Re: [PATCH v2 1/3] dt-bindings: watchdog: sunxi: Add compatible for R329

On 8/18/21 4:07 AM, Maxime Ripard wrote:

Hi,

On Wed, Aug 04, 2021 at 11:57:14PM -0500, Samuel Holland wrote:

quoted

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.

R329 also adds two new registers, to allow software to immediately drive
the SoC reset signal.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---
Changes v1 to v2:
 - Switch from enum to const
 - Add descriptions to "clocks" items

 .../watchdog/allwinner,sun4i-a10-wdt.yaml     | 32 ++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml b/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml
index 9aa3c313c49f..8fa5b0d32381 100644
--- a/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/allwinner,sun4i-a10-wdt.yaml

@@ -24,6 +24,7 @@ properties:
               - allwinner,sun50i-a100-wdt
               - allwinner,sun50i-h6-wdt
               - allwinner,sun50i-h616-wdt
+              - allwinner,sun50i-r329-wdt
           - const: allwinner,sun6i-a31-wdt
       - items:
           - const: allwinner,suniv-f1c100s-wdt

@@ -33,7 +34,18 @@ 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 +56,24 @@ required:
   - clocks
   - interrupts
 
+if:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - allwinner,sun50i-r329-wdt
+
+then:
+  properties:
+    clocks:
+      minItems: 2
+
+    clock-names:
+      minItems: 2
+
+  required:
+    - clock-names
+

We should also make sure through an else clause that all the other SoCs
have a length of one for both clocks and clock-names

Yes, I'll do that for v3.

Also, it looks like you forgot the patch to enable the compatible in the
driver?

R329 has a fallback to A31, so it doesn't need any changes to the driver.

Regards,
Samuel