drivers/input/touchscreen/of_touchscreen.c

   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  */
  24 void 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 }
  45 EXPORT_SYMBOL(touchscreen_parse_of_params);