ebeam.c

/******************************************************************************
 *
 * eBeam driver
 *
 * Copyright (C) 2012 Yann Cantin (yann.cantin@laposte.net)
 *
 *	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.
 *
 *  based on
 *
 *	usbtouchscreen.c by Daniel Ritz <daniel.ritz@gmx.ch>
 *	aiptek.c (sysfs/settings) by Chris Atenasio <chris@crud.net>
 *				     Bryan W. Headley <bwheadley@earthlink.net>
 *
 *****************************************************************************/

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/math64.h>
#include <linux/input.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/usb.h>
#include <linux/usb/input.h>

#define DRIVER_AUTHOR	"Yann Cantin <yann.cantin@laposte.net>"
#define DRIVER_DESC	"USB eBeam Driver"

/* Common values for eBeam devices */
#define REPT_SIZE	8		/* packet size		  */
#define MIN_RAW_X	0		/* raw coordinates ranges */
#define MAX_RAW_X	0xFFFF
#define MIN_RAW_Y	0
#define MAX_RAW_Y	0xFFFF


#define USB_VENDOR_ID_EFI	0x2650	/* Electronics For Imaging, Inc	*/
#define USB_DEVICE_ID_EFI_EBEAM_BT_USB	0x1320	/* eBeam hardware :	 USB Device in USB	*/
#define USB_DEVICE_ID_EFI_EBEAM_USB	0x1315	/* eBeam hardware :	 BT Device in USB	*/
#define USB_DEVICE_ID_EFI_EBEAM_USB2	0x1311	/* eBeam hardware :	 BT Device in USB	*/
#define USB_DEVICE_ID_EFI_EBEAM_BT	0x1313	/* eBeam hardware :	 BT Device in USB	*/
					/*	Luidia Classic and Edge	*/
					/*	Nec NP01Wi1 & NP01Wi2	*/

#define EBEAM_BTN_TIP	0x1      /* tip    */
#define EBEAM_BTN_LIT	0x2      /* little */
#define EBEAM_BTN_BIG	0x4      /* big    */

/* ebeam settings */
struct ebeam_settings {
	int min_x;	/* computed coordinates ranges for the input layer */
	int max_x;
	int min_y;
	int max_y;

	/* H matrix */
	s64 h1;
	s64 h2;
	s64 h3;
	s64 h4;
	s64 h5;
	s64 h6;
	s64 h7;
	s64 h8;
	s64 h9;
};

/* ebeam device */
struct ebeam_device {
	unsigned char		 *data;
	dma_addr_t		 data_dma;
	unsigned char		 *buffer;
	int			 buf_len;
	struct urb		 *irq;
	struct usb_interface	 *interface;
	struct input_dev	 *input;
	char			 name[128];
	char			 phys[64];
	void			 *priv;

	struct ebeam_settings	 cursetting;	/* device's current settings */
	struct ebeam_settings	 newsetting;	/* ... and new ones	     */

	bool			 calibrated;	/* false : send raw	     */
						/* true  : send computed     */

	u16			 raw_x, raw_y;	/* raw coordinates	     */
	int			 x, y;		/* computed coordinates      */
	int			 btn_map;	/* internal buttons map      */
};

/* device types */
enum {
	DEVTYPE_EBEAM,
};

static const struct usb_device_id ebeam_devices[] = {
	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_USB),
			.driver_info = DEVTYPE_EBEAM},
	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_USB2),
			.driver_info = DEVTYPE_EBEAM},
	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_BT_USB),
			.driver_info = DEVTYPE_EBEAM},
	{USB_DEVICE(USB_VENDOR_ID_EFI, USB_DEVICE_ID_EFI_EBEAM_BT),
				.driver_info = DEVTYPE_EBEAM},
	{},
};

static void ebeam_init_settings(struct ebeam_device *ebeam)
{
	ebeam->calibrated = false;

	/* Init (x,y) min/max to raw ones */
	ebeam->cursetting.min_x = ebeam->newsetting.min_x = MIN_RAW_X;
	ebeam->cursetting.max_x = ebeam->newsetting.max_x = MAX_RAW_X;
	ebeam->cursetting.min_y = ebeam->newsetting.min_y = MIN_RAW_Y;
	ebeam->cursetting.max_y = ebeam->newsetting.max_y = MAX_RAW_Y;

	/* Safe values for the H matrix (Identity) */
	ebeam->cursetting.h1 = ebeam->newsetting.h1 = 1;
	ebeam->cursetting.h2 = ebeam->newsetting.h2 = 0;
	ebeam->cursetting.h3 = ebeam->newsetting.h3 = 0;

	ebeam->cursetting.h4 = ebeam->newsetting.h4 = 0;
	ebeam->cursetting.h5 = ebeam->newsetting.h5 = 1;
	ebeam->cursetting.h6 = ebeam->newsetting.h6 = 0;

	ebeam->cursetting.h7 = ebeam->newsetting.h7 = 0;
	ebeam->cursetting.h8 = ebeam->newsetting.h8 = 0;
	ebeam->cursetting.h9 = ebeam->newsetting.h9 = 1;
}

static void ebeam_setup_input(struct ebeam_device *ebeam,
			      struct input_dev *input_dev)
{
	unsigned long flags;

	/* Take event lock while modifying parameters */
	spin_lock_irqsave(&input_dev->event_lock, flags);

	/* Properties */
	set_bit(INPUT_PROP_DIRECT,  input_dev->propbit);

	/* Events generated */
	set_bit(EV_KEY, input_dev->evbit);
	set_bit(EV_ABS, input_dev->evbit);

	/* Keys */
	set_bit(BTN_LEFT,   input_dev->keybit);
	set_bit(BTN_MIDDLE, input_dev->keybit);
	set_bit(BTN_RIGHT,  input_dev->keybit);

	/* Axis */
	if (!ebeam->calibrated) {
		ebeam->cursetting.min_x = MIN_RAW_X;
		ebeam->cursetting.max_x = MAX_RAW_X;
		ebeam->cursetting.min_y = MIN_RAW_Y;
		ebeam->cursetting.max_y = MAX_RAW_Y;
	}

	input_set_abs_params(input_dev, ABS_X,
			     ebeam->cursetting.min_x, ebeam->cursetting.max_x,
			     0, 0);
	input_set_abs_params(input_dev, ABS_Y,
			     ebeam->cursetting.min_y, ebeam->cursetting.max_y,
			     0, 0);

	spin_unlock_irqrestore(&input_dev->event_lock, flags);
}

/*******************************************************************************
 * sysfs part
 */

/*
 * screen min/max and H matrix coefs
 * _get return *current* value
 * _set set new value
 */
#define DEVICE_MINMAX_ATTR(MM)						       \
static ssize_t ebeam_##MM##_get(struct device *dev,			       \
				struct device_attribute *attr,		       \
				char *buf)				       \
{									       \
	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
									       \
	return snprintf(buf, PAGE_SIZE, "%d\n", ebeam->cursetting.MM);	       \
}									       \
static ssize_t ebeam_##MM##_set(struct device *dev,			       \
				struct device_attribute *attr,		       \
				const char *buf,			       \
				size_t count)				       \
{									       \
	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
	int err, MM;							       \
									       \
	err = kstrtoint(buf, 10, &MM);					       \
	if (err)							       \
		return err;						       \
									       \
	ebeam->newsetting.MM = MM;					       \
	return count;							       \
}									       \
static DEVICE_ATTR(MM, S_IRUGO | S_IWUGO,				       \
		   ebeam_##MM##_get,					       \
		   ebeam_##MM##_set)

DEVICE_MINMAX_ATTR(min_x);
DEVICE_MINMAX_ATTR(max_x);
DEVICE_MINMAX_ATTR(min_y);
DEVICE_MINMAX_ATTR(max_y);

#define DEVICE_H_ATTR(SET_ID)						       \
static ssize_t ebeam_h##SET_ID##_get(struct device *dev,		       \
				     struct device_attribute *attr,	       \
				     char *buf)				       \
{									       \
	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
									       \
	return snprintf(buf, PAGE_SIZE, "%lld\n", ebeam->cursetting.h##SET_ID);\
}									       \
static ssize_t ebeam_h##SET_ID##_set(struct device *dev,		       \
				     struct device_attribute *attr,	       \
				     const char *buf,			       \
				     size_t count)			       \
{									       \
	struct ebeam_device *ebeam = dev_get_drvdata(dev);		       \
	int err;							       \
	u64 h;								       \
									       \
	err = kstrtoll(buf, 10, &h);					       \
	if (err)							       \
		return err;						       \
									       \
	ebeam->newsetting.h##SET_ID = h;				       \
	return count;							       \
}									       \
static DEVICE_ATTR(h##SET_ID, S_IRUGO | S_IWUGO,			       \
		   ebeam_h##SET_ID##_get,				       \
		   ebeam_h##SET_ID##_set)

DEVICE_H_ATTR(1);
DEVICE_H_ATTR(2);
DEVICE_H_ATTR(3);
DEVICE_H_ATTR(4);
DEVICE_H_ATTR(5);
DEVICE_H_ATTR(6);
DEVICE_H_ATTR(7);
DEVICE_H_ATTR(8);
DEVICE_H_ATTR(9);

/*
 * sysfs calibrated
 * Once H matrix coefs are set, writing 1 to this file triggers
 * coordinates mapping.
 * Anything else reset the device to un-calibrated mode,
 * storing cursetting in newsetting.
*/
static ssize_t ebeam_calibrated_get(struct device *dev,
				    struct device_attribute *attr,
				    char *buf)
{
	struct ebeam_device *ebeam = dev_get_drvdata(dev);

	return snprintf(buf, PAGE_SIZE, "%d\n", ebeam->calibrated);
}

static ssize_t ebeam_calibrated_set(struct device *dev,
				    struct device_attribute *attr,
				    const char *buf,
				    size_t count)
{
	struct ebeam_device *ebeam = dev_get_drvdata(dev);
	int err, c;

	err = kstrtoint(buf, 10, &c);
	if (err)
		return err;

	if (c == 1) {
		memcpy(&ebeam->cursetting, &ebeam->newsetting,
		       sizeof(struct ebeam_settings));
		ebeam->calibrated = true;
		ebeam_setup_input(ebeam, ebeam->input);
	} else {
		memcpy(&ebeam->newsetting, &ebeam->cursetting,
		       sizeof(struct ebeam_settings));
		ebeam->calibrated = false;
		ebeam_setup_input(ebeam, ebeam->input);
	}

	return count;
}

static DEVICE_ATTR(calibrated, S_IRUGO | S_IWUGO,
		   ebeam_calibrated_get, ebeam_calibrated_set);

static struct attribute *ebeam_attrs[] = {
	&dev_attr_min_x.attr,
	&dev_attr_min_y.attr,
	&dev_attr_max_x.attr,
	&dev_attr_max_y.attr,
	&dev_attr_h1.attr,
	&dev_attr_h2.attr,
	&dev_attr_h3.attr,
	&dev_attr_h4.attr,
	&dev_attr_h5.attr,
	&dev_attr_h6.attr,
	&dev_attr_h7.attr,
	&dev_attr_h8.attr,
	&dev_attr_h9.attr,
	&dev_attr_calibrated.attr,
	NULL
};

static const struct attribute_group ebeam_attr_group = {
	.attrs = ebeam_attrs,
};

/* IRQ */
static int ebeam_read_data(struct ebeam_device *ebeam, unsigned char *pkt)
{

/*
 * Packet description : 8 bytes
 *
 *  nop packet : FF FF FF FF FF FF FF FF
 *
 *  pkt[0] : Sensors
 *	bit 1 : ultrasound signal (guessed)
 *	bit 2 : IR signal (tested with a remote...) ;
 *	readings OK : 0x03 (anything else is a show-stopper)
 *
 *  pkt[1] : raw_x low
 *  pkt[2] : raw_x high
 *
 *  pkt[3] : raw_y low
 *  pkt[4] : raw_y high
 *
 *  pkt[5] : fiability ?
 *	often 0xC0
 *	> 0x80 : OK
 *
 *  pkt[6] :
 *	buttons state (low 4 bits)
 *		0x1 = no buttons
 *		bit 0 : tip (WARNING inversed : 0=pressed)
 *		bit 1 : ? (always 0 during tests)
 *		bit 2 : little (1=pressed)
 *		bit 3 : big (1=pressed)
 *
 *	pointer ID : (hight 4 bits)
 *		Tested  : 0x6=wand ;
 *		Guessed : 0x1=red ; 0x2=blue ; 0x3=green ; 0x4=black ;
 *			  0x5=eraser
 *		bit 4 : pointer ID
 *		bit 5 : pointer ID
 *		bit 6 : pointer ID
 *		bit 7 : pointer ID
 *
 *
 *  pkt[7] : fiability ?
 *	often 0xFF
 *
 */

	/* Filtering bad/nop packet */
	if (pkt[0] != 0x03)
		return 0;

	ebeam->raw_x = (pkt[2] << 8) | pkt[1];
	ebeam->raw_y = (pkt[4] << 8) | pkt[3];

	ebeam->btn_map = (!(pkt[6] & 0x1))	|
			 ((pkt[6] & 0x4) >> 1)	|
			 ((pkt[6] & 0x8) >> 1);

	return 1;
}

/*
 * IRQ
 * compute screen coordinates from raw
 * Overflow and negative values are user space's problem
 */
static bool ebeam_calculate_xy(struct ebeam_device *ebeam)
{
	/* 64-bits divisions handled by div64_s64 */

	s64 scale;

	if (!ebeam->calibrated) {
		ebeam->x = ebeam->raw_x;
		ebeam->y = ebeam->raw_y;
	} else {
		scale = ebeam->cursetting.h7 * ebeam->raw_x +
			ebeam->cursetting.h8 * ebeam->raw_y +
			ebeam->cursetting.h9;

		/* Who want a division by zero in kernel ? */
		if (scale == 0) {
			dev_err(&(ebeam->interface)->dev,
				"%s - Division by zero, wrong calibration.\n",
				__func__);
			dev_err(&(ebeam->interface)->dev,
				"%s - Resetting to un-calibrated mode.\n",
				__func__);
			ebeam->calibrated = false;
			return 0;
		}

		/*
		 * We *must* round the result, but can't do (int) (v1/v2 + 0.5)
		 *
		 * (int) (v1/v2 + 0.5) <=> (int) ( (2*v1 + v2)/(2*v2) )
		 */
		ebeam->x =
			(int) div64_s64((((ebeam->cursetting.h1 * ebeam->raw_x +
					   ebeam->cursetting.h2 * ebeam->raw_y +
					   ebeam->cursetting.h3) << 1) + scale),
					   (scale << 1));
		ebeam->y =
			(int) div64_s64((((ebeam->cursetting.h4 * ebeam->raw_x +
					   ebeam->cursetting.h5 * ebeam->raw_y +
					   ebeam->cursetting.h6) << 1) + scale),
					   (scale << 1));
	}

	return 1;
}

/* IRQ */
static void ebeam_report_input(struct ebeam_device *ebeam)
{
	input_report_key(ebeam->input, BTN_LEFT,
			 (ebeam->btn_map & EBEAM_BTN_TIP));
	input_report_key(ebeam->input, BTN_MIDDLE,
			 (ebeam->btn_map & EBEAM_BTN_LIT));
	input_report_key(ebeam->input, BTN_RIGHT,
			 (ebeam->btn_map & EBEAM_BTN_BIG));

	input_report_abs(ebeam->input, ABS_X, ebeam->x);
	input_report_abs(ebeam->input, ABS_Y, ebeam->y);

	input_sync(ebeam->input);
}

/* IRQ */
static void ebeam_process_pkt(struct ebeam_device *ebeam,
			      unsigned char *pkt, int len)
{
	if (!ebeam_read_data(ebeam, pkt))
		return;

	if (!ebeam_calculate_xy(ebeam))
		return;

	ebeam_report_input(ebeam);
}

/* IRQ
 * handler */
static void ebeam_irq(struct urb *urb)
{
	struct ebeam_device *ebeam = urb->context;
	struct device *dev = &ebeam->interface->dev;
	int retval;

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

	ebeam_process_pkt(ebeam, ebeam->data, urb->actual_length);

exit:
	usb_mark_last_busy(interface_to_usbdev(ebeam->interface));
	retval = usb_submit_urb(urb, GFP_ATOMIC);
	if (retval)
		dev_err(dev, "%s - usb_submit_urb failed with result: %d\n",
			__func__, retval);
}

static int ebeam_open(struct input_dev *input)
{
	struct ebeam_device *ebeam = input_get_drvdata(input);
	int r;

	ebeam->irq->dev = interface_to_usbdev(ebeam->interface);

	r = usb_autopm_get_interface(ebeam->interface) ? -EIO : 0;
	if (r < 0)
		goto out;

	if (usb_submit_urb(ebeam->irq, GFP_KERNEL)) {
		r = -EIO;
		goto out_put;
	}

	ebeam->interface->needs_remote_wakeup = 1;
out_put:
	usb_autopm_put_interface(ebeam->interface);
out:
	return r;
}

static void ebeam_close(struct input_dev *input)
{
	struct ebeam_device *ebeam = input_get_drvdata(input);
	int r;

	usb_kill_urb(ebeam->irq);

	r = usb_autopm_get_interface(ebeam->interface);
	ebeam->interface->needs_remote_wakeup = 0;

	if (!r)
		usb_autopm_put_interface(ebeam->interface);
}

static int ebeam_suspend(struct usb_interface *intf, pm_message_t message)
{
	struct ebeam_device *ebeam = usb_get_intfdata(intf);

	usb_kill_urb(ebeam->irq);

	return 0;
}

static int ebeam_resume(struct usb_interface *intf)
{
	struct ebeam_device *ebeam = usb_get_intfdata(intf);
	struct input_dev *input = ebeam->input;
	int result = 0;

	mutex_lock(&input->mutex);
	if (input->users)
		result = usb_submit_urb(ebeam->irq, GFP_NOIO);
	mutex_unlock(&input->mutex);

	return result;
}

static int ebeam_reset_resume(struct usb_interface *intf)
{
	struct ebeam_device *ebeam = usb_get_intfdata(intf);
	struct input_dev *input = ebeam->input;
	int err = 0;

	/* restart IO if needed */
	mutex_lock(&input->mutex);
	if (input->users)
		err = usb_submit_urb(ebeam->irq, GFP_NOIO);
	mutex_unlock(&input->mutex);

	return err;
}

static void ebeam_free_buffers(struct usb_device *udev,
			       struct ebeam_device *ebeam)
{
	usb_free_coherent(udev, REPT_SIZE,
			  ebeam->data, ebeam->data_dma);
	kfree(ebeam->buffer);
}

static struct usb_endpoint_descriptor *
ebeam_get_input_endpoint(struct usb_host_interface *interface)
{
	int i;

	for (i = 0; i < interface->desc.bNumEndpoints; i++)
		if (usb_endpoint_dir_in(&interface->endpoint[i].desc))
			return &interface->endpoint[i].desc;

	return NULL;
}

static int ebeam_probe(struct usb_interface *intf,
		       const struct usb_device_id *id)
{
	struct ebeam_device *ebeam;
	struct input_dev *input_dev;
	struct usb_endpoint_descriptor *endpoint;
	struct usb_device *udev = interface_to_usbdev(intf);
	int err = -ENOMEM;

	endpoint = ebeam_get_input_endpoint(intf->cur_altsetting);
	if (!endpoint)
		return -ENXIO;

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

	ebeam_init_settings(ebeam);

	ebeam->data = usb_alloc_coherent(udev, REPT_SIZE,
					 GFP_KERNEL, &ebeam->data_dma);
	if (!ebeam->data)
		goto out_free;

	ebeam->irq = usb_alloc_urb(0, GFP_KERNEL);
	if (!ebeam->irq) {
		dev_dbg(&intf->dev,
			"%s - usb_alloc_urb failed: ebeam->irq\n", __func__);
		goto out_free_buffers;
	}

	ebeam->interface = intf;
	ebeam->input = input_dev;

	/* setup name */
	snprintf(ebeam->name, sizeof(ebeam->name),
		 "USB eBeam %04x:%04x",
		 le16_to_cpu(udev->descriptor.idVendor),
		 le16_to_cpu(udev->descriptor.idProduct));

	if (udev->manufacturer || udev->product) {
		strlcat(ebeam->name,
			" (",
			sizeof(ebeam->name));

		if (udev->manufacturer)
			strlcat(ebeam->name,
				udev->manufacturer,
				sizeof(ebeam->name));

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

		if (strlcat(ebeam->name, ")", sizeof(ebeam->name))
			>= sizeof(ebeam->name)) {
			/* overflowed, closing ) anyway */
			ebeam->name[sizeof(ebeam->name)-2] = ')';
		}
	}

	/* usb tree */
	usb_make_path(udev, ebeam->phys, sizeof(ebeam->phys));
	strlcat(ebeam->phys, "/input0", sizeof(ebeam->phys));

	/* input setup */
	input_dev->name = ebeam->name;
	input_dev->phys = ebeam->phys;
	usb_to_input_id(udev, &input_dev->id);
	input_dev->dev.parent = &intf->dev;

	input_set_drvdata(input_dev, ebeam);

	input_dev->open = ebeam_open;
	input_dev->close = ebeam_close;

	/* usb urb setup */
	if (usb_endpoint_type(endpoint) == USB_ENDPOINT_XFER_INT)
		usb_fill_int_urb(ebeam->irq, udev,
			usb_rcvintpipe(udev, endpoint->bEndpointAddress),
			ebeam->data, REPT_SIZE,
			ebeam_irq, ebeam, endpoint->bInterval);
	else
		usb_fill_bulk_urb(ebeam->irq, udev,
			usb_rcvbulkpipe(udev, endpoint->bEndpointAddress),
			ebeam->data, REPT_SIZE,
			ebeam_irq, ebeam);

	ebeam->irq->dev = udev;
	ebeam->irq->transfer_dma = ebeam->data_dma;
	ebeam->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	/* input final setup */
	err = input_register_device(ebeam->input);
	if (err) {
		dev_dbg(&intf->dev,
			"%s - input_register_device failed, err: %d\n",
			__func__, err);
		goto out_free_urb;
	}

	ebeam_setup_input(ebeam, input_dev);

	/* usb final setup */
	usb_set_intfdata(intf, ebeam);

	/* sysfs setup */
	err = sysfs_create_group(&intf->dev.kobj, &ebeam_attr_group);
	if (err) {
		dev_dbg(&intf->dev,
			"%s - cannot create sysfs group, err: %d\n",
			__func__, err);
		goto out_unregister_input;
	}

	return 0;

out_unregister_input:
	input_unregister_device(input_dev);
	input_dev = NULL;
out_free_urb:
	usb_free_urb(ebeam->irq);
out_free_buffers:
	ebeam_free_buffers(udev, ebeam);
out_free:
	input_free_device(input_dev);
	kfree(ebeam);
	return err;
}

static void ebeam_disconnect(struct usb_interface *intf)
{
	struct ebeam_device *ebeam = usb_get_intfdata(intf);

	if (!ebeam)
		return;

	dev_dbg(&intf->dev,
		"%s - ebeam is initialized, cleaning up\n", __func__);

	usb_set_intfdata(intf, NULL);
	/* this will stop IO via close */
	input_unregister_device(ebeam->input);
	sysfs_remove_group(&intf->dev.kobj, &ebeam_attr_group);
	usb_free_urb(ebeam->irq);
	ebeam_free_buffers(interface_to_usbdev(intf), ebeam);
	kfree(ebeam);
}

MODULE_DEVICE_TABLE(usb, ebeam_devices);

static struct usb_driver ebeam_driver = {
	.name			= "ebeam",
	.probe			= ebeam_probe,
	.disconnect		= ebeam_disconnect,
	.suspend		= ebeam_suspend,
	.resume			= ebeam_resume,
	.reset_resume		= ebeam_reset_resume,
	.id_table		= ebeam_devices,
	.supports_autosuspend	= 1,
};

module_usb_driver(ebeam_driver);

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