V4L/DVB (6949): Adds em28xx-audio module

/*

 *  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);