[PATCH 1/2] i2c: Added feature to get bus number from alias

[Alexander Shiyan <eagle.alexander923@gmail.com>]

For the correct assignment of the I2C bus number, let's use an alias
from the devicetree.

Signed-off-by: Alexander Shiyan <eagle.alexander923@gmail.com>
---
 drivers/i2c/i2c.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/i2c.c b/drivers/i2c/i2c.c
index 300365bd1f..df3b968a4b 100644
--- a/drivers/i2c/i2c.c
+++ b/drivers/i2c/i2c.c
@@ -701,17 +701,21 @@ int i2c_add_numbered_adapter(struct i2c_adapter *adapter)
 	int ret;
 
 	if (adapter->nr < 0) {
-		int nr;
+		if (!adapter->dev.of_node) {
+			int nr = adapter->dev.id;
 
-		for (nr = 0;; nr++)
-			if (!i2c_get_adapter(nr))
-				break;
-		adapter->nr = nr;
-	} else {
-		if (i2c_get_adapter(adapter->nr))
-			return -EBUSY;
+			for (nr = 0;; nr++)
+				if (!i2c_get_adapter(nr))
+					break;
+			adapter->nr = nr;
+		} else
+			adapter->nr =
+				of_alias_get_id(adapter->dev.of_node, "i2c");
 	}
 
+	if (i2c_get_adapter(adapter->nr))
+		return -EBUSY;
+
 	adapter->dev.id = adapter->nr;
 	dev_set_name(&adapter->dev, "i2c");
 
-- 
2.38.2