Re: [PATCH V2 03/10] Documentation: dt-bindings: firmware: tegra: add bindings of the BPMP

[Joseph Lo <josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>]

Hi Rob,

Thanks for your reviewing.

On 07/12/2016 12:05 AM, Stephen Warren wrote:
> On 07/11/2016 08:22 AM, Rob Herring wrote:
>> On Tue, Jul 05, 2016 at 05:04:24PM +0800, Joseph Lo wrote:
>>> The BPMP is a specific processor in Tegra chip, which is designed for
>>> booting process handling and offloading the power management, clock
>>> management, and reset control tasks from the CPU. The binding document
>>> defines the resources that would be used by the BPMP firmware driver,
>>> which can create the interprocessor communication (IPC) between the CPU
>>> and BPMP.
>
>>> diff --git
>>> a/Documentation/devicetree/bindings/firmware/nvidia,tegra186-bpmp.txt
>>> b/Documentation/devicetree/bindings/firmware/nvidia,tegra186-bpmp.txt
>
>>> +NVIDIA Tegra Boot and Power Management Processor (BPMP)
>>> +
>>> +The BPMP is a specific processor in Tegra chip, which is designed for
>>> +booting process handling and offloading the power management, clock
>>> +management, and reset control tasks from the CPU. The binding document
>>> +defines the resources that would be used by the BPMP firmware driver,
>>> +which can create the interprocessor communication (IPC) between the CPU
>>> +and BPMP.
>>> +
>>> +Required properties:
>>> +- name : Should be bpmp
>>> +- compatible
>>> +    Array of strings
>>> +    One of:
>>> +    - "nvidia,tegra186-bpmp"
>>> +- mboxes : The phandle of mailbox controller and the mailbox specifier.
>>> +- shmem : List of the phandle of the TX and RX shared memory area that
>>> +      the IPC between CPU and BPMP is based on.
>>
>> I think you can use memory-region here.
>
> Isn't memory-region intended for references into the /reserved-memory
> node. If so, that isn't appropriate in this case since this property
> typically points at on-chip SRAM that isn't included in the OS's view of
> "system RAM".
Agree with that.

>
> Or, should /reserved-memory be used even for (e.g. non-DRAM) memory
> regions that aren't represented by the /memory/reg property?
>

For shmem, I follow the same concept of the binding for arm,scpi 
(.../arm/arm,scpi.txt) that is currently using in mainline. Do you think 
that is more appropriate here?


>>> diff --git a/include/dt-bindings/clock/tegra186-clock.h
>>> b/include/dt-bindings/clock/tegra186-clock.h
>
>>> +/** @file */
>>> +
>>> +#ifndef _MACH_T186_CLK_T186_H
>>> +#define _MACH_T186_CLK_T186_H
>>> +
>>> +/**
>>> + * @defgroup clock_ids Clock Identifiers
>>
>> Aren't these doxygen markup? Does that work with docbook? If not,
>> remove.
>
> These headers are part of the BPMP FW release. It's preferable not to
> edit them when incorporating them into the Linux kernel (or any other SW
> stack) to simplify integration of any updated versions of the header, by
> removing the need to edit the file when doing so. Given that, do you
> still object?

How do you think of this, Rob?

Thanks,
-Joseph