On 7/15/24 23:12, Alexandre Belloni wrote:

Hello,

On 11/07/2024 16:08:39+0200, Valentin Caron wrote:

quoted

This series adds a pinctrl/pinmux interface to control STM32 RTC outputs.

Theses two signals output are possible:
  - LSCO (Low Speed Clock Output) that allow to output LSE clock on a pin.
    On STM32MPU Discovery boards, this feature is used to generate a clock
    to Wifi/Bluetooth module.
  - Alarm out that allow to send a pulse on a pin when alarm A of the RTC
    expires.

First attempt [1] was based on 'st,' vendor properties, this one is based
on pinctrl and pinmux framework.

As device-trees will be upstreamed separately, here is an example:

stm32-pinctrl {
     rtc_rsvd_pins_a: rtc-rsvd-0 {
         pins {
             pinmux = <STM32_PINMUX('B', 2, AF1)>, /* OUT2 */
                      <STM32_PINMUX('I', 8, ANALOG)>; /* OUT2_RMP */
         };
     };
};

stm32-rtc {
     pinctrl-0 = <&rtc_rsvd_pins_a &rtc_alarma_pins_a>;

     /* Enable by foo-device */
     rtc_lsco_pins_a: rtc-lsco-0 {
         pins = "out2_rmp";
         function = "lsco";
     };

     /* Enable by stm32-rtc hog */
     rtc_alarma_pins_a: rtc-alarma-0 {
         pins = "out2";
         function = "alarm-a";
     };
};

foo-device {
     pinctrl-0 = <&rtc_lsco_pins_a>;
};

This all seems good to me, I let you fix the various issues that have
been reported. I was just wondering whether the LSCO clock was registered
early enough to be used but I guess you tested that.

Hi,

Here it is:
https://lore.kernel.org/lkml/20240717074835.2210411-1valentin.caron@foss.st.com/

Yes it works fine, RTC is probed early enough in the boot sequence, and 
so Wifi/BT module does not have an issue to get the LSCO clock.

Thanks,
Valentin