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>;
};
[1] https://lore.kernel.org/linux-arm-kernel/20220504130617.331290-5-valentin.caron@xxxxxxxxxxx/t/#m37935e92315e22bbe085775096175afc05b7ff09
Since v1:
- Select PINMUX and PINCONF_GENERIC to solve:
https://lore.kernel.org/oe-kbuild-all/202407130943.ie6n2Orh-lkp@xxxxxxxxx/
- Make stm32_rtc_pinctrl_pins as static to solve:
https://lore.kernel.org/oe-kbuild-all/202407130612.OEicZbNE-lkp@xxxxxxxxx/
- Change "depends on" to "select" COMMON_CLK config
- Modify regex in dt-binding to avoid properties like "rtc--123" as valid ones.
Valentin Caron (4):
dt-bindings: rtc: stm32: describe pinmux nodes
rtc: stm32: add pinctrl and pinmux interfaces
rtc: stm32: add Low Speed Clock Output (LSCO) support
rtc: stm32: add alarm A out feature
.../devicetree/bindings/rtc/st,stm32-rtc.yaml | 28 ++
drivers/rtc/Kconfig | 3 +
drivers/rtc/rtc-stm32.c | 281 ++++++++++++++++++
3 files changed, 312 insertions(+)
--
2.25.1
