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From: FUKAUMI Naoki <naoki@radxa.com>
To: heiko@sntech.de
Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org,
	dsimic@manjaro.org, devicetree@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	FUKAUMI Naoki <naoki@radxa.com>
Subject: [PATCH v6 2/7] arm64: dts: rockchip: Use a longer PWM period for the fan on Radxa ROCK 5C
Date: Mon, 23 Dec 2024 01:39:21 +0000	[thread overview]
Message-ID: <20241223013926.1134-3-naoki@radxa.com> (raw)
In-Reply-To: <20241223013926.1134-1-naoki@radxa.com>

The fan on Radxa ROCK 5C is driven via an AO3416 MOSFET, which has a
total switch-on time of 0,6us and a total switch-off time of 6us [1],
meaning that the current PWM period of just 10us is too short for
fine-grained fan speed control. Increase the PWM period to 60us, so
that the switch-on and switch-off time of the MOSFET fall within a
more reasonable ~10% of the full period, thus making lower PWM duty
cycles meaningful.

[1] https://www.aosmd.com/pdfs/datasheet/AO3416.pdf

Fixes: 3ddf5cdb77e6 ("arm64: dts: rockchip: add Radxa ROCK 5C")
Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
---
Changes in v6:
- none
Changes in v5:
- Reword commit message (Alexey Charkov)
Changes in v4:
- none
Changes in v3:
- none
Changes in v2:
- Reword commit message
---
 arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts b/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
index 23e9b447b6f0..910ec67bd4eb 100644
--- a/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
@@ -73,7 +73,7 @@ fan {
 		#cooling-cells = <2>;
 		cooling-levels = <0 64 128 192 255>;
 		fan-supply = <&vcc_5v0>;
-		pwms = <&pwm3 0 10000 0>;
+		pwms = <&pwm3 0 60000 0>;
 	};
 
 	pcie2x1l2_3v3: regulator-pcie2x1l2-3v3 {
-- 
2.43.0


_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip

WARNING: multiple messages have this Message-ID (diff)
From: FUKAUMI Naoki <naoki@radxa.com>
To: heiko@sntech.de
Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org,
	dsimic@manjaro.org, devicetree@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	FUKAUMI Naoki <naoki@radxa.com>
Subject: [PATCH v6 2/7] arm64: dts: rockchip: Use a longer PWM period for the fan on Radxa ROCK 5C
Date: Mon, 23 Dec 2024 01:39:21 +0000	[thread overview]
Message-ID: <20241223013926.1134-3-naoki@radxa.com> (raw)
In-Reply-To: <20241223013926.1134-1-naoki@radxa.com>

The fan on Radxa ROCK 5C is driven via an AO3416 MOSFET, which has a
total switch-on time of 0,6us and a total switch-off time of 6us [1],
meaning that the current PWM period of just 10us is too short for
fine-grained fan speed control. Increase the PWM period to 60us, so
that the switch-on and switch-off time of the MOSFET fall within a
more reasonable ~10% of the full period, thus making lower PWM duty
cycles meaningful.

[1] https://www.aosmd.com/pdfs/datasheet/AO3416.pdf

Fixes: 3ddf5cdb77e6 ("arm64: dts: rockchip: add Radxa ROCK 5C")
Signed-off-by: FUKAUMI Naoki <naoki@radxa.com>
---
Changes in v6:
- none
Changes in v5:
- Reword commit message (Alexey Charkov)
Changes in v4:
- none
Changes in v3:
- none
Changes in v2:
- Reword commit message
---
 arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts b/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
index 23e9b447b6f0..910ec67bd4eb 100644
--- a/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3588s-rock-5c.dts
@@ -73,7 +73,7 @@ fan {
 		#cooling-cells = <2>;
 		cooling-levels = <0 64 128 192 255>;
 		fan-supply = <&vcc_5v0>;
-		pwms = <&pwm3 0 10000 0>;
+		pwms = <&pwm3 0 60000 0>;
 	};
 
 	pcie2x1l2_3v3: regulator-pcie2x1l2-3v3 {
-- 
2.43.0


  parent reply	other threads:[~2024-12-23  1:39 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-23  1:39 [PATCH v6 0/7] arm64: dts: rockchip: Refine dts for Radxa ROCK 5C FUKAUMI Naoki
2024-12-23  1:39 ` FUKAUMI Naoki
2024-12-23  1:39 ` [PATCH v6 1/7] arm64: dts: rockchip: Change the function of the blue LED " FUKAUMI Naoki
2024-12-23  1:39   ` FUKAUMI Naoki
2024-12-23  1:39 ` FUKAUMI Naoki [this message]
2024-12-23  1:39   ` [PATCH v6 2/7] arm64: dts: rockchip: Use a longer PWM period for the fan on " FUKAUMI Naoki
2024-12-23 10:33   ` Dragan Simic
2024-12-23 10:33     ` Dragan Simic
2024-12-23  1:39 ` [PATCH v6 3/7] arm64: dts: rockchip: Remove the RTC and related nodes for " FUKAUMI Naoki
2024-12-23  1:39   ` FUKAUMI Naoki
2024-12-23  1:39 ` [PATCH v6 4/7] arm64: dts: rockchip: Add cd-gpios for sdmmc " FUKAUMI Naoki
2024-12-23  1:39   ` FUKAUMI Naoki
2024-12-23  1:39 ` [PATCH v6 5/7] arm64: dts: rockchip: Fix the properties of the PMIC regulators " FUKAUMI Naoki
2024-12-23  1:39   ` FUKAUMI Naoki
2024-12-23  1:39 ` [PATCH v6 6/7] arm64: dts: rockchip: Trivial changes " FUKAUMI Naoki
2024-12-23  1:39   ` FUKAUMI Naoki
2024-12-23  1:39 ` [PATCH v6 7/7] arm64: dts: rockchip: Sort nodes " FUKAUMI Naoki
2024-12-23  1:39   ` FUKAUMI Naoki
2024-12-27 15:18 ` [PATCH v6 0/7] arm64: dts: rockchip: Refine dts " Rob Herring (Arm)
2024-12-27 15:18   ` Rob Herring (Arm)

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