dt-bindings: rtc: update stm32-rtc documentation for stm32mp1 rtc

RTC embedded in stm32mp1 SoC is slightly different from stm32h7 one, it
doesn't require to disable backup domain write protection, and rtc_ck
parent clock assignment isn't allowed.
To sum up, stm32mp1 RTC requires 2 clocks, pclk and rtc_ck, and an RTC
alarm interrupt.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Amelie Delaunay 2018-05-17 14:04:25 +02:00 committed by Alexandre Belloni
parent 02b0cc345c
commit 5c4554d62b
1 changed files with 20 additions and 7 deletions

View File

@ -1,25 +1,29 @@
STM32 Real Time Clock
Required properties:
- compatible: can be either "st,stm32-rtc" or "st,stm32h7-rtc", depending on
the device is compatible with stm32(f4/f7) or stm32h7.
- compatible: can be one of the following:
- "st,stm32-rtc" for devices compatible with stm32(f4/f7).
- "st,stm32h7-rtc" for devices compatible with stm32h7.
- "st,stm32mp1-rtc" for devices compatible with stm32mp1.
- reg: address range of rtc register set.
- clocks: can use up to two clocks, depending on part used:
- "rtc_ck": RTC clock source.
It is required on stm32(f4/f7) and stm32h7.
- "pclk": RTC APB interface clock.
It is not present on stm32(f4/f7).
It is required on stm32h7.
It is required on stm32(h7/mp1).
- clock-names: must be "rtc_ck" and "pclk".
It is required only on stm32h7.
It is required on stm32(h7/mp1).
- interrupt-parent: phandle for the interrupt controller.
- interrupts: rtc alarm interrupt.
It is required on stm32(f4/f7/h7).
- interrupts: rtc alarm interrupt. On stm32mp1, a second interrupt is required
for rtc alarm wakeup interrupt.
- st,syscfg: phandle/offset/mask triplet. The phandle to pwrcfg used to
access control register at offset, and change the dbp (Disable Backup
Protection) bit represented by the mask, mandatory to disable/enable backup
domain (RTC registers) write protection.
It is required on stm32(f4/f7/h7).
Optional properties (to override default rtc_ck parent clock):
Optional properties (to override default rtc_ck parent clock on stm32(f4/f7/h7):
- assigned-clocks: reference to the rtc_ck clock entry.
- assigned-clock-parents: phandle of the new parent clock of rtc_ck.
@ -48,3 +52,12 @@ Example:
interrupt-names = "alarm";
st,syscfg = <&pwrcfg 0x00 0x100>;
};
rtc: rtc@5c004000 {
compatible = "st,stm32mp1-rtc";
reg = <0x5c004000 0x400>;
clocks = <&rcc RTCAPB>, <&rcc RTC>;
clock-names = "pclk", "rtc_ck";
interrupts-extended = <&intc GIC_SPI 3 IRQ_TYPE_NONE>,
<&exti 19 1>;
};