Re: [PATCH RFC 0/3] reset: syscon-reboot: add "reg" property support

["Rafał Miłecki" <zajec5@gmail.com>]

Hi,

On 02.12.2021 18:21, Sebastian Reichel wrote:
> On Fri, Nov 12, 2021 at 04:32:48PM -0600, Rob Herring wrote:
>> On Fri, Nov 12, 2021 at 4:23 PM Rafał Miłecki <zajec5@gmail.com> wrote:
>>>
>>> On 12.11.2021 23:18, Rob Herring wrote:
>>>> On Tue, Nov 2, 2021 at 10:22 AM Rafał Miłecki <zajec5@gmail.com> wrote:
>>>>>
>>>>> From: Rafał Miłecki <rafal@milecki.pl>
>>>>>
>>>>> During my work on MFD binding for Broadcom's TWD block I received
>>>>> comment from Rob saying that "syscon-reboot" should use "reg" property.
>>>>> I'm not sure if my understanding & implementation are correct so I'm
>>>>> sending this RFC.
>>>>>
>>>>> What bothers me is non-standard "reg" property usage. Treating it as a
>>>>> simple (unsigned) integer number means different logic when it comes to
>>>>> ranges.
>>>>
>>>> It shouldn't be. The idea is that 'reg' works like normal. See below.
>>>>
>>>>> Consider this example:
>>>>>
>>>>> timer@400 {
>>>>>           compatible = "simple-mfd", "syscon";
>>>>>           reg = <0x400 0x3c>;
>>>>>           ranges;
>>>>
>>>> ranges = <0 0x400 0x100>; // Just guessing for size
>>>>
>>>>>
>>>>>           #address-cells = <1>;
>>>>>           #size-cells = <1>;
>>>>>
>>>>>           reboot@434 {
>>>>
>>>> reboot@34
>>>>
>>>> Just reading 'reg' is fine, but really, Linux should be either getting
>>>> the translated address or have a function to get the offset from the
>>>> parent base. IOW, it should also work if you just changed 'reg' to
>>>> '<0x434 0x4>'.
>>>
>>> Are you aware of anyone working on support for getting translated
>>> address? Do you recall any efforts on implementing such a helper?
>>
>> All the DT address functions give you translated addresses. It's the
>> latter that doesn't exist that I'm aware of offhand. It's just
>> of_address_to_resource() on the child and parent nodes and then
>> calculate the offset.
> 
> Has a new version beent sent with this change, that I missed?

Not yet, I was sidetracked by pinctrl & OpenWrt stuff.