dt-bindings: watchdog: sunxi: Add compatibles for R329

On existing SoCs, the watchdog has a single clock input: HOSC (OSC24M)
divided by 750.  However, starting with R329, LOSC (OSC32k) is added as
an alternative clock source, with a bit to switch between them.

Since 24 MHz / 750 == 32 kHz, not 32.768 kHz, the hardware adjusts the
cycle counts to keep the timeouts independent of the clock source. This
keeps the programming interface backward-compatible.

Furthermore, the R329 has two watchdogs: one for use by the ARM CPUs
at 0x20000a0, and a second one for use by the DSPs at 0x7020400. The
first of these adds two more new registers, to allow software to
immediately assert the SoC reset signal. Add an additional "-reset"
suffix to signify the presence of this feature.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210902225750.29313-2-samuel@sholland.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml b/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml
index 9aa3c31..877f477 100644 (file)
--- a/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml
@@ -24,6 +24,8 @@ properties:
               - allwinner,sun50i-a100-wdt
               - allwinner,sun50i-h6-wdt
               - allwinner,sun50i-h616-wdt
+              - allwinner,sun50i-r329-wdt
+              - allwinner,sun50i-r329-wdt-reset
           - const: allwinner,sun6i-a31-wdt
       - items:
           - const: allwinner,suniv-f1c100s-wdt
@@ -33,7 +35,18 @@ properties:
     maxItems: 1
 
   clocks:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
+    items:
+      - description: High-frequency oscillator input, divided internally
+      - description: Low-frequency oscillator input, only found on some variants
+
+  clock-names:
+    minItems: 1
+    maxItems: 2
+    items:
+      - const: hosc
+      - const: losc
 
   interrupts:
     maxItems: 1
@@ -44,6 +57,33 @@ required:
   - clocks
   - interrupts
 
+if:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - allwinner,sun50i-r329-wdt
+          - allwinner,sun50i-r329-wdt-reset
+
+then:
+  properties:
+    clocks:
+      minItems: 2
+
+    clock-names:
+      minItems: 2
+
+  required:
+    - clock-names
+
+else:
+  properties:
+    clocks:
+      maxItems: 1
+
+    clock-names:
+      maxItems: 1
+
 unevaluatedProperties: false
 
 examples: