Re: [Linux-stm32] [PATCH 3/3] ARM: dts: stm32: update stm32mp151 for remote proc synchronisation support

[Arnaud POULIQUEN <arnaud.pouliquen@st.com>]

Hi Ahmad,

On 9/24/20 7:45 AM, Ahmad Fatoum wrote:
> Hello Arnaud,
> 
> On 8/27/20 9:21 AM, Arnaud Pouliquen wrote:
>> Two backup registers are used to store the Cortex-M4 state and the resource
>> table address.
>> Declare the tamp node and add associated properties in m4_rproc node
>> to allow Linux to attach to a firmware loaded by the first boot stages.
>>
>> Associated driver implementation is available in commit 9276536f455b3
>> ("remoteproc: stm32: Parse syscon that will manage M4 synchronisation").
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
>> ---
>>  arch/arm/boot/dts/stm32mp151.dtsi | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/stm32mp151.dtsi b/arch/arm/boot/dts/stm32mp151.dtsi
>> index bfe29023fbd5..842ecffae73a 100644
>> --- a/arch/arm/boot/dts/stm32mp151.dtsi
>> +++ b/arch/arm/boot/dts/stm32mp151.dtsi
>> @@ -1541,6 +1541,11 @@
>>  			status = "disabled";
>>  		};
>>  
>> +		tamp: tamp@5c00a000 {
>> +			compatible = "st,stm32-tamp", "syscon";
>> +			reg = <0x5c00a000 0x400>;
>> +		};
>> +
> 
> Just saw this now. I have a pending patch adding this node as well:
> https://lore.kernel.org/patchwork/patch/1306971/
> 
> For my use case, I need a "simple-mfd" compatible to allow child
> nodes to be probed.
> 
> Could you CC me when you send out your v2, so I can rebase?
> (Or if you don't mind, just add the "simple-mfd" into the compatible
> list yourself :-)

I prefer that you propose the "simple-mfd" compatibility. I do not master the
consequence of adding it...
I will add you in cc of my v2 , but as your patch could trig some discussions
I would suggest to send in advance a patchset including this patch and your patch
on top of, just add a reference to this series in the cover letter and explain
potential impact (or non impact) on the legacy.

Regards,
Arnaud
 
> 
> Cheers
> Ahmad
> 
>>  		/*
>>  		 * Break node order to solve dependency probe issue between
>>  		 * pinctrl and exti.
>> @@ -1717,6 +1722,8 @@
>>  			st,syscfg-holdboot = <&rcc 0x10C 0x1>;
>>  			st,syscfg-tz = <&rcc 0x000 0x1>;
>>  			st,syscfg-pdds = <&pwr_mcu 0x0 0x1>;
>> +			st,syscfg-rsc-tbl = <&tamp 0x144 0xFFFFFFFF>;
>> +			st,syscfg-m4-state = <&tamp 0x148 0xFFFFFFFF>;
>>  			status = "disabled";
>>  		};
>>  	};
>>
>