Re: [PATCHv3 01/10] dt-bindings: omap: add new binding for PRM instances

From: Tero Kristo <t-kristo@ti.com>
To: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org, Tony Lindgren <tony@atomide.com>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Santosh Shilimkar <ssantosh@kernel.org>,
	linux-omap <linux-omap@vger.kernel.org>,
	"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCHv3 01/10] dt-bindings: omap: add new binding for PRM instances
Date: Tue, 3 Sep 2019 11:14:19 +0300	[thread overview]
Message-ID: <7c2c8a4d-d24e-ceec-afc1-04cdc4d5d952@ti.com> (raw)
In-Reply-To: <CAL_Jsq+AJj1bgOQYG=c86A5HC_g2UZph387oVEKZyP4M18kURw@mail.gmail.com>

On 03/09/2019 11:10, Rob Herring wrote:
> On Tue, Sep 3, 2019 at 8:26 AM Tero Kristo <t-kristo@ti.com> wrote:
>>
>> On 02/09/2019 16:39, Rob Herring wrote:
>>> On Fri, Aug 30, 2019 at 03:18:07PM +0300, Tero Kristo wrote:
>>>> Add new binding for OMAP PRM (Power and Reset Manager) instances. Each
>>>> of these will act as a power domain controller and potentially as a reset
>>>> provider.
>>>>
>>>
>>> Converting this to schema would be nice.
>>
>> Do you have documentation about schema somewhere? Basically what I need
>> to do to fix this.
> 
> Documentation/devicetree/writing-schema.md (.rst in -next)
> Documentation/devicetree/bindings/example-schema.yaml
> 
>>>> Signed-off-by: Tero Kristo <t-kristo@ti.com>
>>>> ---
>>>>    .../devicetree/bindings/arm/omap/prm-inst.txt | 31 +++++++++++++++++++
>>>
>>> bindings/reset/
>>
>> I did not put this under reset, because this is basically a
>> multi-purpose function. Reset just happens to be the first functionality
>> it is going to provide. It will be followed by power domain support
>> later on.
>>
>> Any thoughts?
> 
> I prefer that bindings be complete as possible even if driver support
> is not there yet. Adding power domain support may only mean adding
> '#power-domain-cells'.
> 
> The location is fine then.

Yeah, I assume just adding power-domain-cells should be enough. I am not 
too sure before I start trying this out though so did not want to add it 
yet.

> 
>>>>    1 file changed, 31 insertions(+)
>>>>    create mode 100644 Documentation/devicetree/bindings/arm/omap/prm-inst.txt
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/arm/omap/prm-inst.txt b/Documentation/devicetree/bindings/arm/omap/prm-inst.txt
>>>> new file mode 100644
>>>> index 000000000000..7c7527c37734
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/arm/omap/prm-inst.txt
>>>> @@ -0,0 +1,31 @@
>>>> +OMAP PRM instance bindings
>>>> +
>>>> +Power and Reset Manager is an IP block on OMAP family of devices which
>>>> +handle the power domains and their current state, and provide reset
>>>> +handling for the domains and/or separate IP blocks under the power domain
>>>> +hierarchy.
>>>> +
>>>> +Required properties:
>>>> +- compatible:       Must be one of:
>>>> +            "ti,am3-prm-inst"
>>>> +            "ti,am4-prm-inst"
>>>> +            "ti,omap4-prm-inst"
>>>> +            "ti,omap5-prm-inst"
>>>> +            "ti,dra7-prm-inst"
>>>
>>> '-inst' seems a bit redundant.
>>
>> ti,xyz-prm is already reserved by the parent node of all these.
>>
>> The hierarchy is basically like this (omap4 as example):
>>
>> prm: prm@4a306000 {
>>     compatible = "ti,omap4-prm";
>>     ...
>>
>>     prm_dsp: prm@400 {
>>       compatible = "ti,omap4-prm-inst";
>>       ...
>>     };
>>
>>     prm_device: prm@1b00 {
>>       compatible = "ti,omap4-prm-inst";
>>       ...
>>     };
>>
>>     ...
>> };
> 
> Okay. Then you need to state this binding must be a child of PRM. The
> schema would need to take this into account too, so probably best to
> not convert this yet.
> 

Ok thanks, I'll make the necessary updates and post v4.

-Tero
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