Hi Alexandre,

May I have your view regarding these new elements ?

Thank you,
Valentin

On 5/23/22 14:34, Valentin CARON wrote:

Hi Alexandre,

On 5/4/22 22:27, Alexandre Belloni wrote:

quoted

Hello,

On 04/05/2022 15:06:13+0200, Valentin Caron wrote:

quoted

STM32 RTC can pulse some SOC pins when an alarm of RTC expires.

This patch adds property to activate alarm A output. The pulse can
output on three pins RTC_OUT1, RTC_OUT2, RTC_OUT2_RMP
(PC13, PB2, PI8 on stm32mp15) (PC13, PB2, PI1 on stm32mp13).

Signed-off-by: Valentin Caron <redacted>
---
  .../devicetree/bindings/rtc/st,stm32-rtc.yaml | 19 
++++++++++++++++++-
  1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml 

b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml
index 56d46ea35c5d..71e02604e8de 100644

--- a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml
+++ b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.yaml

@@ -59,6 +59,13 @@ properties:

        Refer to <include/dt-bindings/rtc/rtc-stm32.h> for the 
supported values.
        Pinctrl state named "default" may be defined to reserve pin 
for RTC output.
  +  st,alarm:
+    $ref: "/schemas/types.yaml#/definitions/uint32"
+    description: |
+      To select and enable RTC Alarm A output.
+      Refer to <include/dt-bindings/rtc/rtc-stm32.h> for the 
supported values.
+      Pinctrl state named "default" may be defined to reserve pin 
for RTC output.
+
  allOf:
    - if:
        properties:

@@ -75,6 +82,9 @@ allOf:

          st,lsco:
            maxItems: 0
  +        st,alarm:
+          maxItems: 0
+
          clock-names: false
          required:

@@ -95,6 +105,9 @@ allOf:

          st,lsco:
            maxItems: 0
  +        st,alarm:
+          maxItems: 0
+
        required:
          - clock-names
          - st,syscfg

@@ -117,6 +130,9 @@ allOf:

          st,lsco:
            maxItems: 1
  +        st,alarm:
+          maxItems: 1
+
        required:
          - clock-names
  @@ -153,8 +169,9 @@ examples:
        clocks = <&rcc RTCAPB>, <&rcc RTC>;
        clock-names = "pclk", "rtc_ck";
        interrupts = <GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>;
+      st,alarm = <RTC_OUT1>;
        st,lsco = <RTC_OUT2_RMP>;

Shouldn't that be exactly the opposite? You have two pins that can
output different functions. The property should be the pin and the value
the function. I'd go even further and I would say this is actually
pinmuxing.

You're right, if the property is the pin and the value the function, 
this looks like a pinctrl node.
We choose to develop theses functionalities in the reverse order, to 
avoid the complexity of adding
the pinctrl framework to our driver. Moreover, LSCO and AlarmA may 
haven't a peripheral client and
this would probably require to also implement pinctrl hogging.

Is the implementation that we have proposed is acceptable regarding 
theses elements ?

Thank you,
Valentin

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