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Input: add common DT binding for touchscreens

Add common DT binding documentation for touchscreen devices and implement input_parse_touchscreen_of_params, which parses the common properties and configures the input device accordingly. The method currently does not interpret the axis inversion properties, since there is no matching flag in the generic linux input device.

Sebastian Reichel committed 12 years ago

Commit b98abe51 parent 50525cb5 files · +99 −0Browse files

Unified · Split

5 files
  1. Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt +27 −0
  2. drivers/input/touchscreen/Kconfig +4 −0
  3. drivers/input/touchscreen/Makefile +1 −0
  4. drivers/input/touchscreen/of_touchscreen.c +45 −0
  5. include/linux/input/touchscreen.h +22 −0
Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt+27−0
@@ -0,0 +1,27 @@
1+General Touchscreen Properties:
2+
3+Optional properties for Touchscreens:
4+ - touchscreen-size-x : horizontal resolution of touchscreen
5+ (in pixels)
6+ - touchscreen-size-y : vertical resolution of touchscreen
7+ (in pixels)
8+ - touchscreen-max-pressure : maximum reported pressure (arbitrary range
9+ dependent on the controller)
10+ - touchscreen-fuzz-x : horizontal noise value of the absolute input
11+ device (in pixels)
12+ - touchscreen-fuzz-y : vertical noise value of the absolute input
13+ device (in pixels)
14+ - touchscreen-fuzz-pressure : pressure noise value of the absolute input
15+ device (arbitrary range dependent on the
16+ controller)
17+ - touchscreen-inverted-x : X axis is inverted (boolean)
18+ - touchscreen-inverted-y : Y axis is inverted (boolean)
19+
20+Deprecated properties for Touchscreens:
21+ - x-size : deprecated name for touchscreen-size-x
22+ - y-size : deprecated name for touchscreen-size-y
23+ - moving-threshold : deprecated name for a combination of
24+ touchscreen-fuzz-x and touchscreen-fuzz-y
25+ - contact-threshold : deprecated name for touchscreen-fuzz-pressure
26+ - x-invert : deprecated name for touchscreen-inverted-x
27+ - y-invert : deprecated name for touchscreen-inverted-y
drivers/input/touchscreen/Kconfig+4−0
@@ -11,6 +11,10 @@ menuconfig INPUT_TOUCHSCREEN · 10 unmodified lines
1111
1212 if INPUT_TOUCHSCREEN
1313
14+config OF_TOUCHSCREEN
15+ def_tristate INPUT
16+ depends on INPUT && OF
17+
1418 config TOUCHSCREEN_88PM860X
1519 tristate "Marvell 88PM860x touchscreen"
1620 depends on MFD_88PM860X
drivers/input/touchscreen/Makefile+1−0
@@ -6,6 +6,7 @@ · 5 unmodified lines
66
77 wm97xx-ts-y := wm97xx-core.o
88
9+obj-$(CONFIG_OF_TOUCHSCREEN) += of_touchscreen.o
910 obj-$(CONFIG_TOUCHSCREEN_88PM860X) += 88pm860x-ts.o
1011 obj-$(CONFIG_TOUCHSCREEN_AD7877) += ad7877.o
1112 obj-$(CONFIG_TOUCHSCREEN_AD7879) += ad7879.o
drivers/input/touchscreen/of_touchscreen.c+45−0
@@ -0,0 +1,45 @@
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);
include/linux/input/touchscreen.h+22−0
@@ -0,0 +1,22 @@
1+/*
2+ * Copyright (c) 2014 Sebastian Reichel <sre@kernel.org>
3+ *
4+ * This program is free software; you can redistribute it and/or modify it
5+ * under the terms of the GNU General Public License version 2 as published by
6+ * the Free Software Foundation.
7+ */
8+
9+#ifndef _TOUCHSCREEN_H
10+#define _TOUCHSCREEN_H
11+
12+#include <linux/input.h>
13+
14+#ifdef CONFIG_OF
15+void touchscreen_parse_of_params(struct input_dev *dev);
16+#else
17+static inline void touchscreen_parse_of_params(struct input_dev *dev)
18+{
19+}
20+#endif
21+
22+#endif