of_touchscreen.c revision b98abe52fa8e2a3797d3cc2db3d0e109f4549c03 
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
12#include <linux/of.h>
13#include <linux/input.h>
14#include <linux/input/touchscreen.h>
15
16/**
17 * touchscreen_parse_of_params - parse common touchscreen DT properties
18 * @dev: device that should be parsed
19 *
20 * This function parses common DT properties for touchscreens and setups the
21 * input device accordingly. The function keeps previously setuped default
22 * values if no value is specified via DT.
23 */
24void touchscreen_parse_of_params(struct input_dev *dev)
25{
26	struct device_node *np = dev->dev.parent->of_node;
27	struct input_absinfo *absinfo;
28
29	input_alloc_absinfo(dev);
30	if (!dev->absinfo)
31		return;
32
33	absinfo = &dev->absinfo[ABS_X];
34	of_property_read_u32(np, "touchscreen-size-x", &absinfo->maximum);
35	of_property_read_u32(np, "touchscreen-fuzz-x", &absinfo->fuzz);
36
37	absinfo = &dev->absinfo[ABS_Y];
38	of_property_read_u32(np, "touchscreen-size-y", &absinfo->maximum);
39	of_property_read_u32(np, "touchscreen-fuzz-y", &absinfo->fuzz);
40
41	absinfo = &dev->absinfo[ABS_PRESSURE];
42	of_property_read_u32(np, "touchscreen-max-pressure", &absinfo->maximum);
43	of_property_read_u32(np, "touchscreen-fuzz-pressure", &absinfo->fuzz);
44}
45EXPORT_SYMBOL(touchscreen_parse_of_params);
46