The Cadence I2C controller has an external reset that needs to be
de-asserted before the I2C controller can be accessed.
Document the `resets` devicetree property that can be used to describe how
the reset signal is connected.
While the reset signal will always be present in hardware the devicetree
property is kept optional for backwards compatibility with existing systems
that do not specify the reset property and where the reset signal might not
be controlled by operating system.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
The depth of the FIFO of the Cadence I2C controller IP is a synthesis
configuration parameter. Different instances of the IP can have different
values. For correct operation software needs to be aware of the size of the
FIFO.
Add the documentation for the devicetree property that describes the FIFO
depth of the IP core.
The default value of 16 is for backwards compatibility reasons with
existing hardware descriptions where this property is not specified and
software has assumed that the FIFO depth is 16.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Michal Simek <michal.simek@amd.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
This doesn't yet do anything in the tools, but make it explicit so we can
check either 'unevaluatedProperties' or 'additionalProperties' is present
in schemas.
'unevaluatedProperties' is appropriate when including another schema (via
'$ref') and all possible properties and/or child nodes are not
explicitly listed in the schema with the '$ref'.
This is in preparation to add a meta-schema to check for missing
'unevaluatedProperties' or 'additionalProperties'. This has been a
constant source of review issues.
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@kernel.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/20201005183830.486085-2-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
The document was migrated to YAML format and renamed cdns,i2c-r1p10.yaml
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Rob Herring <robh@kernel.org>
