1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  ALSA PCM device for the
4 *  ALSA interface to ivtv PCM capture streams
5 *
6 *  Copyright (C) 2009,2012  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 for the cx18 driver
10 */
11
12#include "ivtv-driver.h"
13#include "ivtv-queue.h"
14#include "ivtv-streams.h"
15#include "ivtv-fileops.h"
16#include "ivtv-alsa.h"
17#include "ivtv-alsa-pcm.h"
18
19#include <sound/core.h>
20#include <sound/pcm.h>
21
22
23static unsigned int pcm_debug;
24module_param(pcm_debug, int, 0644);
25MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
26
27#define dprintk(fmt, arg...) \
28	do { \
29		if (pcm_debug) \
30			pr_info("ivtv-alsa-pcm %s: " fmt, __func__, ##arg); \
31	} while (0)
32
33static const struct snd_pcm_hardware snd_ivtv_hw_capture = {
34	.info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
35		SNDRV_PCM_INFO_MMAP           |
36		SNDRV_PCM_INFO_INTERLEAVED    |
37		SNDRV_PCM_INFO_MMAP_VALID,
38
39	.formats = SNDRV_PCM_FMTBIT_S16_LE,
40
41	.rates = SNDRV_PCM_RATE_48000,
42
43	.rate_min = 48000,
44	.rate_max = 48000,
45	.channels_min = 2,
46	.channels_max = 2,
47	.buffer_bytes_max = 62720 * 8,	/* just about the value in usbaudio.c */
48	.period_bytes_min = 64,		/* 12544/2, */
49	.period_bytes_max = 12544,
50	.periods_min = 2,
51	.periods_max = 98,		/* 12544, */
52};
53
54static void ivtv_alsa_announce_pcm_data(struct snd_ivtv_card *itvsc,
55					u8 *pcm_data,
56					size_t num_bytes)
57{
58	struct snd_pcm_substream *substream;
59	struct snd_pcm_runtime *runtime;
60	unsigned int oldptr;
61	unsigned int stride;
62	int period_elapsed = 0;
63	int length;
64
65	dprintk("ivtv alsa announce ptr=%p data=%p num_bytes=%zu\n", itvsc,
66		pcm_data, num_bytes);
67
68	substream = itvsc->capture_pcm_substream;
69	if (substream == NULL) {
70		dprintk("substream was NULL\n");
71		return;
72	}
73
74	runtime = substream->runtime;
75	if (runtime == NULL) {
76		dprintk("runtime was NULL\n");
77		return;
78	}
79
80	stride = runtime->frame_bits >> 3;
81	if (stride == 0) {
82		dprintk("stride is zero\n");
83		return;
84	}
85
86	length = num_bytes / stride;
87	if (length == 0) {
88		dprintk("%s: length was zero\n", __func__);
89		return;
90	}
91
92	if (runtime->dma_area == NULL) {
93		dprintk("dma area was NULL - ignoring\n");
94		return;
95	}
96
97	oldptr = itvsc->hwptr_done_capture;
98	if (oldptr + length >= runtime->buffer_size) {
99		unsigned int cnt =
100			runtime->buffer_size - oldptr;
101		memcpy(runtime->dma_area + oldptr * stride, pcm_data,
102		       cnt * stride);
103		memcpy(runtime->dma_area, pcm_data + cnt * stride,
104		       length * stride - cnt * stride);
105	} else {
106		memcpy(runtime->dma_area + oldptr * stride, pcm_data,
107		       length * stride);
108	}
109	snd_pcm_stream_lock(substream);
110
111	itvsc->hwptr_done_capture += length;
112	if (itvsc->hwptr_done_capture >=
113	    runtime->buffer_size)
114		itvsc->hwptr_done_capture -=
115			runtime->buffer_size;
116
117	itvsc->capture_transfer_done += length;
118	if (itvsc->capture_transfer_done >=
119	    runtime->period_size) {
120		itvsc->capture_transfer_done -=
121			runtime->period_size;
122		period_elapsed = 1;
123	}
124
125	snd_pcm_stream_unlock(substream);
126
127	if (period_elapsed)
128		snd_pcm_period_elapsed(substream);
129}
130
131static int snd_ivtv_pcm_capture_open(struct snd_pcm_substream *substream)
132{
133	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
134	struct snd_pcm_runtime *runtime = substream->runtime;
135	struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
136	struct ivtv *itv = to_ivtv(v4l2_dev);
137	struct ivtv_stream *s;
138	struct ivtv_open_id item;
139	int ret;
140
141	/* Instruct the CX2341[56] to start sending packets */
142	snd_ivtv_lock(itvsc);
143
144	if (ivtv_init_on_first_open(itv)) {
145		snd_ivtv_unlock(itvsc);
146		return -ENXIO;
147	}
148
149	s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
150
151	v4l2_fh_init(&item.fh, &s->vdev);
152	item.itv = itv;
153	item.type = s->type;
154
155	/* See if the stream is available */
156	if (ivtv_claim_stream(&item, item.type)) {
157		/* No, it's already in use */
158		v4l2_fh_exit(&item.fh);
159		snd_ivtv_unlock(itvsc);
160		return -EBUSY;
161	}
162
163	if (test_bit(IVTV_F_S_STREAMOFF, &s->s_flags) ||
164	    test_and_set_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
165		/* We're already streaming.  No additional action required */
166		snd_ivtv_unlock(itvsc);
167		return 0;
168	}
169
170
171	runtime->hw = snd_ivtv_hw_capture;
172	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
173	itvsc->capture_pcm_substream = substream;
174	runtime->private_data = itv;
175
176	itv->pcm_announce_callback = ivtv_alsa_announce_pcm_data;
177
178	/* Not currently streaming, so start it up */
179	set_bit(IVTV_F_S_STREAMING, &s->s_flags);
180	ret = ivtv_start_v4l2_encode_stream(s);
181	snd_ivtv_unlock(itvsc);
182
183	return ret;
184}
185
186static int snd_ivtv_pcm_capture_close(struct snd_pcm_substream *substream)
187{
188	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
189	struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
190	struct ivtv *itv = to_ivtv(v4l2_dev);
191	struct ivtv_stream *s;
192
193	/* Instruct the ivtv to stop sending packets */
194	snd_ivtv_lock(itvsc);
195	s = &itv->streams[IVTV_ENC_STREAM_TYPE_PCM];
196	ivtv_stop_v4l2_encode_stream(s, 0);
197	clear_bit(IVTV_F_S_STREAMING, &s->s_flags);
198
199	ivtv_release_stream(s);
200
201	itv->pcm_announce_callback = NULL;
202	snd_ivtv_unlock(itvsc);
203
204	return 0;
205}
206
207static int snd_ivtv_pcm_prepare(struct snd_pcm_substream *substream)
208{
209	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
210
211	itvsc->hwptr_done_capture = 0;
212	itvsc->capture_transfer_done = 0;
213
214	return 0;
215}
216
217static int snd_ivtv_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
218{
219	return 0;
220}
221
222static
223snd_pcm_uframes_t snd_ivtv_pcm_pointer(struct snd_pcm_substream *substream)
224{
225	unsigned long flags;
226	snd_pcm_uframes_t hwptr_done;
227	struct snd_ivtv_card *itvsc = snd_pcm_substream_chip(substream);
228
229	spin_lock_irqsave(&itvsc->slock, flags);
230	hwptr_done = itvsc->hwptr_done_capture;
231	spin_unlock_irqrestore(&itvsc->slock, flags);
232
233	return hwptr_done;
234}
235
236static const struct snd_pcm_ops snd_ivtv_pcm_capture_ops = {
237	.open		= snd_ivtv_pcm_capture_open,
238	.close		= snd_ivtv_pcm_capture_close,
239	.prepare	= snd_ivtv_pcm_prepare,
240	.trigger	= snd_ivtv_pcm_trigger,
241	.pointer	= snd_ivtv_pcm_pointer,
242};
243
244int snd_ivtv_pcm_create(struct snd_ivtv_card *itvsc)
245{
246	struct snd_pcm *sp;
247	struct snd_card *sc = itvsc->sc;
248	struct v4l2_device *v4l2_dev = itvsc->v4l2_dev;
249	struct ivtv *itv = to_ivtv(v4l2_dev);
250	int ret;
251
252	ret = snd_pcm_new(sc, "CX2341[56] PCM",
253			  0, /* PCM device 0, the only one for this card */
254			  0, /* 0 playback substreams */
255			  1, /* 1 capture substream */
256			  &sp);
257	if (ret) {
258		IVTV_ALSA_ERR("%s: snd_ivtv_pcm_create() failed with err %d\n",
259			      __func__, ret);
260		goto err_exit;
261	}
262
263	spin_lock_init(&itvsc->slock);
264
265	snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
266			&snd_ivtv_pcm_capture_ops);
267	snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
268	sp->info_flags = 0;
269	sp->private_data = itvsc;
270	strscpy(sp->name, itv->card_name, sizeof(sp->name));
271
272	return 0;
273
274err_exit:
275	return ret;
276}
277