Re: [RFC PATCH] led: add Cycle LED trigger.
From: Pavel Machek
Date: Sun Jun 23 2013 - 05:53:16 EST
On Sat 2013-06-22 18:43:01, Sebastian Reichel wrote:
> On Sat, Jun 22, 2013 at 01:26:20PM +0200, Pavel Machek wrote:
> > On Tue 2013-06-18 18:24:23, Gaël PORTAY wrote:
> > > Currently, none of available triggers supports playing with the LED brightness
> > > level. The cycle trigger provides a way to define custom brightness cycle.
> > > For example, it is easy to customize the cycle to mock up the rhythm of human
> > > breathing which is a nice cycle to tell the user the system is doing something.
> > >
> > > This trigger is meant to be usable for waiting an event to happen, for example
> > > when the system gets ready. Those cycles may be used to reflect well known
> > > system status (e.g. idle mode, startup...).
> > >
> > > This implementation provides several interfaces:
> > > - to define the cycle itself:
> > > * plot: definition of plot points using plot or rawplot files,
> > > each points defines the brightness level
> > > * interval: constant time interval between each plot point
> > > - to control the cycle:
> > > * repeat: the number of repetition of the whole plot cycle
> > > 0 for an infinite loop
> > > * control: used to control the cycle trigger
> > > + "start"/"stop": to start/stop the cycle
> > > + "reset" to clear the cycle counter and the internal plot point index
> > > + "pause"/"resume" to pause/resume the cycle
> > >
> > > Signed-off-by: Gaël PORTAY <g.portay@xxxxxxxxxxx>
> > I'd say this should go to userspace.... and maybe should handle RGB
> > leds. ... like the one on n900/HTC dream/....
> > Actually, there's probably some daemon in maemo that already does
> > this.
> Actually the n900 has hardware support for this. There's a
> programmable LED driver on the board, which is called LP5523.
> So... I don't think there's a daemon in maemo ;)
Uh. It seems that LP5523 should get gcc support, not kernel
support. It has limited memory, but 3 cores, and seems turing
Not sure what is reasonable interface for that, but I guess subset
that "makes sense" is enough.
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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