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| author | Fabio Estevam <festevam@gmail.com> | 2020-08-19 19:02:19 -0300 |
|---|---|---|
| committer | Shawn Guo <shawnguo@kernel.org> | 2020-08-30 19:58:50 +0800 |
| commit | 843b993c2d0b5e9aa22965234b914625ed3d3713 (patch) | |
| tree | d5e089ef4500caf6f00b5dcee440555b36ad06fe | |
| parent | bcf7206fe9c35e048e1dc90cf62216b0f5eaf091 (diff) | |
| download | lwn-843b993c2d0b5e9aa22965234b914625ed3d3713.tar.gz lwn-843b993c2d0b5e9aa22965234b914625ed3d3713.zip | |
arm64: dts: imx8m: Fix the SPI chipselect polarity
The conversion of the spi-imx driver to use GPIO descriptors
in commit 8cdcd8aeee28 ("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: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
| -rw-r--r-- | arch/arm64/boot/dts/freescale/imx8mm-beacon-baseboard.dtsi | 2 | ||||
| -rw-r--r-- | arch/arm64/boot/dts/freescale/imx8mq-zii-ultra-rmb3.dts | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm64/boot/dts/freescale/imx8mm-beacon-baseboard.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-beacon-baseboard.dtsi index baa5f997d018..9ac17b284f20 100644 --- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-baseboard.dtsi +++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-baseboard.dtsi @@ -70,7 +70,7 @@ &ecspi2 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_espi2>; - cs-gpios = <&gpio5 9 0>; + cs-gpios = <&gpio5 9 GPIO_ACTIVE_LOW>; status = "okay"; eeprom@0 { diff --git a/arch/arm64/boot/dts/freescale/imx8mq-zii-ultra-rmb3.dts b/arch/arm64/boot/dts/freescale/imx8mq-zii-ultra-rmb3.dts index 6b3581366d67..bfad4b885905 100644 --- a/arch/arm64/boot/dts/freescale/imx8mq-zii-ultra-rmb3.dts +++ b/arch/arm64/boot/dts/freescale/imx8mq-zii-ultra-rmb3.dts @@ -15,7 +15,7 @@ &ecspi1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_ecspi1>; - cs-gpios = <&gpio5 9 GPIO_ACTIVE_HIGH>; + cs-gpios = <&gpio5 9 GPIO_ACTIVE_LOW>; status = "okay"; #address-cells = <1>; #size-cells = <0>; |