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ARM: dts: imx6qp-prtwd3: Fix the SPI chipselect polarity

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The conversion of the spi-imx driver to use GPIO descriptors
in commit 8cdcd8aeee ("spi: imx/fsl-lpspi: Convert to GPIO descriptors")
helped to detect the following SPI chipselect polarity mismatch on an
imx6q-sabresd for example:

[    4.854337] m25p80@0 enforce active low on chipselect handle

Prior to the above commit, the chipselect polarity passed via cs-gpios
property was ignored and considered active-low.

The reason for such mismatch is clearly explained in the comments inside
drivers/gpio/gpiolib-of.c:

* SPI children have active low chip selects
* by default. This can be specified negatively
* by just omitting "spi-cs-high" in the
* device node, or actively by tagging on
* GPIO_ACTIVE_LOW as flag in the device
* tree. If the line is simultaneously
* tagged as active low in the device tree
* and has the "spi-cs-high" set, we get a
* conflict and the "spi-cs-high" flag will
* take precedence.

To properly represent the SPI chipselect polarity, change it to active-low
when the "spi-cs-high" property is absent.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
This commit is contained in:
Fabio Estevam 2021-07-16 10:36:57 -03:00 committed by Shawn Guo
parent 97eb19d884
commit 70b211ddcf
1 changed files with 2 additions and 2 deletions
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4
arch/arm/boot/dts/imx6qp-prtwd3.dts
View File

@ -123,7 +123,7 @@ &can1 {
};
&ecspi2 {
cs-gpios = <&gpio2 26 GPIO_ACTIVE_HIGH>;
cs-gpios = <&gpio2 26 GPIO_ACTIVE_LOW>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi2>;
status = "okay";
@ -189,7 +189,7 @@ fixed-link {
};
&ecspi3 {
cs-gpios = <&gpio4 24 GPIO_ACTIVE_HIGH>;
cs-gpios = <&gpio4 24 GPIO_ACTIVE_LOW>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_ecspi3>;
status = "okay";