drivers/hid/hid-elan.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * HID Driver for ELAN Touchpad
  *
  * Currently only supports touchpad found on HP Pavilion X2 10
  *
  * Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai>
  */

 #include <linux/hid.h>
 #include <linux/input/mt.h>
 #include <linux/leds.h>
 #include <linux/module.h>
 #include <linux/usb.h>

 #include "hid-ids.h"

 #define ELAN_MT_I2C		0x5d
 #define ELAN_SINGLE_FINGER	0x81
 #define ELAN_MT_FIRST_FINGER	0x82
 #define ELAN_MT_SECOND_FINGER	0x83
 #define ELAN_INPUT_REPORT_SIZE	8
 #define ELAN_I2C_REPORT_SIZE	32
 #define ELAN_FINGER_DATA_LEN	5
 #define ELAN_MAX_FINGERS	5
 #define ELAN_MAX_PRESSURE	255
 #define ELAN_TP_USB_INTF	1

 #define ELAN_FEATURE_REPORT	0x0d
 #define ELAN_FEATURE_SIZE	5
 #define ELAN_PARAM_MAX_X	6
 #define ELAN_PARAM_MAX_Y	7
 #define ELAN_PARAM_RES		8

 #define ELAN_MUTE_LED_REPORT	0xBC
 #define ELAN_LED_REPORT_SIZE	8

 #define ELAN_HAS_LED		BIT(0)

 struct elan_drvdata {
 	struct input_dev *input;
 	u8 prev_report[ELAN_INPUT_REPORT_SIZE];
 	struct led_classdev mute_led;
 	u8 mute_led_state;
 	u16 max_x;
 	u16 max_y;
 	u16 res_x;
 	u16 res_y;
 };

 static int is_not_elan_touchpad(struct hid_device *hdev)
 {
 	if (hid_is_usb(hdev)) {
 		struct usb_interface *intf = to_usb_interface(hdev->dev.parent);

 		return (intf->altsetting->desc.bInterfaceNumber !=
 			ELAN_TP_USB_INTF);
 	}

 	return 0;
 }

 static int elan_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 			      struct hid_field *field, struct hid_usage *usage,
 			      unsigned long **bit, int *max)
 {
 	if (is_not_elan_touchpad(hdev))
 		return 0;

 	if (field->report->id == ELAN_SINGLE_FINGER ||
 	    field->report->id == ELAN_MT_FIRST_FINGER ||
 	    field->report->id == ELAN_MT_SECOND_FINGER ||
 	    field->report->id == ELAN_MT_I2C)
 		return -1;

 	return 0;
 }

 static int elan_get_device_param(struct hid_device *hdev,
 				 unsigned char *dmabuf, unsigned char param)
 {
 	int ret;

 	dmabuf[0] = ELAN_FEATURE_REPORT;
 	dmabuf[1] = 0x05;
 	dmabuf[2] = 0x03;
 	dmabuf[3] = param;
 	dmabuf[4] = 0x01;

 	ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
 				 ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
 				 HID_REQ_SET_REPORT);
 	if (ret != ELAN_FEATURE_SIZE) {
 		hid_err(hdev, "Set report error for parm %d: %d\n", param, ret);
 		return ret;
 	}

 	ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
 				 ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
 				 HID_REQ_GET_REPORT);
 	if (ret != ELAN_FEATURE_SIZE) {
 		hid_err(hdev, "Get report error for parm %d: %d\n", param, ret);
 		return ret;
 	}

 	return 0;
 }

 static unsigned int elan_convert_res(char val)
 {
 	/*
 	 * (value from firmware) * 10 + 790 = dpi
 	 * dpi * 10 / 254 = dots/mm
 	 */
 	return (val * 10 + 790) * 10 / 254;
 }

 static int elan_get_device_params(struct hid_device *hdev)
 {
 	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 	unsigned char *dmabuf;
 	int ret;

 	dmabuf = kmalloc(ELAN_FEATURE_SIZE, GFP_KERNEL);
 	if (!dmabuf)
 		return -ENOMEM;

 	ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_X);
 	if (ret)
 		goto err;

 	drvdata->max_x = (dmabuf[4] << 8) | dmabuf[3];

 	ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_Y);
 	if (ret)
 		goto err;

 	drvdata->max_y = (dmabuf[4] << 8) | dmabuf[3];

 	ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_RES);
 	if (ret)
 		goto err;

 	drvdata->res_x = elan_convert_res(dmabuf[3]);
 	drvdata->res_y = elan_convert_res(dmabuf[4]);

 err:
 	kfree(dmabuf);
 	return ret;
 }

 static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi)
 {
 	int ret;
 	struct input_dev *input;
 	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);

 	if (is_not_elan_touchpad(hdev))
 		return 0;

 	ret = elan_get_device_params(hdev);
 	if (ret)
 		return ret;

 	input = devm_input_allocate_device(&hdev->dev);
 	if (!input)
 		return -ENOMEM;

 	input->name = "Elan Touchpad";
 	input->phys = hdev->phys;
 	input->uniq = hdev->uniq;
 	input->id.bustype = hdev->bus;
 	input->id.vendor  = hdev->vendor;
 	input->id.product = hdev->product;
 	input->id.version = hdev->version;
 	input->dev.parent = &hdev->dev;

 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, drvdata->max_x,
 			     0, 0);
 	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, drvdata->max_y,
 			     0, 0);
 	input_set_abs_params(input, ABS_MT_PRESSURE, 0, ELAN_MAX_PRESSURE,
 			     0, 0);

 	__set_bit(BTN_LEFT, input->keybit);
 	__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);

 	ret = input_mt_init_slots(input, ELAN_MAX_FINGERS, INPUT_MT_POINTER);
 	if (ret) {
 		hid_err(hdev, "Failed to init elan MT slots: %d\n", ret);
 		input_free_device(input);
 		return ret;
 	}

 	input_abs_set_res(input, ABS_X, drvdata->res_x);
 	input_abs_set_res(input, ABS_Y, drvdata->res_y);

 	ret = input_register_device(input);
 	if (ret) {
 		hid_err(hdev, "Failed to register elan input device: %d\n",
 			ret);
 		input_mt_destroy_slots(input);
 		input_free_device(input);
 		return ret;
 	}

 	drvdata->input = input;

 	return 0;
 }

 static void elan_report_mt_slot(struct elan_drvdata *drvdata, u8 *data,
 				unsigned int slot_num)
 {
 	struct input_dev *input = drvdata->input;
 	int x, y, p;

 	bool active = !!data;

 	input_mt_slot(input, slot_num);
 	input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
 	if (active) {
 		x = ((data[0] & 0xF0) << 4) | data[1];
 		y = drvdata->max_y -
 		    (((data[0] & 0x07) << 8) | data[2]);
 		p = data[4];

 		input_report_abs(input, ABS_MT_POSITION_X, x);
 		input_report_abs(input, ABS_MT_POSITION_Y, y);
 		input_report_abs(input, ABS_MT_PRESSURE, p);
 	}
 }

 static void elan_usb_report_input(struct elan_drvdata *drvdata, u8 *data)
 {
 	int i;
 	struct input_dev *input = drvdata->input;

 	/*
 	 * There is 3 types of reports: for single touch,
 	 * for multitouch - first finger and for multitouch - second finger
 	 *
 	 * packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER:
 	 *
 	 * byte 1: 1   0   0   0   0   0   0   1  // 0x81 or 0x82
 	 * byte 2: 0   0   0   0   0   0   0   0  // looks like unused
 	 * byte 3: f5  f4  f3  f2  f1  0   0   L
 	 * byte 4: x12 x11 x10 x9  0?  y11 y10 y9
 	 * byte 5: x8  x7  x6  x5  x4  x3  x2  x1
 	 * byte 6: y8  y7  y6  y5  y4  y3  y2  y1
 	 * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 	 * byte 8: p8  p7  p6  p5  p4  p3  p2  p1
 	 *
 	 * packet structure for ELAN_MT_SECOND_FINGER:
 	 *
 	 * byte 1: 1   0   0   0   0   0   1   1  // 0x83
 	 * byte 2: x12 x11 x10 x9  0   y11 y10 y9
 	 * byte 3: x8  x7  x6  x5  x4  x3  x2  x1
 	 * byte 4: y8  y7  y6  y5  y4  y3  y2  y1
 	 * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 	 * byte 6: p8  p7  p6  p5  p4  p3  p2  p1
 	 * byte 7: 0   0   0   0   0   0   0   0
 	 * byte 8: 0   0   0   0   0   0   0   0
 	 *
 	 * f5-f1: finger touch bits
 	 * L: clickpad button
 	 * sy / sx: finger width / height expressed in traces, the total number
 	 *          of traces can be queried by doing a HID_REQ_SET_REPORT
 	 *          { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the
 	 *          returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces.
 	 * p: pressure
 	 */

 	if (data[0] == ELAN_SINGLE_FINGER) {
 		for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 			if (data[2] & BIT(i + 3))
 				elan_report_mt_slot(drvdata, data + 3, i);
 			else
 				elan_report_mt_slot(drvdata, NULL, i);
 		}
 		input_report_key(input, BTN_LEFT, data[2] & 0x01);
 	}
 	/*
 	 * When touched with two fingers Elan touchpad will emit two HID reports
 	 * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER
 	 * we will save ELAN_MT_FIRST_FINGER report and wait for
 	 * ELAN_MT_SECOND_FINGER to finish multitouch
 	 */
 	if (data[0] == ELAN_MT_FIRST_FINGER) {
 		memcpy(drvdata->prev_report, data,
 		       sizeof(drvdata->prev_report));
 		return;
 	}

 	if (data[0] == ELAN_MT_SECOND_FINGER) {
 		int first = 0;
 		u8 *prev_report = drvdata->prev_report;

 		if (prev_report[0] != ELAN_MT_FIRST_FINGER)
 			return;

 		for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 			if (prev_report[2] & BIT(i + 3)) {
 				if (!first) {
 					first = 1;
 					elan_report_mt_slot(drvdata, prev_report + 3, i);
 				} else {
 					elan_report_mt_slot(drvdata, data + 1, i);
 				}
 			} else {
 				elan_report_mt_slot(drvdata, NULL, i);
 			}
 		}
 		input_report_key(input, BTN_LEFT, prev_report[2] & 0x01);
 	}

 	input_mt_sync_frame(input);
 	input_sync(input);
 }

 static void elan_i2c_report_input(struct elan_drvdata *drvdata, u8 *data)
 {
 	struct input_dev *input = drvdata->input;
 	u8 *finger_data;
 	int i;

 	/*
 	 * Elan MT touchpads in i2c mode send finger data in the same format
 	 * as in USB mode, but then with all fingers in a single packet.
 	 *
 	 * packet structure for ELAN_MT_I2C:
 	 *
 	 * byte     1: 1   0   0   1   1   1   0   1   // 0x5d
 	 * byte     2: f5  f4  f3  f2  f1  0   0   L
 	 * byte     3: x12 x11 x10 x9  0?  y11 y10 y9
 	 * byte     4: x8  x7  x6  x5  x4  x3  x2  x1
 	 * byte     5: y8  y7  y6  y5  y4  y3  y2  y1
 	 * byte     6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 	 * byte     7: p8  p7  p6  p5  p4  p3  p2  p1
 	 * byte  8-12: Same as byte 3-7 for second finger down
 	 * byte 13-17: Same as byte 3-7 for third finger down
 	 * byte 18-22: Same as byte 3-7 for fourth finger down
 	 * byte 23-27: Same as byte 3-7 for fifth finger down
 	 */

 	finger_data = data + 2;
 	for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 		if (data[1] & BIT(i + 3)) {
 			elan_report_mt_slot(drvdata, finger_data, i);
 			finger_data += ELAN_FINGER_DATA_LEN;
 		} else {
 			elan_report_mt_slot(drvdata, NULL, i);
 		}
 	}

 	input_report_key(input, BTN_LEFT, data[1] & 0x01);
 	input_mt_sync_frame(input);
 	input_sync(input);
 }

 static int elan_raw_event(struct hid_device *hdev,
 			  struct hid_report *report, u8 *data, int size)
 {
 	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);

 	if (is_not_elan_touchpad(hdev))
 		return 0;

 	if (data[0] == ELAN_SINGLE_FINGER ||
 	    data[0] == ELAN_MT_FIRST_FINGER ||
 	    data[0] == ELAN_MT_SECOND_FINGER) {
 		if (size == ELAN_INPUT_REPORT_SIZE) {
 			elan_usb_report_input(drvdata, data);
 			return 1;
 		}
 	}

 	if (data[0] == ELAN_MT_I2C && size == ELAN_I2C_REPORT_SIZE) {
 		elan_i2c_report_input(drvdata, data);
 		return 1;
 	}

 	return 0;
 }

 static int elan_start_multitouch(struct hid_device *hdev)
 {
 	int ret;

 	/*
 	 * This byte sequence will enable multitouch mode and disable
 	 * mouse emulation
 	 */
 	static const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 };
 	unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL);

 	if (!dmabuf)
 		return -ENOMEM;

 	ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf),
 				 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);

 	kfree(dmabuf);

 	if (ret != sizeof(buf)) {
 		hid_err(hdev, "Failed to start multitouch: %d\n", ret);
 		return ret;
 	}

 	return 0;
 }

 static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
 				       enum led_brightness value)
 {
 	int ret;
 	u8 led_state;
 	struct device *dev = led_cdev->dev->parent;
 	struct hid_device *hdev = to_hid_device(dev);
 	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);

 	unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL);

 	if (!dmabuf)
 		return -ENOMEM;

 	led_state = !!value;

 	dmabuf[0] = ELAN_MUTE_LED_REPORT;
 	dmabuf[1] = 0x02;
 	dmabuf[2] = led_state;

 	ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE,
 				 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);

 	kfree(dmabuf);

 	if (ret != ELAN_LED_REPORT_SIZE) {
 		if (ret != -ENODEV)
 			hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
 		return ret < 0 ? ret : -EIO;
 	}

 	drvdata->mute_led_state = led_state;
 	return 0;
 }

 static int elan_init_mute_led(struct hid_device *hdev)
 {
 	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 	struct led_classdev *mute_led = &drvdata->mute_led;

 	mute_led->name = "elan:red:mute";
 	mute_led->default_trigger = "audio-mute";
 	mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
 	mute_led->max_brightness = LED_ON;
 	mute_led->flags = LED_HW_PLUGGABLE;
 	mute_led->dev = &hdev->dev;

 	return devm_led_classdev_register(&hdev->dev, mute_led);
 }

 static int elan_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
 	int ret;
 	struct elan_drvdata *drvdata;

 	drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);

 	if (!drvdata)
 		return -ENOMEM;

 	hid_set_drvdata(hdev, drvdata);

 	ret = hid_parse(hdev);
 	if (ret) {
 		hid_err(hdev, "Hid Parse failed\n");
 		return ret;
 	}

 	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 	if (ret) {
 		hid_err(hdev, "Hid hw start failed\n");
 		return ret;
 	}

 	if (is_not_elan_touchpad(hdev))
 		return 0;

 	if (!drvdata->input) {
 		hid_err(hdev, "Input device is not registered\n");
 		ret = -ENAVAIL;
 		goto err;
 	}

 	ret = elan_start_multitouch(hdev);
 	if (ret)
 		goto err;

 	if (id->driver_data & ELAN_HAS_LED) {
 		ret = elan_init_mute_led(hdev);
 		if (ret)
 			goto err;
 	}

 	return 0;
 err:
 	hid_hw_stop(hdev);
 	return ret;
 }

 static void elan_remove(struct hid_device *hdev)
 {
 	hid_hw_stop(hdev);
 }

 static const struct hid_device_id elan_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2),
 	  .driver_data = ELAN_HAS_LED },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
 	  .driver_data = ELAN_HAS_LED },
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, elan_devices);

 static struct hid_driver elan_driver = {
 	.name = "elan",
 	.id_table = elan_devices,
 	.input_mapping = elan_input_mapping,
 	.input_configured = elan_input_configured,
 	.raw_event = elan_raw_event,
 	.probe = elan_probe,
 	.remove = elan_remove,
 };

 module_hid_driver(elan_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Alexandrov Stanislav");
 MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* HID Driver for ELAN Touchpad
	*
	* Currently only supports touchpad found on HP Pavilion X2 10
	*
	* Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai>
	*/

	#include <linux/hid.h>
	#include <linux/input/mt.h>
	#include <linux/leds.h>
	#include <linux/module.h>
	#include <linux/usb.h>

	#include "hid-ids.h"

	#define ELAN_MT_I2C 0x5d
	#define ELAN_SINGLE_FINGER 0x81
	#define ELAN_MT_FIRST_FINGER 0x82
	#define ELAN_MT_SECOND_FINGER 0x83
	#define ELAN_INPUT_REPORT_SIZE 8
	#define ELAN_I2C_REPORT_SIZE 32
	#define ELAN_FINGER_DATA_LEN 5
	#define ELAN_MAX_FINGERS 5
	#define ELAN_MAX_PRESSURE 255
	#define ELAN_TP_USB_INTF 1

	#define ELAN_FEATURE_REPORT 0x0d
	#define ELAN_FEATURE_SIZE 5
	#define ELAN_PARAM_MAX_X 6
	#define ELAN_PARAM_MAX_Y 7
	#define ELAN_PARAM_RES 8

	#define ELAN_MUTE_LED_REPORT 0xBC
	#define ELAN_LED_REPORT_SIZE 8

	#define ELAN_HAS_LED BIT(0)

	struct elan_drvdata {
	struct input_dev *input;
	u8 prev_report[ELAN_INPUT_REPORT_SIZE];
	struct led_classdev mute_led;
	u8 mute_led_state;
	u16 max_x;
	u16 max_y;
	u16 res_x;
	u16 res_y;
	};

	static int is_not_elan_touchpad(struct hid_device *hdev)
	{
	if (hid_is_usb(hdev)) {
	struct usb_interface *intf = to_usb_interface(hdev->dev.parent);

	return (intf->altsetting->desc.bInterfaceNumber !=
	ELAN_TP_USB_INTF);
	}

	return 0;
	}

	static int elan_input_mapping(struct hid_device hdev, struct hid_input hi,
	struct hid_field field, struct hid_usage usage,
	unsigned long *bit, int max)
	{
	if (is_not_elan_touchpad(hdev))
	return 0;

	if (field->report->id == ELAN_SINGLE_FINGER \|\|
	field->report->id == ELAN_MT_FIRST_FINGER \|\|
	field->report->id == ELAN_MT_SECOND_FINGER \|\|
	field->report->id == ELAN_MT_I2C)
	return -1;

	return 0;
	}

	static int elan_get_device_param(struct hid_device *hdev,
	unsigned char *dmabuf, unsigned char param)
	{
	int ret;

	dmabuf[0] = ELAN_FEATURE_REPORT;
	dmabuf[1] = 0x05;
	dmabuf[2] = 0x03;
	dmabuf[3] = param;
	dmabuf[4] = 0x01;

	ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
	ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
	HID_REQ_SET_REPORT);
	if (ret != ELAN_FEATURE_SIZE) {
	hid_err(hdev, "Set report error for parm %d: %d\n", param, ret);
	return ret;
	}

	ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
	ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
	HID_REQ_GET_REPORT);
	if (ret != ELAN_FEATURE_SIZE) {
	hid_err(hdev, "Get report error for parm %d: %d\n", param, ret);
	return ret;
	}

	return 0;
	}

	static unsigned int elan_convert_res(char val)
	{
	/*
	* (value from firmware) * 10 + 790 = dpi
	* dpi * 10 / 254 = dots/mm
	*/
	return (val * 10 + 790) * 10 / 254;
	}

	static int elan_get_device_params(struct hid_device *hdev)
	{
	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
	unsigned char *dmabuf;
	int ret;

	dmabuf = kmalloc(ELAN_FEATURE_SIZE, GFP_KERNEL);
	if (!dmabuf)
	return -ENOMEM;

	ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_X);
	if (ret)
	goto err;

	drvdata->max_x = (dmabuf[4] << 8) \| dmabuf[3];

	ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_Y);
	if (ret)
	goto err;

	drvdata->max_y = (dmabuf[4] << 8) \| dmabuf[3];

	ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_RES);
	if (ret)
	goto err;

	drvdata->res_x = elan_convert_res(dmabuf[3]);
	drvdata->res_y = elan_convert_res(dmabuf[4]);

	err:
	kfree(dmabuf);
	return ret;
	}

	static int elan_input_configured(struct hid_device hdev, struct hid_input hi)
	{
	int ret;
	struct input_dev *input;
	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);

	if (is_not_elan_touchpad(hdev))
	return 0;

	ret = elan_get_device_params(hdev);
	if (ret)
	return ret;

	input = devm_input_allocate_device(&hdev->dev);
	if (!input)
	return -ENOMEM;

	input->name = "Elan Touchpad";
	input->phys = hdev->phys;
	input->uniq = hdev->uniq;
	input->id.bustype = hdev->bus;
	input->id.vendor = hdev->vendor;
	input->id.product = hdev->product;
	input->id.version = hdev->version;
	input->dev.parent = &hdev->dev;

	input_set_abs_params(input, ABS_MT_POSITION_X, 0, drvdata->max_x,
	0, 0);
	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, drvdata->max_y,
	0, 0);
	input_set_abs_params(input, ABS_MT_PRESSURE, 0, ELAN_MAX_PRESSURE,
	0, 0);

	__set_bit(BTN_LEFT, input->keybit);
	__set_bit(INPUT_PROP_BUTTONPAD, input->propbit);

	ret = input_mt_init_slots(input, ELAN_MAX_FINGERS, INPUT_MT_POINTER);
	if (ret) {
	hid_err(hdev, "Failed to init elan MT slots: %d\n", ret);
	input_free_device(input);
	return ret;
	}

	input_abs_set_res(input, ABS_X, drvdata->res_x);
	input_abs_set_res(input, ABS_Y, drvdata->res_y);

	ret = input_register_device(input);
	if (ret) {
	hid_err(hdev, "Failed to register elan input device: %d\n",
	ret);
	input_mt_destroy_slots(input);
	input_free_device(input);
	return ret;
	}

	drvdata->input = input;

	return 0;
	}

	static void elan_report_mt_slot(struct elan_drvdata drvdata, u8 data,
	unsigned int slot_num)
	{
	struct input_dev *input = drvdata->input;
	int x, y, p;

	bool active = !!data;

	input_mt_slot(input, slot_num);
	input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
	if (active) {
	x = ((data[0] & 0xF0) << 4) \| data[1];
	y = drvdata->max_y -
	(((data[0] & 0x07) << 8) \| data[2]);
	p = data[4];

	input_report_abs(input, ABS_MT_POSITION_X, x);
	input_report_abs(input, ABS_MT_POSITION_Y, y);
	input_report_abs(input, ABS_MT_PRESSURE, p);
	}
	}

	static void elan_usb_report_input(struct elan_drvdata drvdata, u8 data)
	{
	int i;
	struct input_dev *input = drvdata->input;

	/*
	* There is 3 types of reports: for single touch,
	* for multitouch - first finger and for multitouch - second finger
	*
	* packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER:
	*
	* byte 1: 1 0 0 0 0 0 0 1 // 0x81 or 0x82
	* byte 2: 0 0 0 0 0 0 0 0 // looks like unused
	* byte 3: f5 f4 f3 f2 f1 0 0 L
	* byte 4: x12 x11 x10 x9 0? y11 y10 y9
	* byte 5: x8 x7 x6 x5 x4 x3 x2 x1
	* byte 6: y8 y7 y6 y5 y4 y3 y2 y1
	* byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
	* byte 8: p8 p7 p6 p5 p4 p3 p2 p1
	*
	* packet structure for ELAN_MT_SECOND_FINGER:
	*
	* byte 1: 1 0 0 0 0 0 1 1 // 0x83
	* byte 2: x12 x11 x10 x9 0 y11 y10 y9
	* byte 3: x8 x7 x6 x5 x4 x3 x2 x1
	* byte 4: y8 y7 y6 y5 y4 y3 y2 y1
	* byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
	* byte 6: p8 p7 p6 p5 p4 p3 p2 p1
	* byte 7: 0 0 0 0 0 0 0 0
	* byte 8: 0 0 0 0 0 0 0 0
	*
	* f5-f1: finger touch bits
	* L: clickpad button
	* sy / sx: finger width / height expressed in traces, the total number
	* of traces can be queried by doing a HID_REQ_SET_REPORT
	* { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the
	* returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces.
	* p: pressure
	*/

	if (data[0] == ELAN_SINGLE_FINGER) {
	for (i = 0; i < ELAN_MAX_FINGERS; i++) {
	if (data[2] & BIT(i + 3))
	elan_report_mt_slot(drvdata, data + 3, i);
	else
	elan_report_mt_slot(drvdata, NULL, i);
	}
	input_report_key(input, BTN_LEFT, data[2] & 0x01);
	}
	/*
	* When touched with two fingers Elan touchpad will emit two HID reports
	* first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER
	* we will save ELAN_MT_FIRST_FINGER report and wait for
	* ELAN_MT_SECOND_FINGER to finish multitouch
	*/
	if (data[0] == ELAN_MT_FIRST_FINGER) {
	memcpy(drvdata->prev_report, data,
	sizeof(drvdata->prev_report));
	return;
	}

	if (data[0] == ELAN_MT_SECOND_FINGER) {
	int first = 0;
	u8 *prev_report = drvdata->prev_report;

	if (prev_report[0] != ELAN_MT_FIRST_FINGER)
	return;

	for (i = 0; i < ELAN_MAX_FINGERS; i++) {
	if (prev_report[2] & BIT(i + 3)) {
	if (!first) {
	first = 1;
	elan_report_mt_slot(drvdata, prev_report + 3, i);
	} else {
	elan_report_mt_slot(drvdata, data + 1, i);
	}
	} else {
	elan_report_mt_slot(drvdata, NULL, i);
	}
	}
	input_report_key(input, BTN_LEFT, prev_report[2] & 0x01);
	}

	input_mt_sync_frame(input);
	input_sync(input);
	}

	static void elan_i2c_report_input(struct elan_drvdata drvdata, u8 data)
	{
	struct input_dev *input = drvdata->input;
	u8 *finger_data;
	int i;

	/*
	* Elan MT touchpads in i2c mode send finger data in the same format
	* as in USB mode, but then with all fingers in a single packet.
	*
	* packet structure for ELAN_MT_I2C:
	*
	* byte 1: 1 0 0 1 1 1 0 1 // 0x5d
	* byte 2: f5 f4 f3 f2 f1 0 0 L
	* byte 3: x12 x11 x10 x9 0? y11 y10 y9
	* byte 4: x8 x7 x6 x5 x4 x3 x2 x1
	* byte 5: y8 y7 y6 y5 y4 y3 y2 y1
	* byte 6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
	* byte 7: p8 p7 p6 p5 p4 p3 p2 p1
	* byte 8-12: Same as byte 3-7 for second finger down
	* byte 13-17: Same as byte 3-7 for third finger down
	* byte 18-22: Same as byte 3-7 for fourth finger down
	* byte 23-27: Same as byte 3-7 for fifth finger down
	*/

	finger_data = data + 2;
	for (i = 0; i < ELAN_MAX_FINGERS; i++) {
	if (data[1] & BIT(i + 3)) {
	elan_report_mt_slot(drvdata, finger_data, i);
	finger_data += ELAN_FINGER_DATA_LEN;
	} else {
	elan_report_mt_slot(drvdata, NULL, i);
	}
	}

	input_report_key(input, BTN_LEFT, data[1] & 0x01);
	input_mt_sync_frame(input);
	input_sync(input);
	}

	static int elan_raw_event(struct hid_device *hdev,
	struct hid_report report, u8 data, int size)
	{
	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);

	if (is_not_elan_touchpad(hdev))
	return 0;

	if (data[0] == ELAN_SINGLE_FINGER \|\|
	data[0] == ELAN_MT_FIRST_FINGER \|\|
	data[0] == ELAN_MT_SECOND_FINGER) {
	if (size == ELAN_INPUT_REPORT_SIZE) {
	elan_usb_report_input(drvdata, data);
	return 1;
	}
	}

	if (data[0] == ELAN_MT_I2C && size == ELAN_I2C_REPORT_SIZE) {
	elan_i2c_report_input(drvdata, data);
	return 1;
	}

	return 0;
	}

	static int elan_start_multitouch(struct hid_device *hdev)
	{
	int ret;

	/*
	* This byte sequence will enable multitouch mode and disable
	* mouse emulation
	*/
	static const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 };
	unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL);

	if (!dmabuf)
	return -ENOMEM;

	ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf),
	HID_FEATURE_REPORT, HID_REQ_SET_REPORT);

	kfree(dmabuf);

	if (ret != sizeof(buf)) {
	hid_err(hdev, "Failed to start multitouch: %d\n", ret);
	return ret;
	}

	return 0;
	}

	static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
	enum led_brightness value)
	{
	int ret;
	u8 led_state;
	struct device *dev = led_cdev->dev->parent;
	struct hid_device *hdev = to_hid_device(dev);
	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);

	unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL);

	if (!dmabuf)
	return -ENOMEM;

	led_state = !!value;

	dmabuf[0] = ELAN_MUTE_LED_REPORT;
	dmabuf[1] = 0x02;
	dmabuf[2] = led_state;

	ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE,
	HID_FEATURE_REPORT, HID_REQ_SET_REPORT);

	kfree(dmabuf);

	if (ret != ELAN_LED_REPORT_SIZE) {
	if (ret != -ENODEV)
	hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
	return ret < 0 ? ret : -EIO;
	}

	drvdata->mute_led_state = led_state;
	return 0;
	}

	static int elan_init_mute_led(struct hid_device *hdev)
	{
	struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
	struct led_classdev *mute_led = &drvdata->mute_led;

	mute_led->name = "elan:red:mute";
	mute_led->default_trigger = "audio-mute";
	mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
	mute_led->max_brightness = LED_ON;
	mute_led->flags = LED_HW_PLUGGABLE;
	mute_led->dev = &hdev->dev;

	return devm_led_classdev_register(&hdev->dev, mute_led);
	}

	static int elan_probe(struct hid_device hdev, const struct hid_device_id id)
	{
	int ret;
	struct elan_drvdata *drvdata;

	drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);

	if (!drvdata)
	return -ENOMEM;

	hid_set_drvdata(hdev, drvdata);

	ret = hid_parse(hdev);
	if (ret) {
	hid_err(hdev, "Hid Parse failed\n");
	return ret;
	}

	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
	if (ret) {
	hid_err(hdev, "Hid hw start failed\n");
	return ret;
	}

	if (is_not_elan_touchpad(hdev))
	return 0;

	if (!drvdata->input) {
	hid_err(hdev, "Input device is not registered\n");
	ret = -ENAVAIL;
	goto err;
	}

	ret = elan_start_multitouch(hdev);
	if (ret)
	goto err;

	if (id->driver_data & ELAN_HAS_LED) {
	ret = elan_init_mute_led(hdev);
	if (ret)
	goto err;
	}

	return 0;
	err:
	hid_hw_stop(hdev);
	return ret;
	}

	static void elan_remove(struct hid_device *hdev)
	{
	hid_hw_stop(hdev);
	}

	static const struct hid_device_id elan_devices[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2),
	.driver_data = ELAN_HAS_LED },
	{ HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
	.driver_data = ELAN_HAS_LED },
	{ HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) },
	{ }
	};
	MODULE_DEVICE_TABLE(hid, elan_devices);

	static struct hid_driver elan_driver = {
	.name = "elan",
	.id_table = elan_devices,
	.input_mapping = elan_input_mapping,
	.input_configured = elan_input_configured,
	.raw_event = elan_raw_event,
	.probe = elan_probe,
	.remove = elan_remove,
	};

	module_hid_driver(elan_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Alexandrov Stanislav");
	MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");