Staging: add line6 usb driver

config LINE6_USB

	tristate "Line6 USB support"

	depends on USB

	help

	  This is a driver for the guitar amp, cab, and effects modeller

	  PODxt Pro by Line6 (and similar devices), supporting the

	  following features:

	    * Reading/writing individual parameters

	    * Reading/writing complete channel, effects setup, and amp

	      setup data

	    * Channel switching

	    * Virtual MIDI interface

	    * Tuner access

	    * Playback/capture/mixer device for any ALSA-compatible PCM

	      audio application

	    * Signal routing (record clean/processed guitar signal,

	      re-amping)

	  Preliminary support for the Variax Workbench is included.

obj-$(CONFIG_LINE6_USB)		+= line6usb.o

line6usb-objs := 		\

		audio.o		\

		capture.o	\

		control.o	\

		driver.o	\

		dumprequest.o	\

		midi.o		\

		midibuf.o	\

		pcm.o		\

		playback.o	\

		pod.o		\

		toneport.o	\

		variax.o

/*

 * Line6 Linux USB driver - 0.8.0

 *

 * Copyright (C) 2004-2009 Markus Grabner (grabner@icg.tugraz.at)

 *

 *	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, version 2.

 *

 */

#include "driver.h"

#include <sound/core.h>

#include <sound/initval.h>

static int line6_index[SNDRV_CARDS] = SNDRV_DEFAULT_IDX;

static char *line6_id[SNDRV_CARDS] = SNDRV_DEFAULT_STR;

/*

	Initialize the Line6 USB audio system.

*/

int line6_init_audio(struct usb_line6 *line6)

{

	static int dev = 0;

	struct snd_card *card;

	card = snd_card_new(line6_index[dev], line6_id[dev], THIS_MODULE, 0);

	if(card == NULL)

		return -ENOMEM;

	line6->card = card;

	strcpy(card->driver, DRIVER_NAME);

	strcpy(card->shortname, "Line6-USB");

	sprintf(card->longname, "Line6 %s at USB %s", line6->properties->name, line6->ifcdev->bus_id);  /* 80 chars - see asound.h */

	return 0;

}

/*

	Register the Line6 USB audio system.

*/

int line6_register_audio(struct usb_line6 *line6)

{

	int err;

	if((err = snd_card_register(line6->card)) < 0)

		return err;

	return 0;

}

/*

	Cleanup the Line6 USB audio system.

*/

void line6_cleanup_audio(struct usb_line6 *line6)

{

	struct snd_card *card = line6->card;

	if(card == 0)

		return;

	snd_card_disconnect(card);

	snd_card_free(card);

	line6->card = 0;

}

/*

 * Line6 Linux USB driver - 0.8.0

 *

 * Copyright (C) 2004-2009 Markus Grabner (grabner@icg.tugraz.at)

 *

 *	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, version 2.

 *

 */

#ifndef AUDIO_H

#define AUDIO_H

#include "driver.h"

extern void line6_cleanup_audio(struct usb_line6 *);

extern int line6_init_audio(struct usb_line6 *);

extern int line6_register_audio(struct usb_line6 *);

#endif

/*

 * Line6 Linux USB driver - 0.8.0

 *

 * Copyright (C) 2004-2009 Markus Grabner (grabner@icg.tugraz.at)

 *

 *	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, version 2.

 *

 */

#include "driver.h"

#include <sound/core.h>

#include <sound/pcm.h>

#include <sound/pcm_params.h>

#include "audio.h"

#include "pcm.h"

#include "pod.h"

/*

	Find a free URB and submit it.

*/

static int submit_audio_in_urb(struct snd_pcm_substream *substream)

{

	int index;

	unsigned long flags;

	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	int i, urb_size;

	struct urb *urb_in;

	spin_lock_irqsave(&line6pcm->lock_audio_in, flags);

	index = find_first_zero_bit(&line6pcm->active_urb_in, LINE6_ISO_BUFFERS);

	if(index < 0 || index >= LINE6_ISO_BUFFERS) {

		spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);

		dev_err(s2m(substream), "no free URB found\n");

		return -EINVAL;

	}

	urb_in = line6pcm->urb_audio_in[index];

	urb_size = 0;

	for(i = 0; i < LINE6_ISO_PACKETS; ++i) {

		struct usb_iso_packet_descriptor *fin = &urb_in->iso_frame_desc[i];

		fin->offset = urb_size;

		fin->length = line6pcm->max_packet_size;

		urb_size += line6pcm->max_packet_size;

	}

	urb_in->transfer_buffer = line6pcm->buffer_in + index * LINE6_ISO_PACKETS * line6pcm->max_packet_size;

	urb_in->transfer_buffer_length = urb_size;

	urb_in->context = substream;

	if(usb_submit_urb(urb_in, GFP_ATOMIC) == 0)

		set_bit(index, &line6pcm->active_urb_in);

	else

		dev_err(s2m(substream), "URB in #%d submission failed\n", index);

	spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);

	return 0;

}

/*

	Submit all currently available capture URBs.

*/

static int submit_audio_in_all_urbs(struct snd_pcm_substream *substream)

{

	int ret, i;

	for(i = 0; i < LINE6_ISO_BUFFERS; ++i)

		if((ret = submit_audio_in_urb(substream)) < 0)

			return ret;

	return 0;

}

/*

	Unlink all currently active capture URBs.

*/

static void unlink_audio_in_urbs(struct snd_line6_pcm *line6pcm)

{

	unsigned int i;

	for(i = LINE6_ISO_BUFFERS; i--;) {

		if(test_bit(i, &line6pcm->active_urb_in)) {

			if(!test_and_set_bit(i, &line6pcm->unlink_urb_in)) {

				struct urb *u = line6pcm->urb_audio_in[i];

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 14)

				u->transfer_flags |= URB_ASYNC_UNLINK;

#endif

				usb_unlink_urb(u);

			}

		}

	}

}

/*

	Wait until unlinking of all currently active capture URBs has been finished.

*/

static void wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)

{

	int timeout = HZ;

	unsigned int i;

	int alive;

	do {

		alive = 0;

		for (i = LINE6_ISO_BUFFERS; i--;) {

			if (test_bit(i, &line6pcm->active_urb_in))

				alive++;

		}

		if (! alive)

			break;

		set_current_state(TASK_UNINTERRUPTIBLE);

		schedule_timeout(1);

	} while (--timeout > 0);

	if (alive)

		snd_printk(KERN_ERR "timeout: still %d active urbs..\n", alive);

	line6pcm->active_urb_in = 0;

	line6pcm->unlink_urb_in = 0;

}

/*

	Unlink all currently active capture URBs, and wait for finishing.

*/

void unlink_wait_clear_audio_in_urbs(struct snd_line6_pcm *line6pcm)

{

	unlink_audio_in_urbs(line6pcm);

	wait_clear_audio_in_urbs(line6pcm);

}

/*

	Callback for completed capture URB.

*/

static void audio_in_callback(struct urb *urb PT_REGS)

{

	int i, index, length = 0, shutdown = 0;

	int frames;

	unsigned long flags;

	struct snd_pcm_substream *substream = (struct snd_pcm_substream *)urb->context;

	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	const int bytes_per_frame = line6pcm->properties->bytes_per_frame;

	struct snd_pcm_runtime *runtime = substream->runtime;

	/* find index of URB */

	for(index = 0; index < LINE6_ISO_BUFFERS; ++index)

		if(urb == line6pcm->urb_audio_in[index])

			break;

#if DO_DUMP_PCM_RECEIVE

	for(i = 0; i < LINE6_ISO_PACKETS; ++i) {

		struct usb_iso_packet_descriptor *fout = &urb->iso_frame_desc[i];

		line6_write_hexdump(line6pcm->line6, 'C', urb->transfer_buffer + fout->offset, fout->length);

	}

#endif

	spin_lock_irqsave(&line6pcm->lock_audio_in, flags);

	for(i = 0; i < LINE6_ISO_PACKETS; ++i) {

		char *fbuf;

		int fsize;

		struct usb_iso_packet_descriptor *fin = &urb->iso_frame_desc[i];

		if(fin->status == -18) {

			shutdown = 1;

			break;

		}

		fbuf = urb->transfer_buffer + fin->offset;

		fsize = fin->actual_length;

		length += fsize;

		if(fsize > 0) {

			frames = fsize / bytes_per_frame;

			if(line6pcm->pos_in_done + frames > runtime->buffer_size) {

				/*

					The transferred area goes over buffer boundary,

					copy two separate chunks.

				*/

				int len;

				len = runtime->buffer_size - line6pcm->pos_in_done;

				if(len > 0) {

					memcpy(runtime->dma_area + line6pcm->pos_in_done * bytes_per_frame, fbuf, len * bytes_per_frame);

					memcpy(runtime->dma_area, fbuf + len * bytes_per_frame, (frames - len) * bytes_per_frame);

				}

				else

					dev_err(s2m(substream), "driver bug: len = %d\n", len);  /* this is somewhat paranoid */

			}

			else {

				/* copy single chunk */

				memcpy(runtime->dma_area + line6pcm->pos_in_done * bytes_per_frame, fbuf, fsize * bytes_per_frame);

			}

			if((line6pcm->pos_in_done += frames) >= runtime->buffer_size)

				line6pcm->pos_in_done -= runtime->buffer_size;

		}

	}

	clear_bit(index, &line6pcm->active_urb_in);

	if(test_bit(index, &line6pcm->unlink_urb_in))

		shutdown = 1;

	spin_unlock_irqrestore(&line6pcm->lock_audio_in, flags);

	if(!shutdown) {

		submit_audio_in_urb(substream);

		if((line6pcm->bytes_in += length) >= line6pcm->period_in) {

			line6pcm->bytes_in -= line6pcm->period_in;

			snd_pcm_period_elapsed(substream);

		}

	}

}

/* open capture callback */

static int snd_line6_capture_open(struct snd_pcm_substream *substream)

{

	int err;

	struct snd_pcm_runtime *runtime = substream->runtime;

	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	if((err = snd_pcm_hw_constraint_ratdens(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,

																					(&line6pcm->properties->snd_line6_rates))) < 0)

		return err;

	runtime->hw = line6pcm->properties->snd_line6_capture_hw;

	return 0;

}

/* close capture callback */

static int snd_line6_capture_close(struct snd_pcm_substream *substream)

{

	return 0;

}

/* hw_params capture callback */

static int snd_line6_capture_hw_params(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *hw_params)

{

	int ret;

	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	/* -- Florian Demski [FD] */

	/* don't ask me why, but this fixes the bug on my machine */

	if ( line6pcm == NULL ) {

		if ( substream->pcm == NULL )

			return -ENOMEM;

		if ( substream->pcm->private_data == NULL )

			return -ENOMEM;

		substream->private_data = substream->pcm->private_data;

		line6pcm = snd_pcm_substream_chip( substream );

	}

	/* -- [FD] end */

	if((ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(hw_params))) < 0)

		return ret;

	line6pcm->period_in = params_period_bytes(hw_params);

	line6pcm->buffer_in = kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS * LINE6_ISO_PACKET_SIZE_MAX, GFP_KERNEL);

	if(!line6pcm->buffer_in) {

		dev_err(s2m(substream), "cannot malloc buffer_in\n");

		return -ENOMEM;

	}

	return 0;

}

/* hw_free capture callback */

static int snd_line6_capture_hw_free(struct snd_pcm_substream *substream)

{

	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	unlink_wait_clear_audio_in_urbs(line6pcm);

	if(line6pcm->buffer_in) {

		kfree(line6pcm->buffer_in);

		line6pcm->buffer_in = 0;

	}

	return snd_pcm_lib_free_pages(substream);

}

/* trigger callback */

int snd_line6_capture_trigger(struct snd_pcm_substream *substream, int cmd)

{

	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	int err;

	line6pcm->count_in = 0;

	switch(cmd) {

	case SNDRV_PCM_TRIGGER_START:

		if(!test_and_set_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags)) {

			err = submit_audio_in_all_urbs(substream);

			if(err < 0) {

				clear_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags);

				return err;

			}

		}

		break;

	case SNDRV_PCM_TRIGGER_STOP:

		if(test_and_clear_bit(BIT_RUNNING_CAPTURE, &line6pcm->flags))

			unlink_audio_in_urbs(line6pcm);

		break;

	default:

		return -EINVAL;

	}

	return 0;

}

/* capture pointer callback */

static snd_pcm_uframes_t

snd_line6_capture_pointer(struct snd_pcm_substream *substream)

{

	struct snd_line6_pcm *line6pcm = snd_pcm_substream_chip(substream);

	return line6pcm->pos_in_done;

}

/* capture operators */

struct snd_pcm_ops snd_line6_capture_ops = {

	.open =        snd_line6_capture_open,

	.close =       snd_line6_capture_close,

	.ioctl =       snd_pcm_lib_ioctl,

	.hw_params =   snd_line6_capture_hw_params,

	.hw_free =     snd_line6_capture_hw_free,

	.prepare =     snd_line6_prepare,

	.trigger =     snd_line6_trigger,

	.pointer =     snd_line6_capture_pointer,

};

int create_audio_in_urbs(struct snd_line6_pcm *line6pcm)

{

	int i;

	/* create audio URBs and fill in constant values: */

	for(i = 0; i < LINE6_ISO_BUFFERS; ++i) {

		struct urb *urb;

		/* URB for audio in: */

		urb = line6pcm->urb_audio_in[i] = usb_alloc_urb(LINE6_ISO_PACKETS, GFP_KERNEL);

		if(urb == NULL) {

			dev_err(line6pcm->line6->ifcdev, "Out of memory\n");

			return -ENOMEM;

		}

		urb->dev = line6pcm->line6->usbdev;

		urb->pipe = usb_rcvisocpipe(line6pcm->line6->usbdev, line6pcm->ep_audio_read & USB_ENDPOINT_NUMBER_MASK);

		urb->transfer_flags = URB_ISO_ASAP;

		urb->start_frame = -1;

		urb->number_of_packets = LINE6_ISO_PACKETS;

		urb->interval = LINE6_ISO_INTERVAL;

		urb->error_count = 0;

		urb->complete = audio_in_callback;

	}

	return 0;

}