[PATCH V2 3/8] dmaengine: bcm2835: use shared interrupt for channel 11 to 14.

Eric Anholt eric at anholt.net
Wed Feb 17 20:09:23 PST 2016

kernel at martin.sperl.org writes:

> From: Martin Sperl <kernel at martin.sperl.org>
> The bcm2835 dma channel 11 to 14 only have a single shared irq line,
> so this patch implements shared interrupts for these channels.
> To avoid changes to the device tree (with regards to interrupts listed,
> which reflects on pdev->num_resources) a fixed channel count had
> to get used in the code instead.
> With this patch applied we now have 11 dma channels available to
> the ARM side of the SOC.
> Signed-off-by: Martin Sperl <kernel at martin.sperl.org>

Particularly given the existing DT bindings we have, I actually think
this is a good way to go.  This is internal to the hardware module about
how its features map to interrupt lines that leave the hardware module
(which are exposed in DT appropriately).

I thought about "what if we had the last interrupt line hooked up to a
different interrupt handler that read out and decided which channels to
wake up", but this seems much simpler.

Reviewed-by: Eric Anholt <eric at anholt.net>
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