Linux kernel stable tree (mirror) https://git.radix-linux.su/kernel/linux.git/atom?h=v6.12.80 2023-07-14T11:11:44+00:00 2023-07-14T11:11:44+00:00 Luca Ceresoli luca@lucaceresoli.net 2023-06-19T12:22:06+00:00 urn:sha1:a076a860acae77bbdcbd316541e5552e81fb1772 An ATR is a device that looks similar to an i2c-mux: it has an I2C slave "upstream" port and N master "downstream" ports, and forwards transactions from upstream to the appropriate downstream port. But it is different in that the forwarded transaction has a different slave address. The address used on the upstream bus is called the "alias" and is (potentially) different from the physical slave address of the downstream chip. Add a helper file (just like i2c-mux.c for a mux or switch) to allow implementing ATR features in a device driver. The helper takes care of adapter creation/destruction and translates addresses at each transaction. Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>