linux-kernel - Re: [PATCH v6 06/17] dt-bindings: mfd: amd,pensando-elbasr: Add AMD Pensando Elba System Resource chip

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Message-ID: <8ce3ee59-bc37-ea97-c94d-b6f4f9c28751@amd.com>
Date:   Thu, 29 Sep 2022 22:50:43 +0000
From:   "Larson, Bradley" <Bradley.Larson@....com>
To:     Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
        "Larson, Bradley" <Bradley.Larson@....com>,
        Rob Herring <robh@...nel.org>
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Subject: Re: [PATCH v6 06/17] dt-bindings: mfd: amd,pensando-elbasr: Add AMD
 Pensando Elba System Resource chip

On 9/16/22 2:56 AM, Krzysztof Kozlowski wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
>
>
> On 13/09/2022 22:57, Larson, Bradley wrote:
>> On 9/8/22 4:27 AM, Krzysztof Kozlowski wrote:
>>> On 01/09/2022 22:37, Larson, Bradley wrote:
>>>> On 9/1/22 12:20 AM, Krzysztof Kozlowski wrote:
>>>>> On 01/09/2022 02:01, Larson, Bradley wrote:
>>>>>
> Wait, can we skip the driver entirely? I am not reviewing your driver 
> and what it creates under /dev. 

Yes, see precise answer requested below.

>> In comparision, the pensando device is also on the other end of spi,
>> four chip selects with /dev created for each for userspace control,
>> and one child device on cs0 for hw reset emmc that the Linux block
>> layer controls (single bit managed only by kernel).
>>
>> Pensando:
>> &spi0 {
>>           num-cs = <4>;
>>           cs-gpios = <0>, <0>, <&porta 1 GPIO_ACTIVE_LOW>,
>>                      <&porta 7 GPIO_ACTIVE_LOW>;
>>           status = "okay";
>>           system-controller@0 {
>>                   compatible = "amd,pensando-elbasr";
>>                   reg = <0>;
>>                   #address-cells = <1>;
>>                   #size-cells = <0>;
>>                   spi-max-frequency = <12000000>;
>>
>>                   rstc: reset-controller {
>>                           compatible = "amd,pensando-elbasr-reset";
>>                           #reset-cells = <1>;
>>                   };
>>           };
>>
>>           system-controller@1 {
>>                   compatible = "amd,pensando-elbasr";
>>                   reg = <1>;
>>                   spi-max-frequency = <12000000>;
>>           };
>>
>>           system-controller@2 {
>>                   compatible = "amd,pensando-elbasr";
>>                   reg = <2>;
>>                   spi-max-frequency = <12000000>;
>>                   interrupt-parent = <&porta>;
>>                   interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
>>           };
>>
>>           system-controller@3 {
>>                   compatible = "amd,pensando-elbasr";
>>                   reg = <3>;
>>                   spi-max-frequency = <12000000>;
>>           };
>> };
> You replied with quite a response of which 90% is unrelated talk about 
> driver. Please be specific. We talk here only about hardware.
> Your last DTS might be the answer, but you never explicitly wrote 
> it... So let's check if I understand it correctly. Only some of elbasr 
> block contain reset control?

Yes, only the elbasr block accessed on CS0 provides reset control.  The 
other 3 blocks don't have any reset control and never will.

> This however does not answer my questions before.... You keep ignoring 
> them. So please answer yes or no: "Are there other sub-devices?"

No

> " and your binding is incomplete?"

No

> and a new question: "Is reset block (amd,pensando-elbasr-reset) 
> re-usable so it will appear in different device (not in 
> amd,pensando-elbasr)?"

No its not re-usable

Regards,
Brad