Re: leds-gpio on x86

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Sat, Aug 08, 2015 at 02:06:56PM +0200, Vincent Pelletier wrote:
> On Fri, 7 Aug 2015 13:57:45 +0300, Mika Westerberg
> <mika.westerberg@linux.intel.com> wrote:
> > Ah, this is different GPIO controller that is listed in the DSDT (the
> > Baytrail GPIO host controller).
> > 
> > In order to get ACPI GPIO stuff work here you would need to first add
> > the GPIO device to the ACPI namespace and then modify gpio-f7188x.c to
> > probe it from there. You would also need to invent a _HID to the device
> > in order to get it matched. Unfortunately using random _HID will make
> > upstreaming the changes difficult.
> 
> I gave a shot at writing a module. I got to the point where it builds
> and loads, but it does not appear to do anything (no error
> returned modprobe, nothing in dmesg).
> 
> I have no idea if the ~4 lines of "actual" code (ie, not just data
> definition) are even in the good direction actually. I took
>   http://www.armadeus.com/wiki/index.php?title=GPIO_LEDS
> as an example. This is for a platform definition for a devboard
> (arm ?), so it may be a wrong example. I took a look at other led
> drivers, and their complexity varies a lot.
> 
> Would you mind taking a look ?
>   https://github.com/vpelletier/linux/commits/ts651

One thing I noticed:

	qnap_tsx51_leds_platform_device = platform_device_register_resndata(NULL, "led-gpio", -1, NULL, 0,
		&qnap_tsx51_led_data, sizeof(qnap_tsx51_led_data));

The driver expects "leds-gpio" not "led-gpio".