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

Mark Brown
2009-10-06T12:37:37Z

On Tue, Oct 06, 2009 at 01:23:52PM +0100, Hennerich, Michael wrote:
> >From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com]

> >This notifier stuff looks an awful lot like an interrupt controller
> >driver. Now that it's possible to implement support for an I2C/SPI
> >driven interrupt controller it'd be good to use that rather than having
> >a custom API if that's possible.

> Honestly this notifier chain is a clean approach and serves its purpose
> here pretty well.
> IMHO it's much more preferable than pretending there is a virtual GPIO
> that doesn't exist and a MFD subdev could request.

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.

> >> + u8 led_on_time;

> >I don't know exactly what the on_time option does but if it controls
> >hardware-implemented blinking there's actually a callback function the

> Yes its hardware controlled blinking. I noticed the leds timer trigger
> driver.
> People can still use it - the downside with the hardware assisted
> blinking is that all LEDs share the same on_time. So I decided against
> using the callback.

Ah, if it affects all LEDs then it isn't suitable for the callback at
all.