1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ALSA PCM device for the
4 * ALSA interface to cx18 PCM capture streams
5 *
6 * Copyright (C) 2009 Andy Walls <awalls@md.metrocast.net>
7 * Copyright (C) 2009 Devin Heitmueller <dheitmueller@kernellabs.com>
8 *
9 * Portions of this work were sponsored by ONELAN Limited.
10 */
11
12#include <linux/init.h>
13#include <linux/kernel.h>
14
15#include <media/v4l2-device.h>
16
17#include <sound/core.h>
18#include <sound/pcm.h>
19
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"
26
27static unsigned int pcm_debug;
28module_param(pcm_debug, int, 0644);
29MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
30
31#define dprintk(fmt, arg...) do { \
32 if (pcm_debug) \
33 printk(KERN_INFO "cx18-alsa-pcm %s: " fmt, \
34 __func__, ##arg); \
35 } while (0)
36
37static const struct snd_pcm_hardware snd_cx18_hw_capture = {
38 .info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
39 SNDRV_PCM_INFO_MMAP |
40 SNDRV_PCM_INFO_INTERLEAVED |
41 SNDRV_PCM_INFO_MMAP_VALID,
42
43 .formats = SNDRV_PCM_FMTBIT_S16_LE,
44
45 .rates = SNDRV_PCM_RATE_48000,
46
47 .rate_min = 48000,
48 .rate_max = 48000,
49 .channels_min = 2,
50 .channels_max = 2,
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,
54 .periods_min = 2,
55 .periods_max = 98, /* 12544, */
56};
57
58void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
59 size_t num_bytes)
60{
61 struct snd_pcm_substream *substream;
62 struct snd_pcm_runtime *runtime;
63 unsigned int oldptr;
64 unsigned int stride;
65 int period_elapsed = 0;
66 int length;
67
68 dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc,
69 pcm_data, num_bytes);
70
71 substream = cxsc->capture_pcm_substream;
72 if (substream == NULL) {
73 dprintk("substream was NULL\n");
74 return;
75 }
76
77 runtime = substream->runtime;
78 if (runtime == NULL) {
79 dprintk("runtime was NULL\n");
80 return;
81 }
82
83 stride = runtime->frame_bits >> 3;
84 if (stride == 0) {
85 dprintk("stride is zero\n");
86 return;
87 }
88
89 length = num_bytes / stride;
90 if (length == 0) {
91 dprintk("%s: length was zero\n", __func__);
92 return;
93 }
94
95 if (runtime->dma_area == NULL) {
96 dprintk("dma area was NULL - ignoring\n");
97 return;
98 }
99
100 oldptr = cxsc->hwptr_done_capture;
101 if (oldptr + length >= runtime->buffer_size) {
102 unsigned int cnt =
103 runtime->buffer_size - oldptr;
104 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
105 cnt * stride);
106 memcpy(runtime->dma_area, pcm_data + cnt * stride,
107 length * stride - cnt * stride);
108 } else {
109 memcpy(runtime->dma_area + oldptr * stride, pcm_data,
110 length * stride);
111 }
112 snd_pcm_stream_lock(substream);
113
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;
119
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;
125 period_elapsed = 1;
126 }
127
128 snd_pcm_stream_unlock(substream);
129
130 if (period_elapsed)
131 snd_pcm_period_elapsed(substream);
132}
133
134static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
135{
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;
142 int ret;
143
144 /* Instruct the cx18 to start sending packets */
145 snd_cx18_lock(cxsc);
146 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
147
148 item.cx = cx;
149 item.type = s->type;
150 item.open_id = cx->open_id++;
151
152 /* See if the stream is available */
153 if (cx18_claim_stream(id: &item, type: item.type)) {
154 /* No, it's already in use */
155 snd_cx18_unlock(cxsc);
156 return -EBUSY;
157 }
158
159 if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
160 test_and_set_bit(CX18_F_S_STREAMING, addr: &s->s_flags)) {
161 /* We're already streaming. No additional action required */
162 snd_cx18_unlock(cxsc);
163 return 0;
164 }
165
166
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;
171
172 cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
173
174 /* Not currently streaming, so start it up */
175 set_bit(CX18_F_S_STREAMING, addr: &s->s_flags);
176 ret = cx18_start_v4l2_encode_stream(s);
177 snd_cx18_unlock(cxsc);
178
179 return ret;
180}
181
182static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
183{
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;
188
189 /* Instruct the cx18 to stop sending packets */
190 snd_cx18_lock(cxsc);
191 s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
192 cx18_stop_v4l2_encode_stream(s, gop_end: 0);
193 clear_bit(CX18_F_S_STREAMING, addr: &s->s_flags);
194
195 cx18_release_stream(s);
196
197 cx->pcm_announce_callback = NULL;
198 snd_cx18_unlock(cxsc);
199
200 return 0;
201}
202
203static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
204{
205 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
206
207 cxsc->hwptr_done_capture = 0;
208 cxsc->capture_transfer_done = 0;
209
210 return 0;
211}
212
213static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
214{
215 return 0;
216}
217
218static
219snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
220{
221 unsigned long flags;
222 snd_pcm_uframes_t hwptr_done;
223 struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
224
225 spin_lock_irqsave(&cxsc->slock, flags);
226 hwptr_done = cxsc->hwptr_done_capture;
227 spin_unlock_irqrestore(lock: &cxsc->slock, flags);
228
229 return hwptr_done;
230}
231
232static 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,
238};
239
240int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
241{
242 struct snd_pcm *sp;
243 struct snd_card *sc = cxsc->sc;
244 struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
245 struct cx18 *cx = to_cx18(v4l2_dev);
246 int ret;
247
248 ret = snd_pcm_new(card: sc, id: "CX23418 PCM",
249 device: 0, /* PCM device 0, the only one for this card */
250 playback_count: 0, /* 0 playback substreams */
251 capture_count: 1, /* 1 capture substream */
252 rpcm: &sp);
253 if (ret) {
254 CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
255 __func__, ret);
256 goto err_exit;
257 }
258
259 spin_lock_init(&cxsc->slock);
260
261 snd_pcm_set_ops(pcm: sp, direction: SNDRV_PCM_STREAM_CAPTURE,
262 ops: &snd_cx18_pcm_capture_ops);
263 snd_pcm_set_managed_buffer_all(pcm: sp, SNDRV_DMA_TYPE_VMALLOC, NULL, size: 0, max: 0);
264 sp->info_flags = 0;
265 sp->private_data = cxsc;
266 strscpy(sp->name, cx->card_name, sizeof(sp->name));
267
268 return 0;
269
270err_exit:
271 return ret;
272}
273

source code of linux/drivers/media/pci/cx18/cx18-alsa-pcm.c