i2c-ocores: Adapt for device tree

This patch adapts the i2c-ocores driver for being defined and configured via
a device tree description.

The device tree bits need to be protected by CONFIG_OF guards as this is
still an optional feature.

Signed-off-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 56 insertions, 8 deletions

diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index 0070371b29f3..c05e8c44404a 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -210,6 +210,32 @@ static struct i2c_adapter ocores_adapter = {
         .algo           = &ocores_algorithm,
 };
 
+#ifdef CONFIG_OF
+static int ocores_i2c_of_probe(struct platform_device* pdev,
+                                struct ocores_i2c* i2c)
+{
+        __be32* val;
+
+        val = of_get_property(pdev->dev.of_node, "regstep", NULL);
+        if (!val) {
+                dev_err(&pdev->dev, "Missing required parameter 'regstep'");
+                return -ENODEV;
+        }
+        i2c->regstep = be32_to_cpup(val);
+
+        val = of_get_property(pdev->dev.of_node, "clock-frequency", NULL);
+        if (!val) {
+                dev_err(&pdev->dev,
+                        "Missing required parameter 'clock-frequency'");
+                return -ENODEV;
+        }
+        i2c->clock_khz = be32_to_cpup(val) / 1000;
+
+        return 0;
+}
+#else
+#define ocores_i2c_of_probe(pdev,i2c) -ENODEV
+#endif
 
 static int __devinit ocores_i2c_probe(struct platform_device *pdev)
 {
@@ -227,10 +253,6 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev)
         if (!res2)
                 return -ENODEV;
 
-        pdata = (struct ocores_i2c_platform_data*) pdev->dev.platform_data;
-        if (!pdata)
-                return -ENODEV;
-
         i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
         if (!i2c)
                 return -ENOMEM;
@@ -249,8 +271,16 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev)
                 goto map_failed;
         }
 
-        i2c->regstep = pdata->regstep;
-        i2c->clock_khz = pdata->clock_khz;
+        pdata = pdev->dev.platform_data;
+        if (pdata) {
+                i2c->regstep = pdata->regstep;
+                i2c->clock_khz = pdata->clock_khz;
+        } else {
+                ret = ocores_i2c_of_probe(pdev, i2c);
+                if (ret)
+                        return ret;
+        }
+
         ocores_init(i2c);
 
         init_waitqueue_head(&i2c->wait);
@@ -265,6 +295,9 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev)
         i2c->adap = ocores_adapter;
         i2c_set_adapdata(&i2c->adap, i2c);
         i2c->adap.dev.parent = &pdev->dev;
+#ifdef CONFIG_OF
+        i2c->adap.dev.of_node = pdev->dev.of_node;
+#endif
 
         /* add i2c adapter to i2c tree */
         ret = i2c_add_adapter(&i2c->adap);
@@ -274,8 +307,10 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev)
         }
 
         /* add in known devices to the bus */
-        for (i = 0; i < pdata->num_devices; i++)
-                i2c_new_device(&i2c->adap, pdata->devices + i);
+        if (pdata) {
+                for (i = 0; i < pdata->num_devices; i++)
+                        i2c_new_device(&i2c->adap, pdata->devices + i);
+        }
 
         return 0;
 
@@ -344,6 +379,16 @@ static int ocores_i2c_resume(struct platform_device *pdev)
 #define ocores_i2c_resume       NULL
 #endif
 
+#ifdef CONFIG_OF
+static struct of_device_id ocores_i2c_match[] = {
+        {
+                .compatible = "opencores,i2c-ocores",
+        },
+        {},
+};
+MODULE_DEVICE_TABLE(of, ocores_i2c_match);
+#endif
+
 /* work with hotplug and coldplug */
 MODULE_ALIAS("platform:ocores-i2c");
 
@@ -355,6 +400,9 @@ static struct platform_driver ocores_i2c_driver = {
         .driver  = {
                 .owner = THIS_MODULE,
                 .name = "ocores-i2c",
+#ifdef CONFIG_OF
+                .of_match_table = ocores_i2c_match,
+#endif
         },
 };