Re: [PATCH v2 3/3] firmware: scpi: add device power domain support using genpd

[Kevin Hilman]

"Jon Medhurst (Tixy)" <tixy@xxxxxxxxxx> writes:

> On Thu, 2016-06-16 at 18:59 +0100, Sudeep Holla wrote:
>> 
>> On 16/06/16 18:47, Jon Medhurst (Tixy) wrote:
>> > On Thu, 2016-06-16 at 11:38 +0100, Sudeep Holla wrote:
>> > [...]
>> >> +enum scpi_power_domain_state {
>> >> +	SCPI_PD_STATE_ON = 0,
>> >> +	SCPI_PD_STATE_OFF = 3,
>> >> +};
>> >
>> > The SCPI doc defines the meaning of these numbers (0 and 3) in the 'Juno
>> > specifics' chapter. So does these values need to come from device-tree
>> > to allow for other hardware or SCP implementations?
>> >
>> 
>> Ah unfortunately true :(. I had not noticed that. But I would like to
>> check if this can be made as part of the standard protocol. Adding such
>> details to DT seems overkill and defeat of the whole purpose of the
>> standard protocol.
>
> Well. it seems to me the 'standard protocol' is whatever the current
> implementation of ARM's closed source SCP firmware is. It also seems to
> me that people are making things up as they go along, without a clue as
> to how to make things generic, robust and future proof. Basically,
> Status Normal ARM Fucked Up.

Fully agree here.  Just because ARM calls it a "standard" does not make
it so.  As we've already seen[1], vendors are using initial/older/whatever
versions of SCPI, so pushing the Juno version as standard just becuase
it's in ARM's closed firmware is not the right way forward either.

Kevin

[1] http://marc.info/?l=linux-arm-kernel&m=146425562931515&w=2