forked from Minki/linux
7c494375b7
When applying touchscreen parameters specified in device tree let's make sure we keep whatever setup was done by the driver and not reset the missing values to zero. Reported-by: Pavel Machek <pavel@ucw.cz> Tested-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
/*
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* Generic DT helper functions for touchscreen devices
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*
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* Copyright (c) 2014 Sebastian Reichel <sre@kernel.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/of.h>
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#include <linux/input.h>
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#include <linux/input/mt.h>
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#include <linux/input/touchscreen.h>
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static bool touchscreen_get_prop_u32(struct device_node *np,
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const char *property,
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unsigned int default_value,
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unsigned int *value)
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{
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u32 val;
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int error;
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error = of_property_read_u32(np, property, &val);
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if (error) {
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*value = default_value;
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return false;
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}
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*value = val;
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return true;
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}
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static void touchscreen_set_params(struct input_dev *dev,
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unsigned long axis,
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int max, int fuzz)
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{
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struct input_absinfo *absinfo;
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if (!test_bit(axis, dev->absbit)) {
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/*
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* Emit a warning only if the axis is not a multitouch
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* axis, which might not be set by the driver.
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*/
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if (!input_is_mt_axis(axis))
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dev_warn(&dev->dev,
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"DT specifies parameters but the axis is not set up\n");
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return;
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}
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absinfo = &dev->absinfo[axis];
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absinfo->maximum = max;
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absinfo->fuzz = fuzz;
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}
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/**
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* touchscreen_parse_of_params - parse common touchscreen DT properties
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* @dev: device that should be parsed
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*
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* This function parses common DT properties for touchscreens and setups the
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* input device accordingly. The function keeps previously setuped default
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* values if no value is specified via DT.
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*/
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void touchscreen_parse_of_params(struct input_dev *dev, bool multitouch)
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{
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struct device_node *np = dev->dev.parent->of_node;
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unsigned int axis;
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unsigned int maximum, fuzz;
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bool data_present;
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input_alloc_absinfo(dev);
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if (!dev->absinfo)
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return;
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axis = multitouch ? ABS_MT_POSITION_X : ABS_X;
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data_present = touchscreen_get_prop_u32(np, "touchscreen-size-x",
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input_abs_get_max(dev, axis),
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&maximum) |
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touchscreen_get_prop_u32(np, "touchscreen-fuzz-x",
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input_abs_get_fuzz(dev, axis),
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&fuzz);
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if (data_present)
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touchscreen_set_params(dev, axis, maximum, fuzz);
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axis = multitouch ? ABS_MT_POSITION_Y : ABS_Y;
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data_present = touchscreen_get_prop_u32(np, "touchscreen-size-y",
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input_abs_get_max(dev, axis),
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&maximum) |
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touchscreen_get_prop_u32(np, "touchscreen-fuzz-y",
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input_abs_get_fuzz(dev, axis),
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&fuzz);
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if (data_present)
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touchscreen_set_params(dev, axis, maximum, fuzz);
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axis = multitouch ? ABS_MT_PRESSURE : ABS_PRESSURE;
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data_present = touchscreen_get_prop_u32(np, "touchscreen-max-pressure",
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input_abs_get_max(dev, axis),
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&maximum) |
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touchscreen_get_prop_u32(np, "touchscreen-fuzz-pressure",
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input_abs_get_fuzz(dev, axis),
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&fuzz);
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if (data_present)
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touchscreen_set_params(dev, axis, maximum, fuzz);
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}
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EXPORT_SYMBOL(touchscreen_parse_of_params);
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