* [PATCH 1/3] arm64: dts: imx8mm: Correct WDOG_B pin configuration
@ 2020-10-09 7:47 ` Anson Huang
0 siblings, 0 replies; 12+ messages in thread
From: Anson Huang @ 2020-10-09 7:47 UTC (permalink / raw)
To: robh+dt, shawnguo, s.hauer, kernel, festevam, krzk, aford173,
daniel.baluta, shengjiu.wang, peter.chen, alifer.wsdm, abel.vesa,
yibin.gong, jun.li, l.stach, devicetree, linux-arm-kernel,
linux-kernel
Cc: Linux-imx
Different revision of i.MX8MM EVK boards may have different external
pull up registor design, some are enabled while some are NOT, to make
sure the WDOG_B pin works properly, better to enable internal pull up
resistor. Since enabling internal pull up resistor is NOT harmful and
having benefit of flexibility on different board design, just enable
it for all i.MX8MM boards.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi | 2 +-
arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi | 2 +-
arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
index 6de86a4..a941301 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
@@ -398,7 +398,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
+ MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>;
};
diff --git a/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi
index f305a53..469d570 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi
@@ -468,7 +468,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
+ MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>;
};
};
diff --git a/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
index 4107fe9..38e879d 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi
@@ -555,7 +555,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
+ MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>;
};
};
--
2.7.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 2/3] arm64: dts: imx8mn: Correct WDOG_B pin configuration
2020-10-09 7:47 ` Anson Huang
@ 2020-10-09 7:47 ` Anson Huang
-1 siblings, 0 replies; 12+ messages in thread
From: Anson Huang @ 2020-10-09 7:47 UTC (permalink / raw)
To: robh+dt, shawnguo, s.hauer, kernel, festevam, krzk, aford173,
daniel.baluta, shengjiu.wang, peter.chen, alifer.wsdm, abel.vesa,
yibin.gong, jun.li, l.stach, devicetree, linux-arm-kernel,
linux-kernel
Cc: Linux-imx
Different revision of i.MX8MN EVK boards may have different external
pull up registor design, some are enabled while some are NOT, to make
sure the WDOG_B pin works properly, better to enable internal pull up
resistor. Since enabling internal pull up resistor is NOT harmful and
having benefit of flexibility on different board design, just enable
it for all i.MX8MN boards.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi | 2 +-
arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
index 4aa0dbd..fda8905 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
@@ -340,7 +340,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MN_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
+ MX8MN_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>;
};
};
diff --git a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
index a2d0190..dde01da 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
@@ -545,7 +545,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MN_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
+ MX8MN_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>;
};
};
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 2/3] arm64: dts: imx8mn: Correct WDOG_B pin configuration
@ 2020-10-09 7:47 ` Anson Huang
0 siblings, 0 replies; 12+ messages in thread
From: Anson Huang @ 2020-10-09 7:47 UTC (permalink / raw)
To: robh+dt, shawnguo, s.hauer, kernel, festevam, krzk, aford173,
daniel.baluta, shengjiu.wang, peter.chen, alifer.wsdm, abel.vesa,
yibin.gong, jun.li, l.stach, devicetree, linux-arm-kernel,
linux-kernel
Cc: Linux-imx
Different revision of i.MX8MN EVK boards may have different external
pull up registor design, some are enabled while some are NOT, to make
sure the WDOG_B pin works properly, better to enable internal pull up
resistor. Since enabling internal pull up resistor is NOT harmful and
having benefit of flexibility on different board design, just enable
it for all i.MX8MN boards.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi | 2 +-
arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
index 4aa0dbd..fda8905 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi
@@ -340,7 +340,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MN_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
+ MX8MN_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>;
};
};
diff --git a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
index a2d0190..dde01da 100644
--- a/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi
@@ -545,7 +545,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MN_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
+ MX8MN_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>;
};
};
--
2.7.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 12+ messages in thread* Re: [PATCH 2/3] arm64: dts: imx8mn: Correct WDOG_B pin configuration
2020-10-09 7:47 ` Anson Huang
@ 2020-10-12 6:53 ` Krzysztof Kozlowski
-1 siblings, 0 replies; 12+ messages in thread
From: Krzysztof Kozlowski @ 2020-10-12 6:53 UTC (permalink / raw)
To: Anson Huang
Cc: robh+dt, shawnguo, s.hauer, kernel, festevam, aford173,
daniel.baluta, shengjiu.wang, peter.chen, alifer.wsdm, abel.vesa,
yibin.gong, jun.li, l.stach, devicetree, linux-arm-kernel,
linux-kernel, Linux-imx
On Fri, 9 Oct 2020 at 09:52, Anson Huang <Anson.Huang@nxp.com> wrote:
>
> Different revision of i.MX8MN EVK boards may have different external
> pull up registor design, some are enabled while some are NOT, to make
> sure the WDOG_B pin works properly, better to enable internal pull up
> resistor. Since enabling internal pull up resistor is NOT harmful and
> having benefit of flexibility on different board design, just enable
> it for all i.MX8MN boards.
>
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi | 2 +-
> arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
The same as patch #1 - you do more than just enable pull up.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/3] arm64: dts: imx8mn: Correct WDOG_B pin configuration
@ 2020-10-12 6:53 ` Krzysztof Kozlowski
0 siblings, 0 replies; 12+ messages in thread
From: Krzysztof Kozlowski @ 2020-10-12 6:53 UTC (permalink / raw)
To: Anson Huang
Cc: daniel.baluta, peter.chen, abel.vesa, devicetree, festevam,
s.hauer, linux-kernel, Linux-imx, robh+dt, linux-arm-kernel,
kernel, l.stach, shawnguo, yibin.gong, aford173, shengjiu.wang,
alifer.wsdm, jun.li
On Fri, 9 Oct 2020 at 09:52, Anson Huang <Anson.Huang@nxp.com> wrote:
>
> Different revision of i.MX8MN EVK boards may have different external
> pull up registor design, some are enabled while some are NOT, to make
> sure the WDOG_B pin works properly, better to enable internal pull up
> resistor. Since enabling internal pull up resistor is NOT harmful and
> having benefit of flexibility on different board design, just enable
> it for all i.MX8MN boards.
>
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> arch/arm64/boot/dts/freescale/imx8mn-evk.dtsi | 2 +-
> arch/arm64/boot/dts/freescale/imx8mn-var-som.dtsi | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
The same as patch #1 - you do more than just enable pull up.
Best regards,
Krzysztof
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 3/3] arm64: dts: imx8mp-evk: Correct WDOG_B pin configuration
2020-10-09 7:47 ` Anson Huang
@ 2020-10-09 7:47 ` Anson Huang
-1 siblings, 0 replies; 12+ messages in thread
From: Anson Huang @ 2020-10-09 7:47 UTC (permalink / raw)
To: robh+dt, shawnguo, s.hauer, kernel, festevam, krzk, aford173,
daniel.baluta, shengjiu.wang, peter.chen, alifer.wsdm, abel.vesa,
yibin.gong, jun.li, l.stach, devicetree, linux-arm-kernel,
linux-kernel
Cc: Linux-imx
Different revision of i.MX8MP EVK boards may have different external
pull up registor design, some are enabled while some are NOT, to make
sure the WDOG_B pin works properly, better to enable internal pull up
resistor. Since enabling internal pull up resistor is NOT harmful and
having benefit of flexibility on different board design, just enable
it for all i.MX8MP boards.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
arch/arm64/boot/dts/freescale/imx8mp-evk.dts | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
index ad66f12..908b92b 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
@@ -262,7 +262,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MP_IOMUXC_GPIO1_IO02__WDOG1_WDOG_B 0xc6
+ MX8MP_IOMUXC_GPIO1_IO02__WDOG1_WDOG_B 0x166
>;
};
};
--
2.7.4
^ permalink raw reply related [flat|nested] 12+ messages in thread* [PATCH 3/3] arm64: dts: imx8mp-evk: Correct WDOG_B pin configuration
@ 2020-10-09 7:47 ` Anson Huang
0 siblings, 0 replies; 12+ messages in thread
From: Anson Huang @ 2020-10-09 7:47 UTC (permalink / raw)
To: robh+dt, shawnguo, s.hauer, kernel, festevam, krzk, aford173,
daniel.baluta, shengjiu.wang, peter.chen, alifer.wsdm, abel.vesa,
yibin.gong, jun.li, l.stach, devicetree, linux-arm-kernel,
linux-kernel
Cc: Linux-imx
Different revision of i.MX8MP EVK boards may have different external
pull up registor design, some are enabled while some are NOT, to make
sure the WDOG_B pin works properly, better to enable internal pull up
resistor. Since enabling internal pull up resistor is NOT harmful and
having benefit of flexibility on different board design, just enable
it for all i.MX8MP boards.
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
---
arch/arm64/boot/dts/freescale/imx8mp-evk.dts | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
index ad66f12..908b92b 100644
--- a/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mp-evk.dts
@@ -262,7 +262,7 @@
pinctrl_wdog: wdoggrp {
fsl,pins = <
- MX8MP_IOMUXC_GPIO1_IO02__WDOG1_WDOG_B 0xc6
+ MX8MP_IOMUXC_GPIO1_IO02__WDOG1_WDOG_B 0x166
>;
};
};
--
2.7.4
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH 1/3] arm64: dts: imx8mm: Correct WDOG_B pin configuration
2020-10-09 7:47 ` Anson Huang
@ 2020-10-12 6:52 ` Krzysztof Kozlowski
-1 siblings, 0 replies; 12+ messages in thread
From: Krzysztof Kozlowski @ 2020-10-12 6:52 UTC (permalink / raw)
To: Anson Huang
Cc: robh+dt, shawnguo, s.hauer, kernel, festevam, aford173,
daniel.baluta, shengjiu.wang, peter.chen, alifer.wsdm, abel.vesa,
yibin.gong, jun.li, l.stach, devicetree, linux-arm-kernel,
linux-kernel, Linux-imx
On Fri, 9 Oct 2020 at 09:52, Anson Huang <Anson.Huang@nxp.com> wrote:
>
> Different revision of i.MX8MM EVK boards may have different external
> pull up registor design, some are enabled while some are NOT, to make
> sure the WDOG_B pin works properly, better to enable internal pull up
> resistor. Since enabling internal pull up resistor is NOT harmful and
> having benefit of flexibility on different board design, just enable
> it for all i.MX8MM boards.
>
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi | 2 +-
> arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi | 2 +-
> arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> index 6de86a4..a941301 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> @@ -398,7 +398,7 @@
>
> pinctrl_wdog: wdoggrp {
> fsl,pins = <
> - MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
> + MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
Enabling pull up makes sense but you change other bits - disable
Schmitt input and enable open drain. This change is not documented /
explained in commit msg.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH 1/3] arm64: dts: imx8mm: Correct WDOG_B pin configuration
@ 2020-10-12 6:52 ` Krzysztof Kozlowski
0 siblings, 0 replies; 12+ messages in thread
From: Krzysztof Kozlowski @ 2020-10-12 6:52 UTC (permalink / raw)
To: Anson Huang
Cc: daniel.baluta, peter.chen, abel.vesa, devicetree, festevam,
s.hauer, linux-kernel, Linux-imx, robh+dt, linux-arm-kernel,
kernel, l.stach, shawnguo, yibin.gong, aford173, shengjiu.wang,
alifer.wsdm, jun.li
On Fri, 9 Oct 2020 at 09:52, Anson Huang <Anson.Huang@nxp.com> wrote:
>
> Different revision of i.MX8MM EVK boards may have different external
> pull up registor design, some are enabled while some are NOT, to make
> sure the WDOG_B pin works properly, better to enable internal pull up
> resistor. Since enabling internal pull up resistor is NOT harmful and
> having benefit of flexibility on different board design, just enable
> it for all i.MX8MM boards.
>
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> ---
> arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi | 2 +-
> arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi | 2 +-
> arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> index 6de86a4..a941301 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> @@ -398,7 +398,7 @@
>
> pinctrl_wdog: wdoggrp {
> fsl,pins = <
> - MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
> + MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
Enabling pull up makes sense but you change other bits - disable
Schmitt input and enable open drain. This change is not documented /
explained in commit msg.
Best regards,
Krzysztof
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread* RE: [PATCH 1/3] arm64: dts: imx8mm: Correct WDOG_B pin configuration
2020-10-12 6:52 ` Krzysztof Kozlowski
@ 2020-10-12 12:38 ` Anson Huang
-1 siblings, 0 replies; 12+ messages in thread
From: Anson Huang @ 2020-10-12 12:38 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: robh+dt, shawnguo, s.hauer, kernel, festevam, aford173,
Daniel Baluta, S.j. Wang, Peter Chen, alifer.wsdm, Abel Vesa,
Robin Gong, Jun Li, l.stach, devicetree, linux-arm-kernel,
linux-kernel, dl-linux-imx
Hi, Krzysztof
> Subject: Re: [PATCH 1/3] arm64: dts: imx8mm: Correct WDOG_B pin
> configuration
>
> On Fri, 9 Oct 2020 at 09:52, Anson Huang <Anson.Huang@nxp.com> wrote:
> >
> > Different revision of i.MX8MM EVK boards may have different external
> > pull up registor design, some are enabled while some are NOT, to make
> > sure the WDOG_B pin works properly, better to enable internal pull up
> > resistor. Since enabling internal pull up resistor is NOT harmful and
> > having benefit of flexibility on different board design, just enable
> > it for all i.MX8MM boards.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > ---
> > arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi | 2 +-
> > arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi | 2 +-
> > arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi | 2 +-
> > 3 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> > b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> > index 6de86a4..a941301 100644
> > --- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> > +++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> > @@ -398,7 +398,7 @@
> >
> > pinctrl_wdog: wdoggrp {
> > fsl,pins = <
> > -
> MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
> > +
> MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>
> Enabling pull up makes sense but you change other bits - disable Schmitt input
> and enable open drain. This change is not documented / explained in commit
> msg.
The Schmitt input is NOT necessary for WDOG_B pin which is for output ONLY.
The open drain is to let pull up voltage to decide the actual output voltage,
so it is NOT harmful for WDOG_B pin, hence we set it together.
I will send a V2 patch to add these info in commit msg.
Thanks,
Anson
^ permalink raw reply [flat|nested] 12+ messages in thread* RE: [PATCH 1/3] arm64: dts: imx8mm: Correct WDOG_B pin configuration
@ 2020-10-12 12:38 ` Anson Huang
0 siblings, 0 replies; 12+ messages in thread
From: Anson Huang @ 2020-10-12 12:38 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: Daniel Baluta, Peter Chen, Abel Vesa, devicetree, festevam,
s.hauer, linux-kernel, dl-linux-imx, robh+dt, linux-arm-kernel,
kernel, l.stach, shawnguo, Robin Gong, aford173, S.j. Wang,
alifer.wsdm, Jun Li
Hi, Krzysztof
> Subject: Re: [PATCH 1/3] arm64: dts: imx8mm: Correct WDOG_B pin
> configuration
>
> On Fri, 9 Oct 2020 at 09:52, Anson Huang <Anson.Huang@nxp.com> wrote:
> >
> > Different revision of i.MX8MM EVK boards may have different external
> > pull up registor design, some are enabled while some are NOT, to make
> > sure the WDOG_B pin works properly, better to enable internal pull up
> > resistor. Since enabling internal pull up resistor is NOT harmful and
> > having benefit of flexibility on different board design, just enable
> > it for all i.MX8MM boards.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > ---
> > arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi | 2 +-
> > arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi | 2 +-
> > arch/arm64/boot/dts/freescale/imx8mm-var-som.dtsi | 2 +-
> > 3 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> > b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> > index 6de86a4..a941301 100644
> > --- a/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> > +++ b/arch/arm64/boot/dts/freescale/imx8mm-beacon-som.dtsi
> > @@ -398,7 +398,7 @@
> >
> > pinctrl_wdog: wdoggrp {
> > fsl,pins = <
> > -
> MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0xc6
> > +
> MX8MM_IOMUXC_GPIO1_IO02_WDOG1_WDOG_B 0x166
>
> Enabling pull up makes sense but you change other bits - disable Schmitt input
> and enable open drain. This change is not documented / explained in commit
> msg.
The Schmitt input is NOT necessary for WDOG_B pin which is for output ONLY.
The open drain is to let pull up voltage to decide the actual output voltage,
so it is NOT harmful for WDOG_B pin, hence we set it together.
I will send a V2 patch to add these info in commit msg.
Thanks,
Anson
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 12+ messages in thread