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

Stuart Yoder b08248 at gmail.com
Thu Aug 13 09:23:11 PDT 2015


On Tue, Aug 11, 2015 at 11:01 PM, Dongsheng Wang
<dongsheng.wang at freescale.com> wrote:
> From: Wang Dongsheng <dongsheng.wang at freescale.com>
>
> 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 at freescale.com>
> ---
> 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 at 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 at 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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