// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ALSA PCM device for the
* ALSA interface to cx18 PCM capture streams
*
* Copyright (C) 2009 Andy Walls <[email protected]>
* Copyright (C) 2009 Devin Heitmueller <[email protected]>
*
* Portions of this work were sponsored by ONELAN Limited.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <media/v4l2-device.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include "cx18-driver.h"
#include "cx18-queue.h"
#include "cx18-streams.h"
#include "cx18-fileops.h"
#include "cx18-alsa.h"
#include "cx18-alsa-pcm.h"
static unsigned int pcm_debug;
module_param(pcm_debug, int, 0644);
MODULE_PARM_DESC(pcm_debug, "enable debug messages for pcm");
#define dprintk(fmt, arg...) do { \
if (pcm_debug) \
printk(KERN_INFO "cx18-alsa-pcm %s: " fmt, \
__func__, ##arg); \
} while (0)
static const struct snd_pcm_hardware snd_cx18_hw_capture = {
.info = SNDRV_PCM_INFO_BLOCK_TRANSFER |
SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_MMAP_VALID,
.formats = SNDRV_PCM_FMTBIT_S16_LE,
.rates = SNDRV_PCM_RATE_48000,
.rate_min = 48000,
.rate_max = 48000,
.channels_min = 2,
.channels_max = 2,
.buffer_bytes_max = 62720 * 8, /* just about the value in usbaudio.c */
.period_bytes_min = 64, /* 12544/2, */
.period_bytes_max = 12544,
.periods_min = 2,
.periods_max = 98, /* 12544, */
};
void cx18_alsa_announce_pcm_data(struct snd_cx18_card *cxsc, u8 *pcm_data,
size_t num_bytes)
{
struct snd_pcm_substream *substream;
struct snd_pcm_runtime *runtime;
unsigned int oldptr;
unsigned int stride;
int period_elapsed = 0;
int length;
dprintk("cx18 alsa announce ptr=%p data=%p num_bytes=%zu\n", cxsc,
pcm_data, num_bytes);
substream = cxsc->capture_pcm_substream;
if (substream == NULL) {
dprintk("substream was NULL\n");
return;
}
runtime = substream->runtime;
if (runtime == NULL) {
dprintk("runtime was NULL\n");
return;
}
stride = runtime->frame_bits >> 3;
if (stride == 0) {
dprintk("stride is zero\n");
return;
}
length = num_bytes / stride;
if (length == 0) {
dprintk("%s: length was zero\n", __func__);
return;
}
if (runtime->dma_area == NULL) {
dprintk("dma area was NULL - ignoring\n");
return;
}
oldptr = cxsc->hwptr_done_capture;
if (oldptr + length >= runtime->buffer_size) {
unsigned int cnt =
runtime->buffer_size - oldptr;
memcpy(runtime->dma_area + oldptr * stride, pcm_data,
cnt * stride);
memcpy(runtime->dma_area, pcm_data + cnt * stride,
length * stride - cnt * stride);
} else {
memcpy(runtime->dma_area + oldptr * stride, pcm_data,
length * stride);
}
snd_pcm_stream_lock(substream);
cxsc->hwptr_done_capture += length;
if (cxsc->hwptr_done_capture >=
runtime->buffer_size)
cxsc->hwptr_done_capture -=
runtime->buffer_size;
cxsc->capture_transfer_done += length;
if (cxsc->capture_transfer_done >=
runtime->period_size) {
cxsc->capture_transfer_done -=
runtime->period_size;
period_elapsed = 1;
}
snd_pcm_stream_unlock(substream);
if (period_elapsed)
snd_pcm_period_elapsed(substream);
}
static int snd_cx18_pcm_capture_open(struct snd_pcm_substream *substream)
{
struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
struct snd_pcm_runtime *runtime = substream->runtime;
struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
struct cx18 *cx = to_cx18(v4l2_dev);
struct cx18_stream *s;
struct cx18_open_id item;
int ret;
/* Instruct the cx18 to start sending packets */
snd_cx18_lock(cxsc);
s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
item.cx = cx;
item.type = s->type;
item.open_id = cx->open_id++;
/* See if the stream is available */
if (cx18_claim_stream(&item, item.type)) {
/* No, it's already in use */
snd_cx18_unlock(cxsc);
return -EBUSY;
}
if (test_bit(CX18_F_S_STREAMOFF, &s->s_flags) ||
test_and_set_bit(CX18_F_S_STREAMING, &s->s_flags)) {
/* We're already streaming. No additional action required */
snd_cx18_unlock(cxsc);
return 0;
}
runtime->hw = snd_cx18_hw_capture;
snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
cxsc->capture_pcm_substream = substream;
runtime->private_data = cx;
cx->pcm_announce_callback = cx18_alsa_announce_pcm_data;
/* Not currently streaming, so start it up */
set_bit(CX18_F_S_STREAMING, &s->s_flags);
ret = cx18_start_v4l2_encode_stream(s);
snd_cx18_unlock(cxsc);
return ret;
}
static int snd_cx18_pcm_capture_close(struct snd_pcm_substream *substream)
{
struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
struct cx18 *cx = to_cx18(v4l2_dev);
struct cx18_stream *s;
/* Instruct the cx18 to stop sending packets */
snd_cx18_lock(cxsc);
s = &cx->streams[CX18_ENC_STREAM_TYPE_PCM];
cx18_stop_v4l2_encode_stream(s, 0);
clear_bit(CX18_F_S_STREAMING, &s->s_flags);
cx18_release_stream(s);
cx->pcm_announce_callback = NULL;
snd_cx18_unlock(cxsc);
return 0;
}
static int snd_cx18_pcm_prepare(struct snd_pcm_substream *substream)
{
struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
cxsc->hwptr_done_capture = 0;
cxsc->capture_transfer_done = 0;
return 0;
}
static int snd_cx18_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
return 0;
}
static
snd_pcm_uframes_t snd_cx18_pcm_pointer(struct snd_pcm_substream *substream)
{
unsigned long flags;
snd_pcm_uframes_t hwptr_done;
struct snd_cx18_card *cxsc = snd_pcm_substream_chip(substream);
spin_lock_irqsave(&cxsc->slock, flags);
hwptr_done = cxsc->hwptr_done_capture;
spin_unlock_irqrestore(&cxsc->slock, flags);
return hwptr_done;
}
static const struct snd_pcm_ops snd_cx18_pcm_capture_ops = {
.open = snd_cx18_pcm_capture_open,
.close = snd_cx18_pcm_capture_close,
.prepare = snd_cx18_pcm_prepare,
.trigger = snd_cx18_pcm_trigger,
.pointer = snd_cx18_pcm_pointer,
};
int snd_cx18_pcm_create(struct snd_cx18_card *cxsc)
{
struct snd_pcm *sp;
struct snd_card *sc = cxsc->sc;
struct v4l2_device *v4l2_dev = cxsc->v4l2_dev;
struct cx18 *cx = to_cx18(v4l2_dev);
int ret;
ret = snd_pcm_new(sc, "CX23418 PCM",
0, /* PCM device 0, the only one for this card */
0, /* 0 playback substreams */
1, /* 1 capture substream */
&sp);
if (ret) {
CX18_ALSA_ERR("%s: snd_cx18_pcm_create() failed with err %d\n",
__func__, ret);
goto err_exit;
}
spin_lock_init(&cxsc->slock);
snd_pcm_set_ops(sp, SNDRV_PCM_STREAM_CAPTURE,
&snd_cx18_pcm_capture_ops);
snd_pcm_set_managed_buffer_all(sp, SNDRV_DMA_TYPE_VMALLOC, NULL, 0, 0);
sp->info_flags = 0;
sp->private_data = cxsc;
strscpy(sp->name, cx->card_name, sizeof(sp->name));
return 0;
err_exit:
return ret;
}
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