Re: [PATCH v2 4/9] ARM: dts: add dts files for hi3519-demb board

[xuejiancheng <xuejiancheng@huawei.com>]

On 2015/12/4 18:49, Arnd Bergmann wrote:
> On Friday 04 December 2015 10:27:58 xuejiancheng wrote:
>>>
>>>> +            sysctrl: system-controller@12020000 {
>>>> +                    compatible = "hisilicon,sysctrl";
>>>> +                    reg = <0x12020000 0x1000>;
>>>> +                    reboot-offset = <0x4>;
>>>> +            };
>>>
>>> Is this one identical to the one in hip04?
>>>
>>> If not, pick a new unique compatible string
>>
>> Yes. It's compatible with the one in hip04.
> 
> Ok, we should add a compatible string for that then, as the hip04 apparently
> has a slightly different layout from hip01.
> 
> Can you add a separate patch to clarify the existing hisilicon,sysctrl nodes?
> 
> It look like hi3620 accidentally uses the same string as hip04 already
> but is actually a bit different.
> 
> Maybe split out the sysctrl binding from
> Documentation/devicetree/bindings/arm/hisilicon/hisilicon.txt, as it has
> you already have a couple of those, and it's not clear how they relate
> to one another.
> 
> If we introduce a string for all hip04 compatible sysctrl devices, we should
> document that and use it consistently, so hi3519 becomes
> 
> 	compatible = "hisilicon,hi3519-sysctrl", "hisilicon,hip04-sysctrl", "hisilicon,sysctrl";
> 
> but I'd clarify in the binding documentation that "hisilicon,sysctrl" should
> only be used for hip04 and hi3519 but not the others.
> 
> As this seems to be a standard part, we can also think about making a
> high-level driver for in in drivers/soc rather than relying on the syscon
> driver which we tend to use more for one-off devices with random register
> layouts.
> 
   Sorry. I didn't understand your meaning well and maybe I gave you a wrong description.
Please allow me to clarify it again.
   The "sysctrl" nodes here is just used for the "reboot" function. It is corresponding to
the driver "drivers/power/reset/hisi-reboot.c". The compatible string in the driver is
"hisilicon,sysctrl".
   The layout of this block is also different from the one in HiP04.

>>>> +
>>>> +            crg: crg@12010000 {
>>>> +                    compatible = "hisilicon,hi3519-crg";
>>>
>>>
>>> what is a "crg"? Is there a standard name for these?
>>
>> The "crg" means Clock and Reset Generator. It's a block which supplies clock
>> and reset signals for other modules in the chip. I used "hi3519-clock"
>> in last version patch. Rob Herring suggested that it's better to use "hi3519-crg"
>> as the compatible string if it's a whole block.
>>
>> what about writing like this？
>>
>> crg: clock-reset-controller@12010000 {
>>         compatible = "hisilicon,hi3519-crg";
>>         }
>>
> 
> Ok, that's better.
> 
> 	Arnd
> 
> .
>