arm64: dts: imx8mm-kontron-n801x-som: 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 <[email protected]>

---
 arch/arm64/boot/dts/freescale/imx8mm-venice-gw71xx.dtsi | 2 +-
 arch/arm64/boot/dts/freescale/imx8mm-venice-gw72xx.dtsi | 2 +-
 arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx.dtsi | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

arch/arm64/boot/dts/freescale/imx8mm-venice-gw71xx.dtsi +1 -1

index 905b68a3daa5..138bb8c9bf56 100644
@@ -57,7 +57,7 @@ reg_usb_otg1_vbus: regulator-usb-otg1 {
 &ecspi2 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_spi2>;
-       cs-gpios = <&gpio5 13 GPIO_ACTIVE_HIGH>;
+       cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
        status = "okay";
 };
 

arch/arm64/boot/dts/freescale/imx8mm-venice-gw72xx.dtsi +1 -1

index b7c91bdc21dd..27afa46a253a 100644
@@ -76,7 +76,7 @@ reg_usb_otg2_vbus: regulator-usb-otg2 {
 &ecspi2 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_spi2>;
-       cs-gpios = <&gpio5 13 GPIO_ACTIVE_HIGH>;
+       cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
        status = "okay";
 };
 

arch/arm64/boot/dts/freescale/imx8mm-venice-gw73xx.dtsi +1 -2

index d2ffd62a3bd4..a59e849c7be2 100644
@@ -96,7 +96,7 @@ reg_wifi_en: regulator-wifi-en {
 &ecspi2 {
        pinctrl-names = "default";
        pinctrl-0 = <&pinctrl_spi2>;
-       cs-gpios = <&gpio5 13 GPIO_ACTIVE_HIGH>;
+       cs-gpios = <&gpio5 13 GPIO_ACTIVE_LOW>;
        status = "okay";
 };
 
--

2.25.1

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 <[email protected]>

---
 arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi +0 -0

index d0456daefda8..5a2805c51361 100644

Thanks for the fix!

Reviewed-by Frieder Schrempf <[email protected]>

Shouldn't we consider to add the following tag, as this is clearly a bug in the original implementation of the DTS and the commit that uncovers this is already in multiple stable releases?

Fixes 8668d8b2e67f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")

Hi Shawn,

Quoted 2 lines · Frieder Schrempf

Thanks for the fix!

Quoted 5 lines

Reviewed-by Frieder Schrempf <[email protected]>

Shouldn't we consider to add the following tag, as this is clearly a bug in the original implementation of the DTS and the commit that uncovers this is already in multiple stable releases?

Fixes 8668d8b2e67f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")

Can you add the Fixes tag, or should I resend it?

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 <[email protected]>