Re: [PATCH v2 3/6] dt-bindings: brcmstb-gpio: document properties for wakeup

From: Brian Norris
Date: Fri May 29 2015 - 20:36:31 EST


On Thu, May 28, 2015 at 07:14:07PM -0700, Gregory Fong wrote:
> Some brcmstb GPIO controllers can be used to wake from suspend, so use the
> de facto standard property 'wakeup-source' to mark the nodes of controllers
> with that capability.
>
> Also document interrupts-extended, which will be used for wakeup handling
> because the interrupt parent for the wake IRQ is different from the regular
> IRQ.
>
> Signed-off-by: Gregory Fong <gregory.0xf0@xxxxxxxxx>
> ---
> New in v2.
>
> .../devicetree/bindings/gpio/brcm,brcmstb-gpio.txt | 26 +++++++++++++++++++++-
> 1 file changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt b/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt
> index 435f1bc..568814f 100644
> --- a/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt
> +++ b/Documentation/devicetree/bindings/gpio/brcm,brcmstb-gpio.txt
> @@ -33,6 +33,12 @@ Optional properties:
> - interrupt-parent:
> phandle of the parent interrupt controller
>
> +- interrupts-extended:
> + Alternate form of specifying interrupts and parents that allows for
> + multiple parents. This takes precedence over 'interrupts' and
> + 'interrupt-parent'. This probably must be used if the wakeup-source
> + property is provided because that may have a different interrupt parent.
> +

"This probably must be used" seems a little awkward, especially when
you're just explaining an implementation detail of our SoCs, rather than
something unique about this binding. Maybe:

"Wakeup-capable GPIO controllers often route their wakeup interrupt
lines through a different interrupt controller than the primary
interrupt line, making this property necessary."

> - #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.

> +
> +- wakeup-source:
> + GPIOs for this controller can be used as a wakeup source
>
> Example:
> upg_gio: gpio@f040a700 {
> @@ -63,3 +72,18 @@ Example:
> interrupt-names = "upg_gio";
> brcm,gpio-bank-widths = <0x20 0x20 0x20 0x18>;
> };
> +
> + upg_gio_aon: gpio@f04172c0 {
> + #gpio-cells = <0x2>;
> + #interrupt-cells = <0x2>;

Might use decimal instead of hex for the above 2 lines?

> + compatible = "brcm,bcm7445-gpio", "brcm,brcmstb-gpio";
> + gpio-controller;
> + interrupt-controller;
> + reg = <0xf04172c0 0x40>;
> + interrupt-parent = <0xc>;

That should be a phandle, not an int (I realize phandles resolve down to
an integer, but we're speaking DTS, not DTB).

> + interrupts = <0x6>;
> + interrupts-extended = <0xc 0x6 0xa 0x5>;

Same here (phandles).

Also, even though the interrupt binding semantics specify precedence
between interrupts and interrupts-extended, I'd think an example should
stick to one or the other, no?

> + interrupt-names = "upg_gio_aon", "upg_gio_aon_wakeup";
> + wakeup-source;
> + brcm,gpio-bank-widths = <0x12 0x4>;
> + };

Reviewed-by: Brian Norris <computersforpeace@xxxxxxxxx>
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