On Fri, May 29, 2015 at 05:57:50PM -0700, Gregory Fong wrote:

On Fri, May 29, 2015 at 5:36 PM, Brian Norris
[off-list ref] wrote:

quoted

On Thu, May 28, 2015 at 07:14:07PM -0700, Gregory Fong wrote:

quoted

--- a/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt
+++ b/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt

@@ -33,6 +33,12 @@ Optional properties:

...

quoted

quoted

 - #interrupt-cells:
     Should be <2>.  The first cell is the GPIO number, the second should specify
     flags.  The following subset of flags is supported:

@@ -48,7 +54,10 @@ Optional properties:
     Marks the device node as an interrupt controller

 - interrupt-names:
-    The name of the IRQ resource used by this controller
+    The names of the IRQ resources used by this controller

If you're specifying names, you should list them here.

I was wondering about that.  Some bindings have them listed, some
don't.  In this case I know what names currently exist but there could
certainly be different ones in the future.  How does that work?  Or am
I misunderstanding what this field is used for?  Where are the
documented rules for this?

The only documentation I see is:
Documentation/devicetree/bindings/resource-names.txt

That documents the basics of the *-names properties, not their expected
usage.

In practice, they're only useful if you have enough optional resources
that fixed indexing isn't sufficient, and you need to use
platform_get_resource_byname().

So IMO, their purposes seems to be one of these:
(1) functional (e.g., for get_resource_byname(), when you have more than
    one optional resource)
(2) self-documentation (which might run counter to #1, as you begin
    generating too many unique names)
(3) no purpose

So IMO, if you ever want (1), they shouldn't have instance-specific
naming, but should use something generic to the device class. Otherwise,
they are just self-documentation, and aren't functionally useful. So
IMO, these sorts of names:

	interrupt-names = "upg_gio_aon", "upg_gio_aon_wakeup";

work better as functional descriptions:

	interrupt-names = "gio", "wakeup";

But in the end, I wouldn't foresee you needing to do (1), so you're left
with (2) or (3), at which point I'm not sure if you should even mention
the property.

Just my 2 cents (and those cents may not even be worth face value),
Brian