1STM32 Real Time Clock 2 3Required properties: 4- compatible: can be one of the following: 5 - "st,stm32-rtc" for devices compatible with stm32(f4/f7). 6 - "st,stm32h7-rtc" for devices compatible with stm32h7. 7 - "st,stm32mp1-rtc" for devices compatible with stm32mp1. 8- reg: address range of rtc register set. 9- clocks: can use up to two clocks, depending on part used: 10 - "rtc_ck": RTC clock source. 11 - "pclk": RTC APB interface clock. 12 It is not present on stm32(f4/f7). 13 It is required on stm32(h7/mp1). 14- clock-names: must be "rtc_ck" and "pclk". 15 It is required on stm32(h7/mp1). 16- interrupts: rtc alarm interrupt. On stm32mp1, a second interrupt is required 17 for rtc alarm wakeup interrupt. 18- st,syscfg: phandle/offset/mask triplet. The phandle to pwrcfg used to 19 access control register at offset, and change the dbp (Disable Backup 20 Protection) bit represented by the mask, mandatory to disable/enable backup 21 domain (RTC registers) write protection. 22 It is required on stm32(f4/f7/h7). 23 24Optional properties (to override default rtc_ck parent clock on stm32(f4/f7/h7): 25- assigned-clocks: reference to the rtc_ck clock entry. 26- assigned-clock-parents: phandle of the new parent clock of rtc_ck. 27 28Example: 29 30 rtc: rtc@40002800 { 31 compatible = "st,stm32-rtc"; 32 reg = <0x40002800 0x400>; 33 clocks = <&rcc 1 CLK_RTC>; 34 assigned-clocks = <&rcc 1 CLK_RTC>; 35 assigned-clock-parents = <&rcc 1 CLK_LSE>; 36 interrupt-parent = <&exti>; 37 interrupts = <17 1>; 38 st,syscfg = <&pwrcfg 0x00 0x100>; 39 }; 40 41 rtc: rtc@58004000 { 42 compatible = "st,stm32h7-rtc"; 43 reg = <0x58004000 0x400>; 44 clocks = <&rcc RTCAPB_CK>, <&rcc RTC_CK>; 45 clock-names = "pclk", "rtc_ck"; 46 assigned-clocks = <&rcc RTC_CK>; 47 assigned-clock-parents = <&rcc LSE_CK>; 48 interrupt-parent = <&exti>; 49 interrupts = <17 1>; 50 interrupt-names = "alarm"; 51 st,syscfg = <&pwrcfg 0x00 0x100>; 52 }; 53 54 rtc: rtc@5c004000 { 55 compatible = "st,stm32mp1-rtc"; 56 reg = <0x5c004000 0x400>; 57 clocks = <&rcc RTCAPB>, <&rcc RTC>; 58 clock-names = "pclk", "rtc_ck"; 59 interrupts-extended = <&intc GIC_SPI 3 IRQ_TYPE_NONE>, 60 <&exti 19 1>; 61 }; 62