caiaq-audio.c

linux 内核源代码

/*
 *   Copyright (c) 2006,2007 Daniel Mack, Karsten Wiese
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
*/

#include <sound/driver.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/interrupt.h>
#include <linux/usb.h>
#include <linux/spinlock.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/rawmidi.h>
#ifdef CONFIG_SND_USB_CAIAQ_INPUT
#include <linux/input.h>
#endif

#include "caiaq-device.h"
#include "caiaq-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 ENDPOINT_CAPTURE	2
#define ENDPOINT_PLAYBACK	6

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

static 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 = 4096,
	.period_bytes_max = MAX_BUFFER_SIZE,
	.periods_min	= 1,
	.periods_max	= 1024,
};

static void
activate_substream(struct snd_usb_caiaqdev *dev,
	           struct snd_pcm_substream *sub)
{
	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
		dev->sub_playback[sub->number] = sub;
	else
		dev->sub_capture[sub->number] = sub;
}

static void 
deactivate_substream(struct snd_usb_caiaqdev *dev,
		     struct snd_pcm_substream *sub)
{
	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
		dev->sub_playback[sub->number] = NULL;
	else
		dev->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 *dev)
{
	int i, ret;

	debug("stream_start(%p)\n", dev);
	spin_lock_irq(&dev->spinlock);
	if (dev->streaming) {
		spin_unlock_irq(&dev->spinlock);
		return -EINVAL;
	}

	dev->input_panic = 0;
	dev->output_panic = 0;
	dev->first_packet = 1;
	dev->streaming = 1;

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

static void stream_stop(struct snd_usb_caiaqdev *dev)
{
	int i;
	
	debug("stream_stop(%p)\n", dev);
	if (!dev->streaming)
		return;
	
	dev->streaming = 0;
	for (i = 0; i < N_URBS; i++) {
		usb_unlink_urb(dev->data_urbs_in[i]);
		usb_unlink_urb(dev->data_urbs_out[i]);
	}
}

static int snd_usb_caiaq_substream_open(struct snd_pcm_substream *substream)
{
	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
	debug("snd_usb_caiaq_substream_open(%p)\n", substream);
	substream->runtime->hw = dev->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 *dev = snd_pcm_substream_chip(substream);

	debug("snd_usb_caiaq_substream_close(%p)\n", substream);
	if (all_substreams_zero(dev->sub_playback) &&
	    all_substreams_zero(dev->sub_capture)) {
		/* when the last client has stopped streaming, 
		 * all sample rates are allowed again */
		stream_stop(dev);
		dev->pcm_info.rates = dev->samplerates;
	}
	
	return 0;
}

static int snd_usb_caiaq_pcm_hw_params(struct snd_pcm_substream *sub,
			     		struct snd_pcm_hw_params *hw_params)
{
	debug("snd_usb_caiaq_pcm_hw_params(%p)\n", sub);
	return snd_pcm_lib_malloc_pages(sub, params_buffer_bytes(hw_params));
}

static int snd_usb_caiaq_pcm_hw_free(struct snd_pcm_substream *sub)
{
	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);
	debug("snd_usb_caiaq_pcm_hw_free(%p)\n", sub);
	spin_lock_irq(&dev->spinlock);
	deactivate_substream(dev, sub);
	spin_unlock_irq(&dev->spinlock);
	return snd_pcm_lib_free_pages(sub);
}

/* this should probably go upstream */
#if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
#error "Change this table"
#endif

static unsigned int rates[] = { 5512, 8000, 11025, 16000, 22050, 32000, 44100,
                                 48000, 64000, 88200, 96000, 176400, 192000 };

static int snd_usb_caiaq_pcm_prepare(struct snd_pcm_substream *substream)
{
	int bytes_per_sample, bpp, ret, i;
	int index = substream->number;
	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;

	debug("snd_usb_caiaq_pcm_prepare(%p)\n", substream);
	
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		dev->audio_out_buf_pos[index] = BYTES_PER_SAMPLE + 1;
	else
		dev->audio_in_buf_pos[index] = 0;
	
	if (dev->streaming)
		return 0;
	
	/* the first client that opens a stream defines the sample rate
	 * setting for all subsequent calls, until the last client closed. */
	for (i=0; i < ARRAY_SIZE(rates); i++)
		if (runtime->rate == rates[i])
			dev->pcm_info.rates = 1 << i;
	
	snd_pcm_limit_hw_rates(runtime);

	bytes_per_sample = BYTES_PER_SAMPLE;
	if (dev->spec.data_alignment == 2)
		bytes_per_sample++;
	
	bpp = ((runtime->rate / 8000) + CLOCK_DRIFT_TOLERANCE)
		* bytes_per_sample * CHANNELS_PER_STREAM * dev->n_streams;
	
	ret = snd_usb_caiaq_set_audio_params(dev, runtime->rate,
					     runtime->sample_bits, bpp);
	if (ret)
		return ret;

	ret = stream_start(dev);
	if (ret)
		return ret;
	
	dev->output_running = 0;
	wait_event_timeout(dev->prepare_wait_queue, dev->output_running, HZ);
	if (!dev->output_running) {
		stream_stop(dev);
		return -EPIPE;
	}

	return 0;
}

static int snd_usb_caiaq_pcm_trigger(struct snd_pcm_substream *sub, int cmd)
{
	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		spin_lock(&dev->spinlock);
		activate_substream(dev, sub);
		spin_unlock(&dev->spinlock);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		spin_lock(&dev->spinlock);
		deactivate_substream(dev, sub);
		spin_unlock(&dev->spinlock);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static snd_pcm_uframes_t
snd_usb_caiaq_pcm_pointer(struct snd_pcm_substream *sub)
{
	int index = sub->number;
	struct snd_usb_caiaqdev *dev = snd_pcm_substream_chip(sub);

	if (dev->input_panic || dev->output_panic)
		return SNDRV_PCM_POS_XRUN;

	if (sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
		return bytes_to_frames(sub->runtime, 
					dev->audio_out_buf_pos[index]);
	else
		return bytes_to_frames(sub->runtime,
					dev->audio_in_buf_pos[index]);
}

/* operators for both playback and capture */
static struct snd_pcm_ops snd_usb_caiaq_ops = {
	.open =		snd_usb_caiaq_substream_open,
	.close =	snd_usb_caiaq_substream_close,
	.ioctl =	snd_pcm_lib_ioctl,
	.hw_params =	snd_usb_caiaq_pcm_hw_params,
	.hw_free =	snd_usb_caiaq_pcm_hw_free,
	.prepare =	snd_usb_caiaq_pcm_prepare,
	.trigger =	snd_usb_caiaq_pcm_trigger,
	.pointer =	snd_usb_caiaq_pcm_pointer
};
	
static void check_for_elapsed_periods(struct snd_usb_caiaqdev *dev,
				      struct snd_pcm_substream **subs)
{
	int stream, pb, *cnt;
	struct snd_pcm_substream *sub;

	for (stream = 0; stream < dev->n_streams; stream++) {
		sub = subs[stream];
		if (!sub)
			continue;

		pb = frames_to_bytes(sub->runtime, 
				     sub->runtime->period_size);
		cnt = (sub->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
					&dev->period_out_count[stream] :
					&dev->period_in_count[stream];

		if (*cnt >= pb) {
			snd_pcm_period_elapsed(sub);
			*cnt %= pb;
		}
	}
}

static void read_in_urb_mode0(struct snd_usb_caiaqdev *dev,
			      const struct urb *urb,
			      const struct usb_iso_packet_descriptor *iso)
{
	unsigned char *usb_buf = urb->transfer_buffer + iso->offset;
	struct snd_pcm_substream *sub;
	int stream, i;

	if (all_substreams_zero(dev->sub_capture))
		return;

	spin_lock(&dev->spinlock);
	
	for (i = 0; i < iso->actual_length;) {
		for (stream = 0; stream < dev->n_streams; stream++, i++) {
			sub = dev->sub_capture[stream];
			if (sub) {
				struct snd_pcm_runtime *rt = sub->runtime;
				char *audio_buf = rt->dma_area;
				int sz = frames_to_bytes(rt, rt->buffer_size);
				audio_buf[dev->audio_in_buf_pos[stream]++] 
					= usb_buf[i];
				dev->period_in_count[stream]++;
				if (dev->audio_in_buf_pos[stream] == sz)
					dev->audio_in_buf_pos[stream] = 0;
			}
		}
	}
	
	spin_unlock(&dev->spinlock);
}

static void read_in_urb_mode2(struct snd_usb_caiaqdev *dev,