Re: [PATCH] dt-bindings: rtc: convert at91sam9 bindings to json-schema

[Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>]

On 15/02/2022 15:46, Sergiu Moga wrote:
> Convert RTC binding for Atmel/Microchip SoCs to Device Tree Schema
> format.
> 
> Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
> ---
>  .../bindings/rtc/atmel,at91sam9-rtc.txt       | 25 --------
>  .../bindings/rtc/atmel,at91sam9-rtc.yaml      | 61 +++++++++++++++++++
>  2 files changed, 61 insertions(+), 25 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/rtc/atmel,at91sam9-rtc.txt
>  create mode 100644 Documentation/devicetree/bindings/rtc/atmel,at91sam9-rtc.yaml
> 
> diff --git a/Documentation/devicetree/bindings/rtc/atmel,at91sam9-rtc.txt b/Documentation/devicetree/bindings/rtc/atmel,at91sam9-rtc.txt
> deleted file mode 100644
> index 3f0e2a5950eb..000000000000
> --- a/Documentation/devicetree/bindings/rtc/atmel,at91sam9-rtc.txt
> +++ /dev/null
> @@ -1,25 +0,0 @@
> -Atmel AT91SAM9260 Real Time Timer
> -
> -Required properties:
> -- compatible: should be one of the following:
> -	- "atmel,at91sam9260-rtt"
> -	- "microchip,sam9x60-rtt", "atmel,at91sam9260-rtt"
> -- reg: should encode the memory region of the RTT controller
> -- interrupts: rtt alarm/event interrupt
> -- clocks: should contain the 32 KHz slow clk that will drive the RTT block.
> -- atmel,rtt-rtc-time-reg: should encode the GPBR register used to store
> -	the time base when the RTT is used as an RTC.
> -	The first cell should point to the GPBR node and the second one
> -	encode the offset within the GPBR block (or in other words, the
> -	GPBR register used to store the time base).
> -
> -
> -Example:
> -
> -rtt@fffffd20 {
> -	compatible = "atmel,at91sam9260-rtt";
> -	reg = <0xfffffd20 0x10>;
> -	interrupts = <1 4 7>;
> -	clocks = <&clk32k>;
> -	atmel,rtt-rtc-time-reg = <&gpbr 0x0>;
> -};
> diff --git a/Documentation/devicetree/bindings/rtc/atmel,at91sam9-rtc.yaml b/Documentation/devicetree/bindings/rtc/atmel,at91sam9-rtc.yaml
> new file mode 100644
> index 000000000000..c78a8c1c9314
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/rtc/atmel,at91sam9-rtc.yaml
> @@ -0,0 +1,61 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/rtc/atmel,at91sam9-rtc.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Atmel AT91 RTT Device Tree Bindings
> +
> +allOf:
> +  - $ref: "rtc.yaml#"
> +
> +maintainers:
> +  - Alexandre Belloni <alexandre.belloni@bootlin.com>
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - items:
> +        - const: atmel,at91sam9260-rtt
> +      - items:
> +        - const: microchip,sam9x60-rtt
> +        - const: atmel,at91sam9260-rtt
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  atmel,rtt-rtc-time-reg:
> +    $ref: /schemas/types.yaml#/definitions/uint32-array
> +    description: |
> +      Should encode the GPBR register used to store the time base when the
> +      RTT is used as an RTC. The first cell should point to the GPBR node
> +      and the second one encodes the offset within the GPBR block (or in
> +      other words, the GPBR register used to store the time base).

The first cell points to a phandle, so this does not look like
uint32-array. I think this matches something like syscon. Look for
example at samsung,sysreg:
Documentation/devicetree/bindings/soc/samsung/exynos-usi.yaml

> +    items:
> +      maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +  - clocks
> +  - atmel,rtt-rtc-time-reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    rtt@fffffd20 {

Is it a timer or a clock? If more like a RTC, then the node name should
be "rtc".

rtc.yaml requires this, so it looks like you did not test the bindings
at all?

> +        compatible = "atmel,at91sam9260-rtt";
> +        reg = <0xfffffd20 0x10>;
> +        interrupts = <1 4 7>;
> +        clocks = <&clk32k>;
> +        atmel,rtt-rtc-time-reg = <&gpbr 0x0>;
> +    };


Best regards,
Krzysztof