[U-Boot] [PATCH v2 03/19] dm: i2c: Add support for multiplexed I2C buses

[Simon Glass]

On 3 August 2015 at 08:19, Simon Glass <sjg at chromium.org> wrote:
> Add a new I2C_MUX uclass. Devices in this class can multiplex between
> several I2C buses, selecting them one at a time for use by the system.
> The multiplexing mechanism is left to the driver to decide - it may be
> controlled by GPIOs, for example.
>
> The uclass supports only two methods: select() and deselect().
>
> The current mux state is expected to be stored in the mux itself since
> it is the only thing that knows how to make things work. The mux can
> record the current state and then avoid switching unless it is necessary.
> So select() can be skipped if the mux is already in the correct state.
> Also deselect() can be made a nop if required.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
>
> Changes in v2:
> - Update commit message and header file to better explain select()/deselect()
>
>  doc/device-tree-bindings/i2c/i2c-mux.txt |  60 ++++++++++
>  drivers/i2c/Kconfig                      |   2 +
>  drivers/i2c/Makefile                     |   2 +
>  drivers/i2c/muxes/Kconfig                |   8 ++
>  drivers/i2c/muxes/Makefile               |   6 +
>  drivers/i2c/muxes/i2c-mux-uclass.c       | 198 +++++++++++++++++++++++++++++++
>  include/dm/uclass-id.h                   |   1 +
>  include/i2c.h                            |  39 ++++++
>  8 files changed, 316 insertions(+)
>  create mode 100644 doc/device-tree-bindings/i2c/i2c-mux.txt
>  create mode 100644 drivers/i2c/muxes/Kconfig
>  create mode 100644 drivers/i2c/muxes/Makefile
>  create mode 100644 drivers/i2c/muxes/i2c-mux-uclass.c

Applied to u-boot-dm.