i2c: Add i2c_new_probed_device()

Add a new helper function to instantiate an i2c device. It is meant as a
replacement for i2c_new_device() when you don't know for sure at which
address your I2C/SMBus device lives. This happens frequently on TV
adapters for example, you know there is a tuner chip on the bus, but
depending on the exact board model and revision, it can live at different
addresses. So, the new i2c_new_probed_device() function will probe the bus
according to a list of addresses, and as soon as one of these addresses
responds, it will call i2c_new_device() on that one address.

This function will make it possible to port the old i2c drivers to the
new model quickly.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 36d6814a6df4..da95ce79d075 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -245,6 +245,15 @@ struct i2c_board_info {
 extern struct i2c_client *
 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
 
+/* If you don't know the exact address of an I2C device, use this variant
+ * instead, which can probe for device presence in a list of possible
+ * addresses.
+ */
+extern struct i2c_client *
+i2c_new_probed_device(struct i2c_adapter *adap,
+		      struct i2c_board_info *info,
+		      unsigned short const *addr_list);
+
 extern void i2c_unregister_device(struct i2c_client *);
 
 /* Mainboard arch_initcall() code should register all its I2C devices.