[PATCHv3 2/8] mailbox/omap: add support for parsing dt devices

[Kumar Gala]

On Aug 7, 2013, at 3:08 PM, Suman Anna wrote:

> On 08/07/2013 12:41 PM, Kumar Gala wrote:
>> 
>> On Aug 7, 2013, at 11:59 AM, Suman Anna wrote:
>> 
>>> Kumar,
>>> 
>>>>> Logic has been added to the OMAP2+ mailbox code to
>>>>> parse the mailbox dt nodes and construct the different
>>>>> mailboxes associated with the instance. The design is
>>>>> based on gathering the same information that was being
>>>>> passed previously through the platform data, except for
>>>>> the interrupt type configuration information.
>>>>> 
>>>>> Signed-off-by: Suman Anna <s-anna at ti.com>
>>>>> ---
>>>>> .../devicetree/bindings/mailbox/omap-mailbox.txt   |  43 +++++++
>>>>> drivers/mailbox/mailbox-omap2.c                    | 130 ++++++++++++++++++---
>>>>> 2 files changed, 158 insertions(+), 15 deletions(-)
>>>>> create mode 100644 Documentation/devicetree/bindings/mailbox/omap-mailbox.txt
>>>>> 
>>>>> diff --git a/Documentation/devicetree/bindings/mailbox/omap-mailbox.txt b/Documentation/devicetree/bindings/mailbox/omap-mailbox.txt
>>>>> new file mode 100644
>>>>> index 0000000..8ffb08a
>>>>> --- /dev/null
>>>>> +++ b/Documentation/devicetree/bindings/mailbox/omap-mailbox.txt
>>>>> @@ -0,0 +1,43 @@
>>>>> +OMAP2+ Mailbox Driver
>>>>> +
>>>>> +Required properties:
>>>>> +- compatible:		Should be one of the following,
>>>>> +			    "ti,omap2-mailbox" for
>>>>> +				OMAP2420, OMAP2430, OMAP3430, OMAP3630 SoCs
>>>>> +			    "ti,omap4-mailbox" for
>>>>> +				OMAP44xx, OMAP54xx, AM33xx, AM43xx, DRA7xx SoCs
>>>>> +- reg:			Contains the mailbox register address range (base address
>>>>> +			and length)
>>>>> +- interrupts: 		Contains the interrupt information for the mailbox
>>>>> +			device. The format is dependent on which interrupt
>>>>> +			controller the OMAP device uses
>>>>> +- ti,hwmods:		Name of the hwmod associated with the mailbox
>>>>> +- ti,mbox-num-users:	Number of targets (processor devices) that the mailbox device
>>>>> +			can interrupt
>>>>> +- ti,mbox-num-fifos:	Number of h/w fifos within the mailbox device
>>>> 
>>>> Isn't "ti,mbox-num-users", "ti,mbox-num-fifos" this SoC specific, why do we need to encode in the device tree.  Can we not have a more SoC specific compatiable and encode such info in the driver as part of the .data field in of_device_id ?
>>> 
>>> They are IP design parameters for the number of h/w fifos and interrupts
>>> coming out of the IP block, with the functionality identical. This
>>> information could not be read from any registers. Until OMAP5, we always
>>> had a single IP in the SoC and so these could been encoded in the
>>> driver. But in DRA7xx, a new SoC, we have 13 mailboxes which have
>>> differing number of these properties even though the functional IP block
>>> is same.
>> 
>> Ah, I see.  Since you've got examples of the same IP with different design params in a given SoC than this makes sense.
>> 
>> Is that true of ti,mbox-num-users?
> 
> Yes, it is true of both "ti,mbox-num-users" and "ti,mbox-num-fifos".

So I think it would be good to update the binding to convey that SoCs might have multiple mbox units w/different design pararms (maybe a short blurb as part of the intro).

- k

--
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