[PATCH 1/3] misc: Add crossbar driver

Sricharan R r.sricharan at ti.com
Wed Jul 24 14:43:53 EDT 2013


On Wednesday 24 July 2013 10:17 PM, Nishanth Menon wrote:
> On 07/24/2013 11:38 AM, Santosh Shilimkar wrote:
>> On Wednesday 24 July 2013 12:08 PM, Nishanth Menon wrote: 
>>> That said, maybe a intermediate pinctrl approach might be more pragmatic and less theoretically flexible.
>>> an option might be to "statically allocate" default number of interrupts to a domain - example:
>>> * GIC IRQ 72->78 allotted to UARTs
>>> * pinctrl mapping provided for those but only 6 can be used (rest are marked status="disabled" as default) at any given time (choice of pinctrl option determines GIC interrupt line to use)
>>> * All modules will have a pinctrl definition to have a mapping - to avoid bootloader overriding default cross bar setting in ways un-expected by kernel.
>>>
>>> Does that sound fair trade off?
>> This sounds better. That way we can get all the devices in the DT at least.
>
> Fair enough - if Linus and Tony are still ok with this approach to the problem, seeing a patch series with the effect would be beneficial.
>
 Ok, i will use this idea of certain number interrupts to groups.
Yes on DRA7XX, we have about 160 gic lines and 320 irq crossbar device inputs contending for it.
1:2 and fully arbitrary.  But will we be really exhausting them ?

Regards,
 Sricharan



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