[deliverable/linux.git] / drivers / input / touchscreen / of_touchscreen.c

/*
 *  Generic DT helper functions for touchscreen devices
 *
 *  Copyright (c) 2014 Sebastian Reichel <sre@kernel.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 */

#include <linux/property.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>

static bool touchscreen_get_prop_u32(struct device *dev,
				     const char *property,
				     unsigned int default_value,
				     unsigned int *value)
{
	u32 val;
	int error;

	error = device_property_read_u32(dev, property, &val);
	if (error) {
		*value = default_value;
		return false;
	}

	*value = val;
	return true;
}

static void touchscreen_set_params(struct input_dev *dev,
				   unsigned long axis,
				   int max, int fuzz)
{
	struct input_absinfo *absinfo;

	if (!test_bit(axis, dev->absbit)) {
		dev_warn(&dev->dev,
			 "DT specifies parameters but the axis %lu is not set up\n",
			 axis);
		return;
	}

	absinfo = &dev->absinfo[axis];
	absinfo->maximum = max;
	absinfo->fuzz = fuzz;
}

/**
 * touchscreen_parse_properties - parse common touchscreen DT properties
 * @input: input device that should be parsed
 * @multitouch: specifies whether parsed properties should be applied to
 *	single-touch or multi-touch axes
 *
 * This function parses common DT properties for touchscreens and setups the
 * input device accordingly. The function keeps previously set up default
 * values if no value is specified via DT.
 */
void touchscreen_parse_properties(struct input_dev *input, bool multitouch)
{
	struct device *dev = input->dev.parent;
	unsigned int axis;
	unsigned int maximum, fuzz;
	bool data_present;

	input_alloc_absinfo(input);
	if (!input->absinfo)
		return;

	axis = multitouch ? ABS_MT_POSITION_X : ABS_X;
	data_present = touchscreen_get_prop_u32(dev, "touchscreen-size-x",
						input_abs_get_max(input,
								  axis) + 1,
						&maximum) |
		       touchscreen_get_prop_u32(dev, "touchscreen-fuzz-x",
						input_abs_get_fuzz(input, axis),
						&fuzz);
	if (data_present)
		touchscreen_set_params(input, axis, maximum - 1, fuzz);

	axis = multitouch ? ABS_MT_POSITION_Y : ABS_Y;
	data_present = touchscreen_get_prop_u32(dev, "touchscreen-size-y",
						input_abs_get_max(input,
								  axis) + 1,
						&maximum) |
		       touchscreen_get_prop_u32(dev, "touchscreen-fuzz-y",
						input_abs_get_fuzz(input, axis),
						&fuzz);
	if (data_present)
		touchscreen_set_params(input, axis, maximum - 1, fuzz);

	axis = multitouch ? ABS_MT_PRESSURE : ABS_PRESSURE;
	data_present = touchscreen_get_prop_u32(dev,
						"touchscreen-max-pressure",
						input_abs_get_max(input, axis),
						&maximum) |
		       touchscreen_get_prop_u32(dev,
						"touchscreen-fuzz-pressure",
						input_abs_get_fuzz(input, axis),
						&fuzz);
	if (data_present)
		touchscreen_set_params(input, axis, maximum, fuzz);
}
EXPORT_SYMBOL(touchscreen_parse_properties);
Commit	Line	Data
b98abe52 SR	1	/*
	2	* Generic DT helper functions for touchscreen devices
	3	*
	4	* Copyright (c) 2014 Sebastian Reichel <sre@kernel.org>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*
	10	*/
	11
4200e831	12	#include <linux/property.h>
b98abe52	13	#include <linux/input.h>
0a363a38	14	#include <linux/input/mt.h>
b98abe52 SR	15	#include <linux/input/touchscreen.h>
b98abe52 SR	16
4200e831	17	static bool touchscreen_get_prop_u32(struct device *dev,
7c494375 DT	18	const char *property,
	19	unsigned int default_value,
	20	unsigned int *value)
3eea8b5d	21	{
7c494375 DT	22	u32 val;
7c494375 DT	23	int error;
3eea8b5d	24
4200e831	25	error = device_property_read_u32(dev, property, &val);
7c494375 DT	26	if (error) {
	27	*value = default_value;
	28	return false;
	29	}
3eea8b5d	30
7c494375 DT	31	*value = val;
7c494375 DT	32	return true;
3eea8b5d MR	33	}
	34
	35	static void touchscreen_set_params(struct input_dev *dev,
	36	unsigned long axis,
	37	int max, int fuzz)
	38	{
	39	struct input_absinfo *absinfo;
	40
	41	if (!test_bit(axis, dev->absbit)) {
f61fd21d DT	42	dev_warn(&dev->dev,
	43	"DT specifies parameters but the axis %lu is not set up\n",
	44	axis);
3eea8b5d MR	45	return;
	46	}
	47
	48	absinfo = &dev->absinfo[axis];
	49	absinfo->maximum = max;
	50	absinfo->fuzz = fuzz;
	51	}
	52
b98abe52	53	/**
4200e831 DT	54	* touchscreen_parse_properties - parse common touchscreen DT properties
	55	* @input: input device that should be parsed
	56	* @multitouch: specifies whether parsed properties should be applied to
	57	* single-touch or multi-touch axes
b98abe52 SR	58	*
b98abe52 SR	59	* This function parses common DT properties for touchscreens and setups the
4200e831	60	* input device accordingly. The function keeps previously set up default
b98abe52 SR	61	* values if no value is specified via DT.
b98abe52 SR	62	*/
4200e831	63	void touchscreen_parse_properties(struct input_dev *input, bool multitouch)
b98abe52	64	{
4200e831	65	struct device *dev = input->dev.parent;
7c494375 DT	66	unsigned int axis;
	67	unsigned int maximum, fuzz;
	68	bool data_present;
b98abe52	69
4200e831 DT	70	input_alloc_absinfo(input);
4200e831 DT	71	if (!input->absinfo)
b98abe52 SR	72	return;
b98abe52 SR	73
7c494375	74	axis = multitouch ? ABS_MT_POSITION_X : ABS_X;
4200e831 DT	75	data_present = touchscreen_get_prop_u32(dev, "touchscreen-size-x",
4200e831 DT	76	input_abs_get_max(input,
51717869	77	axis) + 1,
7c494375	78	&maximum) \|
4200e831 DT	79	touchscreen_get_prop_u32(dev, "touchscreen-fuzz-x",
4200e831 DT	80	input_abs_get_fuzz(input, axis),
7c494375 DT	81	&fuzz);
7c494375 DT	82	if (data_present)
4200e831	83	touchscreen_set_params(input, axis, maximum - 1, fuzz);
b98abe52	84
7c494375	85	axis = multitouch ? ABS_MT_POSITION_Y : ABS_Y;
4200e831 DT	86	data_present = touchscreen_get_prop_u32(dev, "touchscreen-size-y",
4200e831 DT	87	input_abs_get_max(input,
51717869	88	axis) + 1,
7c494375	89	&maximum) \|
4200e831 DT	90	touchscreen_get_prop_u32(dev, "touchscreen-fuzz-y",
4200e831 DT	91	input_abs_get_fuzz(input, axis),
7c494375 DT	92	&fuzz);
7c494375 DT	93	if (data_present)
4200e831	94	touchscreen_set_params(input, axis, maximum - 1, fuzz);
b98abe52	95
7c494375	96	axis = multitouch ? ABS_MT_PRESSURE : ABS_PRESSURE;
4200e831 DT	97	data_present = touchscreen_get_prop_u32(dev,
	98	"touchscreen-max-pressure",
	99	input_abs_get_max(input, axis),
7c494375	100	&maximum) \|
4200e831 DT	101	touchscreen_get_prop_u32(dev,
	102	"touchscreen-fuzz-pressure",
	103	input_abs_get_fuzz(input, axis),
7c494375 DT	104	&fuzz);
7c494375 DT	105	if (data_present)
4200e831	106	touchscreen_set_params(input, axis, maximum, fuzz);
b98abe52	107	}
4200e831	108	EXPORT_SYMBOL(touchscreen_parse_properties);