[PATCH v2 1/3] dt-bindings: serial: Add Loongson UART controller

[zhenghaowei]

From: Haowei Zheng <zhenghaowei@xxxxxxxxxxx>

Add Loongson UART controller binding with DT schema format using
json-schema.

Signed-off-by: Haowei Zheng <zhenghaowei@xxxxxxxxxxx>
---
 .../bindings/serial/loongson,ls7a-uart.yaml   | 74 +++++++++++++++++++
 MAINTAINERS                                   |  7 ++
 2 files changed, 81 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/serial/loongson,ls7a-uart.yaml

diff --git a/Documentation/devicetree/bindings/serial/loongson,ls7a-uart.yaml b/Documentation/devicetree/bindings/serial/loongson,ls7a-uart.yaml
new file mode 100644
index 000000000000..22d9cca5569e
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/loongson,ls7a-uart.yaml
@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/loongson,ls7a-uart.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Loongson UART
+
+maintainers:
+  - Haowei Zheng <zhenghaowei@xxxxxxxxxxx>
+
+properties:
+  compatible:
+    const: loongson,ls7a-uart
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  fractional-division:
+    description: Enables fractional-N division. Currently,
+      only LS2K1500 and LS2K2000 support this feature.
+
+  rts-invert:
+    description: Inverts the RTS value in the MCR register.
+      This should be used on Loongson-3 series CPUs, Loongson-2K
+      series CPUs, and Loongson LS7A bridge chips.
+
+  dtr-invert:
+    description: Inverts the DTR value in the MCR register.
+      This should be used on Loongson-3 series CPUs, Loongson-2K
+      series CPUs, and Loongson LS7A bridge chips.
+
+  cts-invert:
+    description: Inverts the CTS value in the MSR register.
+      This should be used on Loongson-2K0500, Loongson-2K1000,
+      and Loongson LS7A bridge chips.
+
+  dsr-invert:
+    description: Inverts the DSR value in the MSR register.
+      This should be used on Loongson-2K0500, Loongson-2K1000,
+      and Loongson LS7A bridge chips.
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+
+allOf:
+  - $ref: serial.yaml
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/clock/loongson,ls2k-clk.h>
+
+    serial@1fe001e0 {
+        compatible = "loongson,ls7a-uart";
+        reg = <0x0 0x1fe001e0 0x0 0x10>;
+        clock-frequency = <100000000>;
+        interrupt-parent = <&liointc>;
+        interrupts = <10 IRQ_TYPE_LEVEL_HIGH>;
+        fractional-division;
+        rts-invert;
+        dtr-invert;
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 8766f3e5e87e..a6306327dba5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13189,6 +13189,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/i2c/loongson,ls2x-i2c.yaml
 F:	drivers/i2c/busses/i2c-ls2x.c
 
+LOONGSON UART DRIVER
+M:	Haowei Zheng <zhenghaowei@xxxxxxxxxxx>
+L:	linux-serial@xxxxxxxxxxxxxxx
+S:	Maintained
+F:	Documentation/devicetree/bindings/serial/loongson,ls7a-uart.yaml
+F:	drivers/tty/serial/8250/8250_loongson.c
+
 LOONGSON-2 SOC SERIES CLOCK DRIVER
 M:	Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
 L:	linux-clk@xxxxxxxxxxxxxxx
-- 
2.43.0