Re: [PATCH 2/3] dt-bindings: rtc: update stm32-rtc documentation for stm32mp1 rtc

From: Rob Herring
Date: Thu Apr 26 2018 - 23:01:48 EST


On Thu, Apr 19, 2018 at 03:34:04PM +0200, Amelie Delaunay wrote:
> RTC embedded in stm32mp1 SoC is slightly different from stm32h7 one, it
> doesn't require to disable backup domain write protection, and rtc_ck
> parent clock assignment isn't allowed.
> To sum up, stm32mp1 RTC requires 2 clocks, pclk and rtc_ck, and an RTC
> alarm interrupt.
>
> Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxx>
> ---
> .../devicetree/bindings/rtc/st,stm32-rtc.txt | 27 +++++++++++++++++-----
> 1 file changed, 21 insertions(+), 6 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt
> index 00f8b5d..f1c2080 100644
> --- a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt
> +++ b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt
> @@ -1,25 +1,31 @@
> STM32 Real Time Clock
>
> Required properties:
> -- compatible: can be either "st,stm32-rtc" or "st,stm32h7-rtc", depending on
> - the device is compatible with stm32(f4/f7) or stm32h7.
> +- compatible: can be "st,stm32-rtc", "st,stm32h7-rtc" or "st,stm32mp1-rtc",
> + depending on the device is compatible with stm32(f4/f7), stm32h7
> + or stm32mp1.

One compatible per line please.

> - reg: address range of rtc register set.
> - clocks: can use up to two clocks, depending on part used:
> - "rtc_ck": RTC clock source.
> - It is required on stm32(f4/f7) and stm32h7.
> + It is required on stm32(f4/f7/h7/mp1).

IOW, required for all?

> - "pclk": RTC APB interface clock.
> It is not present on stm32(f4/f7).
> - It is required on stm32h7.
> + It is required on stm32(h7/mp1).
> - clock-names: must be "rtc_ck" and "pclk".
> - It is required only on stm32h7.
> + It is required on stm32(h7/mp1).
> - interrupt-parent: phandle for the interrupt controller.
> + It is required on stm32(f4/f7/h7).
> - interrupts: rtc alarm interrupt.
> +- interrupts-extended: replace interrupts property on stm32mp1, to specify rtc
> + alarm wakeup interrupt, which is on exti interrupt controller instead of gic.
> + It is required on stm32mp1.

Just document 'interrupts'. interrupts-extended is implicitly supported
and what the interrupts are connected to is outside the scope of this
binding.

> - st,syscfg: phandle/offset/mask triplet. The phandle to pwrcfg used to
> access control register at offset, and change the dbp (Disable Backup
> Protection) bit represented by the mask, mandatory to disable/enable backup
> domain (RTC registers) write protection.
> + It is required on stm32(f4/f7/h7).
>
> -Optional properties (to override default rtc_ck parent clock):
> +Optional properties (to override default rtc_ck parent clock on stm32(f4/f7/h7):
> - assigned-clocks: reference to the rtc_ck clock entry.
> - assigned-clock-parents: phandle of the new parent clock of rtc_ck.
>
> @@ -48,3 +54,12 @@ Example:
> interrupt-names = "alarm";
> st,syscfg = <&pwrcfg 0x00 0x100>;
> };
> +
> + rtc: rtc@5c004000 {
> + compatible = "st,stm32mp1-rtc";
> + reg = <0x5c004000 0x400>;
> + clocks = <&rcc RTCAPB>, <&rcc RTC>;
> + clock-names = "pclk", "rtc_ck";
> + interrupts-extended = <&intc GIC_SPI 3 IRQ_TYPE_NONE>,
> + <&exti 19 1>;
> + };
> --
> 2.7.4
>