Re: [PATCH v4 04/14] dt-bindings: rtc: add bindings for microchip mpfs rtc

[Conor.Dooley]

On 19/01/2022 03:12, Rob Herring wrote:
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> 
> On Mon, Jan 17, 2022 at 11:07:45AM +0000, conor.dooley@xxxxxxxxxxxxx wrote:
>> From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>>
>> Add device tree bindings for the real time clock on
>> the Microchip PolarFire SoC.
>>
>> Signed-off-by: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
>> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>> ---
>>   .../bindings/rtc/microchip,mfps-rtc.yaml      | 63 +++++++++++++++++++
>>   1 file changed, 63 insertions(+)
>>   create mode 100644 Documentation/devicetree/bindings/rtc/microchip,mfps-rtc.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/rtc/microchip,mfps-rtc.yaml b/Documentation/devicetree/bindings/rtc/microchip,mfps-rtc.yaml
>> new file mode 100644
>> index 000000000000..d57460cbe5e3
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/rtc/microchip,mfps-rtc.yaml
>> @@ -0,0 +1,63 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/rtc/microchip,mfps-rtc.yaml#
>> +
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Microchip PolarFire Soc (MPFS) RTC Device Tree Bindings
>> +
>> +allOf:
>> +  - $ref: rtc.yaml#
>> +
>> +maintainers:
>> +  - Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
>> +  - Lewis Hanly <lewis.hanly@xxxxxxxxxxxxx>
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - microchip,mpfs-rtc
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  interrupts:
>> +    maxItems: 2
> 
> Need to define what each one is.
Sure.
> 
>> +
>> +  microchip,prescaler:
>> +    description: |
>> +      The prescaler divides the input frequency to create a time-based strobe (typically 1 Hz) for
>> +      the calendar counter. The Alarm and Compare Registers, in conjunction with the calendar
>> +      counter, facilitate time-matched events. To properly operate in Calendar or Binary mode,
>> +      the 26-bit prescaler must be programmed to generate a strobe to the RTC.
>> +    maxItems: 1
>> +    $ref: /schemas/types.yaml#/definitions/uint32
> 
> Can't you calculate this based on the clock input freq?

I mistakenly thought this was set when the bitstream was programmed to 
the FPGA but it is just an APB register & should be calculated. I'll 
drop the property.

> 
>> +
>> +  clocks:
>> +    maxItems: 1
>> +
>> +  clock-names:
>> +    items:
>> +      - const: rtc
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - interrupts
>> +  - clocks
>> +  - clock-names
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/clock/microchip,mpfs-clock.h>
>> +    rtc@20124000 {
>> +        compatible = "microchip,mpfs-rtc";
>> +        reg = <0x20124000 0x1000>;
>> +        clocks = <&clkcfg CLK_RTC>;
>> +        clock-names = "rtc";
>> +        interrupts = <80>, <81>;
>> +    };
>> +...
>> --
>> 2.32.0
>>
>>