path: root/sound/usb/caiaq/audio.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (c) 2006-2008 Daniel Mack, Karsten Wiese
*/

#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/usb.h>
#include <sound/core.h>
#include <sound/pcm.h>

#include "device.h"
#include "audio.h"

#define N_URBS			32
#define CLOCK_DRIFT_TOLERANCE	5
#define FRAMES_PER_URB		8
#define BYTES_PER_FRAME		512
#define CHANNELS_PER_STREAM	2
#define BYTES_PER_SAMPLE	3
#define BYTES_PER_SAMPLE_USB	4
#define MAX_BUFFER_SIZE		(128*1024)
#define MAX_ENDPOINT_SIZE	512

#define ENDPOINT_CAPTURE	2
#define ENDPOINT_PLAYBACK	6

#define MAKE_CHECKBYTE(cdev,stream,i) \
	(stream << 1) | (~(i / (cdev->n_streams * BYTES_PER_SAMPLE_USB)) & 1)

static const struct snd_pcm_hardware snd_usb_caiaq_pcm_hardware = {
	.info 		= (SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_INTERLEAVED |
			   SNDRV_PCM_INFO_BLOCK_TRANSFER),
	.formats 	= SNDRV_PCM_FMTBIT_S24_3BE,
	.rates 		= (SNDRV_PCM_RATE_44100 | SNDRV_PCM_RATE_48000 |
			   SNDRV_PCM_RATE_96000),
	.rate_min	= 44100,
	.rate_max	= 0, /* will overwrite later */
	.channels_min	= CHANNELS_PER_STREAM,
	.channels_max	= CHANNELS_PER_STREAM,
	.buffer_bytes_max = MAX_BUFFER_SIZE,
	.period_bytes_min = 128,
	.period_bytes_max = MAX_BUFFER_SIZE,
	.periods_min	= 1,
	.periods_max	= 1024,
};

static void
activate_substream(struct snd_usb_caiaqdev *cdev,
	           struct snd_pcm_substream *sub)
{
	guard(spinlock)(&cdev->spinlock);

	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
		cdev->sub_playback[sub->number] = sub;
	else
		cdev->sub_capture[sub->number] = sub;
}

static void
deactivate_substream(struct snd_usb_caiaqdev *cdev,
		     struct snd_pcm_substream *sub)
{
	guard(spinlock_irqsave)(&cdev->spinlock);

	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
		cdev->sub_playback[sub->number] = NULL;
	else
		cdev->sub_capture[sub->number] = NULL;
}

static int
all_substreams_zero(struct snd_pcm_substream **subs)
{
	int i;
	for (i = 0; i < MAX_STREAMS; i++)
		if (subs[i] != NULL)
			return 0;
	return 1;
}

static int stream_start(struct snd_usb_caiaqdev *cdev)
{
	int i, ret;
	struct device *dev = caiaqdev_to_dev(cdev);

	dev_dbg(dev, "%s(%p)\n", __func__, cdev);

	if (cdev->streaming)
		return -EINVAL;

	memset(cdev->sub_playback, 0, sizeof(cdev->sub_playback));
	memset(cdev->sub_capture, 0, sizeof(cdev->sub_capture));
	cdev->input_panic = 0;
	cdev->output_panic = 0;
	cdev->first_packet = 4;
	cdev->streaming = 1;
	cdev->warned = 0;

	for (i = 0; i < N_URBS; i++) {
		ret = usb_submit_urb(cdev->data_urbs_in[i], GFP_ATOMIC);
		if (ret) {
			dev_err(dev, "unable to trigger read #%d! (ret %d)\n",
				i, ret);
			cdev->streaming = 0;
			return -EPIPE;
		}
	}

	return 0;
}

static void stream_stop(struct snd_usb_caiaqdev *cdev)
{
	int i;
	struct device *dev = caiaqdev_to_dev(cdev);

	dev_dbg(dev, "%s(%p)\n", __func__, cdev);
	if (!cdev->streaming)
		return;

	cdev->streaming = 0;

	for (i = 0; i < N_URBS; i++) {
		usb_kill_urb(cdev->data_urbs_in[i]);

		if (test_bit(i, &cdev->outurb_active_mask))
			usb_kill_urb(cdev->data_urbs_out[i]);
	}

	cdev->outurb_active_mask = 0;
}

static int snd_usb_caiaq_substream_open(struct snd_pcm_substream *substream)
{
	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(substream);
	struct device *dev = caiaqdev_to_dev(cdev);

	dev_dbg(dev, "%s(%p)\n", __func__, substream);
	substream->runtime->hw = cdev->pcm_info;
	snd_pcm_limit_hw_rates(substream->runtime);

	return 0;
}

static int snd_usb_caiaq_substream_close(struct snd_pcm_substream *substream)
{
	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(substream);
	struct device *dev = caiaqdev_to_dev(cdev);

	dev_dbg(dev, "%s(%p)\n", __func__, substream);
	if (all_substreams_zero(cdev->sub_playback) &&
	    all_substreams_zero(cdev->sub_capture)) {
		/* when the last client has stopped streaming,
		 * all sample rates are allowed again */
		stream_stop(cdev);
		cdev->pcm_info.rates = cdev->samplerates;
	}

	return 0;
}

static int snd_usb_caiaq_pcm_hw_free(struct snd_pcm_substream *sub)
{
	struct snd_usb_caiaqdev *cdev = snd_pcm_substream_chip(sub);
	deactivate_substream(