[PATCH] ARM: dts: stm32: declare device tree syscon node for TAMP peripheral

[PATCH] ARM: dts: stm32: declare device tree syscon node for TAMP peripheral

[Ahmad Fatoum]

The stm32mp1 TAMP (Tamper and backup registers) does tamper detection
and features 32 backup registers that, being in the RTC domain, may
survive even with Vdd switched off.

We don't have a driver for the peripheral, but handling it as syscon
allows using it with existing drivers that work with them, in particular
a syscon-reboot-mode child node can be defined in board.dts (or fixed up
by the bootloader) to exchange reboot mode information with the bootloader.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/arm/boot/dts/stm32mp151.dtsi | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/boot/dts/stm32mp151.dtsi b/arch/arm/boot/dts/stm32mp151.dtsi
index bfe29023fbd5..fa4eb96c95af 100644
--- a/arch/arm/boot/dts/stm32mp151.dtsi
+++ b/arch/arm/boot/dts/stm32mp151.dtsi
@@ -1144,6 +1144,11 @@ syscfg: syscon@50020000 {
 			clocks = <&rcc SYSCFG>;
 		};
 
+		tamp: tamp@5c00a000 {
+			compatible = "simple-bus", "syscon", "simple-mfd";
+			reg = <0x5c00a000 0x400>;
+		};
+
 		lptimer2: timer@50021000 {
 			#address-cells = <1>;
 			#size-cells = <0>;
-- 
2.28.0

Re: [PATCH] ARM: dts: stm32: declare device tree syscon node for TAMP peripheral

[Ahmad Fatoum]

On 9/16/20 4:22 PM, Ahmad Fatoum wrote:
> The stm32mp1 TAMP (Tamper and backup registers) does tamper detection
> and features 32 backup registers that, being in the RTC domain, may
> survive even with Vdd switched off.
> 
> We don't have a driver for the peripheral, but handling it as syscon
> allows using it with existing drivers that work with them, in particular
> a syscon-reboot-mode child node can be defined in board.dts (or fixed up
> by the bootloader) to exchange reboot mode information with the bootloader.
> 

Looking at the title, I see now that there is nothing stm32mp specific in it.
I will rename the patch to
"ARM: dts: stm32: declare syscon node for TAMP peripheral in stm32mp151.dtsi"
when I send out v2.

> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  arch/arm/boot/dts/stm32mp151.dtsi | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/arch/arm/boot/dts/stm32mp151.dtsi b/arch/arm/boot/dts/stm32mp151.dtsi
> index bfe29023fbd5..fa4eb96c95af 100644
> --- a/arch/arm/boot/dts/stm32mp151.dtsi
> +++ b/arch/arm/boot/dts/stm32mp151.dtsi
> @@ -1144,6 +1144,11 @@ syscfg: syscon@50020000 {
>  			clocks = <&rcc SYSCFG>;
>  		};
>  
> +		tamp: tamp@5c00a000 {
> +			compatible = "simple-bus", "syscon", "simple-mfd";
> +			reg = <0x5c00a000 0x400>;
> +		};
> +
>  		lptimer2: timer@50021000 {
>  			#address-cells = <1>;
>  			#size-cells = <0>;
> 

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