[RFC 1/2] ACPI: Add support for Platform Communication Channel

[Jassi Brar]

On 30 May 2014 18:58, Ashwin Chaugule <ashwin.chaugule at linaro.org> wrote:
> Hello,
>
> On 30 May 2014 09:03, Jassi Brar <jassisinghbrar at gmail.com> wrote:
>> On Fri, May 30, 2014 at 3:47 PM, Mark Brown <broonie at kernel.org> wrote:
>>> On Tue, May 27, 2014 at 04:29:58PM -0400, Ashwin Chaugule wrote:
>>>> ACPI 5.0a+ spec defines a generic mode of communication
>>>> between the OS and a platform such as the BMC. This medium
>>>> (PCC) is typically used by CPPC (ACPI CPU Performance management),
>>>> RAS (ACPI reliability protocol) and MPST (ACPI Memory power
>>>> states).
>>>>
>>>> This patch adds initial support for PCC to be usable by the
>>>> aforementioned PCC clients.
>>>
>>> This looks an awful lot like a mailbox - should it be integrated with
>>> the mailbox system that Jassi (CCed) has been working on getting
>>> upstream?  Not deleting any context for Jassi's benefit.
>>>
>> Yeah, the mailbox api should support PCC as such, with pcc-test.c as
>> the client above and pcc.c as the controller driver below it.
>
> Interesting. Do you have a git repo with this framework where I could
> have a look?
>
Please scrape it from https://lkml.org/lkml/2014/5/15/49
My platform also uses the doorbell mechanism with request and response
written in shared-memory, so I am confident the mailbox api should
work for PCC.

Regards,
-Jassi