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.
Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>
---
.../bindings/input/touchscreen/touchscreen.txt | 9 ++++++
drivers/input/input.c | 34 ++++++++++++++++++++++
include/linux/input.h | 8 +++++
3 files changed, 51 insertions(+)
create mode 100644 Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
diff --git a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
new file mode 100644
index 0000000..a2ff0a0
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.txt
@@ -0,0 +1,9 @@
+General Touchscreen Properties:
+
+Optional properties for Touchscreens:
+ - touchscreen-size-x : horizontal resolution of touchscreen
+ - touchscreen-size-y : vertical resolution of touchscreen
+ - touchscreen-max-pressure : maximum reported pressure
+ - touchscreen-fuzz-x : horizontal noise value of the absolute input device
+ - touchscreen-fuzz-y : vertical noise value of the absolute input device
+ - touchscreen-fuzz-pressure : pressure noise value of the absolute input device
diff --git a/drivers/input/input.c b/drivers/input/input.c
index 1c4c0db..97966d93 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -27,6 +27,7 @@
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/rcupdate.h>
+#include <linux/of.h>
#include "input-compat.h"
MODULE_AUTHOR("Vojtech Pavlik <vojtech@xxxxxxx>");
@@ -2398,6 +2399,39 @@ void input_free_minor(unsigned int minor)
}
EXPORT_SYMBOL(input_free_minor);
+#if defined(CONFIG_OF)
+/**
+ * input_parse_touchscreen_of_params - parse common touchscreen DT properties
+ * @dev: device that should be parsed
+ *
+ * This function parses common DT properties for touchscreens and setups the
+ * input device accordingly. The function keeps previously setuped default
+ * values if no value is specified via DT.
+ */
+void input_parse_touchscreen_of_params(struct input_dev *dev)
+{
+ struct device_node *np = dev->dev.parent->of_node;
+ struct input_absinfo *absinfo;
+
+ input_alloc_absinfo(dev);
+ if (!dev->absinfo)
+ return;
+
+ absinfo = &dev->absinfo[ABS_X];
+ of_property_read_u32(np, "touchscreen-size-x", &absinfo->maximum);
+ of_property_read_u32(np, "touchscreen-fuzz-x", &absinfo->fuzz);
+
+ absinfo = &dev->absinfo[ABS_Y];
+ of_property_read_u32(np, "touchscreen-size-y", &absinfo->maximum);
+ of_property_read_u32(np, "touchscreen-fuzz-y", &absinfo->fuzz);
+
+ absinfo = &dev->absinfo[ABS_PRESSURE];
+ of_property_read_u32(np, "touchscreen-max-pressure", &absinfo->maximum);
+ of_property_read_u32(np, "touchscreen-fuzz-pressure", &absinfo->fuzz);
+}
+EXPORT_SYMBOL(input_parse_touchscreen_of_params);
+#endif
+
static int __init input_init(void)
{
int err;
diff --git a/include/linux/input.h b/include/linux/input.h
index 82ce323..3dc3b1e 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -531,4 +531,12 @@ int input_ff_erase(struct input_dev *dev, int effect_id, struct file *file);
int input_ff_create_memless(struct input_dev *dev, void *data,
int (*play_effect)(struct input_dev *, void *, struct ff_effect *));
+#if defined(CONFIG_OF)
+void input_parse_touchscreen_of_params(struct input_dev *dev);
+#else
+static inline void input_parse_touchscreen_of_params(struct input_dev *dev) {
+ return;
+}
+#endif
+
#endif
--
1.9.1
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