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>
Append i2c-sysfs to toctree in order to get rid of building warnings.
Fixes: 31df7195b1 ("Documentation: i2c: Add doc for I2C sysfs")
Signed-off-by: Hu Haowen <src.res@email.cn>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
All the drivers have long since been upgraded, and all the important
information here is also included in the "Implementing I2C device
drivers" guide.
Signed-off-by: Stephen Kitt <steve@sk2.org>
Reviewed-by: Wolfram Sang <wsa@kernel.org>
Link: https://lore.kernel.org/r/20200806161456.8680-1-steve@sk2.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The index page currently lists sections in alphabetical file order without
caring about their content. Sort sections based on their content logically,
according to the following structure:
* Intro to I2C/SMBus and their usage in Linux: summary, i2c-protocol,
smbus-protocol, instantiating-devices, busses/index, i2c-topology,
muxes/i2c-mux-gpio
* Implementing drivers: writing-clients, dev-interface,
dma-considerations, fault-codes, functionality
* Debugging: gpio-fault-injection, i2c-stub
* Slave I2C: slave-interface, slave-eeprom-backend
* Advanced: ten-bit-addresses
* Obsolete info: upgrading-clients, old-module-parameters
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
ReST directives are introduced with two dots.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Convert each file at I2C subsystem, renaming them to .rst and
adding to the driver-api book.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Luca Ceresoli