Re: [RFC PATCH 6/7] ARM: dts: stm32: add ETZPC as a system bus for STM32MP15x boards

From: Gatien CHEVALLIER <gatien.chevallier@foss.st.com>
To: Krzysztof Kozlowski <krzk@kernel.org>,
	<alexandre.torgue@foss.st.com>, <robh+dt@kernel.org>,
	<Oleksii_Moisieiev@epam.com>, <linus.walleij@linaro.org>,
	<gregkh@linuxfoundation.org>
Cc: <linux-stm32@st-md-mailman.stormreply.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>, <loic.pallardy@st.com>,
	<devicetree@vger.kernel.org>, <mark.rutland@arm.com>,
	<arnd@arndb.de>
Subject: Re: [RFC PATCH 6/7] ARM: dts: stm32: add ETZPC as a system bus for STM32MP15x boards
Date: Thu, 22 Dec 2022 15:42:09 +0100	[thread overview]
Message-ID: <0bff5b2d-2837-57cb-5434-58158acc1483@foss.st.com> (raw)
In-Reply-To: <2e7c901c-e322-ded6-b170-6d2436d74c0f@kernel.org>

Hello,

On 12/22/22 11:30, Krzysztof Kozlowski wrote:
> On 21/12/2022 18:30, Gatien Chevallier wrote:
>> The STM32 System Bus is an internal bus on which devices are connected.
>> ETZPC is a peripheral overseeing the firewall bus that configures
>> and control access to the peripherals connected on it.
>>
>> For more information on which peripheral is securable, please read
>> the STM32MP15 reference manual.
>>
>> Signed-off-by: Gatien Chevallier <gatien.chevallier@foss.st.com>
>> ---
>>   arch/arm/boot/dts/stm32mp151.dtsi | 2737 +++++++++++++++--------------
>>   1 file changed, 1406 insertions(+), 1331 deletions(-)
>>   
>> -		lptimer1: timer@40009000 {
>> +		etzpc: etzpc@5c007000 {
> 
> Node names should be generic.
> https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation

Will change to etzpc: bus@5c007000 in V3

> 
>> +			compatible = "st,stm32mp15-sys-bus";
>> +			reg = <0x5c007000 0x400>;
>>   			#address-cells = <1>;
>> -			#size-cells = <0>;
>> -			compatible = "st,stm32-lptimer";
>> -			reg = <0x40009000 0x400>;
>> -			interrupts-extended = <&exti 47 IRQ_TYPE_LEVEL_HIGH>;
>> -			clocks = <&rcc LPTIM1_K>;
>> -			clock-names = "mux";
>> -			wakeup-source;
>> -			status = "disabled";
> 
> Why entire bus is disabled? What resources do you miss?

Here, I did not want to modify the status of the nodes in the device 
tree. Nodes that are default enabled in the SoC device tree stay enabled 
and vice-versa. IMO think this patch should not include these kind of 
changes in its scope. I describe the bus and the peripherals connected 
to it, nothing more :)

> 
>> +			#size-cells = <1>;
>> +			feature-domain-controller;
>> +			#feature-domain-cells = <2>;
>> +			ranges;
>>   
> Best regards,
> Krzysztof
> 

Best regards,
Gatien

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