i2c: support 10 bit and slave addresses in sysfs 'new_device'

We now have seperate address spaces for 10 bit and we-are-slave clients.
Update the sysfs device instantiation method to support these types by
accepting the address offsets that are assigned to the extra address
spaces. Update the documentation, too.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/Documentation/i2c/ten-bit-addresses b/Documentation/i2c/ten-bit-addresses
index cdfe139..7b2d11e 100644
--- a/Documentation/i2c/ten-bit-addresses
+++ b/Documentation/i2c/ten-bit-addresses
@@ -2,6 +2,10 @@ The I2C protocol knows about two kinds of device addresses: normal 7 bit
 addresses, and an extended set of 10 bit addresses. The sets of addresses
 do not intersect: the 7 bit address 0x10 is not the same as the 10 bit
 address 0x10 (though a single device could respond to both of them).
+To avoid ambiguity, the user sees 10 bit addresses mapped to a different
+address space, namely 0xa000-0xa3ff. The leading 0xa (= 10) represents the
+10 bit mode. This is used for creating device names in sysfs. It is also
+needed when instantiating 10 bit devices via the new_device file in sysfs.
 
 I2C messages to and from 10-bit address devices have a different format.
 See the I2C specification for the details.