;
329 struct snd_card *sc = cxsc->sc;
330 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
331 struct cx18 *cx = to_cx18(v4l2_dev);
332 int ret;
333
334 ret = snd_pcm_new(sc, "CX23418 PCM",
335 0, /* PCM device 0, the only one for this card */
336 0, /* 0 playback substreams */
337 1, /* 1 capture substream */
338 &sp);
339 if (ret) {
340 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
341 __func__, ret);
342 goto err_exit;
343 }
344
345 spin_lock_init(&cxsc->slock);
346
347 snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
348 &snd_cx18_pcm_capture_ops);
349 sp->info_flags = 0;
350 sp->private_data = cxsc;
351 strlcpy(sp->name, cx->card_name, sizeof(sp->name));
352
353 return 0;
354
355 err_exit:
356 return ret;
357 }
358