[PATCH v2 2/3] dt-bindings: rtc: update stm32-rtc documentation for stm32mp1 rtc

From: Amelie Delaunay
Date: Wed May 09 2018 - 11:50:27 EST

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@xxxxxx>
.../devicetree/bindings/rtc/st,stm32-rtc.txt | 27 ++++++++++++++++------
1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt
index 00f8b5d..c920e27 100644
--- a/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt
+++ b/Documentation/devicetree/bindings/rtc/st,stm32-rtc.txt
@@ -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>;
+ };