[PATCH v2 2/3] i2c: s3c2410: Add device tree support

[Thomas Abraham]

Add device tree probe support for Samsung's s3c2410 i2c driver.

Signed-off-by: Thomas Abraham <thomas.abraham at linaro.org>
---
 .../devicetree/bindings/i2c/samsung-i2c.txt        |   44 +++++++++++++++++
 drivers/i2c/busses/i2c-s3c2410.c                   |   51 +++++++++++++++++++-
 2 files changed, 94 insertions(+), 1 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/i2c/samsung-i2c.txt

diff --git a/Documentation/devicetree/bindings/i2c/samsung-i2c.txt b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
new file mode 100644
index 0000000..4e1a2ef
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/samsung-i2c.txt
@@ -0,0 +1,44 @@
+* Samsung's I2C controller
+
+The Samsung's I2C controller is used to interface with I2C devices.
+
+Required properties:
+  - compatible: value should be either of the following.
+      (a) "samsung, s3c2410-i2c", for i2c compatible with s3c2410 i2c.
+      (b) "samsung, s3c2440-i2c", for i2c compatible with s3c2440 i2c.
+
+  - reg: physical base address of the controller and length of memory mapped
+    region.
+
+  - interrupts: interrupt number to the cpu.
+
+  - samsung,i2c-sda-delay: Delay (in ns) applied to data line (SDA) edges.
+
+  - gpios: The order of the gpios should be in the following order.
+       <SDA, SCL>
+
+Optional properties:
+  - samsung,i2c-slave-addr: Slave address in multi-master enviroment. If not
+    specified, default value is 0.
+
+  - samsung,i2c-max-bus-freq: Desired frequency in Hz of the bus. If not
+    specified, the default value in Hz is 100000.
+
+Example:
+
+	i2c at 13870000 {
+		compatible = "samsung,s3c2440-i2c";
+		reg = <0x13870000 0x100>;
+		interrupts = <345>;
+		samsung,i2c-sda-delay = <100>;
+		samsung,i2c-max-bus-freq = <100000>;
+		gpios = <&gpd1 2 0 /* SDA */
+			 &gpd1 3 0 /* SCL */>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		wm8994 at 1a {
+			compatible = "wlf,wm8994";
+			reg = <0x1a>;
+		};
+	};
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
index e132168..40264b0 100644
--- a/drivers/i2c/busses/i2c-s3c2410.c
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -35,6 +35,7 @@
 #include <linux/cpufreq.h>
 #include <linux/slab.h>
 #include <linux/io.h>
+#include <linux/of_i2c.h>
 
 #include <asm/irq.h>
 
@@ -96,6 +97,10 @@ static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
 	struct platform_device *pdev = to_platform_device(i2c->dev);
 	enum s3c24xx_i2c_type type;
 
+	if (i2c->dev->of_node)
+		return of_device_is_compatible(i2c->dev->of_node,
+						"samsung,s3c2440-i2c");
+
 	type = platform_get_device_id(pdev)->driver_data;
 	return type == TYPE_S3C2440;
 }
@@ -787,6 +792,34 @@ static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
 	return 0;
 }
 
+#ifdef CONFIG_OF
+
+/* s3c24xx_i2c_parse_dt
+ *
+ * Parse the device tree node and retreive the platform data.
+*/
+
+static void
+s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
+{
+	struct s3c2410_platform_i2c *pdata = &i2c->pdata;
+
+	if (!np)
+		return;
+
+	of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay);
+	of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr);
+	of_property_read_u32(np, "samsung,i2c-max-bus-freq",
+				(u32 *)&pdata->frequency);
+}
+#else
+static void
+s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c)
+{
+	return;
+}
+#endif
+
 /* s3c24xx_i2c_probe
  *
  * called by the bus driver when a suitable device is found
@@ -812,6 +845,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 	}
 
 	memcpy(&i2c->pdata, pdata, sizeof(*pdata));
+	s3c24xx_i2c_parse_dt(pdev->dev.of_node, i2c);
 
 	strlcpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name));
 	i2c->adap.owner   = THIS_MODULE;
@@ -908,13 +942,16 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
 	 */
 
 	i2c->adap.nr = pdata->bus_num;
+	i2c->adap.dev.of_node = pdev->dev.of_node;
 
-	ret = i2c_add_numbered_adapter(&i2c->adap);
+	ret = (pdev->dev.of_node) ? i2c_add_adapter(&i2c->adap) :
+					i2c_add_numbered_adapter(&i2c->adap);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add bus to i2c core\n");
 		goto err_cpufreq;
 	}
 
+	of_i2c_register_devices(&i2c->adap);
 	platform_set_drvdata(pdev, i2c);
 
 	dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev));
@@ -1016,6 +1053,17 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
 };
 MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
 
+#ifdef CONFIG_OF
+static const struct of_device_id s3c24xx_i2c_match[] = {
+	{ .compatible = "samsung,s3c2410-i2c" },
+	{ .compatible = "samsung,s3c2440-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
+#else
+#define s3c24xx_i2c_match NULL
+#endif
+
 static struct platform_driver s3c24xx_i2c_driver = {
 	.probe		= s3c24xx_i2c_probe,
 	.remove		= s3c24xx_i2c_remove,
@@ -1024,6 +1072,7 @@ static struct platform_driver s3c24xx_i2c_driver = {
 		.owner	= THIS_MODULE,
 		.name	= "s3c-i2c",
 		.pm	= S3C24XX_DEV_PM_OPS,
+		.of_match_table	= s3c24xx_i2c_match,
 	},
 };
 
-- 
1.6.6.rc2