RE: [PATCH v3] mfd: ADP5520 Multifunction LCD Backlight and KeypadInput Device Driver

Hennerich, Michael
2009-10-06T14:33:40Z

>From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com]
>On Tue, Oct 06, 2009 at 01:55:45PM +0100, Hennerich, Michael wrote:
>> >From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com]
>
>> >I'm not sure what the association with virtual gpios is? This is
all
>> >separate to gpiolib except in that it would mean that a gpio driver
for
>> >the device would be able to export these interrupts to its clients.
>
>> This is what I meant.
>> So you propose having the MFD Core as well as its subdevs requesting
the
>> ADP5520 IRQ (client->irq) IRQF_SHARED? I think we already excluded us
>> from using this option when we were asked to move to the NEW threaded
>> irqs?
>
>No, I'm suggesting implementing an IRQ controller driver for the device
>- register an irq_chip for the interrupt controller on it. Support for
>doing this on I2C devices was added at pretty much the same time as the
>IRQ_ONESHOT support. This gives access to all the genirq infrastrure
>features rather than having to implement a custom IRQ handling stack.
>
>Like I say, I'm not sure what you meant when you were talking about
>virtual gpios.

This is not an interrupt controller.
The only ADP5520 subdev that needs to be notified is the adp5520-keys
input driver, if present.
Sounds like overshoot, registering a irq_chip using
set_irq_chip_and_handler() and friends, for exactly one dedicated and
known consumer.

-Michael