Hi Geert,

Thanks for the feedback.

-----Original Message-----
From: Geert Uytterhoeven <geert@linux-m68k.org>
Sent: 05 May 2026 08:32
Subject: Re: [PATCH] dt-bindings: watchdog: renesas,wdt: Document RZ/G3L support

Hi Biju,

On Fri, 6 Feb 2026 at 12:22, Biju [off-list ref] wrote:

quoted

From: Biju Das <biju.das.jz@bp.renesas.com>

Document the support for the watchdog IP available on RZ/G3L SoC. The
watchdog IP available on RZ/G3L SoC is identical to the one found on
RZ/G2L SoC.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>

Thanks for your patch!

quoted

---
a/Documentation/devicetree/bindings/watchdog/renesas,rzg2l-wdt.yaml

+++ b/Documentation/devicetree/bindings/watchdog/renesas,rzg2l-wdt.yam
+++ l

@@ -18,6 +18,7 @@ properties:
               - renesas,r9a07g044-wdt    # RZ/G2{L,LC}
               - renesas,r9a07g054-wdt    # RZ/V2L
               - renesas,r9a08g045-wdt    # RZ/G3S
+              - renesas,r9a08g046-wdt    # RZ/G3L
           - const: renesas,rzg2l-wdt

       - items:

However, there seems to be a small difference in the formulas for the timeout register value on the
various SoCs:

RZ/G2L, RZ/G2UL, and RZ/V2L:

    WDTTIME setting value = \frac{WDT cycle}{(WDTn_CLK (n = 0,1,2) cycle × 1024 × 1024) − 1}

RZ/G3S and RZ/G3E:

    WDTTIME setting value = \frac{WDT cycle}{(WDTn_CLK (n = 0,1,2) cycle × 1024 × 1024} − 1

I.e. on the former, the "- 1" offset is inside the denominator, while on the former, it is outside the
fraction.  I assume this is just a typo in the documentation, and both formulas are supposed to be
identical, so

I agree it is a typo on RZ/G2L, RZ/G2UL, and RZ/V2L hardware manual, I will report this issue to
Documentation team.

as

Watchdog timer cycle = WDTn_CLK (n = 0, 1, 2) cycle × 1024 × 1024 × (WDTTIME setting value + 1)

To get min/max value 43.69/178956.97 msec with 24 MHz mentioned on all DoCs,

WDT min Cycle = 1024 * 1024 * (0 + 1) / (24 * 10^6) = 0.043690 = 43.69 msec
WDT max cycle = 1024 * 1024 * (0xfff + 1) / (24 * 10^6) = 178956.97 msec
	
Cheers,
Biju

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