drivers/media/video/em28xx/em28xx-audio.c

/*
 *  Empiatech em28x1 audio extension
 *
 *  Copyright (C) 2006 Markus Rechberger <mrechberger@gmail.com>
 *
 *  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/moduleparam.h>
#include <sound/driver.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 <linux/video_decoder.h>
//#include <media/tuner.h>
#include <media/v4l2-common.h>
#include "em28xx.h"

static int index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;
static int em28xx_cmd(struct em28xx *dev, int cmd, int arg);

static int snd_pcm_alloc_vmalloc_buffer(struct snd_pcm_substream *subs,
					size_t size)
{
	struct snd_pcm_runtime *runtime = subs->runtime;
	if (runtime->dma_area) {
		if (runtime->dma_bytes > size)
			return 0;
		vfree(runtime->dma_area);
	}
	runtime->dma_area = vmalloc(size);
	if (!runtime->dma_area)
		return -ENOMEM;
	runtime->dma_bytes = size;
	return 0;
}

static struct snd_pcm_hardware snd_em28xx_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_CONTINUOUS | SNDRV_PCM_RATE_KNOT,
	.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,
};

static int snd_em28xx_capture_open(struct snd_pcm_substream *substream)
{
	int ret = 0;
	int mode;
	struct em28xx *dev = snd_pcm_substream_chip(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	printk("opening radio device and trying to acquire exclusive lock\n");
	switch (dev->mode) {
	case TUNER_STUB_DVBC_TV:
	case TUNER_STUB_DVBT_TV:
	case TUNER_STUB_ATSC_TV:
		/* digital has no support for analog audio */
		if (ret != 0) {
			printk("device is already in use by DVB-T\n");
			return -EINVAL;
		} else {
			struct v4l2_tuner tuner;
			printk("switching device to FM mode\n");

			mode = TUNER_STUB_RADIO;
			memset(&tuner, 0x0, sizeof(struct v4l2_tuner));
			tuner.type = V4L2_TUNER_RADIO;

			/* enable GPIO for analog TV */
			dev->em28xx_gpio_control(dev, EM28XX_MODE,
						 (void *)mode);
			dev->mode = mode;
			/* upload firmware */
			tuner_run_cmd(dev->tobj, TUNER_CMD_INIT, (void *)mode);

			/* required for devices which have kerneldriver dependencies */
//                              em28xx_config(dev);
//                              em28xx_config_i2c(dev);

			/* this is moreover to switch the decoder to FM */
			em28xx_i2c_call_clients(dev, VIDIOC_S_TUNER, &tuner);

			dev->em28xx_write_regs(dev, 0x0f, "\x87", 1);
			ret = dev->em28xx_acquire(dev, EM28XX_RADIO, 1);
			em28xx_i2c_call_clients(dev, VIDIOC_INT_RESET, 0);
			/* TODO switch to FM mode */

			printk("em28xx-audio: %d mode\n", mode);
			tuner_run_cmd(dev->tobj, TUNER_CMD_G_MODE, &mode);
			printk("retrieved mode from tuner: %d\n", mode);
		}
		break;

	case TUNER_STUB_ANALOG_TV:
		printk("em28xx-audio: device is currently in analog TV mode\n");
		/* unmute by default */
		dev->em28xx_write_regs(dev, 0x0f, "\x87", 1);
		break;
	case TUNER_STUB_RADIO:
		/* check current mode and put a hard lock onto it */
		printk
		    ("em28xx-audio: device is currently in analogue FM mode\n");
		/* unmute by default here */
		dev->em28xx_write_regs(dev, 0x0f, "\x87", 1);
		ret = dev->em28xx_acquire(dev, EM28XX_RADIO, 1);
		if (ret == 0)
			printk("device is locked in fmradio mode now\n");
		break;
	default:
		printk("em28xx-audio: unhandled mode %d\n", dev->mode);
	}

	runtime->hw = snd_em28xx_hw_capture;
	if (dev->alt == 0 && dev->adev->users == 0) {
		int errCode;
		dev->alt = 7;
		errCode = usb_set_interface(dev->udev, 0, 7);
		printk("changing alternate number to 7\n");
	}
	dev->adev->users++;
	snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
	dev->adev->capture_pcm_substream = substream;
	runtime->private_data = dev;
	return 0;
}

static int snd_em28xx_pcm_close(struct snd_pcm_substream *substream)
{
	struct em28xx *dev = snd_pcm_substream_chip(substream);
	int amode = 0;
	dev->adev->users--;

	/* decrease audio reference */
	switch (dev->mode) {
	case TUNER_STUB_ANALOG_TV:
		amode = EM28XX_VIDEO;
		break;
	case TUNER_STUB_RADIO:
		amode = EM28XX_RADIO;
		break;
	default:
		printk("invalid mode: %d\n", dev->mode);
		break;
	}

	dev->em28xx_acquire(dev, amode, 0);

	if (dev->adev->users == 0 && dev->adev->shutdown == 1) {
		printk("audio users: %d\n", dev->adev->users);
		printk("disabling audio stream!\n");
		dev->adev->shutdown = 0;
		printk("released lock\n");
		em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, 0);
	}
	return 0;
}

static int snd_em28xx_hw_capture_params(struct snd_pcm_substream *substream,
					struct snd_pcm_hw_params *hw_params)
{
	unsigned int channels, rate, format;
	int ret;
	ret =
	    snd_pcm_alloc_vmalloc_buffer(substream,
					 params_buffer_bytes(hw_params));
	format = params_format(hw_params);
	rate = params_rate(hw_params);
	channels = params_channels(hw_params);
	/* TODO: set up em28xx audio chip to deliver the correct audio format, current default is 48000hz multiplexed => 96000hz mono
	   which shouldn't matter since analogue TV only supports mono */
	return 0;
}

static int snd_em28xx_hw_capture_free(struct snd_pcm_substream *substream)
{
	struct em28xx *dev = snd_pcm_substream_chip(substream);
	if (dev->adev->capture_stream == STREAM_ON) {
		em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, 0);
	}
	return 0;
}

static int snd_em28xx_prepare(struct snd_pcm_substream *substream)
{
	return 0;
}

static int snd_em28xx_capture_trigger(struct snd_pcm_substream *substream,
				      int cmd)
{
	struct em28xx *dev = snd_pcm_substream_chip(substream);
	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		em28xx_cmd(dev, EM28XX_CAPTURE_STREAM_EN, 1);
		return 0;
	case SNDRV_PCM_TRIGGER_STOP:
		dev->adev->shutdown = 1;
		return 0;
	default:
		return -EINVAL;
	}
}

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

			spin_lock_irqsave(&dev->adev->slock, flags);
			oldptr = dev->adev->hwptr_done_capture;
			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;
				period_elapsed = 1;
			}
			spin_unlock_irqrestore(&dev->adev->slock, flags);

			if (oldptr + length >= runtime->buffer_size) {
				unsigned int cnt =
				    runtime->buffer_size - oldptr - 1;
				memcpy(runtime->dma_area + oldptr * stride, cp,
				       cnt * stride);
				memcpy(runtime->dma_area, cp + cnt,
				       length * stride - cnt * stride);
			} else {
				memcpy(runtime->dma_area + oldptr * stride, cp,
				       length * stride);
			}
		}
		if (period_elapsed) {
			snd_pcm_period_elapsed(substream);
		}
	}
	urb->status = 0;

	if (dev->adev->shutdown)
		return;

	if ((status = usb_submit_urb(urb, GFP_ATOMIC))) {
		em28xx_errdev("resubmit of audio urb failed (error=%i)\n",
			      status);
	}
	return;
}

static int em28xx_isoc_audio_deinit(struct em28xx *dev)
{
	int i;
	for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
		usb_kill_urb(dev->adev->urb[i]);
		usb_free_urb(dev->adev->urb[i]);
		dev->adev->urb[i] = NULL;
	}
	return 0;
}

static int em28xx_init_audio_isoc(struct em28xx *dev)
{
	int i;
	int errCode;
	const int sb_size =
	    EM28XX_NUM_AUDIO_PACKETS * EM28XX_AUDIO_MAX_PACKET_SIZE;

	for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
		struct urb *urb;
		int j, k;
		dev->adev->transfer_buffer[i] = kmalloc(sb_size, GFP_ATOMIC);
		if (!dev->adev->transfer_buffer[i]) {
			return -ENOMEM;
		}
		memset(dev->adev->transfer_buffer[i], 0x80, sb_size);
		urb = usb_alloc_urb(EM28XX_NUM_AUDIO_PACKETS, GFP_ATOMIC);
		if (urb) {
			urb->dev = dev->udev;
			urb->context = dev;
			urb->pipe = usb_rcvisocpipe(dev->udev, 0x83);
			urb->transfer_flags = URB_ISO_ASAP;
			urb->transfer_buffer = dev->adev->transfer_buffer[i];
			urb->interval = 1;
			urb->complete = em28xx_audio_isocirq;
			urb->number_of_packets = EM28XX_NUM_AUDIO_PACKETS;
			urb->transfer_buffer_length = sb_size;
			for (j = k = 0; j < EM28XX_NUM_AUDIO_PACKETS;
			     j++, k += EM28XX_AUDIO_MAX_PACKET_SIZE) {
				urb->iso_frame_desc[j].offset = k;
				urb->iso_frame_desc[j].length =
				    EM28XX_AUDIO_MAX_PACKET_SIZE;
			}
			dev->adev->urb[i] = urb;
		} else {
			return -ENOMEM;
		}
	}
	for (i = 0; i < EM28XX_AUDIO_BUFS; i++) {
		errCode = usb_submit_urb(dev->adev->urb[i], GFP_ATOMIC);
		if (errCode) {
			em28xx_isoc_audio_deinit(dev);
			return errCode;
		}
	}
	return 0;
}

static int em28xx_cmd(struct em28xx *dev, int cmd, int arg)
{
	switch (cmd) {
	case EM28XX_CAPTURE_STREAM_EN:
		if (dev->adev->capture_stream == STREAM_OFF && arg == 1) {
			dev->adev->capture_stream = STREAM_ON;
			em28xx_init_audio_isoc(dev);
		} else if (dev->adev->capture_stream == STREAM_ON && arg == 0) {
			dev->adev->capture_stream = STREAM_OFF;
			em28xx_isoc_audio_deinit(dev);
		} else {
			printk
			    ("An underrun occured very likely... ignoring it\n");
		}
		return 0;
	default:
		return -EINVAL;
	}
}

static snd_pcm_uframes_t snd_em28xx_capture_pointer(struct snd_pcm_substream
						    *substream)
{
	struct em28xx *dev;
	snd_pcm_uframes_t hwptr_done;
	dev = snd_pcm_substream_chip(substream);
	hwptr_done = dev->adev->hwptr_done_capture;
	return hwptr_done;
}

static struct page *snd_pcm_get_vmalloc_page(struct snd_pcm_substream *subs,
					     unsigned long offset)
{
	void *pageptr = subs->runtime->dma_area + offset;
	return vmalloc_to_page(pageptr);
}

static struct snd_pcm_ops snd_em28xx_pcm_capture = {
	.open = snd_em28xx_capture_open,
	.close = snd_em28xx_pcm_close,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = snd_em28xx_hw_capture_params,
	.hw_free = snd_em28xx_hw_capture_free,
	.prepare = snd_em28xx_prepare,
	.trigger = snd_em28xx_capture_trigger,
	.pointer = snd_em28xx_capture_pointer,
	.page = snd_pcm_get_vmalloc_page,
};

static int em28xx_audio_init(struct em28xx *dev)
{
	struct em28xx_audio *adev;
	struct snd_pcm *pcm;
	struct snd_card *card;
	static int devnr;
	int ret;
	int err;
	printk("em28xx-audio.c: probing for em28x1 non standard usbaudio\n");
	printk("em28xx-audio.c: Copyright (C) 2006 Markus Rechberger\n");
	adev = kzalloc(sizeof(*adev), GFP_KERNEL);
	if (!adev) {
		printk("em28xx-audio.c: out of memory\n");
		return -1;
	}
	card = snd_card_new(index[devnr], "Em28xx Audio", THIS_MODULE, 0);
	if (card == NULL) {
		kfree(adev);
		return -ENOMEM;
	}

	spin_lock_init(&adev->slock);
	ret = snd_pcm_new(card, "Em28xx Audio", 0, 0, 1, &pcm);
	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_em28xx_pcm_capture);
	pcm->info_flags = 0;
	pcm->private_data = dev;
	strcpy(pcm->name, "Empia 28xx Capture");
	strcpy(card->driver, "Empia Em28xx Audio");
	strcpy(card->shortname, "Em28xx Audio");
	strcpy(card->longname, "Empia Em28xx Audio");

	if ((err = snd_card_register(card)) < 0) {
		snd_card_free(card);
		return -ENOMEM;
	}
	adev->sndcard = card;
	adev->udev = dev->udev;
	dev->adev = adev;
	return 0;
}

static int em28xx_audio_fini(struct em28xx *dev)
{
	if (dev == NULL)
		return 0;
	if (dev->adev) {
		snd_card_free(dev->adev->sndcard);
		kfree(dev->adev);
		dev->adev = NULL;
	}
	return 0;
}

static struct em28xx_ops audio_ops = {
	.id = EM28XX_AUDIO,
	.name = "Em28xx Audio Extension",
	.init = em28xx_audio_init,
	.fini = em28xx_audio_fini,
};

static int __init em28xx_alsa_register(void)
{
	request_module("em28xx");
	request_module("tuner");
	return em28xx_register_extension(&audio_ops);
}

static void __exit em28xx_alsa_unregister(void)
{
	em28xx_unregister_extension(&audio_ops);
}

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Markus Rechberger <mrechberger@gmail.com>");
MODULE_DESCRIPTION("Em28xx Audio driver");

module_init(em28xx_alsa_register);
module_exit(em28xx_alsa_unregister);