/******************************************************************************
 * usbtouchscreen.c
 * Driver for USB Touchscreens, supporting those devices:
 *  - eGalax Touchkit
 *  - 3M/Microtouch
 *  - ITM
 *  - PanJit TouchSet
 *
 * Copyright (C) 2004-2006 by Daniel Ritz <daniel.ritz@gmx.ch>
 * Copyright (C) by Todd E. Johnson (mtouchusb.c)
 *
 * 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.
 *
 * Driver is based on touchkitusb.c
 * - ITM parts are from itmtouch.c
 * - 3M parts are from mtouchusb.c
 * - PanJit parts are from an unmerged driver by Lanslott Gish
 *
 *****************************************************************************/

//#define DEBUG

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/usb.h>
#include <linux/usb/input.h>


#define DRIVER_VERSION		"v0.3"
#define DRIVER_AUTHOR		"Daniel Ritz <daniel.ritz@gmx.ch>"
#define DRIVER_DESC		"USB Touchscreen Driver"

static int swap_xy;
module_param(swap_xy, bool, 0644);
MODULE_PARM_DESC(swap_xy, "If set X and Y axes are swapped.");

/* device specifc data/functions */
struct usbtouch_usb;
struct usbtouch_device_info {
	int min_xc, max_xc;
	int min_yc, max_yc;
	int min_press, max_press;
	int rept_size;
	int flags;

	void (*process_pkt) (struct usbtouch_usb *usbtouch, struct pt_regs *regs, unsigned char *pkt, int len);
	int  (*read_data)   (unsigned char *pkt, int *x, int *y, int *touch, int *press);
	int  (*init)        (struct usbtouch_usb *usbtouch);
};

#define USBTOUCH_FLG_BUFFER	0x01


/* a usbtouch device */
struct usbtouch_usb {
	unsigned char *data;
	dma_addr_t data_dma;
	unsigned char *buffer;
	int buf_len;
	struct urb *irq;
	struct usb_device *udev;
	struct input_dev *input;
	struct usbtouch_device_info *type;
	char name[128];
	char phys[64];
};

static void usbtouch_process_pkt(struct usbtouch_usb *usbtouch,
                                 struct pt_regs *regs, unsigned char *pkt, int len);

/* device types */
enum {
	DEVTPYE_DUMMY = -1,
	DEVTYPE_EGALAX,
	DEVTYPE_PANJIT,
	DEVTYPE_3M,
	DEVTYPE_ITM,
};

static struct usb_device_id usbtouch_devices[] = {
#ifdef CONFIG_USB_TOUCHSCREEN_EGALAX
	{USB_DEVICE(0x3823, 0x0001), .driver_info = DEVTYPE_EGALAX},
	{USB_DEVICE(0x0123, 0x0001), .driver_info = DEVTYPE_EGALAX},
	{USB_DEVICE(0x0eef, 0x0001), .driver_info = DEVTYPE_EGALAX},
	{USB_DEVICE(0x0eef, 0x0002), .driver_info = DEVTYPE_EGALAX},
#endif

#ifdef CONFIG_USB_TOUCHSCREEN_PANJIT
	{USB_DEVICE(0x134c, 0x0001), .driver_info = DEVTYPE_PANJIT},
	{USB_DEVICE(0x134c, 0x0002), .driver_info = DEVTYPE_PANJIT},
	{USB_DEVICE(0x134c, 0x0003), .driver_info = DEVTYPE_PANJIT},
	{USB_DEVICE(0x134c, 0x0004), .driver_info = DEVTYPE_PANJIT},
#endif

#ifdef CONFIG_USB_TOUCHSCREEN_3M
	{USB_DEVICE(0x0596, 0x0001), .driver_info = DEVTYPE_3M},
#endif

#ifdef CONFIG_USB_TOUCHSCREEN_ITM
	{USB_DEVICE(0x0403, 0xf9e9), .driver_info = DEVTYPE_ITM},
#endif

	{}
};


/*****************************************************************************
 * eGalax part
 */

#ifdef CONFIG_USB_TOUCHSCREEN_EGALAX

#define EGALAX_PKT_TYPE_MASK		0xFE
#define EGALAX_PKT_TYPE_REPT		0x80
#define EGALAX_PKT_TYPE_DIAG		0x0A

static int egalax_read_data(unsigned char *pkt, int *x, int *y, int *touch, int *press)
{
	if ((pkt[0] & EGALAX_PKT_TYPE_MASK) != EGALAX_PKT_TYPE_REPT)
		return 0;

	*x = ((pkt[3] & 0x0F) << 7) | (pkt[4] & 0x7F);
	*y = ((pkt[1] & 0x0F) << 7) | (pkt[2] & 0x7F);
	*touch = pkt[0] & 0x01;

	return 1;

}

static int egalax_get_pkt_len(unsigned char *buf)
{
	switch (buf[0] & EGALAX_PKT_TYPE_MASK) {
	case EGALAX_PKT_TYPE_REPT:
		return 5;

	case EGALAX_PKT_TYPE_DIAG:
		return buf[1] + 2;
	}

	return 0;
}

static void egalax_process(struct usbtouch_usb *usbtouch, struct pt_regs *regs,
                           unsigned char *pkt, int len)
{
	unsigned char *buffer;
	int pkt_len, buf_len, pos;

	/* if the buffer contains data, append */
	if (unlikely(usbtouch->buf_len)) {
		int tmp;

		/* if only 1 byte in buffer, add another one to get length */
		if (usbtouch->buf_len == 1)
			usbtouch->buffer[1] = pkt[0];

		pkt_len = egalax_get_pkt_len(usbtouch->buffer);

		/* unknown packet: drop everything */
		if (!pkt_len)
			return;

		/* append, process */
		tmp = pkt_len - usbtouch->buf_len;
		memcpy(usbtouch->buffer + usbtouch->buf_len, pkt, tmp);
		usbtouch_process_pkt(usbtouch, regs, usbtouch->buffer, pkt_len);

		buffer = pkt + tmp;
		buf_len = len - tmp;
	} else {
		buffer = pkt;
		buf_len = len;
	}

	/* only one byte left in buffer */
	if (unlikely(buf_len == 1)) {
		usbtouch->buffer[0] = buffer[0];
		usbtouch->buf_len = 1;
		return;
	}

	/* loop over the buffer */
	pos = 0;
	while (pos < buf_len) {
		/* get packet len */
		pkt_len = egalax_get_pkt_len(buffer + pos);

		/* unknown packet: drop everything */
		if (unlikely(!pkt_len))
			return;

		/* full packet: process */
		if (likely(pkt_len <= buf_len)) {
			usbtouch_process_pkt(usbtouch, regs, buffer + pos, pkt_len);
		} else {
			/* incomplete packet: save in buffer */
			memcpy(usbtouch->buffer, buffer + pos, buf_len - pos);
			usbtouch->buf_len = buf_len - pos;
		}
		pos += pkt_len;
	}
}
#endif


/*****************************************************************************
 * PanJit Part
 */
#ifdef CONFIG_USB_TOUCHSCREEN_PANJIT
static int panjit_read_data(unsigned char *pkt, int *x, int *y, int *touch, int *press)
{
	*x = ((pkt[2] & 0x0F) << 8) | pkt[1];
	*y = ((pkt[4] & 0x0F) << 8) | pkt[3];
	*touch = pkt[0] & 0x01;

	return 1;
}
#endif


/*****************************************************************************
 * 3M/Microtouch Part
 */
#ifdef CONFIG_USB_TOUCHSCREEN_3M

#define MTOUCHUSB_ASYNC_REPORT          1
#define MTOUCHUSB_RESET                 7
#define MTOUCHUSB_REQ_CTRLLR_ID         10

static int mtouch_read_data(unsigned char *pkt, int *x, int *y, int *touch, int *press)
{
	*x = (pkt[8] << 8) | pkt[7];
	*y = (pkt[10] << 8) | pkt[9];
	*touch = (pkt[2] & 0x40) ? 1 : 0;

	return 1;
}

static int mtouch_init(struct usbtouch_usb *usbtouch)
{
	int ret;

	ret = usb_control_msg(usbtouch->udev, usb_rcvctrlpipe(usbtouch->udev, 0),
	                      MTOUCHUSB_RESET,
	                      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
	                      1, 0, NULL, 0, USB_CTRL_SET_TIMEOUT);
	dbg("%s - usb_control_msg - MTOUCHUSB_RESET - bytes|err: %d",
	    __FUNCTION__, ret);
	if (ret < 0)
		return ret;

	ret = usb_control_msg(usbtouch->udev, usb_rcvctrlpipe(usbtouch->udev, 0),
	                      MTOUCHUSB_ASYNC_REPORT,
	                      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
	                      1, 1, NULL, 0, USB_CTRL_SET_TIMEOUT);
	dbg("%s - usb_control_msg - MTOUCHUSB_ASYNC_REPORT - bytes|err: %d",
	    __FUNCTION__, ret);
	if (ret < 0)
		return ret;

	return 0;
}
#endif


/*****************************************************************************
 * ITM Part
 */
#ifdef CONFIG_USB_TOUCHSCREEN_ITM
static int itm_read_data(unsigned char *pkt, int *x, int *y, int *touch, int *press)
{
	*x = ((pkt[0] & 0x1F) << 7) | (pkt[3] & 0x7F);
	*x = ((pkt[1] & 0x1F) << 7) | (pkt[4] & 0x7F);
	*press = ((pkt[2] & 0x1F) << 7) | (pkt[5] & 0x7F);
	*touch = ~pkt[7] & 0x20;

	return 1;
}
#endif


/*****************************************************************************
 * the different device descriptors
 */
static struct usbtouch_device_info usbtouch_dev_info[] = {
#ifdef CONFIG_USB_TOUCHSCREEN_EGALAX
	[DEVTYPE_EGALAX] = {
		.min_xc		= 0x0,
		.max_xc		= 0x07ff,
		.min_yc		= 0x0,
		.max_yc		= 0x07ff,
		.rept_size	= 16,
		.flags		= USBTOUCH_FLG_BUFFER,
		.process_pkt	= egalax_process,
		.read_data	= egalax_read_data,
	},
#endif

#ifdef CONFIG_USB_TOUCHSCREEN_PANJIT
	[DEVTYPE_PANJIT] = {
		.min_xc		= 0x0,
		.max_xc		= 0x0fff,
		.min_yc		= 0x0,
		.max_yc		= 0x0fff,
		.rept_size	= 8,
		.read_data	= panjit_read_data,
	},
#endif

#ifdef CONFIG_USB_TOUCHSCREEN_3M
	[DEVTYPE_3M] = {
		.min_xc		= 0x0,
		.max_xc		= 0x4000,
		.min_yc		= 0x0,
		.max_yc		= 0x4000,
		.rept_size	= 11,
		.read_data	= mtouch_read_data,
		.init		= mtouch_init,
	},
#endif

#ifdef CONFIG_USB_TOUCHSCREEN_ITM
	[DEVTYPE_ITM] = {
		.min_xc		= 0x0,
		.max_xc		= 0x0fff,
		.min_yc		= 0x0,
		.max_yc		= 0x0fff,
		.max_press	= 0xff,
		.rept_size	= 8,
		.read_data	= itm_read_data,
	},
#endif
};


/*****************************************************************************
 * Generic Part
 */
static void usbtouch_process_pkt(struct usbtouch_usb *usbtouch,
                                 struct pt_regs *regs, unsigned char *pkt, int len)
{
	int x, y, touch, press;
	struct usbtouch_device_info *type = usbtouch->type;

	if (!type->read_data(pkt, &x, &y, &touch, &press))
			return;

	input_regs(usbtouch->input, regs);
	input_report_key(usbtouch->input, BTN_TOUCH, touch);

	if (swap_xy) {
		input_report_abs(usbtouch->input, ABS_X, y);
		input_report_abs(usbtouch->input, ABS_Y, x);
	} else {
		input_report_abs(usbtouch->input, ABS_X, x);
		input_report_abs(usbtouch->input, ABS_Y, y);
	}
	if (type->max_press)
		input_report_abs(usbtouch->input, ABS_PRESSURE, press);
	input_sync(usbtouch->input);
}


static void usbtouch_irq(struct urb *urb, struct pt_regs *regs)
{
	struct usbtouch_usb *usbtouch = urb->context;
	int retval;

	switch (urb->status) {
	case 0:
		/* success */
		break;
	case -ETIMEDOUT:
		/* this urb is timing out */
		dbg("%s - urb timed out - was the device unplugged?",
		    __FUNCTION__);
		return;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dbg("%s - urb shutting down with status: %d",
		    __FUNCTION__, urb->status);
		return;
	default:
		dbg("%s - nonzero urb status received: %d",
		    __FUNCTION__, urb->status);
		goto exit;
	}

	usbtouch->type->process_pkt(usbtouch, regs, usbtouch->data, urb->actual_length);

exit:
	retval = usb_submit_urb(urb, GFP_ATOMIC);
	if (retval)
		err("%s - usb_submit_urb failed with result: %d",
		    __FUNCTION__, retval);
}

static int usbtouch_open(struct input_dev *input)
{
	struct usbtouch_usb *usbtouch = input->private;

	usbtouch->irq->dev = usbtouch->udev;

	if (usb_submit_urb(usbtouch->irq, GFP_KERNEL))
		return -EIO;

	return 0;
}

static void usbtouch_close(struct input_dev *input)
{
	struct usbtouch_usb *usbtouch = input->private;

	usb_kill_urb(usbtouch->irq);
}


static void usbtouch_free_buffers(struct usb_device *udev,
				  struct usbtouch_usb *usbtouch)
{
	if (usbtouch->data)
		usb_buffer_free(udev, usbtouch->type->rept_size,
		                usbtouch->data, usbtouch->data_dma);
	kfree(usbtouch->buffer);
}


static int usbtouch_probe(struct usb_interface *intf,
			  const struct usb_device_id *id)
{
	struct usbtouch_usb *usbtouch;
	struct input_dev *input_dev;
	struct usb_host_interface *interface;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_device *udev = interface_to_usbdev(intf);
	struct usbtouch_device_info *type;
	int err;

	interface = intf->cur_altsetting;
	endpoint = &interface->endpoint[0].desc;

	usbtouch = kzalloc(sizeof(struct usbtouch_usb), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!usbtouch || !input_dev)
		goto out_free;

	type = &usbtouch_dev_info[id->driver_info];
	usbtouch->type = type;
	if (!type->process_pkt)
		type->process_pkt = usbtouch_process_pkt;

	usbtouch->data = usb_buffer_alloc(udev, type->rept_size,
	                                  SLAB_KERNEL, &usbtouch->data_dma);
	if (!usbtouch->data)
		goto out_free;

	if (type->flags & USBTOUCH_FLG_BUFFER) {
		usbtouch->buffer = kmalloc(type->rept_size, GFP_KERNEL);
		if (!usbtouch->buffer)
			goto out_free_buffers;
	}

	usbtouch->irq = usb_alloc_urb(0, GFP_KERNEL);
	if (!usbtouch->irq) {
		dbg("%s - usb_alloc_urb failed: usbtouch->irq", __FUNCTION__);
		goto out_free_buffers;
	}

	usbtouch->udev = udev;
	usbtouch->input = input_dev;

	if (udev->manufacturer)
		strlcpy(usbtouch->name, udev->manufacturer, sizeof(usbtouch->name));

	if (udev->product) {
		if (udev->manufacturer)
			strlcat(usbtouch->name, " ", sizeof(usbtouch->name));
		strlcat(usbtouch->name, udev->product, sizeof(usbtouch->name));
	}

	if (!strlen(usbtouch->name))
		snprintf(usbtouch->name, sizeof(usbtouch->name),
			"USB Touchscreen %04x:%04x",
			 le16_to_cpu(udev->descriptor.idVendor),
			 le16_to_cpu(udev->descriptor.idProduct));

	usb_make_path(udev, usbtouch->phys, sizeof(usbtouch->phys));
	strlcpy(usbtouch->phys, "/input0", sizeof(usbtouch->phys));

	input_dev->name = usbtouch->name;
	input_dev->phys = usbtouch->phys;
	usb_to_input_id(udev, &input_dev->id);
	input_dev->cdev.dev = &intf->dev;
	input_dev->private = usbtouch;
	input_dev->open = usbtouch_open;
	input_dev->close = usbtouch_close;

	input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
	input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
	input_set_abs_params(input_dev, ABS_X, type->min_xc, type->max_xc, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, type->min_yc, type->max_yc, 0, 0);
	if (type->max_press)
		input_set_abs_params(input_dev, ABS_PRESSURE, type->min_press,
		                     type->max_press, 0, 0);

	usb_fill_int_urb(usbtouch->irq, usbtouch->udev,
			 usb_rcvintpipe(usbtouch->udev, 0x81),
			 usbtouch->data, type->rept_size,
			 usbtouch_irq, usbtouch, endpoint->bInterval);

	usbtouch->irq->transfer_dma = usbtouch->data_dma;
	usbtouch->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	/* device specific init */
	if (type->init) {
		err = type->init(usbtouch);
		if (err) {
			dbg("%s - type->init() failed, err: %d", __FUNCTION__, err);
			goto out_free_buffers;
		}
	}

	err = input_register_device(usbtouch->input);
	if (err) {
		dbg("%s - input_register_device failed, err: %d", __FUNCTION__, err);
		goto out_free_buffers;
	}

	usb_set_intfdata(intf, usbtouch);

	return 0;

out_free_buffers:
	usbtouch_free_buffers(udev, usbtouch);
out_free:
	input_free_device(input_dev);
	kfree(usbtouch);
	return -ENOMEM;
}

static void usbtouch_disconnect(struct usb_interface *intf)
{
	struct usbtouch_usb *usbtouch = usb_get_intfdata(intf);

	dbg("%s - called", __FUNCTION__);

	if (!usbtouch)
		return;

	dbg("%s - usbtouch is initialized, cleaning up", __FUNCTION__);
	usb_set_intfdata(intf, NULL);
	usb_kill_urb(usbtouch->irq);
	input_unregister_device(usbtouch->input);
	usb_free_urb(usbtouch->irq);
	usbtouch_free_buffers(interface_to_usbdev(intf), usbtouch);
	kfree(usbtouch);
}

MODULE_DEVICE_TABLE(usb, usbtouch_devices);

static struct usb_driver usbtouch_driver = {
	.name		= "usbtouchscreen",
	.probe		= usbtouch_probe,
	.disconnect	= usbtouch_disconnect,
	.id_table	= usbtouch_devices,
};

static int __init usbtouch_init(void)
{
	return usb_register(&usbtouch_driver);
}

static void __exit usbtouch_cleanup(void)
{
	usb_deregister(&usbtouch_driver);
}

module_init(usbtouch_init);
module_exit(usbtouch_cleanup);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");

MODULE_ALIAS("touchkitusb");
MODULE_ALIAS("itmtouch");
MODULE_ALIAS("mtouchusb");