Thread (2 messages) 2 messages, 2 authors, 2012-07-27

Re: [DT] API to determine if interrupt is PPI or SPI ?

From: <hidden>
Date: 2012-07-27 20:00:24
Also in: linux-arm-kernel

Possibly related (same subject, not in this thread)

On Fri, Jul 27, 2012 at 01:33:36PM +0100, Rob Herring wrote:
quoted
On 07/26/2012 02:18 PM, rvaswani@codeaurora.org wrote:
quoted
Hello,

We can specify the interrupt information in the device tree using the
arm
quoted
gic convention.
Is there an API to read directly the 1st cell and determine if an
interrupt is a PPI or a SPI ? This information is directly relevant to
the
quoted
driver because it needs to call request_irq or request_percpu_irq
based on
quoted
this data.

How should this be done ideally ?
Seems a bit strange to me that you would have a h/w block that can be
connected either way...
The CPU PMU can be wired as either SPI or PPI. The latter makes more sense
to
me but usually (although not exclusively) it's wired using the former.

Will
We have the same driver for a hardware for different chipsets and
unfortunately the hardware team decided to connect this GIC interrupt
differently across these chipsets. This leaves us with a software choice
to make.
We could add another property to the device tree (like irq-is-percpu,
irq-is-not-percpu), but that seems redundant.
We were hoping to have an API to tell us the SPI/PPI difference since this
information is already encoded in the interrupt-cells in the device tree
for this device.
Would that be the right way to go or there is something better that can be
done ?

Thanks,
Rohit

-- 
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help