[PATCH 1/2] arm64: juno: Add APB registers and LEDs using syscon

[Liviu.Dudau@arm.com (Liviu Dudau)]

On Wed, Feb 25, 2015 at 03:00:23PM +0000, Will Deacon wrote:
> On Wed, Feb 25, 2015 at 02:47:56PM +0000, Liviu Dudau wrote:
> > On Wed, Feb 25, 2015 at 01:55:12PM +0000, Will Deacon wrote:
> > > On Wed, Feb 25, 2015 at 12:16:29PM +0000, Linus Walleij wrote:
> > > > This defines the Juno "APB system registers" as a syscon device,
> > > > and all the LEDs controlled by the APB system registers right
> > > > below it using the syscon LEDs driver on top of syscon. Define
> > > > LED0 for heartbeat, LED1 for MMC0 activity and the following
> > > > four LEDs indicating CPU activity using the Linux-specific
> > > > DT bindings for triggers.
> > > > 
> > > > This is the pattern and same drivers as used on the legacy
> > > > platform device trees for the ARM Integrators and the RealView
> > > > PB1176.
> > > 
> > > Stupid question, but where are these LEDs located on the platform? I tried
> > > enabling this, but all it seemed to do was make hackbench slightly slower :)
> > 
> > http://infocenter.arm.com/help/topic/com.arm.doc.ddi0524c/deb1353593789871.html
> > 
> > Section 1.3, look at the left hand side, above the user push buttons.
> 
> Right, so these LEDs are *inside* the case. Is that really something worth
> enabling for defconfig?

Depends on the case :) You might have a nice cutout in the plastic of the VExpress
box, or have your own custom acrylic box.

Maybe Linus can explain to us why he thinks this functionality is useful given
that quite a lot of people tend to use the Juno boards inside the original boxes
for fear of ESD accidents.

Best regards,
Liviu

> 
> Will
> 

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