drivers/hid/hid-cando.c - kernel/skids - Git at Google

 /*
  *  HID driver for Cando dual-touch panels
  *
  *  Copyright (c) 2010 Stephane Chatty <chatty@enac.fr>
  *
  */

 /*
  * 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.
  */

 #include <linux/device.h>
 #include <linux/hid.h>
 #include <linux/module.h>
 #include <linux/slab.h>

 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
 MODULE_DESCRIPTION("Cando dual-touch panel");
 MODULE_LICENSE("GPL");

 #include "hid-ids.h"

 struct cando_data {
 	__u16 x, y;
 	__u8 id;
 	__s8 oldest;		/* id of the oldest finger in previous frame */
 	bool valid;		/* valid finger data, or just placeholder? */
 	bool first;		/* is this the first finger in this frame? */
 	__s8 firstid;		/* id of the first finger in the frame */
 	__u16 firstx, firsty;	/* (x, y) of the first finger in the frame */
 };

 static int cando_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 		struct hid_field *field, struct hid_usage *usage,
 		unsigned long **bit, int *max)
 {
 	switch (usage->hid & HID_USAGE_PAGE) {

 	case HID_UP_GENDESK:
 		switch (usage->hid) {
 		case HID_GD_X:
 			hid_map_usage(hi, usage, bit, max,
 					EV_ABS, ABS_MT_POSITION_X);
 			/* touchscreen emulation */
 			input_set_abs_params(hi->input, ABS_X,
 						field->logical_minimum,
 						field->logical_maximum, 0, 0);
 			return 1;
 		case HID_GD_Y:
 			hid_map_usage(hi, usage, bit, max,
 					EV_ABS, ABS_MT_POSITION_Y);
 			/* touchscreen emulation */
 			input_set_abs_params(hi->input, ABS_Y,
 						field->logical_minimum,
 						field->logical_maximum, 0, 0);
 			return 1;
 		}
 		return 0;

 	case HID_UP_DIGITIZER:
 		switch (usage->hid) {
 		case HID_DG_TIPSWITCH:
 		case HID_DG_CONTACTMAX:
 			return -1;
 		case HID_DG_INRANGE:
 			/* touchscreen emulation */
 			hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
 			return 1;
 		case HID_DG_CONTACTID:
 			hid_map_usage(hi, usage, bit, max,
 					EV_ABS, ABS_MT_TRACKING_ID);
 			return 1;
 		}
 		return 0;
 	}

 	return 0;
 }

 static int cando_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 		struct hid_field *field, struct hid_usage *usage,
 		unsigned long **bit, int *max)
 {
 	if (usage->type == EV_KEY || usage->type == EV_ABS)
 		clear_bit(usage->code, *bit);

 	return 0;
 }

 /*
  * this function is called when a whole finger has been parsed,
  * so that it can decide what to send to the input layer.
  */
 static void cando_filter_event(struct cando_data *td, struct input_dev *input)
 {
 	td->first = !td->first; /* touchscreen emulation */

 	if (!td->valid) {
 		/*
 		 * touchscreen emulation: if this is the second finger and
 		 * the first was valid, the first was the oldest; if the
 		 * first was not valid and there was a valid finger in the
 		 * previous frame, this is a release.
 		 */
 		if (td->first) {
 			td->firstid = -1;
 		} else if (td->firstid >= 0) {
 			input_event(input, EV_ABS, ABS_X, td->firstx);
 			input_event(input, EV_ABS, ABS_Y, td->firsty);
 			td->oldest = td->firstid;
 		} else if (td->oldest >= 0) {
 			input_event(input, EV_KEY, BTN_TOUCH, 0);
 			td->oldest = -1;
 		}

 		return;
 	}

 	input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
 	input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
 	input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);

 	input_mt_sync(input);

 	/*
 	 * touchscreen emulation: if there was no touching finger previously,
 	 * emit touch event
 	 */
 	if (td->oldest < 0) {
 		input_event(input, EV_KEY, BTN_TOUCH, 1);
 		td->oldest = td->id;
 	}

 	/*
 	 * touchscreen emulation: if this is the first finger, wait for the
 	 * second; the oldest is then the second if it was the oldest already
 	 * or if there was no first, the first otherwise.
 	 */
 	if (td->first) {
 		td->firstx = td->x;
 		td->firsty = td->y;
 		td->firstid = td->id;
 	} else {
 		int x, y, oldest;
 		if (td->id == td->oldest || td->firstid < 0) {
 			x = td->x;
 			y = td->y;
 			oldest = td->id;
 		} else {
 			x = td->firstx;
 			y = td->firsty;
 			oldest = td->firstid;
 		}
 		input_event(input, EV_ABS, ABS_X, x);
 		input_event(input, EV_ABS, ABS_Y, y);
 		td->oldest = oldest;
 	}
 }


 static int cando_event(struct hid_device *hid, struct hid_field *field,
 				struct hid_usage *usage, __s32 value)
 {
 	struct cando_data *td = hid_get_drvdata(hid);

 	if (hid->claimed & HID_CLAIMED_INPUT) {
 		struct input_dev *input = field->hidinput->input;

 		switch (usage->hid) {
 		case HID_DG_INRANGE:
 			td->valid = value;
 			break;
 		case HID_DG_CONTACTID:
 			td->id = value;
 			break;
 		case HID_GD_X:
 			td->x = value;
 			break;
 		case HID_GD_Y:
 			td->y = value;
 			cando_filter_event(td, input);
 			break;
 		case HID_DG_TIPSWITCH:
 			/* avoid interference from generic hidinput handling */
 			break;

 		default:
 			/* fallback to the generic hidinput handling */
 			return 0;
 		}
 	}

 	/* we have handled the hidinput part, now remains hiddev */
 	if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 		hid->hiddev_hid_event(hid, field, usage, value);

 	return 1;
 }

 static int cando_probe(struct hid_device *hdev, const struct hid_device_id *id)
 {
 	int ret;
 	struct cando_data *td;

 	td = kmalloc(sizeof(struct cando_data), GFP_KERNEL);
 	if (!td) {
 		dev_err(&hdev->dev, "cannot allocate Cando Touch data\n");
 		return -ENOMEM;
 	}
 	hid_set_drvdata(hdev, td);
 	td->first = false;
 	td->oldest = -1;
 	td->valid = false;

 	ret = hid_parse(hdev);
 	if (!ret)
 		ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);

 	if (ret)
 		kfree(td);

 	return ret;
 }

 static void cando_remove(struct hid_device *hdev)
 {
 	hid_hw_stop(hdev);
 	kfree(hid_get_drvdata(hdev));
 	hid_set_drvdata(hdev, NULL);
 }

 static const struct hid_device_id cando_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 			USB_DEVICE_ID_CANDO_MULTI_TOUCH) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 			USB_DEVICE_ID_CANDO_MULTI_TOUCH_11_6) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, cando_devices);

 static const struct hid_usage_id cando_grabbed_usages[] = {
 	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 };

 static struct hid_driver cando_driver = {
 	.name = "cando-touch",
 	.id_table = cando_devices,
 	.probe = cando_probe,
 	.remove = cando_remove,
 	.input_mapping = cando_input_mapping,
 	.input_mapped = cando_input_mapped,
 	.usage_table = cando_grabbed_usages,
 	.event = cando_event,
 };

 static int __init cando_init(void)
 {
 	return hid_register_driver(&cando_driver);
 }

 static void __exit cando_exit(void)
 {
 	hid_unregister_driver(&cando_driver);
 }

 module_init(cando_init);
 module_exit(cando_exit);
	/*
	* HID driver for Cando dual-touch panels
	*
	* Copyright (c) 2010 Stephane Chatty <chatty@enac.fr>
	*
	*/

	/*
	* 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.
	*/

	#include <linux/device.h>
	#include <linux/hid.h>
	#include <linux/module.h>
	#include <linux/slab.h>

	MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
	MODULE_DESCRIPTION("Cando dual-touch panel");
	MODULE_LICENSE("GPL");

	#include "hid-ids.h"

	struct cando_data {
	__u16 x, y;
	__u8 id;
	__s8 oldest; /* id of the oldest finger in previous frame */
	bool valid; /* valid finger data, or just placeholder? */
	bool first; /* is this the first finger in this frame? */
	__s8 firstid; /* id of the first finger in the frame */
	__u16 firstx, firsty; /* (x, y) of the first finger in the frame */
	};

	static int cando_input_mapping(struct hid_device hdev, struct hid_input hi,
	struct hid_field field, struct hid_usage usage,
	unsigned long *bit, int max)
	{
	switch (usage->hid & HID_USAGE_PAGE) {

	case HID_UP_GENDESK:
	switch (usage->hid) {
	case HID_GD_X:
	hid_map_usage(hi, usage, bit, max,
	EV_ABS, ABS_MT_POSITION_X);
	/* touchscreen emulation */
	input_set_abs_params(hi->input, ABS_X,
	field->logical_minimum,
	field->logical_maximum, 0, 0);
	return 1;
	case HID_GD_Y:
	hid_map_usage(hi, usage, bit, max,
	EV_ABS, ABS_MT_POSITION_Y);
	/* touchscreen emulation */
	input_set_abs_params(hi->input, ABS_Y,
	field->logical_minimum,
	field->logical_maximum, 0, 0);
	return 1;
	}
	return 0;

	case HID_UP_DIGITIZER:
	switch (usage->hid) {
	case HID_DG_TIPSWITCH:
	case HID_DG_CONTACTMAX:
	return -1;
	case HID_DG_INRANGE:
	/* touchscreen emulation */
	hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
	return 1;
	case HID_DG_CONTACTID:
	hid_map_usage(hi, usage, bit, max,
	EV_ABS, ABS_MT_TRACKING_ID);
	return 1;
	}
	return 0;
	}

	return 0;
	}

	static int cando_input_mapped(struct hid_device hdev, struct hid_input hi,
	struct hid_field field, struct hid_usage usage,
	unsigned long *bit, int max)
	{
	if (usage->type == EV_KEY \|\| usage->type == EV_ABS)
	clear_bit(usage->code, *bit);

	return 0;
	}

	/*
	* this function is called when a whole finger has been parsed,
	* so that it can decide what to send to the input layer.
	*/
	static void cando_filter_event(struct cando_data td, struct input_dev input)
	{
	td->first = !td->first; /* touchscreen emulation */

	if (!td->valid) {
	/*
	* touchscreen emulation: if this is the second finger and
	* the first was valid, the first was the oldest; if the
	* first was not valid and there was a valid finger in the
	* previous frame, this is a release.
	*/
	if (td->first) {
	td->firstid = -1;
	} else if (td->firstid >= 0) {
	input_event(input, EV_ABS, ABS_X, td->firstx);
	input_event(input, EV_ABS, ABS_Y, td->firsty);
	td->oldest = td->firstid;
	} else if (td->oldest >= 0) {
	input_event(input, EV_KEY, BTN_TOUCH, 0);
	td->oldest = -1;
	}

	return;
	}

	input_event(input, EV_ABS, ABS_MT_TRACKING_ID, td->id);
	input_event(input, EV_ABS, ABS_MT_POSITION_X, td->x);
	input_event(input, EV_ABS, ABS_MT_POSITION_Y, td->y);

	input_mt_sync(input);

	/*
	* touchscreen emulation: if there was no touching finger previously,
	* emit touch event
	*/
	if (td->oldest < 0) {
	input_event(input, EV_KEY, BTN_TOUCH, 1);
	td->oldest = td->id;
	}

	/*
	* touchscreen emulation: if this is the first finger, wait for the
	* second; the oldest is then the second if it was the oldest already
	* or if there was no first, the first otherwise.
	*/
	if (td->first) {
	td->firstx = td->x;
	td->firsty = td->y;
	td->firstid = td->id;
	} else {
	int x, y, oldest;
	if (td->id == td->oldest \|\| td->firstid < 0) {
	x = td->x;
	y = td->y;
	oldest = td->id;
	} else {
	x = td->firstx;
	y = td->firsty;
	oldest = td->firstid;
	}
	input_event(input, EV_ABS, ABS_X, x);
	input_event(input, EV_ABS, ABS_Y, y);
	td->oldest = oldest;
	}
	}


	static int cando_event(struct hid_device hid, struct hid_field field,
	struct hid_usage *usage, __s32 value)
	{
	struct cando_data *td = hid_get_drvdata(hid);

	if (hid->claimed & HID_CLAIMED_INPUT) {
	struct input_dev *input = field->hidinput->input;

	switch (usage->hid) {
	case HID_DG_INRANGE:
	td->valid = value;
	break;
	case HID_DG_CONTACTID:
	td->id = value;
	break;
	case HID_GD_X:
	td->x = value;
	break;
	case HID_GD_Y:
	td->y = value;
	cando_filter_event(td, input);
	break;
	case HID_DG_TIPSWITCH:
	/* avoid interference from generic hidinput handling */
	break;

	default:
	/* fallback to the generic hidinput handling */
	return 0;
	}
	}

	/* we have handled the hidinput part, now remains hiddev */
	if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
	hid->hiddev_hid_event(hid, field, usage, value);

	return 1;
	}

	static int cando_probe(struct hid_device hdev, const struct hid_device_id id)
	{
	int ret;
	struct cando_data *td;

	td = kmalloc(sizeof(struct cando_data), GFP_KERNEL);
	if (!td) {
	dev_err(&hdev->dev, "cannot allocate Cando Touch data\n");
	return -ENOMEM;
	}
	hid_set_drvdata(hdev, td);
	td->first = false;
	td->oldest = -1;
	td->valid = false;

	ret = hid_parse(hdev);
	if (!ret)
	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);

	if (ret)
	kfree(td);

	return ret;
	}

	static void cando_remove(struct hid_device *hdev)
	{
	hid_hw_stop(hdev);
	kfree(hid_get_drvdata(hdev));
	hid_set_drvdata(hdev, NULL);
	}

	static const struct hid_device_id cando_devices[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
	USB_DEVICE_ID_CANDO_MULTI_TOUCH) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
	USB_DEVICE_ID_CANDO_MULTI_TOUCH_11_6) },
	{ }
	};
	MODULE_DEVICE_TABLE(hid, cando_devices);

	static const struct hid_usage_id cando_grabbed_usages[] = {
	{ HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
	{ HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
	};

	static struct hid_driver cando_driver = {
	.name = "cando-touch",
	.id_table = cando_devices,
	.probe = cando_probe,
	.remove = cando_remove,
	.input_mapping = cando_input_mapping,
	.input_mapped = cando_input_mapped,
	.usage_table = cando_grabbed_usages,
	.event = cando_event,
	};

	static int __init cando_init(void)
	{
	return hid_register_driver(&cando_driver);
	}

	static void __exit cando_exit(void)
	{
	hid_unregister_driver(&cando_driver);
	}

	module_init(cando_init);
	module_exit(cando_exit);