1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * ALSA PCM device for the
4 * ALSA interface to cx18 PCM capture streams
6 * Copyright (C) 2009 Andy Walls <awalls@md.metrocast.net>
7 * Copyright (C) 2009 Devin Heitmueller <dheitmueller@kernellabs.com>
9 * Portions of this work were sponsored by ONELAN Limited.
12 #include <linux/init.h>
13 #include <linux/kernel.h>
15 #include <media/v4l2-device.h>
17 #include <sound/core.h>
18 #include <sound/pcm.h>
20 #include "cx18-driver.h"
21 #include "cx18-queue.h"
22 #include "cx18-streams.h"
23 #include "cx18-fileops.h"
24 #include "cx18-alsa.h"
25 #include "cx18-alsa-pcm.h"
27 static unsigned int pcm_debug;
28 module_param(pcm_debug, int, 0644);
29 MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
31 #define dprintk(fmt, arg...) do { \
33 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt, \
37 static const struct snd_pcm_hardware snd_cx18_hw_capture = {
38 .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
40 SNDRV_PCM_INFO_INTERLEAVED |
41 SNDRV_PCM_INFO_MMAP_VALID,
43 .formats = SNDRV_PCM_FMTBIT_S16_LE,
45 .rates = SNDRV_PCM_RATE_48000,
51 .buffer_bytes_max = 62720 * 8, /* just about the value in usbaudio.c */
52 .period_bytes_min = 64, /* 12544/2, */
53 .period_bytes_max = 12544,
55 .periods_max = 98, /* 12544, */
58 void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
61 struct snd_pcm_substream *substream;
62 struct snd_pcm_runtime *runtime;
65 int period_elapsed = 0;
68 dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc,
71 substream = cxsc->capture_pcm_substream;
72 if (substream == NULL) {
73 dprintk("substream was NULL\n");
77 runtime = substream->runtime;
78 if (runtime == NULL) {
79 dprintk("runtime was NULL\n");
83 stride = runtime->frame_bits >> 3;
85 dprintk("stride is zero\n");
89 length = num_bytes / stride;
91 dprintk("%s: length was zero\n", __func__);
95 if (runtime->dma_area == NULL) {
96 dprintk("dma area was NULL - ignoring\n");
100 oldptr = cxsc->hwptr_done_capture;
101 if (oldptr + length >= runtime->buffer_size) {
103 runtime->buffer_size - oldptr;
104 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
106 memcpy(runtime->dma_area, pcm_data + cnt * stride,
107 length * stride - cnt * stride);
109 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
112 snd_pcm_stream_lock(substream);
114 cxsc->hwptr_done_capture += length;
115 if (cxsc->hwptr_done_capture >=
116 runtime->buffer_size)
117 cxsc->hwptr_done_capture -=
118 runtime->buffer_size;
120 cxsc->capture_transfer_done += length;
121 if (cxsc->capture_transfer_done >=
122 runtime->period_size) {
123 cxsc->capture_transfer_done -=
124 runtime->period_size;
128 snd_pcm_stream_unlock(substream);
131 snd_pcm_period_elapsed(substream);
134 static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
136 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
137 struct snd_pcm_runtime *runtime = substream->runtime;
138 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
139 struct cx18 *cx = to_cx18(v4l2_dev);
140 struct cx18_stream *s;
141 struct cx18_open_id item;
144 /* Instruct the cx18 to start sending packets */
146 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
150 item.open_id = cx->open_id++;
152 /* See if the stream is available */
153 if (cx18_claim_stream(&item, item.type)) {
154 /* No, it's already in use */
155 snd_cx18_unlock(cxsc);
159 if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
160 test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
161 /* We're already streaming. No additional action required */
162 snd_cx18_unlock(cxsc);
167 runtime->hw = snd_cx18_hw_capture;
168 snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
169 cxsc->capture_pcm_substream = substream;
170 runtime->private_data = cx;
172 cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
174 /* Not currently streaming, so start it up */
175 set_bit(CX18_F_S_STREAMING, &s->s_flags);
176 ret = cx18_start_v4l2_encode_stream(s);
177 snd_cx18_unlock(cxsc);
182 static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
184 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
185 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
186 struct cx18 *cx = to_cx18(v4l2_dev);
187 struct cx18_stream *s;
189 /* Instruct the cx18 to stop sending packets */
191 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
192 cx18_stop_v4l2_encode_stream(s, 0);
193 clear_bit(CX18_F_S_STREAMING, &s->s_flags);
195 cx18_release_stream(s);
197 cx->pcm_announce_callback = NULL;
198 snd_cx18_unlock(cxsc);
203 static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
205 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
207 cxsc->hwptr_done_capture = 0;
208 cxsc->capture_transfer_done = 0;
213 static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
219 snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
222 snd_pcm_uframes_t hwptr_done;
223 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
225 spin_lock_irqsave(&cxsc->slock, flags);
226 hwptr_done = cxsc->hwptr_done_capture;
227 spin_unlock_irqrestore(&cxsc->slock, flags);
232 static const struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
233 .open = snd_cx18_pcm_capture_open,
234 .close = snd_cx18_pcm_capture_close,
235 .prepare = snd_cx18_pcm_prepare,
236 .trigger = snd_cx18_pcm_trigger,
237 .pointer = snd_cx18_pcm_pointer,
240 int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
243 struct snd_card *sc = cxsc->sc;
244 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
245 struct cx18 *cx = to_cx18(v4l2_dev);
248 ret = snd_pcm_new(sc, "CX23418 PCM",
249 0, /* PCM device 0, the only one for this card */
250 0, /* 0 playback substreams */
251 1, /* 1 capture substream */
254 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
259 spin_lock_init(&cxsc->slock);
261 snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
262 &snd_cx18_pcm_capture_ops);
263 snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
265 sp->private_data = cxsc;
266 strscpy(sp->name, cx->card_name, sizeof(sp->name));