Re: [PATCH] leds: gpio: support multi-level brightness

[Akinobu Mita <akinobu.mita@xxxxxxxxx>]

2019年10月6日(日) 13:06 Bjorn Andersson <bjorn@xxxxxxx>:
>
> On Fri, Oct 4, 2019 at 8:35 AM Akinobu Mita <akinobu.mita@xxxxxxxxx> wrote:
> >
> > Currently, GPIO LED driver allows the GPIO properties to contain one GPIO
> > phandle.  This enables to contain more than one GPIO phandle and the
> > brightness of the LEDs is proportional to the number of active GPIOs.
> >
> > Describing multi-level brightness GPIO LED is only supported in DT.  It is
> > not supported in ACPI and platform data.
> >
>
> This looks interesting.
>
> I have a half-baked driver for the NXP PCA9956B; which is a 24-channel
> LED driver, each channel with brightness control. With these LEDs
> mounted in a line (like on my devboard), an interface for setting e.g.
> a percentage and have the appropriate number of LEDs light up seems
> like an interesting thing to pursue.
>
> So I think this would be better represented in some more generic form,
> perhaps a trigger?

I think it's good idea to create a generalized multiple LED driver.
The device consists of multiple LED devices by different drivers and can
be used as a single LED device.  Although there is a lot more work to do
than this LED GPIO enhancement.