linux/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);