drivers/input/tablet/pegasus_notetaker.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Pegasus Mobile Notetaker Pen input tablet driver
  *
  * Copyright (c) 2016 Martin Kepplinger <martink@posteo.de>
  */

 /*
  * request packet (control endpoint):
  * |-------------------------------------|
  * | Report ID | Nr of bytes | command   |
  * | (1 byte)  | (1 byte)    | (n bytes) |
  * |-------------------------------------|
  * | 0x02      | n           |           |
  * |-------------------------------------|
  *
  * data packet after set xy mode command, 0x80 0xb5 0x02 0x01
  * and pen is in range:
  *
  * byte	byte name		value (bits)
  * --------------------------------------------
  * 0	status			0 1 0 0 0 0 X X
  * 1	color			0 0 0 0 H 0 S T
  * 2	X low
  * 3	X high
  * 4	Y low
  * 5	Y high
  *
  * X X	battery state:
  *	no state reported	0x00
  *	battery low		0x01
  *	battery good		0x02
  *
  * H	Hovering
  * S	Switch 1 (pen button)
  * T	Tip
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/input.h>
 #include <linux/usb/input.h>
 #include <linux/slab.h>
 #include <linux/workqueue.h>
 #include <linux/mutex.h>

 /* USB HID defines */
 #define USB_REQ_GET_REPORT		0x01
 #define USB_REQ_SET_REPORT		0x09

 #define USB_VENDOR_ID_PEGASUSTECH	0x0e20
 #define USB_DEVICE_ID_PEGASUS_NOTETAKER_EN100	0x0101

 /* device specific defines */
 #define NOTETAKER_REPORT_ID		0x02
 #define NOTETAKER_SET_CMD		0x80
 #define NOTETAKER_SET_MODE		0xb5

 #define NOTETAKER_LED_MOUSE		0x02
 #define PEN_MODE_XY			0x01

 #define SPECIAL_COMMAND			0x80
 #define BUTTON_PRESSED			0xb5
 #define COMMAND_VERSION			0xa9

 /* in xy data packet */
 #define BATTERY_NO_REPORT		0x40
 #define BATTERY_LOW			0x41
 #define BATTERY_GOOD			0x42
 #define PEN_BUTTON_PRESSED		BIT(1)
 #define PEN_TIP				BIT(0)

 struct pegasus {
 	unsigned char *data;
 	u8 data_len;
 	dma_addr_t data_dma;
 	struct input_dev *dev;
 	struct usb_device *usbdev;
 	struct usb_interface *intf;
 	struct urb *irq;

 	/* serialize access to open/suspend */
 	struct mutex pm_mutex;
 	bool is_open;

 	char name[128];
 	char phys[64];
 	struct work_struct init;
 };

 static int pegasus_control_msg(struct pegasus *pegasus, u8 *data, int len)
 {
 	const int sizeof_buf = len + 2;
 	int result;
 	int error;
 	u8 *cmd_buf;

 	cmd_buf = kmalloc(sizeof_buf, GFP_KERNEL);
 	if (!cmd_buf)
 		return -ENOMEM;

 	cmd_buf[0] = NOTETAKER_REPORT_ID;
 	cmd_buf[1] = len;
 	memcpy(cmd_buf + 2, data, len);

 	result = usb_control_msg(pegasus->usbdev,
 				 usb_sndctrlpipe(pegasus->usbdev, 0),
 				 USB_REQ_SET_REPORT,
 				 USB_TYPE_VENDOR | USB_DIR_OUT,
 				 0, 0, cmd_buf, sizeof_buf,
 				 USB_CTRL_SET_TIMEOUT);

 	kfree(cmd_buf);

 	if (unlikely(result != sizeof_buf)) {
 		error = result < 0 ? result : -EIO;
 		dev_err(&pegasus->usbdev->dev, "control msg error: %d\n",
 			error);
 		return error;
 	}

 	return 0;
 }

 static int pegasus_set_mode(struct pegasus *pegasus, u8 mode, u8 led)
 {
 	u8 cmd[] = { NOTETAKER_SET_CMD, NOTETAKER_SET_MODE, led, mode };

 	return pegasus_control_msg(pegasus, cmd, sizeof(cmd));
 }

 static void pegasus_parse_packet(struct pegasus *pegasus)
 {
 	unsigned char *data = pegasus->data;
 	struct input_dev *dev = pegasus->dev;
 	u16 x, y;

 	switch (data[0]) {
 	case SPECIAL_COMMAND:
 		/* device button pressed */
 		if (data[1] == BUTTON_PRESSED)
 			schedule_work(&pegasus->init);

 		break;

 	/* xy data */
 	case BATTERY_LOW:
 		dev_warn_once(&dev->dev, "Pen battery low\n");
 		/* fall through */

 	case BATTERY_NO_REPORT:
 	case BATTERY_GOOD:
 		x = le16_to_cpup((__le16 *)&data[2]);
 		y = le16_to_cpup((__le16 *)&data[4]);

 		/* pen-up event */
 		if (x == 0 && y == 0)
 			break;

 		input_report_key(dev, BTN_TOUCH, data[1] & PEN_TIP);
 		input_report_key(dev, BTN_RIGHT, data[1] & PEN_BUTTON_PRESSED);
 		input_report_key(dev, BTN_TOOL_PEN, 1);
 		input_report_abs(dev, ABS_X, (s16)x);
 		input_report_abs(dev, ABS_Y, y);

 		input_sync(dev);
 		break;

 	default:
 		dev_warn_once(&pegasus->usbdev->dev,
 			      "unknown answer from device\n");
 	}
 }

 static void pegasus_irq(struct urb *urb)
 {
 	struct pegasus *pegasus = urb->context;
 	struct usb_device *dev = pegasus->usbdev;
 	int retval;

 	switch (urb->status) {
 	case 0:
 		pegasus_parse_packet(pegasus);
 		usb_mark_last_busy(pegasus->usbdev);
 		break;

 	case -ECONNRESET:
 	case -ENOENT:
 	case -ESHUTDOWN:
 		dev_err(&dev->dev, "%s - urb shutting down with status: %d",
 			__func__, urb->status);
 		return;

 	default:
 		dev_err(&dev->dev, "%s - nonzero urb status received: %d",
 			__func__, urb->status);
 		break;
 	}

 	retval = usb_submit_urb(urb, GFP_ATOMIC);
 	if (retval)
 		dev_err(&dev->dev, "%s - usb_submit_urb failed with result %d",
 			__func__, retval);
 }

 static void pegasus_init(struct work_struct *work)
 {
 	struct pegasus *pegasus = container_of(work, struct pegasus, init);
 	int error;

 	error = pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
 	if (error)
 		dev_err(&pegasus->usbdev->dev, "pegasus_set_mode error: %d\n",
 			error);
 }

 static int pegasus_open(struct input_dev *dev)
 {
 	struct pegasus *pegasus = input_get_drvdata(dev);
 	int error;

 	error = usb_autopm_get_interface(pegasus->intf);
 	if (error)
 		return error;

 	mutex_lock(&pegasus->pm_mutex);
 	pegasus->irq->dev = pegasus->usbdev;
 	if (usb_submit_urb(pegasus->irq, GFP_KERNEL)) {
 		error = -EIO;
 		goto err_autopm_put;
 	}

 	error = pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
 	if (error)
 		goto err_kill_urb;

 	pegasus->is_open = true;
 	mutex_unlock(&pegasus->pm_mutex);
 	return 0;

 err_kill_urb:
 	usb_kill_urb(pegasus->irq);
 	cancel_work_sync(&pegasus->init);
 err_autopm_put:
 	mutex_unlock(&pegasus->pm_mutex);
 	usb_autopm_put_interface(pegasus->intf);
 	return error;
 }

 static void pegasus_close(struct input_dev *dev)
 {
 	struct pegasus *pegasus = input_get_drvdata(dev);

 	mutex_lock(&pegasus->pm_mutex);
 	usb_kill_urb(pegasus->irq);
 	cancel_work_sync(&pegasus->init);
 	pegasus->is_open = false;
 	mutex_unlock(&pegasus->pm_mutex);

 	usb_autopm_put_interface(pegasus->intf);
 }

 static int pegasus_probe(struct usb_interface *intf,
 			 const struct usb_device_id *id)
 {
 	struct usb_device *dev = interface_to_usbdev(intf);
 	struct usb_endpoint_descriptor *endpoint;
 	struct pegasus *pegasus;
 	struct input_dev *input_dev;
 	int error;
 	int pipe;

 	/* We control interface 0 */
 	if (intf->cur_altsetting->desc.bInterfaceNumber >= 1)
 		return -ENODEV;

 	/* Sanity check that the device has an endpoint */
 	if (intf->altsetting[0].desc.bNumEndpoints < 1) {
 		dev_err(&intf->dev, "Invalid number of endpoints\n");
 		return -EINVAL;
 	}

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

 	pegasus = kzalloc(sizeof(*pegasus), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!pegasus || !input_dev) {
 		error = -ENOMEM;
 		goto err_free_mem;
 	}

 	mutex_init(&pegasus->pm_mutex);

 	pegasus->usbdev = dev;
 	pegasus->dev = input_dev;
 	pegasus->intf = intf;

 	pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
 	pegasus->data_len = usb_maxpacket(dev, pipe, usb_pipeout(pipe));

 	pegasus->data = usb_alloc_coherent(dev, pegasus->data_len, GFP_KERNEL,
 					   &pegasus->data_dma);
 	if (!pegasus->data) {
 		error = -ENOMEM;
 		goto err_free_mem;
 	}

 	pegasus->irq = usb_alloc_urb(0, GFP_KERNEL);
 	if (!pegasus->irq) {
 		error = -ENOMEM;
 		goto err_free_dma;
 	}

 	usb_fill_int_urb(pegasus->irq, dev, pipe,
 			 pegasus->data, pegasus->data_len,
 			 pegasus_irq, pegasus, endpoint->bInterval);

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

 	if (dev->manufacturer)
 		strlcpy(pegasus->name, dev->manufacturer,
 			sizeof(pegasus->name));

 	if (dev->product) {
 		if (dev->manufacturer)
 			strlcat(pegasus->name, " ", sizeof(pegasus->name));
 		strlcat(pegasus->name, dev->product, sizeof(pegasus->name));
 	}

 	if (!strlen(pegasus->name))
 		snprintf(pegasus->name, sizeof(pegasus->name),
 			 "USB Pegasus Device %04x:%04x",
 			 le16_to_cpu(dev->descriptor.idVendor),
 			 le16_to_cpu(dev->descriptor.idProduct));

 	usb_make_path(dev, pegasus->phys, sizeof(pegasus->phys));
 	strlcat(pegasus->phys, "/input0", sizeof(pegasus->phys));

 	INIT_WORK(&pegasus->init, pegasus_init);

 	usb_set_intfdata(intf, pegasus);

 	input_dev->name = pegasus->name;
 	input_dev->phys = pegasus->phys;
 	usb_to_input_id(dev, &input_dev->id);
 	input_dev->dev.parent = &intf->dev;

 	input_set_drvdata(input_dev, pegasus);

 	input_dev->open = pegasus_open;
 	input_dev->close = pegasus_close;

 	__set_bit(EV_ABS, input_dev->evbit);
 	__set_bit(EV_KEY, input_dev->evbit);

 	__set_bit(ABS_X, input_dev->absbit);
 	__set_bit(ABS_Y, input_dev->absbit);

 	__set_bit(BTN_TOUCH, input_dev->keybit);
 	__set_bit(BTN_RIGHT, input_dev->keybit);
 	__set_bit(BTN_TOOL_PEN, input_dev->keybit);

 	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
 	__set_bit(INPUT_PROP_POINTER, input_dev->propbit);

 	input_set_abs_params(input_dev, ABS_X, -1500, 1500, 8, 0);
 	input_set_abs_params(input_dev, ABS_Y, 1600, 3000, 8, 0);

 	error = input_register_device(pegasus->dev);
 	if (error)
 		goto err_free_urb;

 	return 0;

 err_free_urb:
 	usb_free_urb(pegasus->irq);
 err_free_dma:
 	usb_free_coherent(dev, pegasus->data_len,
 			  pegasus->data, pegasus->data_dma);
 err_free_mem:
 	input_free_device(input_dev);
 	kfree(pegasus);
 	usb_set_intfdata(intf, NULL);

 	return error;
 }

 static void pegasus_disconnect(struct usb_interface *intf)
 {
 	struct pegasus *pegasus = usb_get_intfdata(intf);

 	input_unregister_device(pegasus->dev);

 	usb_free_urb(pegasus->irq);
 	usb_free_coherent(interface_to_usbdev(intf),
 			  pegasus->data_len, pegasus->data,
 			  pegasus->data_dma);

 	kfree(pegasus);
 	usb_set_intfdata(intf, NULL);
 }

 static int pegasus_suspend(struct usb_interface *intf, pm_message_t message)
 {
 	struct pegasus *pegasus = usb_get_intfdata(intf);

 	mutex_lock(&pegasus->pm_mutex);
 	usb_kill_urb(pegasus->irq);
 	cancel_work_sync(&pegasus->init);
 	mutex_unlock(&pegasus->pm_mutex);

 	return 0;
 }

 static int pegasus_resume(struct usb_interface *intf)
 {
 	struct pegasus *pegasus = usb_get_intfdata(intf);
 	int retval = 0;

 	mutex_lock(&pegasus->pm_mutex);
 	if (pegasus->is_open && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
 		retval = -EIO;
 	mutex_unlock(&pegasus->pm_mutex);

 	return retval;
 }

 static int pegasus_reset_resume(struct usb_interface *intf)
 {
 	struct pegasus *pegasus = usb_get_intfdata(intf);
 	int retval = 0;

 	mutex_lock(&pegasus->pm_mutex);
 	if (pegasus->is_open) {
 		retval = pegasus_set_mode(pegasus, PEN_MODE_XY,
 					  NOTETAKER_LED_MOUSE);
 		if (!retval && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
 			retval = -EIO;
 	}
 	mutex_unlock(&pegasus->pm_mutex);

 	return retval;
 }

 static const struct usb_device_id pegasus_ids[] = {
 	{ USB_DEVICE(USB_VENDOR_ID_PEGASUSTECH,
 		     USB_DEVICE_ID_PEGASUS_NOTETAKER_EN100) },
 	{ }
 };
 MODULE_DEVICE_TABLE(usb, pegasus_ids);

 static struct usb_driver pegasus_driver = {
 	.name		= "pegasus_notetaker",
 	.probe		= pegasus_probe,
 	.disconnect	= pegasus_disconnect,
 	.suspend	= pegasus_suspend,
 	.resume		= pegasus_resume,
 	.reset_resume	= pegasus_reset_resume,
 	.id_table	= pegasus_ids,
 	.supports_autosuspend = 1,
 };

 module_usb_driver(pegasus_driver);

 MODULE_AUTHOR("Martin Kepplinger <martink@posteo.de>");
 MODULE_DESCRIPTION("Pegasus Mobile Notetaker Pen tablet driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Pegasus Mobile Notetaker Pen input tablet driver
	*
	* Copyright (c) 2016 Martin Kepplinger <martink@posteo.de>
	*/

	/*
	* request packet (control endpoint):
	* \|-------------------------------------\|
	* \| Report ID \| Nr of bytes \| command \|
	* \| (1 byte) \| (1 byte) \| (n bytes) \|
	* \|-------------------------------------\|
	* \| 0x02 \| n \| \|
	* \|-------------------------------------\|
	*
	* data packet after set xy mode command, 0x80 0xb5 0x02 0x01
	* and pen is in range:
	*
	* byte byte name value (bits)
	* --------------------------------------------
	* 0 status 0 1 0 0 0 0 X X
	* 1 color 0 0 0 0 H 0 S T
	* 2 X low
	* 3 X high
	* 4 Y low
	* 5 Y high
	*
	* X X battery state:
	* no state reported 0x00
	* battery low 0x01
	* battery good 0x02
	*
	* H Hovering
	* S Switch 1 (pen button)
	* T Tip
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/input.h>
	#include <linux/usb/input.h>
	#include <linux/slab.h>
	#include <linux/workqueue.h>
	#include <linux/mutex.h>

	/* USB HID defines */
	#define USB_REQ_GET_REPORT 0x01
	#define USB_REQ_SET_REPORT 0x09

	#define USB_VENDOR_ID_PEGASUSTECH 0x0e20
	#define USB_DEVICE_ID_PEGASUS_NOTETAKER_EN100 0x0101

	/* device specific defines */
	#define NOTETAKER_REPORT_ID 0x02
	#define NOTETAKER_SET_CMD 0x80
	#define NOTETAKER_SET_MODE 0xb5

	#define NOTETAKER_LED_MOUSE 0x02
	#define PEN_MODE_XY 0x01

	#define SPECIAL_COMMAND 0x80
	#define BUTTON_PRESSED 0xb5
	#define COMMAND_VERSION 0xa9

	/* in xy data packet */
	#define BATTERY_NO_REPORT 0x40
	#define BATTERY_LOW 0x41
	#define BATTERY_GOOD 0x42
	#define PEN_BUTTON_PRESSED BIT(1)
	#define PEN_TIP BIT(0)

	struct pegasus {
	unsigned char *data;
	u8 data_len;
	dma_addr_t data_dma;
	struct input_dev *dev;
	struct usb_device *usbdev;
	struct usb_interface *intf;
	struct urb *irq;

	/* serialize access to open/suspend */
	struct mutex pm_mutex;
	bool is_open;

	char name[128];
	char phys[64];
	struct work_struct init;
	};

	static int pegasus_control_msg(struct pegasus pegasus, u8 data, int len)
	{
	const int sizeof_buf = len + 2;
	int result;
	int error;
	u8 *cmd_buf;

	cmd_buf = kmalloc(sizeof_buf, GFP_KERNEL);
	if (!cmd_buf)
	return -ENOMEM;

	cmd_buf[0] = NOTETAKER_REPORT_ID;
	cmd_buf[1] = len;
	memcpy(cmd_buf + 2, data, len);

	result = usb_control_msg(pegasus->usbdev,
	usb_sndctrlpipe(pegasus->usbdev, 0),
	USB_REQ_SET_REPORT,
	USB_TYPE_VENDOR \| USB_DIR_OUT,
	0, 0, cmd_buf, sizeof_buf,
	USB_CTRL_SET_TIMEOUT);

	kfree(cmd_buf);

	if (unlikely(result != sizeof_buf)) {
	error = result < 0 ? result : -EIO;
	dev_err(&pegasus->usbdev->dev, "control msg error: %d\n",
	error);
	return error;
	}

	return 0;
	}

	static int pegasus_set_mode(struct pegasus *pegasus, u8 mode, u8 led)
	{
	u8 cmd[] = { NOTETAKER_SET_CMD, NOTETAKER_SET_MODE, led, mode };

	return pegasus_control_msg(pegasus, cmd, sizeof(cmd));
	}

	static void pegasus_parse_packet(struct pegasus *pegasus)
	{
	unsigned char *data = pegasus->data;
	struct input_dev *dev = pegasus->dev;
	u16 x, y;

	switch (data[0]) {
	case SPECIAL_COMMAND:
	/* device button pressed */
	if (data[1] == BUTTON_PRESSED)
	schedule_work(&pegasus->init);

	break;

	/* xy data */
	case BATTERY_LOW:
	dev_warn_once(&dev->dev, "Pen battery low\n");
	/* fall through */

	case BATTERY_NO_REPORT:
	case BATTERY_GOOD:
	x = le16_to_cpup((__le16 *)&data[2]);
	y = le16_to_cpup((__le16 *)&data[4]);

	/* pen-up event */
	if (x == 0 && y == 0)
	break;

	input_report_key(dev, BTN_TOUCH, data[1] & PEN_TIP);
	input_report_key(dev, BTN_RIGHT, data[1] & PEN_BUTTON_PRESSED);
	input_report_key(dev, BTN_TOOL_PEN, 1);
	input_report_abs(dev, ABS_X, (s16)x);
	input_report_abs(dev, ABS_Y, y);

	input_sync(dev);
	break;

	default:
	dev_warn_once(&pegasus->usbdev->dev,
	"unknown answer from device\n");
	}
	}

	static void pegasus_irq(struct urb *urb)
	{
	struct pegasus *pegasus = urb->context;
	struct usb_device *dev = pegasus->usbdev;
	int retval;

	switch (urb->status) {
	case 0:
	pegasus_parse_packet(pegasus);
	usb_mark_last_busy(pegasus->usbdev);
	break;

	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
	dev_err(&dev->dev, "%s - urb shutting down with status: %d",
	__func__, urb->status);
	return;

	default:
	dev_err(&dev->dev, "%s - nonzero urb status received: %d",
	__func__, urb->status);
	break;
	}

	retval = usb_submit_urb(urb, GFP_ATOMIC);
	if (retval)
	dev_err(&dev->dev, "%s - usb_submit_urb failed with result %d",
	__func__, retval);
	}

	static void pegasus_init(struct work_struct *work)
	{
	struct pegasus *pegasus = container_of(work, struct pegasus, init);
	int error;

	error = pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
	if (error)
	dev_err(&pegasus->usbdev->dev, "pegasus_set_mode error: %d\n",
	error);
	}

	static int pegasus_open(struct input_dev *dev)
	{
	struct pegasus *pegasus = input_get_drvdata(dev);
	int error;

	error = usb_autopm_get_interface(pegasus->intf);
	if (error)
	return error;

	mutex_lock(&pegasus->pm_mutex);
	pegasus->irq->dev = pegasus->usbdev;
	if (usb_submit_urb(pegasus->irq, GFP_KERNEL)) {
	error = -EIO;
	goto err_autopm_put;
	}

	error = pegasus_set_mode(pegasus, PEN_MODE_XY, NOTETAKER_LED_MOUSE);
	if (error)
	goto err_kill_urb;

	pegasus->is_open = true;
	mutex_unlock(&pegasus->pm_mutex);
	return 0;

	err_kill_urb:
	usb_kill_urb(pegasus->irq);
	cancel_work_sync(&pegasus->init);
	err_autopm_put:
	mutex_unlock(&pegasus->pm_mutex);
	usb_autopm_put_interface(pegasus->intf);
	return error;
	}

	static void pegasus_close(struct input_dev *dev)
	{
	struct pegasus *pegasus = input_get_drvdata(dev);

	mutex_lock(&pegasus->pm_mutex);
	usb_kill_urb(pegasus->irq);
	cancel_work_sync(&pegasus->init);
	pegasus->is_open = false;
	mutex_unlock(&pegasus->pm_mutex);

	usb_autopm_put_interface(pegasus->intf);
	}

	static int pegasus_probe(struct usb_interface *intf,
	const struct usb_device_id *id)
	{
	struct usb_device *dev = interface_to_usbdev(intf);
	struct usb_endpoint_descriptor *endpoint;
	struct pegasus *pegasus;
	struct input_dev *input_dev;
	int error;
	int pipe;

	/* We control interface 0 */
	if (intf->cur_altsetting->desc.bInterfaceNumber >= 1)
	return -ENODEV;

	/* Sanity check that the device has an endpoint */
	if (intf->altsetting[0].desc.bNumEndpoints < 1) {
	dev_err(&intf->dev, "Invalid number of endpoints\n");
	return -EINVAL;
	}

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

	pegasus = kzalloc(sizeof(*pegasus), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!pegasus \|\| !input_dev) {
	error = -ENOMEM;
	goto err_free_mem;
	}

	mutex_init(&pegasus->pm_mutex);

	pegasus->usbdev = dev;
	pegasus->dev = input_dev;
	pegasus->intf = intf;

	pipe = usb_rcvintpipe(dev, endpoint->bEndpointAddress);
	pegasus->data_len = usb_maxpacket(dev, pipe, usb_pipeout(pipe));

	pegasus->data = usb_alloc_coherent(dev, pegasus->data_len, GFP_KERNEL,
	&pegasus->data_dma);
	if (!pegasus->data) {
	error = -ENOMEM;
	goto err_free_mem;
	}

	pegasus->irq = usb_alloc_urb(0, GFP_KERNEL);
	if (!pegasus->irq) {
	error = -ENOMEM;
	goto err_free_dma;
	}

	usb_fill_int_urb(pegasus->irq, dev, pipe,
	pegasus->data, pegasus->data_len,
	pegasus_irq, pegasus, endpoint->bInterval);

	pegasus->irq->transfer_dma = pegasus->data_dma;
	pegasus->irq->transfer_flags \|= URB_NO_TRANSFER_DMA_MAP;

	if (dev->manufacturer)
	strlcpy(pegasus->name, dev->manufacturer,
	sizeof(pegasus->name));

	if (dev->product) {
	if (dev->manufacturer)
	strlcat(pegasus->name, " ", sizeof(pegasus->name));
	strlcat(pegasus->name, dev->product, sizeof(pegasus->name));
	}

	if (!strlen(pegasus->name))
	snprintf(pegasus->name, sizeof(pegasus->name),
	"USB Pegasus Device %04x:%04x",
	le16_to_cpu(dev->descriptor.idVendor),
	le16_to_cpu(dev->descriptor.idProduct));

	usb_make_path(dev, pegasus->phys, sizeof(pegasus->phys));
	strlcat(pegasus->phys, "/input0", sizeof(pegasus->phys));

	INIT_WORK(&pegasus->init, pegasus_init);

	usb_set_intfdata(intf, pegasus);

	input_dev->name = pegasus->name;
	input_dev->phys = pegasus->phys;
	usb_to_input_id(dev, &input_dev->id);
	input_dev->dev.parent = &intf->dev;

	input_set_drvdata(input_dev, pegasus);

	input_dev->open = pegasus_open;
	input_dev->close = pegasus_close;

	__set_bit(EV_ABS, input_dev->evbit);
	__set_bit(EV_KEY, input_dev->evbit);

	__set_bit(ABS_X, input_dev->absbit);
	__set_bit(ABS_Y, input_dev->absbit);

	__set_bit(BTN_TOUCH, input_dev->keybit);
	__set_bit(BTN_RIGHT, input_dev->keybit);
	__set_bit(BTN_TOOL_PEN, input_dev->keybit);

	__set_bit(INPUT_PROP_DIRECT, input_dev->propbit);
	__set_bit(INPUT_PROP_POINTER, input_dev->propbit);

	input_set_abs_params(input_dev, ABS_X, -1500, 1500, 8, 0);
	input_set_abs_params(input_dev, ABS_Y, 1600, 3000, 8, 0);

	error = input_register_device(pegasus->dev);
	if (error)
	goto err_free_urb;

	return 0;

	err_free_urb:
	usb_free_urb(pegasus->irq);
	err_free_dma:
	usb_free_coherent(dev, pegasus->data_len,
	pegasus->data, pegasus->data_dma);
	err_free_mem:
	input_free_device(input_dev);
	kfree(pegasus);
	usb_set_intfdata(intf, NULL);

	return error;
	}

	static void pegasus_disconnect(struct usb_interface *intf)
	{
	struct pegasus *pegasus = usb_get_intfdata(intf);

	input_unregister_device(pegasus->dev);

	usb_free_urb(pegasus->irq);
	usb_free_coherent(interface_to_usbdev(intf),
	pegasus->data_len, pegasus->data,
	pegasus->data_dma);

	kfree(pegasus);
	usb_set_intfdata(intf, NULL);
	}

	static int pegasus_suspend(struct usb_interface *intf, pm_message_t message)
	{
	struct pegasus *pegasus = usb_get_intfdata(intf);

	mutex_lock(&pegasus->pm_mutex);
	usb_kill_urb(pegasus->irq);
	cancel_work_sync(&pegasus->init);
	mutex_unlock(&pegasus->pm_mutex);

	return 0;
	}

	static int pegasus_resume(struct usb_interface *intf)
	{
	struct pegasus *pegasus = usb_get_intfdata(intf);
	int retval = 0;

	mutex_lock(&pegasus->pm_mutex);
	if (pegasus->is_open && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
	retval = -EIO;
	mutex_unlock(&pegasus->pm_mutex);

	return retval;
	}

	static int pegasus_reset_resume(struct usb_interface *intf)
	{
	struct pegasus *pegasus = usb_get_intfdata(intf);
	int retval = 0;

	mutex_lock(&pegasus->pm_mutex);
	if (pegasus->is_open) {
	retval = pegasus_set_mode(pegasus, PEN_MODE_XY,
	NOTETAKER_LED_MOUSE);
	if (!retval && usb_submit_urb(pegasus->irq, GFP_NOIO) < 0)
	retval = -EIO;
	}
	mutex_unlock(&pegasus->pm_mutex);

	return retval;
	}

	static const struct usb_device_id pegasus_ids[] = {
	{ USB_DEVICE(USB_VENDOR_ID_PEGASUSTECH,
	USB_DEVICE_ID_PEGASUS_NOTETAKER_EN100) },
	{ }
	};
	MODULE_DEVICE_TABLE(usb, pegasus_ids);

	static struct usb_driver pegasus_driver = {
	.name = "pegasus_notetaker",
	.probe = pegasus_probe,
	.disconnect = pegasus_disconnect,
	.suspend = pegasus_suspend,
	.resume = pegasus_resume,
	.reset_resume = pegasus_reset_resume,
	.id_table = pegasus_ids,
	.supports_autosuspend = 1,
	};

	module_usb_driver(pegasus_driver);

	MODULE_AUTHOR("Martin Kepplinger <martink@posteo.de>");
	MODULE_DESCRIPTION("Pegasus Mobile Notetaker Pen tablet driver");
	MODULE_LICENSE("GPL");