[PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

Subsystems: the rest

STALE1781d

13 messages, 3 authors, 2021-09-22 · open the first message on its own page

[PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

From: Fabio Estevam <festevam@gmail.com>
Date: 2021-07-16 13:39:19

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>
---
 arch/arm/boot/dts/imx6dl-alti6p.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/imx6dl-alti6p.dts b/arch/arm/boot/dts/imx6dl-alti6p.dts
index 4329b372d8cb..e8325fd680d9 100644
--- a/arch/arm/boot/dts/imx6dl-alti6p.dts
+++ b/arch/arm/boot/dts/imx6dl-alti6p.dts
@@ -192,7 +192,7 @@ &can1 {
 };
 
 &ecspi1 {
-	cs-gpios = <&gpio3 19 GPIO_ACTIVE_HIGH>;
+	cs-gpios = <&gpio3 19 GPIO_ACTIVE_LOW>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_ecspi1>;
 	status = "okay";
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 2/4] ARM: dts: imx6qp-prtwd3: Fix the SPI chipselect polarity

From: Fabio Estevam <festevam@gmail.com>
Date: 2021-07-16 13:39:33

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.

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>
---
 arch/arm/boot/dts/imx6qp-prtwd3.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/boot/dts/imx6qp-prtwd3.dts b/arch/arm/boot/dts/imx6qp-prtwd3.dts
index c42723989bc0..1a334918f9ca 100644
--- a/arch/arm/boot/dts/imx6qp-prtwd3.dts
+++ b/arch/arm/boot/dts/imx6qp-prtwd3.dts
@@ -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";
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 3/4] ARM: dts: imx6qdl-tqma6: Fix the SPI chipselect polarity

From: Fabio Estevam <festevam@gmail.com>
Date: 2021-07-16 13:39:40

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>
---
 arch/arm/boot/dts/imx6qdl-tqma6.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/imx6qdl-tqma6.dtsi b/arch/arm/boot/dts/imx6qdl-tqma6.dtsi
index b18b83ac6aee..51a3a5392c95 100644
--- a/arch/arm/boot/dts/imx6qdl-tqma6.dtsi
+++ b/arch/arm/boot/dts/imx6qdl-tqma6.dtsi
@@ -20,7 +20,7 @@ reg_3p3v: regulator-3p3v {
 &ecspi1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_ecspi1>;
-	cs-gpios = <&gpio3 19 GPIO_ACTIVE_HIGH>;
+	cs-gpios = <&gpio3 19 GPIO_ACTIVE_LOW>;
 	status = "okay";
 
 	m25p80: flash@0 {
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 4/4] ARM: dts: imx7d-sdb: Fix the SPI chipselect polarity

From: Fabio Estevam <festevam@gmail.com>
Date: 2021-07-16 13:39:58

The following warning is seen when the SPI GPIO driver probes:

gpio-expander@0 enforce active low on chipselect handle

The reason for this warning 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>
---
 arch/arm/boot/dts/imx7d-sdb.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/imx7d-sdb.dts b/arch/arm/boot/dts/imx7d-sdb.dts
index 4a0d83784d7d..7813ef960f6e 100644
--- a/arch/arm/boot/dts/imx7d-sdb.dts
+++ b/arch/arm/boot/dts/imx7d-sdb.dts
@@ -45,7 +45,7 @@ spi4 {
 		pinctrl-0 = <&pinctrl_spi4>;
 		gpio-sck = <&gpio1 13 GPIO_ACTIVE_HIGH>;
 		gpio-mosi = <&gpio1 9 GPIO_ACTIVE_HIGH>;
-		cs-gpios = <&gpio1 12 GPIO_ACTIVE_HIGH>;
+		cs-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
 		num-chipselects = <1>;
 		#address-cells = <1>;
 		#size-cells = <0>;
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

From: Oleksij Rempel <o.rempel@pengutronix.de>
Date: 2021-07-17 05:03:00

On Fri, Jul 16, 2021 at 10:36:56AM -0300, Fabio Estevam wrote:
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: Oleksij Rempel <o.rempel@pengutronix.de>
Thank you!
quoted hunk
---
 arch/arm/boot/dts/imx6dl-alti6p.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/imx6dl-alti6p.dts b/arch/arm/boot/dts/imx6dl-alti6p.dts
index 4329b372d8cb..e8325fd680d9 100644
--- a/arch/arm/boot/dts/imx6dl-alti6p.dts
+++ b/arch/arm/boot/dts/imx6dl-alti6p.dts
@@ -192,7 +192,7 @@ &can1 {
 };
 
 &ecspi1 {
-	cs-gpios = <&gpio3 19 GPIO_ACTIVE_HIGH>;
+	cs-gpios = <&gpio3 19 GPIO_ACTIVE_LOW>;
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_ecspi1>;
 	status = "okay";
-- 
2.25.1
-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 2/4] ARM: dts: imx6qp-prtwd3: Fix the SPI chipselect polarity

From: Oleksij Rempel <o.rempel@pengutronix.de>
Date: 2021-07-17 05:03:32

On Fri, Jul 16, 2021 at 10:36:57AM -0300, Fabio Estevam wrote:
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.

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: Oleksij Rempel <o.rempel@pengutronix.de>
Thank you!
quoted hunk
---
 arch/arm/boot/dts/imx6qp-prtwd3.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/boot/dts/imx6qp-prtwd3.dts b/arch/arm/boot/dts/imx6qp-prtwd3.dts
index c42723989bc0..1a334918f9ca 100644
--- a/arch/arm/boot/dts/imx6qp-prtwd3.dts
+++ b/arch/arm/boot/dts/imx6qp-prtwd3.dts
@@ -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";
-- 
2.25.1
-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

From: Fabio Estevam <festevam@gmail.com>
Date: 2021-08-14 13:29:17

Hi Shawn,

On Sat, Jul 17, 2021 at 1:57 AM Oleksij Rempel [off-list ref] wrote:
On Fri, Jul 16, 2021 at 10:36:56AM -0300, Fabio Estevam wrote:
quoted
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: Oleksij Rempel <o.rempel@pengutronix.de>
Thank you!
A gentle ping on this series.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

From: Shawn Guo <shawnguo@kernel.org>
Date: 2021-09-22 01:25:39

On Sat, Aug 14, 2021 at 10:27:13AM -0300, Fabio Estevam wrote:
Hi Shawn,

On Sat, Jul 17, 2021 at 1:57 AM Oleksij Rempel [off-list ref] wrote:
quoted
On Fri, Jul 16, 2021 at 10:36:56AM -0300, Fabio Estevam wrote:
quoted
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: Oleksij Rempel <o.rempel@pengutronix.de>
Thank you!
A gentle ping on this series.
Should we have Fixes tags for the patches?

Shawn

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

From: Fabio Estevam <festevam@gmail.com>
Date: 2021-09-22 01:30:18

Hi Shawn,

On Tue, Sep 21, 2021 at 10:23 PM Shawn Guo [off-list ref] wrote:
Should we have Fixes tags for the patches?
As this does not change the functionality, I did not put a Fixes tag.

It will only fix a warning like this:

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

IMHO it is OK to apply them without a Fixes tag.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

From: Shawn Guo <shawnguo@kernel.org>
Date: 2021-09-22 02:05:34

On Tue, Sep 21, 2021 at 10:28:08PM -0300, Fabio Estevam wrote:
Hi Shawn,

On Tue, Sep 21, 2021 at 10:23 PM Shawn Guo [off-list ref] wrote:
quoted
Should we have Fixes tags for the patches?
As this does not change the functionality, I did not put a Fixes tag.

It will only fix a warning like this:

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

IMHO it is OK to apply them without a Fixes tag.
Okay, then I assume it applies to imx8mm-kontron-n801x-som and
imx8mm-venice patches as well?

Shawn

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

From: Fabio Estevam <festevam@gmail.com>
Date: 2021-09-22 02:06:45

On Tue, Sep 21, 2021 at 11:03 PM Shawn Guo [off-list ref] wrote:
Okay, then I assume it applies to imx8mm-kontron-n801x-som and
imx8mm-venice patches as well?
Yes, that's correct.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 2/4] ARM: dts: imx6qp-prtwd3: Fix the SPI chipselect polarity

From: Shawn Guo <shawnguo@kernel.org>
Date: 2021-09-22 03:05:00

On Fri, Jul 16, 2021 at 10:36:57AM -0300, Fabio Estevam wrote:
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.
...
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.
So the commit log was written twice?  I will fix it up.

Shawn
quoted hunk
Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
 arch/arm/boot/dts/imx6qp-prtwd3.dts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm/boot/dts/imx6qp-prtwd3.dts b/arch/arm/boot/dts/imx6qp-prtwd3.dts
index c42723989bc0..1a334918f9ca 100644
--- a/arch/arm/boot/dts/imx6qp-prtwd3.dts
+++ b/arch/arm/boot/dts/imx6qp-prtwd3.dts
@@ -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";
-- 
2.25.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 1/4] ARM: dts: imx6dl-alti6p: Fix the SPI chipselect polarity

From: Shawn Guo <shawnguo@kernel.org>
Date: 2021-09-22 03:06:45

On Fri, Jul 16, 2021 at 10:36:56AM -0300, Fabio Estevam wrote:
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>
Applied all, thanks!

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help