DTS example in the bindings should be indented with 2- or 4-spaces and
aligned with opening '- |', so correct any differences like 3-spaces or
mixtures 2- and 4-spaces in one binding. While re-indenting, drop
unused labels.
No functional changes here, but saves some comments during reviews of
new patches built on existing code.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Sander Vanheule <sander@svanheule.net>
Reviewed-by: Manikandan Muralidharan <manikandan.m@microchip.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20250324125326.82270-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
A few of the I2C GPIO expander chips supported by this binding have a
RESETN pin to be able to reset the chip. The chip is held in reset while
the pin is low, therefore the polarity of reset-gpios is expected to
reflect that, i.e. a GPIO_ACTIVE_HIGH means the GPIO will be driven high
for reset and then driven low, GPIO_ACTIVE_LOW means the GPIO will be
driven low for reset and then driven high. If a GPIO is directly routed
to RESETN pin on the IC without any inverter, GPIO_ACTIVE_LOW is thus
expected.
Out of the supported chips, only PCA9670, PCA9671, PCA9672 and PCA9673
show a RESETN pin in their datasheets. They all share the same reset
timings, that is 4+us reset pulse[0] and 100+us reset time[0].
When performing a reset, "The PCA9670 registers and I2C-bus state
machine will be held in their default state until the RESET input is
once again HIGH."[1] meaning we now know the state of each line
controlled by the GPIO expander. Therefore, setting lines-initial-states
and reset-gpios both does not make sense and their presence is XOR'ed.
[0] https://www.nxp.com/docs/en/data-sheet/PCA9670.pdf Fig 22.
[1] https://www.nxp.com/docs/en/data-sheet/PCA9670.pdf 8.5
Tested-by: Heiko Stuebner <heiko@sntech.de> # exclusion logic
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
Link: https://lore.kernel.org/r/20250224-pca976x-reset-driver-v3-1-58370ef405be@cherry.de
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
The devices described in this binding represent 8-bit and 16-bit i2c i/o
expanders. Allow the user to specify names for up to 16 gpio lines.
Signed-off-by: Trevor Woerner <twoerner@gmail.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230210025132.36605-1-twoerner@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
