2003-07-30 12:12:45

by Ghozlane Toumi

[permalink] [raw]
Subject: Re: PATCH : LEDs - possibly the most pointless kernel subsystemever

Hi,

You wrote:

> On Tue, 2003-07-29 at 14:00, Pavel Machek wrote:
> > Hi!
> >
> > I'd not said this is so pointless... handhelds tend to have "new mail"
led for example.
> > Better question is why it is not integrated with input subsystem
(similar to kbd leds).
>
> I would have thought that leds are output? Why would output devices be
> integrated into the input subsystem?

Perhaps because the input subsystem could/should be renamed to event
subsytem ?

ghoz


2003-07-30 12:28:50

by Philip Graham Willoughby

[permalink] [raw]
Subject: Re: PATCH : LEDs - possibly the most pointless kernel subsystemever

On 2003-07-30 14:06:43 +0000, Ghozlane Toumi wrote:
> > I would have thought that leds are output? Why would output devices be
> > integrated into the input subsystem?
>
> Perhaps because the input subsystem could/should be renamed to event
> subsytem ?

The LED devices I'm using are nothing like any of the devices in the
input subsystem at all -- they don't generate events _ever_ for
instance. /dev/input/event## for a pure LED device would be rather
boring.

IMO it's cleaner to have a LED subsystem and proxy drivers to expose
LEDs provided by other subsystems to the generic interface, rather than
trying to ram everything onto the input subsystem regardless of how well
it fits.

Of course, other opinions may (will) differ ;-).

If you did want to get the LED change events from the LED subsystem
through the input layer, you could add a hook into led_set_real in
leds.c, but since all changes are software triggered I don't really see
the value in that.

Regards,

Philip Willoughby

Systems Programmer, Department of Computing, Imperial College, London, UK
--
echo [email protected] | tr "bizndfohces" "pwgd9ociaku"
Why reinvent the wheel? Because we can make it rounder...

2003-07-30 12:39:23

by Wichert Akkerman

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Subject: Re: PATCH : LEDs - possibly the most pointless kernel subsystemever

Previously Philip Graham Willoughby wrote:
> The LED devices I'm using are nothing like any of the devices in the
> input subsystem at all -- they don't generate events _ever_ for
> instance. /dev/input/event## for a pure LED device would be rather
> boring.

Neither does the PC speaker but it still uses the input subsystem.

Wichert.

--
Wichert Akkerman <[email protected]> It is simple to make things.
http://www.wiggy.net/ It is hard to make things simple.