Re: [PATCHv2 1/4] dt-bindings: mfd: Add Altera Arria10 SR Monitor

[Rob Herring]

On Mon, Oct 31, 2016 at 10:28 AM, Thor Thayer
<tthayer@xxxxxxxxxxxxxxxxxxxxx> wrote:
> Hi Rob,
>
> On 10/31/2016 12:36 AM, Rob Herring wrote:
>>
>> On Thu, Oct 27, 2016 at 03:00:23PM -0500, tthayer@xxxxxxxxxxxxxxxxxxxxx
>> wrote:
>>>
>>> From: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
>>>
>>> Add the Arria10 DevKit System Resource Chip register and state
>>> monitoring module to the MFD.
>>>
>>> Signed-off-by: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
>>> ---
>>> Note: This needs to be applied to the bindings document that
>>> was Acked & Applied but didn't reach the for-next branch.
>>> See https://patchwork.ozlabs.org/patch/629397/
>>> ---
>>> v2  Change compatible string -mon to -monitor for clarity
>>> ---
>>>  Documentation/devicetree/bindings/mfd/altera-a10sr.txt | 9 +++++++++
>>>  1 file changed, 9 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/mfd/altera-a10sr.txt
>>> b/Documentation/devicetree/bindings/mfd/altera-a10sr.txt
>>> index ea151f2..c47be28 100644
>>> --- a/Documentation/devicetree/bindings/mfd/altera-a10sr.txt
>>> +++ b/Documentation/devicetree/bindings/mfd/altera-a10sr.txt
>>> @@ -18,6 +18,7 @@ The A10SR consists of these sub-devices:
>>>  Device                   Description
>>>  ------                   ----------
>>>  a10sr_gpio               GPIO Controller
>>
>>
>> This should be just "gpio" BTW.
>
>
> I reason I preprend a10sr_ is to distinguish this GPIO from the other GPIOs
> when binding to our LEDs (see below). I think the LEDs need a unique node
> name (unless I'm not understanding something).

You are confusing DTS labels and node names. Labels are global and
just convenience for the DTS source only instead of using full paths
(and can be anything you want). The node name is local to the level it
is at.

> A less important reason I use a10sr_gpio on the node name is that I can cat
> the /sys/class/gpio/gpioxxx/label and see that it is associated with the
> a10sr instead of one of our other general GPIOs. Is there a better way to
> distinguish these?

label should come from the label property I think. This is one of the
problems with the GPIO sysfs interface and why it is being replaced
with the char dev interface.

Rob

>
>>
>>> +a10sr_monitor            Register and State Monitoring
>>
>>
>> s/_/-/ or maybe just "monitor". Not really a generic node name to use
>> for this.
>>
>
> The reason I use _ for the node name is that the DTC fails if I reference a
> node name with "-" but works OK for "_". For instance, I get an error if the
> LEDs reference "a10sr-gpio" but "a10sr_gpio" compiles ok.

Again, I'm talking node names. You are talking labels. And yes, DTS
labels can't use '-'.

Rob