Re: [PATCH 2/2] DT: watchdog: Add ImgTec PDC Watchdog Timer binding documentation

Andrew Bresticker
2014-11-13T04:09:26Z

On Wed, Nov 12, 2014 at 7:18 AM, <Naidu.Tellapati@imgtec.com> wrote:
> From: Naidu Tellapati <Naidu.Tellapati@imgtec.com>
>
> Add the devicetree binding document for ImgTec PDC Watchdog Timer.
>
> Signed-off-by: Jude Abraham <Jude.Abraham@imgtec.com>
> Signed-off-by: Naidu Tellapati <Naidu.Tellapati@imgtec.com>

> diff --git a/Documentation/devicetree/bindings/watchdog/imgpdc-wdt.txt b/Documentation/devicetree/bindings/watchdog/imgpdc-wdt.txt
> new file mode 100644
> index 0000000..2f13896
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/watchdog/imgpdc-wdt.txt
> @@ -0,0 +1,18 @@
> +*ImgTec PowerDown Controller (PDC) Watchdog Timer (WDT)
> +
> +Required properties:
> +- compatible : Should be "img,pistachio-pdc-wdt"

I don't see anything Pistachio-specific about this driver or binding
and it looks like IP revision is probable via the WD_CORE_REV
register, so I think you can drop the "pistachio".

> +- reg : Should contain WDT registers location and length
> +- clock-names: Should contain "wdt"

I believe there are two clocks: the 32kHz watchdog timer operating
clock and the system interface gate clock. Perhaps call them "wdt"
and "sys"?

> +- clocks: phandles to input clocks
> +- interrupts : Should contain WDT interrupt

Not sure the interrupt will really be necessary.

> +Examples:
> +
> +wdt@18102100 {
> + compatible = "img,pistachio-pdc-wdt";
> + reg = <0x18102100 0x20>;

The TRM I have shows the watchdog registers occupying a full 256 bytes.

> + clocks = <&pdc_wdt_clk>;
> + clock-names = "wdt";
> + interrupts = <0 52 IRQ_TYPE_LEVEL_HIGH>;
> +};
> --
> 1.7.0.4
>