[PATCH RFC v2] media: i2c: mt9p031: add OF support

[Prabhakar Lad <prabhakar.csengg@gmail.com>]

From: Lad, Prabhakar <prabhakar.csengg@gmail.com>

add OF support for the mt9p031 sensor driver.
Alongside this patch sorts the header inclusion alphabetically.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Rob Landley <rob@landley.net>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: davinci-linux-open-source@linux.davincidsp.com
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 Changes for v2:
 1: Used '-' instead of '_' for device properties.
 2: Specified gpio reset pin as phandle in device node.
 3: Handle platform data properly even if kernel is compiled with
    devicetree support.
 4: Used dev_* for messages in drivers instead of pr_*.
 5: Changed compatible property to "aptina,mt9p031" and "aptina,mt9p031m".
 6: Sorted the header inclusion alphabetically and fixed some minor code nits.

 .../devicetree/bindings/media/i2c/mt9p031.txt      |   37 ++++++++++++
 drivers/media/i2c/mt9p031.c                        |   62 +++++++++++++++++++-
 2 files changed, 97 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/media/i2c/mt9p031.txt

diff --git a/Documentation/devicetree/bindings/media/i2c/mt9p031.txt b/Documentation/devicetree/bindings/media/i2c/mt9p031.txt
new file mode 100644
index 0000000..cbe352b
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/i2c/mt9p031.txt
@@ -0,0 +1,37 @@
+* Aptina 1/2.5-Inch 5Mp CMOS Digital Image Sensor
+
+The Aptina MT9P031 is a 1/2.5-inch CMOS active pixel digital image sensor with
+an active array size of 2592H x 1944V. It is programmable through a simple
+two-wire serial interface.
+
+Required Properties :
+- compatible : value should be either one among the following
+	(a) "aptina,mt9p031" for mt9p031 sensor
+	(b) "aptina,mt9p031m" for mt9p031m sensor
+
+- input-clock-frequency : Input clock frequency.
+
+- pixel-clock-frequency : Pixel clock frequency.
+
+Optional Properties :
+-gpio-reset: Chip reset GPIO
+
+Example:
+
+i2c0@1c22000 {
+	...
+	...
+	mt9p031@5d {
+		compatible = "aptina,mt9p031";
+		reg = <0x5d>;
+		gpio-reset = <&gpio3 30 0>;
+
+		port {
+			mt9p031_1: endpoint {
+				input-clock-frequency = <6000000>;
+				pixel-clock-frequency = <96000000>;
+			};
+		};
+	};
+	...
+};
diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c
index 28cf95b..8ce3561 100644
--- a/drivers/media/i2c/mt9p031.c
+++ b/drivers/media/i2c/mt9p031.c
@@ -16,9 +16,11 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/gpio.h>
-#include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
 #include <linux/pm.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
@@ -28,6 +30,7 @@
 #include <media/v4l2-chip-ident.h>
 #include <media/v4l2-ctrls.h>
 #include <media/v4l2-device.h>
+#include <media/v4l2-of.h>
 #include <media/v4l2-subdev.h>
 
 #include "aptina-pll.h"
@@ -928,10 +931,57 @@ static const struct v4l2_subdev_internal_ops mt9p031_subdev_internal_ops = {
  * Driver initialization and probing
  */
 
+#if defined(CONFIG_OF)
+static struct mt9p031_platform_data *
+	mt9p031_get_pdata(struct i2c_client *client)
+
+{
+	if (client->dev.of_node) {
+		struct device_node *np;
+		struct mt9p031_platform_data *pdata;
+
+		np = v4l2_of_get_next_endpoint(client->dev.of_node, NULL);
+		if (!np)
+			return NULL;
+
+		pdata = devm_kzalloc(&client->dev,
+				     sizeof(struct mt9p031_platform_data),
+				     GFP_KERNEL);
+		if (!pdata) {
+			dev_err(&client->dev,
+				"mt9p031 failed allocate memeory\n");
+			return NULL;
+		}
+		pdata->reset = of_get_named_gpio(client->dev.of_node,
+						 "gpio-reset", 0);
+		if (!gpio_is_valid(pdata->reset))
+			pdata->reset = -1;
+
+		if (of_property_read_u32(np, "input-clock-frequency",
+					 &pdata->ext_freq))
+			return NULL;
+
+		if (of_property_read_u32(np, "pixel-clock-frequency",
+					 &pdata->target_freq))
+			return NULL;
+
+		return pdata;
+	}
+
+	return client->dev.platform_data;
+}
+#else
+static struct mt9p031_platform_data *
+	mt9p031_get_pdata(struct i2c_client *client)
+{
+	return client->dev.platform_data;
+}
+#endif
+
 static int mt9p031_probe(struct i2c_client *client,
 			 const struct i2c_device_id *did)
 {
-	struct mt9p031_platform_data *pdata = client->dev.platform_data;
+	struct mt9p031_platform_data *pdata = mt9p031_get_pdata(client);
 	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 	struct mt9p031 *mt9p031;
 	unsigned int i;
@@ -1070,8 +1120,16 @@ static const struct i2c_device_id mt9p031_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, mt9p031_id);
 
+static const struct of_device_id mt9p031_of_match[] = {
+	{ .compatible = "aptina,mt9p031", },
+	{ .compatible = "aptina,mt9p031m", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mt9p031_of_match);
+
 static struct i2c_driver mt9p031_i2c_driver = {
 	.driver = {
+		.of_match_table = of_match_ptr(mt9p031_of_match),
 		.name = "mt9p031",
 	},
 	.probe          = mt9p031_probe,
-- 
1.7.4.1