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

Hennerich, Michael
2009-10-07T08:51:28Z

>From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com]
>On Tue, Oct 06, 2009 at 04:05:45PM +0100, Hennerich, Michael wrote:
>> >From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com]
>
>> >According to the datasheet the GPIOs, light sensor and regulator can
>> >also generate interrupts?
>
>> Right - I know - but none of the subdevs are currently using this
>> functionality.
>
>You weren't very clear on the difference between the current state of
>the drivers and the capabilities of the chip there.

As you said there are chip internal interrupt sources for I/Os, keypad
presses and releases, ambient light sensor comparator states, and
overvoltage conditions.
The current state of the driver uses only interrupts for the keypad.
I think you agree that its common practice to only implement
functionality for chip features that are typically used.
There are exactly 8 GP signals which are muxed with Keypad and GPIO. In
case you use a 4x4 Keypad there is no GPIO left.
In case you use a 3x4 Keypad there is exactly 1 GPIO that can be exposed
to the gpiolib.

In one of your earlier posts you mentioned: "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."

Can you point me to what exactly was added to support this on I2C/SPI
devices?

-Michael