i2c: Multiplexed I2C bus core support
Add multiplexed bus core support. I2C multiplexer and switches
like pca954x get instantiated as new adapters per port.
Signed-off-by: Michael Lawnick <ml.lawnick@gmx.de>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c
index 0b0427f..5f3a52d 100644
--- a/drivers/i2c/i2c-dev.c
+++ b/drivers/i2c/i2c-dev.c
@@ -189,12 +189,50 @@
return dev->driver ? -EBUSY : 0;
}
+/* walk up mux tree */
+static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr)
+{
+ int result;
+
+ result = device_for_each_child(&adapter->dev, &addr, i2cdev_check);
+
+ if (!result && i2c_parent_is_i2c_adapter(adapter))
+ result = i2cdev_check_mux_parents(
+ to_i2c_adapter(adapter->dev.parent), addr);
+
+ return result;
+}
+
+/* recurse down mux tree */
+static int i2cdev_check_mux_children(struct device *dev, void *addrp)
+{
+ int result;
+
+ if (dev->type == &i2c_adapter_type)
+ result = device_for_each_child(dev, addrp,
+ i2cdev_check_mux_children);
+ else
+ result = i2cdev_check(dev, addrp);
+
+ return result;
+}
+
/* This address checking function differs from the one in i2c-core
in that it considers an address with a registered device, but no
driver bound to it, as NOT busy. */
static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr)
{
- return device_for_each_child(&adapter->dev, &addr, i2cdev_check);
+ int result = 0;
+
+ if (i2c_parent_is_i2c_adapter(adapter))
+ result = i2cdev_check_mux_parents(
+ to_i2c_adapter(adapter->dev.parent), addr);
+
+ if (!result)
+ result = device_for_each_child(&adapter->dev, &addr,
+ i2cdev_check_mux_children);
+
+ return result;
}
static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client,