[PATCH v13 1/3] dt-bindings: soc: sophgo: add RTC support for Sophgo CV1800 series

[Alexander Sverdlin <alexander.sverdlin@gmail.com>]

From: Jingbao Qiu <qiujingbao.dlmu@gmail.com>

Add RTC devicetree binding for Sophgo CV1800 series SoC. The device is
called RTC, but contains control registers of other HW blocks in its
address space, most notably of Power-on-Reset (PoR) module, DW8051 IP
(MCU core), accompanying SRAM, hence putting it in SoC subsystem.

Signed-off-by: Jingbao Qiu <qiujingbao.dlmu@gmail.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
---
Changelog:
v13:
- Moved bindings from MFD into SOC subsystem

v12:
- maintainer Jingbao Qiu <qiujingbao.dlmu@gmail.com> -> sophgo@lists.linux.dev
- dropped Reviewed-by: Krzysztof Kozlowski
- link to TRM
- mentioned 8051 core in the description
- binding is now MFD, not RTC
- added "syscon" compatible
- added "interrupt-names", "clock-names" (because of added PM/remoteproc)
- main compatible "sophgo,cv1800-rtc" -> "sophgo,cv1800b-rtc"

 .../soc/sophgo/sophgo,cv1800b-rtc.yaml        | 86 +++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/sophgo/sophgo,cv1800b-rtc.yaml

diff --git a/Documentation/devicetree/bindings/soc/sophgo/sophgo,cv1800b-rtc.yaml b/Documentation/devicetree/bindings/soc/sophgo/sophgo,cv1800b-rtc.yaml
new file mode 100644
index 000000000000..5cf186c396c9
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/sophgo/sophgo,cv1800b-rtc.yaml
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sophgo/sophgo,cv1800b-rtc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Real Time Clock of the Sophgo CV1800 SoC
+
+description:
+  The RTC (Real Time Clock) is an independently powered module in the chip. It
+  contains a 32KHz oscillator and a Power-On-Reset (POR) sub-module, which can
+  be used for time display and scheduled alarm produce. In addition, the
+  hardware state machine provides triggering and timing control for chip
+  power-on, power-off and reset.
+
+  Furthermore, the 8051 subsystem is located within RTCSYS and is independently
+  powered. System software can use the 8051 to manage wake conditions and wake
+  the system while the system is asleep, and communicate with external devices
+  through peripheral controllers.
+
+  Technical Reference Manual available at
+    https://github.com/sophgo/sophgo-doc/tree/main/SG200X/TRM
+
+maintainers:
+  - sophgo@lists.linux.dev
+
+allOf:
+  - $ref: /schemas/rtc/rtc.yaml#
+
+properties:
+  compatible:
+    items:
+      - const: sophgo,cv1800b-rtc
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    items:
+      - description: RTC Alarm
+      - description: RTC Longpress
+      - description: VBAT DET
+
+  interrupt-names:
+    items:
+      - const: alarm
+      - const: longpress
+      - const: vbat
+
+  clocks:
+    items:
+      - description: RTC clock source
+      - description: DW8051 MCU clock source
+
+  clock-names:
+    items:
+      - const: rtc
+      - const: mcu
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-names
+  - clocks
+  - clock-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/sophgo,cv1800.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    rtc@5025000 {
+        compatible = "sophgo,cv1800b-rtc", "syscon";
+        reg = <0x5025000 0x2000>;
+        interrupts = <17 IRQ_TYPE_LEVEL_HIGH>,
+                     <18 IRQ_TYPE_LEVEL_HIGH>,
+                     <19 IRQ_TYPE_LEVEL_HIGH>;
+        interrupt-names = "alarm", "longpress", "vbat";
+        clocks = <&clk CLK_RTC_25M>,
+                 <&clk CLK_SRC_RTC_SYS_0>;
+        clock-names = "rtc", "mcu";
+    };
-- 
2.48.1