Re: [PATCH v3] leds: implement OpenFirmare GPIO LED driver

From: Anton Vorontsov
Date: Thu Jul 17 2008 - 10:05:31 EST


On Wed, Jul 16, 2008 at 10:15:31PM -0600, Grant Likely wrote:
> On Wed, Jul 16, 2008 at 04:18:52PM -0700, Trent Piepho wrote:
> > On Tue, 15 Jul 2008, Anton Vorontsov wrote:
> > > Despite leds-gpio and leds-openfirmware-gpio similar purposes, there
> > > is not much code can be shared between the two drivers (both are mostly
> > > driver bindings anyway).
> >
> > Why can't this driver use the existing gpio-led driver? Basically, do
> > something like this:
> >
> > of_gpio_leds_probe(...)
> > {
> > gpio = of_get_gpio(np, 0);
> > label = of_get_property(np, "label", NULL);
> >
> > struct gpio_led led = {
> > .name = label,
> > .gpio = gpio,
> > };
> >
> > pdev = platform_device_register_simple("leds-gpio", 0, NULL, 0);
> > platform_device_add_data(pdev, &led, sizeof(led));
> > }
>
> Ugh; that means registering *2* 'struct device' with the kernel instead of
> one. One as a platform device and one as an of_platform device.
> It's bad enough that the LED scheme we're using for OF bindings has a
> separate registration for every single LED.
>
> Now that it comes to it, I worry that this driver takes the wrong
> approach. The number of resources dedicated per LED in this driver
> seems pretty loony to me (one of_platform device per LED). The fact
> that the binding specifies one node per LED makes of_platform not a very
> efficient solution.
>
> I think it would be better to have a module that scans the device tree
> for LED nodes and registers a single leds-gpio platform device for the
> whole lot.
>
> Thoughts?

I like the idea, thanks.

--
Anton Vorontsov
email: cbouatmailru@xxxxxxxxx
irc://irc.freenode.net/bd2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/