Re: [PATCH] leds-alix2: add support for button connected to J15

[Constantin Baranov <const@mimas.ru>]

On Wed, 21 Oct 2009 22:41:58 +0200 Daniel Mack <daniel@caiaq.de> wrote:
> On Thu, Oct 22, 2009 at 01:21:21AM +0500, Constantin Baranov wrote:
> > I wonder why do you integrate the input driver into the leds driver. They
> > should be separated. Or at least the complex driver should be moved to the
> > "X86 Platform Specific Device Drivers" and renamed to some like "PC Engines
> > ALIX Extras". I personally would prefer the separation way.
> 
> I would as well, yes. And I was of course considerating this when I
> hacked these lines. However, the major part of the LED driver and what
> it currently shares with the button implementation is the BIOS detection
> code which is so ugly that I didn't want to duplicate it ;) That would,
> however, be the only option if you wanted to split the drivers up. Or
> do you have any better idea?

We may introduce new ALIX2 extended platform (module in arch/x86/kernel).
In the init function it shall perform detection. The module shall export
the is_alix2() function which shall be called from init functions of drivers.
Also the cs5535_gpio driver could be reused for gpio access (the previous
patch for leds-alix2 is copy&paste from cs5535_gpio).

> > Also ALIX.2 documentation describes the "Mode switch" driven by GPIO which is a
> > small button on front side of a board. I guessed your driver is not for this
> > button. If so, would it be better to provide the mode switch as KEY_PROG1 and
> > the J15 connected button as KEY_PROG2 at once?
> 
> Correct, the button this code is for is not the one on the 'front' side
> of the PCB. The other one I didn't try yet, but according the the
> CS5536A datasheet, the alternate function for that pin is WORK_AUX which
> can be used for power switching purposes. So that might need some extra
> care probably.

Is there an ALIX board which uses that pin for something but button?
The driver ensures that it works with ALIX, not any CS5536.

Constantin