Re: [PATCH 2/2] input: Add LED support to Synaptics device

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Mon, Apr 19, 2010 at 12:44:08PM +0200, Takashi Iwai wrote:
> At Fri, 16 Apr 2010 10:00:20 +0200,
> I wrote:
> > 
> > At Thu, 15 Apr 2010 21:12:18 +0200,
> > Pavel Machek wrote:
> > > 
> > > Hi!
> > > 
> > > > The new Synaptics devices have an LED on the top-left corner.
> > > > This is controlled via the command 0x0a with parameters 0x88 or 0x10.
> > > > 
> > > > The detection of the LED isn't clear yet.  It should have been the new
> > > > capability bits that indicate the presence, but on real machines, it
> > > > doesn't fit.  So, for the time being, the driver checks the product id
> > > > in the ext capability bits and assumes that LED exists on the known
> > > > devices.
> > > > 
> > > > The support of LED is controlled via a normal input event with EV_LED
> > > > bit mask.  It supports LED_MUTE bit.  X driver can detect the LED
> > > > support by checking these bits.
> > > 
> > > Could we use generic LED API for this?
> > 
> > Yeah, actually I started implementing with LED ADI at first.
> > 
> > But, then it turned out to be that it's much easier to use the
> > existing LED input bits since this LED is really tightly coupled with
> > the synaptics input device.  An individual LED device makes hard to
> > find out the corresponding input device.
> > 
> > If we assume there is only one synaptics and only one synaptics-LED
> > device, then yes, the situation can be a bit easier, though.
> > 
> > > It is not really 'mute' led after all...
> > 
> > If the problem is the misuse of LED_MUTE bit, how about adding a new
> > LED bit, e.g. LED_TOUCHPAD?
> 
> The revised patch with an addition of LED_TOUCHPAD is below.
> 

Sorry Takashi, but I will not add any new LED types to input. Even
current input LEDs are going to be accessible thought standard LED
framework (even though I have not apploed Samuel's patch yet I do think
it would move kernel in the right direction).

Thanks.

-- 
Dmitry