Re: [PATCH 01/10] dt/bindings: Add binding for BCM2835 mailbox driver

Stephen Warren
2015-03-04T02:37:17Z

On 03/03/2015 12:28 PM, Eric Anholt wrote:
> Lee Jones <lee-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> writes:
>
>> On Mon, 02 Mar 2015, Eric Anholt wrote:
>>
>>> From: Lubomir Rintel <lkundrak-NGH9Lh4a5iE@public.gmane.org>
>>>
>>> v2: Split into a separate patch for submitting to the
>>> devicetree list.
...
>>> ---

Generally, the changelog should go below the --- since most people
don't want to see the changelog committed into the source.

>>> .../devicetree/bindings/mailbox/brcm,bcm2835-mbox.txt | 19
>>> +++++++++++++++++++ 1 file changed, 19 insertions(+) create
>>> mode 100644
>>> Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox.txt
>>>
>>>
>>>
>>>
diff --git
a/Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox.txt
b/Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox.txt
>>> new file mode 100644 index 0000000..f5741a0 --- /dev/null +++
>>> b/Documentation/devicetree/bindings/mailbox/brcm,bcm2835-mbox.txt
>>
>>
>>>
>>>
Rename these files to conform to the current naming convention. In
>> -next we currently have 'altera-mailbox.txt' and
>> 'omap-mailbox.txt', so 'bcm2835-mbox.txt' seems appropriate.
>
> Will do.

I believe all the current bcm2835 bindings use the compatible value as
the filename. I personally prefer this to picking a different "random"
name for the filenames. It means you only have to name the thing once,
and then use the same value for the compatible property and binding
document.

>>> +Example: + +mailbox: mailbox@7e00b800 { + compatible =
>>> "brcm,bcm2835-mbox"; + reg = <0x7e00b880 0x40>; + interrupts =
>>> <0 1>; + #mbox-cells = <1>; +};
>>
>> It would be good to see the client examples here as well.
>> Please consider pulling in brcm,bcm2835-mbox-power.txt and
>> brcm,bcm2835-mbox-property.txt.
>
> Oh, so have those two just smashed into this file as one set of
> documentation for everything to do with mailbox on bcm2835? That
> seems good to me. When I was adding the client drivers, the fact
> that the other brcm file was named after the compatible string
> made me generate new files under then new compatible strings, but
> the other drivers already in the tree obviously aren't formatted
> that way.

The HW mailbox seems like a different process to the upper-layer
protocols/message formats running over the top of it. Sure right now
the Pi has a single firmware, but do all bcm2835-based devices share
the same firmware? Is so, we'd be warranted in lumping the HW and
firmware protocol together, but I rather wonder whether e.g. the
bcm2835-based Roku uses the same firmware protocol?