[PATCH] i2c: implement detect callback for virtual adapter device as well

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

For MMCs, we already support detect on both the hardware device and the
mmcX virtual device. Let's do the same for i2c, so users have the option
to do `detect i2c0` instead of `detect 30a30000.i2c@30a30000.of`.

`detect -a` still works as expected, as the detect callback is a no-op
if everything on the bus is already registered.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 drivers/i2c/i2c.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/i2c.c b/drivers/i2c/i2c.c
index 7e1cea49f3b6..4ecf7bb163e6 100644
--- a/drivers/i2c/i2c.c
+++ b/drivers/i2c/i2c.c
@@ -472,6 +472,14 @@ int of_i2c_register_devices_by_node(struct device_node *node)
 }
 
 static int i2c_bus_detect(struct device *dev)
+{
+	struct i2c_adapter *adap = container_of(dev, struct i2c_adapter, dev);
+
+	of_i2c_register_devices(adap);
+	return 0;
+}
+
+static int i2c_hw_detect(struct device *dev)
 {
 	struct i2c_adapter *adap;
 
@@ -712,6 +720,7 @@ int i2c_add_numbered_adapter(struct i2c_adapter *adapter)
 	}
 
 	adapter->dev.id = adapter->nr;
+	adapter->dev.detect = i2c_bus_detect;
 	dev_set_name(&adapter->dev, "i2c");
 
 	ret = register_device(&adapter->dev);
@@ -726,8 +735,8 @@ int i2c_add_numbered_adapter(struct i2c_adapter *adapter)
 	hw_dev = adapter->dev.parent;
 	if (hw_dev && dev_of_node(hw_dev)) {
 		if (!hw_dev->detect)
-			hw_dev->detect = i2c_bus_detect;
-		i2c_bus_detect(hw_dev);
+			hw_dev->detect = i2c_hw_detect;
+		i2c_hw_detect(hw_dev);
 	}
 
 	return 0;
-- 
2.30.2