path: root/drivers/media/usb/em28xx/em28xx-audio.c

/*
 *  Empiatech em28x1 audio extension
 *
 *  Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
 *
 *  Copyright (C) 2007-2014 Mauro Carvalho Chehab
 *	- Port to work with the in-kernel driver
 *	- Cleanups, fixes, alsa-controls, etc.
 *
 *  This driver is based on my previous au600 usb pstn audio driver
 *  and inherits all the copyrights
 *
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/usb.h>
#include <linux/init.h>
#include <linux/sound.h>
#include <linux/spinlock.h>
#include <linux/soundcard.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/info.h>
#include <sound/initval.h>
#include <sound/control.h>
#include <sound/tlv.h>
#include <sound/ac97_codec.h>
#include <media/v4l2-common.h>
#include "em28xx.h"

static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "activates debug info");

#define EM28XX_MAX_AUDIO_BUFS		5
#define EM28XX_MIN_AUDIO_PACKETS	64

#define dprintk(fmt, arg...) do {					\
	    if (debug)							\
		printk(KERN_INFO "em28xx-audio %s: " fmt,		\
				  __func__, ##arg); 		\
	} while (0)

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;

static int em28xx_deinit_isoc_audio(struct em28xx *dev)
{
	int i;

	dprintk("Stopping isoc\n");
	for (i = 0; i < dev->adev.num_urb; i++) {
		struct urb *urb = dev->adev.urb[i];

		if (!irqs_disabled())
			usb_kill_urb(urb);
		else
			usb_unlink_urb(urb);
	}

	return 0;
}

static void em28xx_audio_isocirq(struct urb *urb)
{
	struct em28xx            *dev = urb->context;
	int                      i;
	unsigned int             oldptr;
	int                      period_elapsed = 0;
	int                      status;
	unsigned char            *cp;
	unsigned int             stride;
	struct snd_pcm_substream *substream;
	struct snd_pcm_runtime   *runtime;

	if (dev->disconnected) {
		dprintk("device disconnected while streaming. URB status=%d.\n", urb->status);
		atomic_set(&dev->stream_started, 0);
		return;
	}

	switch (urb->status) {
	case 0:             /* success */
	case -ETIMEDOUT:    /* NAK */
		break;
	case -ECONNRESET:   /* kill */
	case -ENOENT:
	case -ESHUTDOWN:
		return;
	default:            /* error */
		dprintk("urb completition error %d.\n", urb->status);
		break;
	}

	if (atomic_read(&dev->stream_started) == 0)
		return;

	if (dev->adev.capture_pcm_substream) {
		substream = dev->adev.capture_pcm_substream;
		runtime = substream->runtime;
		stride = runtime->frame_bits >> 3;

		for (i = 0; i < urb->number_of_packets; i++) {
			int length =
			    urb->iso_frame_desc[i].actual_length / stride;
			cp = (unsigned char *)urb->transfer_buffer +
			    urb->iso_frame_desc[i].offset;

			if (!length)
				continue;

			oldptr = dev->adev.hwptr_done_capture;
			if (oldptr + length >= runtime->buffer_size) {
				unsigned int cnt =
				    runtime->buffer_size - oldptr;
				memcpy(runtime->dma_area + oldptr * stride, cp,
				       cnt * stride);
				memcpy(runtime->dma_area, cp + cnt * stride,
				       length * stride - cnt * stride);
			} else {
				memcpy(runtime->dma_area + oldptr * stride, cp,
				       length * stride);
			}

			snd_pcm_stream_lock(substream);

			dev->adev.hwptr_done_capture += length;
			if (dev->adev.hwptr_done_capture >=
			    runtime->buffer_size)
				dev->adev.hwptr_done_capture -=
				    runtime->buffer_size;

			dev->adev.capture_transfer_done += length;
			if (dev->adev.capture_transfer_done >=
			    runtime->period_size) {
				dev->adev.capture_transfer_done -=
				    runtime->period_size;