[PATCH 3/8] arm64: dts: imx8mm-kontron: Set VDD_SNVS to 800 mV

[PATCH 3/8] arm64: dts: imx8mm-kontron: Set VDD_SNVS to 800 mV

[Frieder Schrempf]

From: Frieder Schrempf <frieder.schrempf@kontron.de>

According to the datasheet VDD_SNVS should be 800 mV, so let's
make sure that the voltage won't be different.

Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
Cc: stable@vger.kernel.org
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
 arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
index b12fb7ce6686..213014f59b46 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
@@ -152,8 +152,8 @@ reg_nvcc_snvs: LDO1 {
 
 			reg_vdd_snvs: LDO2 {
 				regulator-name = "ldo2";
-				regulator-min-microvolt = <850000>;
-				regulator-max-microvolt = <900000>;
+				regulator-min-microvolt = <800000>;
+				regulator-max-microvolt = <800000>;
 				regulator-boot-on;
 				regulator-always-on;
 			};
-- 
2.33.0

[PATCH 4/8] arm64: dts: imx8mm-kontron: Fix reg_rst_eth2 and reg_vdd_5v regulators

[Frieder Schrempf]

From: Frieder Schrempf <frieder.schrempf@kontron.de>

The regulator reg_vdd_5v represents the fixed 5V supply on the board which
can't be switched off. Mark it as always-on.

The regulator reg_rst_eth2 should keep the reset signal of the USB ethernet
adapter deassertet anytime. Fix the polarity and mark it as always-on.

Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
Cc: stable@vger.kernel.org
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
 arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
index 62ba3bd08a0c..f2c8ccefd1bf 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
@@ -70,7 +70,9 @@ reg_rst_eth2: regulator-rst-eth2 {
 		regulator-name = "rst-usb-eth2";
 		pinctrl-names = "default";
 		pinctrl-0 = <&pinctrl_usb_eth2>;
-		gpio = <&gpio3 2 GPIO_ACTIVE_LOW>;
+		gpio = <&gpio3 2 GPIO_ACTIVE_HIGH>;
+		enable-active-high;
+		regulator-always-on;
 	};
 
 	reg_vdd_5v: regulator-5v {
@@ -78,6 +80,7 @@ reg_vdd_5v: regulator-5v {
 		regulator-name = "vdd-5v";
 		regulator-min-microvolt = <5000000>;
 		regulator-max-microvolt = <5000000>;
+		regulator-always-on;
 	};
 };
 
-- 
2.33.0

[PATCH 5/8] arm64: dts: imx8mm-kontron: Fix CAN SPI clock frequency

[Frieder Schrempf]

From: Frieder Schrempf <frieder.schrempf@kontron.de>

The MCP2515 can be used with an SPI clock of up to 10 MHz. Set the
limit accordingly to prevent any performance issues caused by the
really low clock speed of 100 kHz.

Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
Cc: stable@vger.kernel.org
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
 arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
index f2c8ccefd1bf..dbf11e03ecce 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
@@ -98,7 +98,7 @@ can0: can@0 {
 		clocks = <&osc_can>;
 		interrupt-parent = <&gpio4>;
 		interrupts = <28 IRQ_TYPE_EDGE_FALLING>;
-		spi-max-frequency = <100000>;
+		spi-max-frequency = <10000000>;
 		vdd-supply = <&reg_vdd_3v3>;
 		xceiver-supply = <&reg_vdd_5v>;
 	};
-- 
2.33.0

[PATCH 6/8] arm64: dts: imx8mm-kontron: Fix connection type for VSC8531 RGMII PHY

[Frieder Schrempf]

From: Frieder Schrempf <frieder.schrempf@kontron.de>

Previously we falsely relied on the PHY driver to unconditionally
enable the internal RX delay. Since the following fix for the PHY
driver this is not the case anymore:

commit 7b005a1742be ("net: phy: mscc: configure both RX and TX internal
delays for RGMII")

In order to enable the delay we need to set the connection type to
"rgmii-rxid".

Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
Cc: stable@vger.kernel.org
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
 arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
index dbf11e03ecce..0e4509287a92 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
+++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
@@ -114,7 +114,7 @@ &ecspi3 {
 &fec1 {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_enet>;
-	phy-connection-type = "rgmii";
+	phy-connection-type = "rgmii-rxid";
 	phy-handle = <&ethphy>;
 	status = "okay";
 
-- 
2.33.0

[PATCH 8/8] arm64: dts: imx8mm-kontron: Leave reg_vdd_arm always powered on

[Frieder Schrempf]

From: Frieder Schrempf <frieder.schrempf@kontron.de>

When the cpufreq driver is enabled, the buck2 regulator is kept powered on
by the dependency between the CPU nodes with 'cpu-supply' set. Without the
cpufreq driver the kernel will power off the regulator as it doesn't see
any users. This is obviously not what we want, therefore keep the regulator
powered on in any case.

Reported-by: Heiko Thiery <heiko.thiery@gmail.com>
Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
Cc: stable@vger.kernel.org
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
 arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
index 213014f59b46..c3418d263eb4 100644
--- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
+++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
@@ -105,6 +105,7 @@ reg_vdd_arm: BUCK2 {
 				regulator-min-microvolt = <850000>;
 				regulator-max-microvolt = <950000>;
 				regulator-boot-on;
+				regulator-always-on;
 				regulator-ramp-delay = <3125>;
 				nxp,dvs-run-voltage = <950000>;
 				nxp,dvs-standby-voltage = <850000>;
-- 
2.33.0

Re: [PATCH 8/8] arm64: dts: imx8mm-kontron: Leave reg_vdd_arm always powered on

[Heiko Thiery]

Hi Frieder,

Am Do., 30. Sept. 2021 um 17:57 Uhr schrieb Frieder Schrempf <frieder@fris.de>:
>
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>
> When the cpufreq driver is enabled, the buck2 regulator is kept powered on
> by the dependency between the CPU nodes with 'cpu-supply' set. Without the
> cpufreq driver the kernel will power off the regulator as it doesn't see
> any users. This is obviously not what we want, therefore keep the regulator
> powered on in any case.
>
> Reported-by: Heiko Thiery <heiko.thiery@gmail.com>
> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> Cc: stable@vger.kernel.org
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>

Tested-by: Heiko Thiery <heiko.thiery@gmail.com>

> ---
>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> index 213014f59b46..c3418d263eb4 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> @@ -105,6 +105,7 @@ reg_vdd_arm: BUCK2 {
>                                 regulator-min-microvolt = <850000>;
>                                 regulator-max-microvolt = <950000>;
>                                 regulator-boot-on;
> +                               regulator-always-on;
>                                 regulator-ramp-delay = <3125>;
>                                 nxp,dvs-run-voltage = <950000>;
>                                 nxp,dvs-standby-voltage = <850000>;
> --
> 2.33.0
>

Re: [PATCH 3/8] arm64: dts: imx8mm-kontron: Set VDD_SNVS to 800 mV

[Shawn Guo]

On Thu, Sep 30, 2021 at 05:56:26PM +0200, Frieder Schrempf wrote:
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> 
> According to the datasheet VDD_SNVS should be 800 mV, so let's
> make sure that the voltage won't be different.

Could you share the datasheet?

Shawn

> 
> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> Cc: stable@vger.kernel.org
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> ---
>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> index b12fb7ce6686..213014f59b46 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> @@ -152,8 +152,8 @@ reg_nvcc_snvs: LDO1 {
>  
>  			reg_vdd_snvs: LDO2 {
>  				regulator-name = "ldo2";
> -				regulator-min-microvolt = <850000>;
> -				regulator-max-microvolt = <900000>;
> +				regulator-min-microvolt = <800000>;
> +				regulator-max-microvolt = <800000>;
>  				regulator-boot-on;
>  				regulator-always-on;
>  			};
> -- 
> 2.33.0
> 

Re: [PATCH 4/8] arm64: dts: imx8mm-kontron: Fix reg_rst_eth2 and reg_vdd_5v regulators

[Shawn Guo]

On Thu, Sep 30, 2021 at 05:56:27PM +0200, Frieder Schrempf wrote:
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> 
> The regulator reg_vdd_5v represents the fixed 5V supply on the board which
> can't be switched off. Mark it as always-on.
> 
> The regulator reg_rst_eth2 should keep the reset signal of the USB ethernet
> adapter deassertet anytime. Fix the polarity and mark it as always-on.

It seems to be wrong from the beginning that the reset is modelled by a
regulator.

> 
> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> Cc: stable@vger.kernel.org
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> ---
>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> index 62ba3bd08a0c..f2c8ccefd1bf 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> @@ -70,7 +70,9 @@ reg_rst_eth2: regulator-rst-eth2 {
>  		regulator-name = "rst-usb-eth2";
>  		pinctrl-names = "default";
>  		pinctrl-0 = <&pinctrl_usb_eth2>;
> -		gpio = <&gpio3 2 GPIO_ACTIVE_LOW>;
> +		gpio = <&gpio3 2 GPIO_ACTIVE_HIGH>;
> +		enable-active-high;
> +		regulator-always-on;
>  	};
>  
>  	reg_vdd_5v: regulator-5v {
> @@ -78,6 +80,7 @@ reg_vdd_5v: regulator-5v {
>  		regulator-name = "vdd-5v";
>  		regulator-min-microvolt = <5000000>;
>  		regulator-max-microvolt = <5000000>;
> +		regulator-always-on;

You do not have any on/off control over the regulator.  So how does this
always-on property make any difference?

Shawn

>  	};
>  };
>  
> -- 
> 2.33.0
> 

Re: [PATCH 5/8] arm64: dts: imx8mm-kontron: Fix CAN SPI clock frequency

[Shawn Guo]

On Thu, Sep 30, 2021 at 05:56:28PM +0200, Frieder Schrempf wrote:
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> 
> The MCP2515 can be used with an SPI clock of up to 10 MHz. Set the
> limit accordingly to prevent any performance issues caused by the
> really low clock speed of 100 kHz.

Could you share some testing result of this change?

> 
> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")

It's really an optimization rather than fix, isn't it?

Shawn

> Cc: stable@vger.kernel.org
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> ---
>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> index f2c8ccefd1bf..dbf11e03ecce 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> @@ -98,7 +98,7 @@ can0: can@0 {
>  		clocks = <&osc_can>;
>  		interrupt-parent = <&gpio4>;
>  		interrupts = <28 IRQ_TYPE_EDGE_FALLING>;
> -		spi-max-frequency = <100000>;
> +		spi-max-frequency = <10000000>;
>  		vdd-supply = <&reg_vdd_3v3>;
>  		xceiver-supply = <&reg_vdd_5v>;
>  	};
> -- 
> 2.33.0
> 

Re: [PATCH 6/8] arm64: dts: imx8mm-kontron: Fix connection type for VSC8531 RGMII PHY

[Shawn Guo]

On Thu, Sep 30, 2021 at 05:56:29PM +0200, Frieder Schrempf wrote:
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> 
> Previously we falsely relied on the PHY driver to unconditionally
> enable the internal RX delay. Since the following fix for the PHY
> driver this is not the case anymore:
> 
> commit 7b005a1742be ("net: phy: mscc: configure both RX and TX internal
> delays for RGMII")
> 
> In order to enable the delay we need to set the connection type to
> "rgmii-rxid".

Could you share some details of the issue that the delay is not enabled,
e.g. how broken the Ethernet support is without this change?

Shawn

> 
> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> Cc: stable@vger.kernel.org
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> ---
>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> index dbf11e03ecce..0e4509287a92 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> @@ -114,7 +114,7 @@ &ecspi3 {
>  &fec1 {
>  	pinctrl-names = "default";
>  	pinctrl-0 = <&pinctrl_enet>;
> -	phy-connection-type = "rgmii";
> +	phy-connection-type = "rgmii-rxid";
>  	phy-handle = <&ethphy>;
>  	status = "okay";
>  
> -- 
> 2.33.0
> 

Re: [PATCH 8/8] arm64: dts: imx8mm-kontron: Leave reg_vdd_arm always powered on

[Shawn Guo]

On Thu, Sep 30, 2021 at 05:56:31PM +0200, Frieder Schrempf wrote:
> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> 
> When the cpufreq driver is enabled, the buck2 regulator is kept powered on
> by the dependency between the CPU nodes with 'cpu-supply' set. Without the
> cpufreq driver the kernel will power off the regulator as it doesn't see
> any users. This is obviously not what we want, therefore keep the regulator
> powered on in any case.
> 
> Reported-by: Heiko Thiery <heiko.thiery@gmail.com>
> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> Cc: stable@vger.kernel.org
> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>

Already picked up the one from Heiko.

https://lore.kernel.org/all/20210915120325.20248-1-heiko.thiery@gmail.com/

Shawn

> ---
>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> index 213014f59b46..c3418d263eb4 100644
> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> @@ -105,6 +105,7 @@ reg_vdd_arm: BUCK2 {
>  				regulator-min-microvolt = <850000>;
>  				regulator-max-microvolt = <950000>;
>  				regulator-boot-on;
> +				regulator-always-on;
>  				regulator-ramp-delay = <3125>;
>  				nxp,dvs-run-voltage = <950000>;
>  				nxp,dvs-standby-voltage = <850000>;
> -- 
> 2.33.0
> 

Re: [PATCH 3/8] arm64: dts: imx8mm-kontron: Set VDD_SNVS to 800 mV

[Frieder Schrempf]

On 05.10.21 08:56, Shawn Guo wrote:
> On Thu, Sep 30, 2021 at 05:56:26PM +0200, Frieder Schrempf wrote:
>> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>>
>> According to the datasheet VDD_SNVS should be 800 mV, so let's
>> make sure that the voltage won't be different.
> 
> Could you share the datasheet?

Sure, it's here: https://www.nxp.com/docs/en/data-sheet/IMX8MMIEC.pdf.
See table 10 for the operating voltages.

>>
>> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
>> ---
>>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
>> index b12fb7ce6686..213014f59b46 100644
>> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
>> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
>> @@ -152,8 +152,8 @@ reg_nvcc_snvs: LDO1 {
>>  
>>  			reg_vdd_snvs: LDO2 {
>>  				regulator-name = "ldo2";
>> -				regulator-min-microvolt = <850000>;
>> -				regulator-max-microvolt = <900000>;
>> +				regulator-min-microvolt = <800000>;
>> +				regulator-max-microvolt = <800000>;
>>  				regulator-boot-on;
>>  				regulator-always-on;
>>  			};
>> -- 
>> 2.33.0
>>

Re: [PATCH 4/8] arm64: dts: imx8mm-kontron: Fix reg_rst_eth2 and reg_vdd_5v regulators

[Frieder Schrempf]

On 05.10.21 09:09, Shawn Guo wrote:
> On Thu, Sep 30, 2021 at 05:56:27PM +0200, Frieder Schrempf wrote:
>> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>>
>> The regulator reg_vdd_5v represents the fixed 5V supply on the board which
>> can't be switched off. Mark it as always-on.
>>
>> The regulator reg_rst_eth2 should keep the reset signal of the USB ethernet
>> adapter deassertet anytime. Fix the polarity and mark it as always-on.
> 
> It seems to be wrong from the beginning that the reset is modelled by a
> regulator.

Right, but at least at the time when I upstreamed this, there was no way
to pass the reset GPIO to a USB device driver and using a regulator
seems to be an accepted workaround as far as I understand.

> 
>>
>> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
>> ---
>>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 5 ++++-
>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>> index 62ba3bd08a0c..f2c8ccefd1bf 100644
>> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>> @@ -70,7 +70,9 @@ reg_rst_eth2: regulator-rst-eth2 {
>>  		regulator-name = "rst-usb-eth2";
>>  		pinctrl-names = "default";
>>  		pinctrl-0 = <&pinctrl_usb_eth2>;
>> -		gpio = <&gpio3 2 GPIO_ACTIVE_LOW>;
>> +		gpio = <&gpio3 2 GPIO_ACTIVE_HIGH>;
>> +		enable-active-high;
>> +		regulator-always-on;
>>  	};
>>  
>>  	reg_vdd_5v: regulator-5v {
>> @@ -78,6 +80,7 @@ reg_vdd_5v: regulator-5v {
>>  		regulator-name = "vdd-5v";
>>  		regulator-min-microvolt = <5000000>;
>>  		regulator-max-microvolt = <5000000>;
>> +		regulator-always-on;
> 
> You do not have any on/off control over the regulator.  So how does this
> always-on property make any difference?

Right, this doesn't make a difference and is definitely not a fix, I
will drop it. Anyway, this regulator is just there for completeness of
the hardware description.

> 
>>  	};
>>  };
>>  
>> -- 
>> 2.33.0
>>

Re: [PATCH 5/8] arm64: dts: imx8mm-kontron: Fix CAN SPI clock frequency

[Frieder Schrempf]

On 05.10.21 09:12, Shawn Guo wrote:
> On Thu, Sep 30, 2021 at 05:56:28PM +0200, Frieder Schrempf wrote:
>> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>>
>> The MCP2515 can be used with an SPI clock of up to 10 MHz. Set the
>> limit accordingly to prevent any performance issues caused by the
>> really low clock speed of 100 kHz.
> 
> Could you share some testing result of this change?

Without this change, receiving CAN messages on the board beyond a
certain bitrate will cause overrun errors (see 'ip -det -stat link show
can0').

With this fix, receiving messages on the bus works without any overrun
errors for bitrates up to 1 MBit.


> 
>>
>> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> 
> It's really an optimization rather than fix, isn't it?

It removes the arbitrarily low limit on the SPI frequency, that was
caused by a typo in the original dts. As the usage of the CAN bus is
seriously affected by this I would consider it a fix. But if you think
otherwise, feel free to remove the Fixes tag.

> 
> Shawn
> 
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
>> ---
>>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>> index f2c8ccefd1bf..dbf11e03ecce 100644
>> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>> @@ -98,7 +98,7 @@ can0: can@0 {
>>  		clocks = <&osc_can>;
>>  		interrupt-parent = <&gpio4>;
>>  		interrupts = <28 IRQ_TYPE_EDGE_FALLING>;
>> -		spi-max-frequency = <100000>;
>> +		spi-max-frequency = <10000000>;
>>  		vdd-supply = <&reg_vdd_3v3>;
>>  		xceiver-supply = <&reg_vdd_5v>;
>>  	};
>> -- 
>> 2.33.0
>>

Re: [PATCH 3/8] arm64: dts: imx8mm-kontron: Set VDD_SNVS to 800 mV

[Shawn Guo]

On Tue, Oct 05, 2021 at 03:14:40PM +0200, Frieder Schrempf wrote:
> On 05.10.21 08:56, Shawn Guo wrote:
> > On Thu, Sep 30, 2021 at 05:56:26PM +0200, Frieder Schrempf wrote:
> >> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> >>
> >> According to the datasheet VDD_SNVS should be 800 mV, so let's
> >> make sure that the voltage won't be different.
> > 
> > Could you share the datasheet?
> 
> Sure, it's here: https://www.nxp.com/docs/en/data-sheet/IMX8MMIEC.pdf.
> See table 10 for the operating voltages.

Thanks for the link!

But datasheet specifies a voltage range. 800 mV is just the typical one.
The only problem I see is that regulator-min-microvolt should be lowered
to 800 mV.  regulator-max-microvolt looks correct to me.

Shawn

> 
> >>
> >> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> >> Cc: stable@vger.kernel.org
> >> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> >> ---
> >>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi | 4 ++--
> >>  1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> >> index b12fb7ce6686..213014f59b46 100644
> >> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> >> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-som.dtsi
> >> @@ -152,8 +152,8 @@ reg_nvcc_snvs: LDO1 {
> >>  
> >>  			reg_vdd_snvs: LDO2 {
> >>  				regulator-name = "ldo2";
> >> -				regulator-min-microvolt = <850000>;
> >> -				regulator-max-microvolt = <900000>;
> >> +				regulator-min-microvolt = <800000>;
> >> +				regulator-max-microvolt = <800000>;
> >>  				regulator-boot-on;
> >>  				regulator-always-on;
> >>  			};
> >> -- 
> >> 2.33.0
> >>

Re: [PATCH 4/8] arm64: dts: imx8mm-kontron: Fix reg_rst_eth2 and reg_vdd_5v regulators

[Shawn Guo]

On Tue, Oct 05, 2021 at 07:06:57PM +0200, Frieder Schrempf wrote:
> On 05.10.21 09:09, Shawn Guo wrote:
> > On Thu, Sep 30, 2021 at 05:56:27PM +0200, Frieder Schrempf wrote:
> >> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> >>
> >> The regulator reg_vdd_5v represents the fixed 5V supply on the board which
> >> can't be switched off. Mark it as always-on.
> >>
> >> The regulator reg_rst_eth2 should keep the reset signal of the USB ethernet
> >> adapter deassertet anytime. Fix the polarity and mark it as always-on.
> > 
> > It seems to be wrong from the beginning that the reset is modelled by a
> > regulator.
> 
> Right, but at least at the time when I upstreamed this, there was no way
> to pass the reset GPIO to a USB device driver and using a regulator
> seems to be an accepted workaround as far as I understand.

Do we have the solution in usb driver now?  If so, we should probably
switch to that, instead of patching the workaround?

Shawn

> 
> > 
> >>
> >> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> >> Cc: stable@vger.kernel.org
> >> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> >> ---
> >>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 5 ++++-
> >>  1 file changed, 4 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> >> index 62ba3bd08a0c..f2c8ccefd1bf 100644
> >> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> >> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> >> @@ -70,7 +70,9 @@ reg_rst_eth2: regulator-rst-eth2 {
> >>  		regulator-name = "rst-usb-eth2";
> >>  		pinctrl-names = "default";
> >>  		pinctrl-0 = <&pinctrl_usb_eth2>;
> >> -		gpio = <&gpio3 2 GPIO_ACTIVE_LOW>;
> >> +		gpio = <&gpio3 2 GPIO_ACTIVE_HIGH>;
> >> +		enable-active-high;
> >> +		regulator-always-on;
> >>  	};
> >>  
> >>  	reg_vdd_5v: regulator-5v {
> >> @@ -78,6 +80,7 @@ reg_vdd_5v: regulator-5v {
> >>  		regulator-name = "vdd-5v";
> >>  		regulator-min-microvolt = <5000000>;
> >>  		regulator-max-microvolt = <5000000>;
> >> +		regulator-always-on;
> > 
> > You do not have any on/off control over the regulator.  So how does this
> > always-on property make any difference?
> 
> Right, this doesn't make a difference and is definitely not a fix, I
> will drop it. Anyway, this regulator is just there for completeness of
> the hardware description.
> 
> > 
> >>  	};
> >>  };
> >>  
> >> -- 
> >> 2.33.0
> >>

Re: [PATCH 5/8] arm64: dts: imx8mm-kontron: Fix CAN SPI clock frequency

[Shawn Guo]

On Tue, Oct 05, 2021 at 07:17:13PM +0200, Frieder Schrempf wrote:
> On 05.10.21 09:12, Shawn Guo wrote:
> > On Thu, Sep 30, 2021 at 05:56:28PM +0200, Frieder Schrempf wrote:
> >> From: Frieder Schrempf <frieder.schrempf@kontron.de>
> >>
> >> The MCP2515 can be used with an SPI clock of up to 10 MHz. Set the
> >> limit accordingly to prevent any performance issues caused by the
> >> really low clock speed of 100 kHz.
> > 
> > Could you share some testing result of this change?
> 
> Without this change, receiving CAN messages on the board beyond a
> certain bitrate will cause overrun errors (see 'ip -det -stat link show
> can0').
> 
> With this fix, receiving messages on the bus works without any overrun
> errors for bitrates up to 1 MBit.
> 
> 
> > 
> >>
> >> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
> > 
> > It's really an optimization rather than fix, isn't it?
> 
> It removes the arbitrarily low limit on the SPI frequency, that was
> caused by a typo in the original dts. As the usage of the CAN bus is
> seriously affected by this I would consider it a fix. But if you think
> otherwise, feel free to remove the Fixes tag.

Put all these good information into commit log, and I will be happy to
take it as a fix.

Shawn

> >> Cc: stable@vger.kernel.org
> >> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
> >> ---
> >>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> >> index f2c8ccefd1bf..dbf11e03ecce 100644
> >> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> >> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
> >> @@ -98,7 +98,7 @@ can0: can@0 {
> >>  		clocks = <&osc_can>;
> >>  		interrupt-parent = <&gpio4>;
> >>  		interrupts = <28 IRQ_TYPE_EDGE_FALLING>;
> >> -		spi-max-frequency = <100000>;
> >> +		spi-max-frequency = <10000000>;
> >>  		vdd-supply = <&reg_vdd_3v3>;
> >>  		xceiver-supply = <&reg_vdd_5v>;
> >>  	};
> >> -- 
> >> 2.33.0
> >>

Re: [PATCH 4/8] arm64: dts: imx8mm-kontron: Fix reg_rst_eth2 and reg_vdd_5v regulators

[Frieder Schrempf]

On 15.10.21 06:09, Shawn Guo wrote:
> On Tue, Oct 05, 2021 at 07:06:57PM +0200, Frieder Schrempf wrote:
>> On 05.10.21 09:09, Shawn Guo wrote:
>>> On Thu, Sep 30, 2021 at 05:56:27PM +0200, Frieder Schrempf wrote:
>>>> From: Frieder Schrempf <frieder.schrempf@kontron.de>
>>>>
>>>> The regulator reg_vdd_5v represents the fixed 5V supply on the board which
>>>> can't be switched off. Mark it as always-on.
>>>>
>>>> The regulator reg_rst_eth2 should keep the reset signal of the USB ethernet
>>>> adapter deassertet anytime. Fix the polarity and mark it as always-on.
>>>
>>> It seems to be wrong from the beginning that the reset is modelled by a
>>> regulator.
>>
>> Right, but at least at the time when I upstreamed this, there was no way
>> to pass the reset GPIO to a USB device driver and using a regulator
>> seems to be an accepted workaround as far as I understand.
> 
> Do we have the solution in usb driver now?  If so, we should probably
> switch to that, instead of patching the workaround?

I had a look, but couldn't find anything. I remember there have been
efforts in the past to provide a generic way for usb devices to manage
resources like reset GPIOs and clocks (e.g. [1]), but it seems like
nothing of this ever got merged.

So for the moment I'd like to fix the existing solution, but I totally
agree that this should be solved properly in the future.

[1] https://lkml.org/lkml/2017/6/21/90

> 
>>
>>>
>>>>
>>>> Fixes: 21c4f45b335f ("arm64: dts: Add the Kontron i.MX8M Mini SoMs and baseboards")
>>>> Cc: stable@vger.kernel.org
>>>> Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
>>>> ---
>>>>  arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts | 5 ++++-
>>>>  1 file changed, 4 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>>>> index 62ba3bd08a0c..f2c8ccefd1bf 100644
>>>> --- a/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>>>> +++ b/arch/arm64/boot/dts/freescale/imx8mm-kontron-n801x-s.dts
>>>> @@ -70,7 +70,9 @@ reg_rst_eth2: regulator-rst-eth2 {
>>>>  		regulator-name = "rst-usb-eth2";
>>>>  		pinctrl-names = "default";
>>>>  		pinctrl-0 = <&pinctrl_usb_eth2>;
>>>> -		gpio = <&gpio3 2 GPIO_ACTIVE_LOW>;
>>>> +		gpio = <&gpio3 2 GPIO_ACTIVE_HIGH>;
>>>> +		enable-active-high;
>>>> +		regulator-always-on;
>>>>  	};
>>>>  
>>>>  	reg_vdd_5v: regulator-5v {
>>>> @@ -78,6 +80,7 @@ reg_vdd_5v: regulator-5v {
>>>>  		regulator-name = "vdd-5v";
>>>>  		regulator-min-microvolt = <5000000>;
>>>>  		regulator-max-microvolt = <5000000>;
>>>> +		regulator-always-on;
>>>
>>> You do not have any on/off control over the regulator.  So how does this
>>> always-on property make any difference?
>>
>> Right, this doesn't make a difference and is definitely not a fix, I
>> will drop it. Anyway, this regulator is just there for completeness of
>> the hardware description.
>>
>>>
>>>>  	};
>>>>  };
>>>>  
>>>> -- 
>>>> 2.33.0
>>>>