i2c: Driver IDs are optional
Document the fact that I2C driver IDs are optional.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/include/linux/i2c-id.h b/include/linux/i2c-id.h
index 88c8140..e18017d 100644
--- a/include/linux/i2c-id.h
+++ b/include/linux/i2c-id.h
@@ -23,6 +23,10 @@
#ifndef LINUX_I2C_ID_H
#define LINUX_I2C_ID_H
+/* Please note that I2C driver IDs are optional. They are only needed if a
+ legacy chip driver needs to identify a bus or a bus driver needs to
+ identify a legacy client. If you don't need them, just don't set them. */
+
/*
* ---- Driver types -----------------------------------------------------
*/