[PATCH v7 1/2] dt-bindings: pwm: dwc: Add eswin compatible and resets property

[dongxuyang@eswincomputing.com]

From: Xuyang Dong <dongxuyang@eswincomputing.com>

EIC7700 use DesignWare IP for PWM controllers. Add ESWIN EIC7700 support
in snps,dw-apb-timers-pwm2.yaml.

The DesignWare PWM includes separate reset signals dedicated to each clock
domain:
The presetn signal resets logic in pclk domain.
The timer_N_resetn signal resets logic in the timer_N_clk domain.
The resets are active-low.

The generic snps,dw-apb-timers-pwm2 binding allows one or two optional
reset lines depending on SoC integration.

On EIC7700, the presetn and timer_N_resetn inputs are physically tied
to a single reset line, therefore exactly one reset is required.

Signed-off-by: Xuyang Dong <dongxuyang@eswincomputing.com>
---
 .../bindings/pwm/snps,dw-apb-timers-pwm2.yaml | 38 +++++++++++++++++--
 1 file changed, 34 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml b/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
index 7523a89a1773..a4b7929f2e05 100644
--- a/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
+++ b/Documentation/devicetree/bindings/pwm/snps,dw-apb-timers-pwm2.yaml
@@ -20,12 +20,11 @@ description:
   instead of having to encode the IP version number in the device tree
   compatible.
 
-allOf:
-  - $ref: pwm.yaml#
-
 properties:
   compatible:
-    const: snps,dw-apb-timers-pwm2
+    enum:
+      - snps,dw-apb-timers-pwm2
+      - eswin,eic7700-pwm
 
   reg:
     maxItems: 1
@@ -43,6 +42,12 @@ properties:
       - const: bus
       - const: timer
 
+  resets:
+    minItems: 1
+    items:
+      - description: Interface bus reset
+      - description: PWM timer logic reset
+
   snps,pwm-number:
     $ref: /schemas/types.yaml#/definitions/uint32
     description: The number of PWM channels configured for this instance
@@ -54,6 +59,22 @@ required:
   - clocks
   - clock-names
 
+allOf:
+  - $ref: pwm.yaml#
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: eswin,eic7700-pwm
+    then:
+      properties:
+        resets:
+          minItems: 1
+          maxItems: 1
+      required:
+        - resets
+
 additionalProperties: false
 
 examples:
@@ -65,3 +86,12 @@ examples:
       clocks = <&bus>, <&timer>;
       clock-names = "bus", "timer";
     };
+  - |
+    pwm@50818000 {
+      compatible = "eswin,eic7700-pwm";
+      reg = <0x50818000 0x4000>;
+      #pwm-cells = <3>;
+      clocks = <&bus>, <&timer>;
+      clock-names = "bus", "timer";
+      resets = <&reset>;
+    };
-- 
2.34.1