[PATCH 04/15] Input: atmel_mxt_ts - implement device tree support

[nick.dyer@itdev.co.uk]

From: Stephen Warren <swarren@nvidia.com>

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
 .../devicetree/bindings/input/atmel,maxtouch.txt   | 25 +++++++++++
 drivers/input/touchscreen/atmel_mxt_ts.c           | 48 ++++++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/atmel,maxtouch.txt

diff --git a/Documentation/devicetree/bindings/input/atmel,maxtouch.txt b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt
new file mode 100644
index 0000000..60d6339
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/atmel,maxtouch.txt
@@ -0,0 +1,25 @@
+Atmel maXTouch touchscreen/touchpad
+
+Required properties:
+- compatible:
+    atmel,maxtouch
+
+- reg: The I2C address of the device
+
+- interrupts: The sink for the touchpad's IRQ output
+    See ../interrupt-controller/interrupts.txt
+
+Optional properties for main touchpad device:
+
+- linux,gpio-keymap: An array of up to 4 entries indicating the Linux
+    keycode generated by each GPIO. Linux keycodes are defined in
+    <dt-bindings/input/input.h>.
+
+Example:
+
+	touch@4b {
+		compatible = "atmel,maxtouch";
+		reg = <0x4b>;
+		interrupt-parent = <&gpio>;
+		interrupts = <TEGRA_GPIO(W, 3) GPIO_ACTIVE_HIGH>;
+	};
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 31113c3..5a095f6 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -22,6 +22,7 @@
 #include <linux/i2c/atmel_mxt_ts.h>
 #include <linux/input/mt.h>
 #include <linux/interrupt.h>
+#include <linux/of.h>
 #include <linux/slab.h>
 
 /* Version */
@@ -1527,6 +1528,42 @@ static void mxt_input_close(struct input_dev *dev)
 	mxt_stop(data);
 }
 
+#ifdef CONFIG_OF
+static struct mxt_platform_data *mxt_parse_dt(struct i2c_client *client)
+{
+	struct mxt_platform_data *pdata;
+	struct property *prop;
+	unsigned int *keymap;
+	int proplen, i, ret;
+	u32 keycode;
+
+	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return NULL;
+
+	prop = of_find_property(client->dev.of_node, "linux,gpio-keymap",
+				&proplen);
+	if (prop) {
+		pdata->t19_num_keys = proplen / sizeof(u32);
+
+		keymap = devm_kzalloc(&client->dev,
+			pdata->t19_num_keys * sizeof(u32), GFP_KERNEL);
+		if (!keymap)
+			return NULL;
+		pdata->t19_keymap = keymap;
+		for (i = 0; i < pdata->t19_num_keys; i++) {
+			ret = of_property_read_u32_index(client->dev.of_node,
+					"linux,gpio-keymap", i, &keycode);
+			if (ret)
+				keycode = 0;
+			keymap[i] = keycode;
+		}
+	}
+
+	return pdata;
+}
+#endif
+
 static int mxt_probe(struct i2c_client *client,
 		const struct i2c_device_id *id)
 {
@@ -1534,6 +1571,10 @@ static int mxt_probe(struct i2c_client *client,
 	const struct mxt_platform_data *pdata = dev_get_platdata(&client->dev);
 	int error;
 
+#ifdef CONFIG_OF
+	if (!pdata && client->dev.of_node)
+		pdata = mxt_parse_dt(client);
+#endif
 	if (!pdata)
 		return -EINVAL;
 
@@ -1638,6 +1679,12 @@ static int mxt_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(mxt_pm_ops, mxt_suspend, mxt_resume);
 
+static const struct of_device_id mxt_of_match[] = {
+	{ .compatible = "atmel,maxtouch", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mxt_of_match);
+
 static const struct i2c_device_id mxt_id[] = {
 	{ "qt602240_ts", 0 },
 	{ "atmel_mxt_ts", 0 },
@@ -1651,6 +1698,7 @@ static struct i2c_driver mxt_driver = {
 	.driver = {
 		.name	= "atmel_mxt_ts",
 		.owner	= THIS_MODULE,
+		.of_match_table = of_match_ptr(mxt_of_match),
 		.pm	= &mxt_pm_ops,
 	},
 	.probe		= mxt_probe,
-- 
2.0.1