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// SPDX-License-Identifier: GPL-2.0-only
/*
* Generic DT helper functions for touchscreen devices
*
* Copyright (c) 2014 Sebastian Reichel <sre@kernel.org>
*/
#include <linux/property.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/module.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 min, 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->minimum = min;
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
* @prop: pointer to a struct touchscreen_properties into which to store
* axis swap and invert info for use with touchscreen_report_x_y();
* or %NULL
*
* 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 touchscreen_properties *prop)
{
struct device *dev = input->dev.parent;
struct input_absinfo *absinfo;
unsigned int axis;
unsigned int minimum, 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-min-x",
input_abs_get_min(input, axis),
&minimum) |
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, minimum, maximum - 1, fuzz);
axis = multitouch ? ABS_MT_POSITION_Y : ABS_Y;
data_present = touchscreen_get_prop_u32(dev, "touchscreen-min-y",
input_abs_get_min(input, axis),
&minimum) |
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, minimum, 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, 0, maximum, fuzz);
if (!prop)
return;
axis = multitouch ? ABS_MT_POSITION_X : ABS_X;
prop->max_x = input_abs_get_max(input, axis);
prop->max_y = input_abs_get_max(input, axis + 1);
prop->invert_x =
device_property_read_bool(dev, "touchscreen-inverted-x");
if (prop->invert_x) {
absinfo = &input->absinfo[axis];
absinfo->maximum -= absinfo->minimum;
absinfo->minimum = 0;
}
prop->invert_y =
device_property_read_bool(dev, "touchscreen-inverted-y");
if (prop->invert_y) {
absinfo = &input->absinfo[axis + 1];
absinfo->maximum -= absinfo->minimum;
absinfo->minimum = 0;
}
prop->swap_x_y =
device_property_read_bool(dev, "touchscreen-swapped-x-y");
if (prop->swap_x_y)
swap(input->absinfo[axis], input->absinfo[axis + 1]);
}
EXPORT_SYMBOL(touchscreen_parse_properties);
static void
touchscreen_apply_prop_to_x_y(const struct touchscreen_properties *prop,
unsigned int *x, unsigned int *y)
{
if (prop->invert_x)
*x = prop->max_x - *x;
if (prop->invert_y)
*y = prop->max_y - *y;
if (prop->swap_x_y)
swap(*x, *y);
}
/**
* touchscreen_set_mt_pos - Set input_mt_pos coordinates
* @pos: input_mt_pos to set coordinates of
* @prop: pointer to a struct touchscreen_properties
* @x: X coordinate to store in pos
* @y: Y coordinate to store in pos
*
* Adjust the passed in x and y values applying any axis inversion and
* swapping requested in the passed in touchscreen_properties and store
* the result in a struct input_mt_pos.
*/
void touchscreen_set_mt_pos(struct input_mt_pos *pos,
const struct touchscreen_properties *prop,
unsigned int x, unsigned int y)
{
touchscreen_apply_prop_to_x_y(prop, &x, &y);
pos->x = x;
pos->y = y;
}
EXPORT_SYMBOL(touchscreen_set_mt_pos);
/**
* touchscreen_report_pos - Report touchscreen coordinates
* @input: input_device to report coordinates for
* @prop: pointer to a struct touchscreen_properties
* @x: X coordinate to report
* @y: Y coordinate to report
* @multitouch: Report coordinates on single-touch or multi-touch axes
*
* Adjust the passed in x and y values applying any axis inversion and
* swapping requested in the passed in touchscreen_properties and then
* report the resulting coordinates on the input_dev's x and y axis.
*/
void touchscreen_report_pos(struct input_dev *input,
const struct touchscreen_properties *prop,
unsigned int x, unsigned int y,
bool multitouch)
{
touchscreen_apply_prop_to_x_y(prop, &x, &y);
input_report_abs(input, multitouch ? ABS_MT_POSITION_X : ABS_X, x);
input_report_abs(input, multitouch ? ABS_MT_POSITION_Y : ABS_Y, y);
}
EXPORT_SYMBOL(touchscreen_report_pos);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Device-tree helpers functions for touchscreen devices");
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