Re: [RFC PATCH] led: add Cycle LED trigger.

["Gaël PORTAY" <g.portay@overkiz.com>]

On 22/06/2013 21:45, Pavel Machek wrote:
> 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@overkiz.com>
>>> 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 ;)
> You are right. LP5523 seems to do such effects on its own.
>
> But that means that there's good reason to include effects in the
> kernel, and that we should make sure same it has same interface as on
> n900.
>
> (Or invent suitable interface that can work on n900).
> 									Pavel
Hi Pavel,

I'm working on a new version that handle hardware support (like LP5523 
chip).

I will provide an implementation of the cycle trigger for LP5523 driver; 
but I will not be able to test it.

It will extend led class with new callbacks dedicated to cycle trigger.

Gaël