From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: Marek Vasut <marek.vasut@mailbox.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
linux-renesas-soc@vger.kernel.org,
Magnus Damm <magnus.damm@gmail.com>,
Rob Herring <robh@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
devicetree@vger.kernel.org
Subject: Re: [PATCH] arm64: dts: renesas: sparrow-hawk: don't reserve SWDT
Date: Wed, 22 Oct 2025 09:01:37 +0200 [thread overview]
Message-ID: <aPiBUaTQZcFK8UF_@shikoro> (raw)
In-Reply-To: <0e81437f-a13f-4605-b7f7-6e6640411f30@mailbox.org>
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Hi Marek,
sorry for the late reply. I am on holiday this week with only limited
time for work and net access.
> I think this can be tested on Sparrow Hawk easily , with and without TFA.
> Wolfram, how do I test the SWDT ?
1) enable the node in DT
2) apply the patch "[PATCH] soc: renesas: rcar-rst: keep RESBAR2S in default state"
3) apply the diff attached to this mail (untested but quite sure that's
what i did a few days ago) which allows SWDT to reset
4) access it like any other watchdog. IIRC I did this to enforce a reset
# watchdog -T1 -t3 /dev/watchdog1
(with busybox watchdog)
I think that's it. It uses the same driver as the RWDT, so you probably
have this activated already.
Happy hacking,
Wolfram
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diff --git a/drivers/soc/renesas/rcar-rst.c b/drivers/soc/renesas/rcar-rst.c
index 0541990901fc..a78ea77dba16 100644
--- a/drivers/soc/renesas/rcar-rst.c
+++ b/drivers/soc/renesas/rcar-rst.c
@@ -12,7 +12,7 @@
#define WDTRSTCR_RESET 0xA55A0002
#define WDTRSTCR 0x0054
-#define GEN4_WDTRSTCR_RESET 0xA55A8002
+#define GEN4_WDTRSTCR_RESET 0xA55A8000
#define GEN4_WDTRSTCR 0x0010
#define CR7BAR 0x0070
@@ -117,7 +117,7 @@ static const struct of_device_id rcar_rst_matches[] __initconst = {
/* R-Car Gen4 */
{ .compatible = "renesas,r8a779a0-rst", .data = &rcar_rst_v3u },
{ .compatible = "renesas,r8a779f0-rst", .data = &rcar_rst_gen4 },
- { .compatible = "renesas,r8a779g0-rst", .data = &rcar_rst_gen4 },
+ { .compatible = "renesas,r8a779g0-rst", .data = &rcar_rst_v3u },
{ .compatible = "renesas,r8a779h0-rst", .data = &rcar_rst_gen4 },
{ /* sentinel */ }
};
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next prev parent reply other threads:[~2025-10-22 7:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-17 11:51 [PATCH] arm64: dts: renesas: sparrow-hawk: don't reserve SWDT Wolfram Sang
2025-10-17 11:54 ` Marek Vasut
2025-10-20 13:07 ` Geert Uytterhoeven
2025-10-20 19:48 ` Wolfram Sang
2025-10-21 7:09 ` Geert Uytterhoeven
2025-10-21 13:14 ` Marek Vasut
2025-10-21 13:22 ` Geert Uytterhoeven
2025-10-21 16:07 ` Marek Vasut
2025-10-22 7:01 ` Wolfram Sang [this message]
2025-10-27 10:09 ` Geert Uytterhoeven
2025-10-27 18:21 ` Marek Vasut
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