Thread (15 messages) 15 messages, 3 authors, 2025-09-05

Re: [PATCH v3 1/6] dt-bindings: watchdog: renesas,wdt: Add support for RZ/T2H and RZ/N2H

From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2025-08-18 10:01:12
Also in: linux-renesas-soc, linux-watchdog, lkml

Hi Prabhakar,

On Mon, 4 Aug 2025 at 21:57, Prabhakar [off-list ref] wrote:
From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Extend the Renesas WDT device tree bindings to support the watchdog timer
found on the RZ/T2H (R9A09G077) and RZ/N2H (R9A09G087) SoCs.

The RZ/T2H WDT is mostly compatible with the one found on the RZ/V2H(P),
but includes an additional register and differs in the clock division
ratio settings for the WDTCR[CKS] field. To reflect these differences,
introduce a new compatible string, "renesas,r9a09g077-wdt".

The binding schema is updated accordingly. On RZ/T2H, the WDT does not
require the "resets" property. It also requires two register regions and
the presence of a "power-domains" property. The "clock-names" property is
limited to a single entry, "pclk", for this SoC.

The RZ/N2H SoC uses the same WDT IP as the RZ/T2H. It is supported by
using "renesas,r9a09g087-wdt" as the primary compatible string, with
"renesas,r9a09g077-wdt" listed as a fallback to describe the shared
hardware features.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Thanks for your patch!
quoted hunk ↗ jump to hunk
--- a/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml
+++ b/Documentation/devicetree/bindings/watchdog/renesas,wdt.yaml
@@ -81,10 +81,17 @@ properties:
               - renesas,r9a09g056-wdt # RZ/V2N
           - const: renesas,r9a09g057-wdt # RZ/V2H(P)

-      - const: renesas,r9a09g057-wdt       # RZ/V2H(P)
+      - enum:
+          - renesas,r9a09g057-wdt    # RZ/V2H(P)
+          - renesas,r9a09g077-wdt    # RZ/T2H
+
+      - items:
+          - const: renesas,r9a09g087-wdt # RZ/N2H
+          - const: renesas,r9a09g077-wdt # RZ/T2H

   reg:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
The second register block is just a single register, right?
Showing an (early) example of the device node would make such
details easier to notice...

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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