Re: [PATCH v3 1/2] Documentation: DT: FTM: add FTM0 be used as alarm timer

From: Stuart Yoder
Date: Thu Aug 13 2015 - 12:23:20 EST


On Tue, Aug 11, 2015 at 11:01 PM, Dongsheng Wang
<dongsheng.wang@xxxxxxxxxxxxx> wrote:
> From: Wang Dongsheng <dongsheng.wang@xxxxxxxxxxxxx>
>
> In freescale layerscape platform there is only FTM0 can be used as
> alarm timer to wake up system. So add FTM0 description for devicetree
> document.

Suggestion:

In the Freescale Layerscape platform a flextimer module can be used
as an alarm timer to wake up the system. Define a binding for this
alarm.

> Signed-off-by: Wang Dongsheng <dongsheng.wang@xxxxxxxxxxxxx>
> ---
> V3:
> Include this patch in V3.
>
> diff --git a/Documentation/devicetree/bindings/timer/fsl,ftm-timer.txt b/Documentation/devicetree/bindings/timer/fsl,ftm-timer.txt
> index aa8c402..380a0b3d 100644
> --- a/Documentation/devicetree/bindings/timer/fsl,ftm-timer.txt
> +++ b/Documentation/devicetree/bindings/timer/fsl,ftm-timer.txt
> @@ -1,5 +1,7 @@
> Freescale FlexTimer Module (FTM) Timer
>
> +* Default FTM Timer
> +
> Required properties:
>
> - compatible : should be "fsl,ftm-timer"
> @@ -29,3 +31,26 @@ ftm: ftm@400b8000 {
> <&clks VF610_CLK_FTM3_EXT_FIX_EN>;
> big-endian;
> };
> +
> +* FTM Alarm Timer
> + The default FTM device contains eight FlexTimer modules. FlexTimer1 is in
> + on-domain(power is not switched off in deep sleep mode). Other seven FlexTimer
> + modules(flextimer2/3/4/5/6/7/8) are in off-domain (power is switched off in
> + deep sleep mode).

Suggestion:

This binding describes a Flextimer (FTM) instance that can be used as an alarm
to wake up a system in deep sleep. The flextimer module with alarm
support is in a power domain that remains awake when the SoC is in
deep sleep mode.

(don't use flextimer1 in the binding...for all you know in the next SoC it
will be flextimer7 that has this capability)

> +Required properties:
> +
> +- compatible : should be "fsl,ftm-alarm".
> +- reg : should contain base address and length of FTM timer 0 register.

"should contain the address and size of the FTM alarm module registers"

(don't use the number 0)

> +- interrupts : Should contain FTM 0 interrupt.

"describes the FTM alarm interrupt"

> +- big-endian: One boolean property, the big endian mode will be in use if it is
> + present, or the little endian mode will be in use for all the device registers.
> +
> +Example:
> +ftm0: ftm0@29d0000 {
> + compatible = "fsl,ftm-alarm";
> + reg = <0x0 0x29d0000 0x0 0x10000>;
> + interrupts = <GIC_SPI 118 IRQ_TYPE_LEVEL_HIGH>;
> + big-endian;
> + status = "disabled";
> +};

Drop the number 0 from the names in your example.

Thanks,
Stuart
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