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From: Chen Minqiang <ptpt52@gmail.com>
To: Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno
	<angelogioacchino.delregno@collabora.com>,
	"Chester A. Unal" <chester.a.unal@arinc9.com>,
	Daniel Golle <daniel@makrotopia.org>,
	DENG Qingfang <dqfext@gmail.com>,
	Sean Wang <sean.wang@mediatek.com>, Andrew Lunn <andrew@lunn.ch>
Cc: linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org, netdev@vger.kernel.org,
	Chen Minqiang <ptpt52@gmail.com>
Subject: [PATCH] ARM64: dts: mediatek: fix MT7531 reset polarity and reset sequence
Date: Fri, 21 Nov 2025 00:22:24 +0800	[thread overview]
Message-ID: <20251120162225.13993-1-ptpt52@gmail.com> (raw)

The MT7531 reset pin is active-low, but multiple MediaTek boards describe
the reset-gpios property without GPIO_ACTIVE_LOW or incorrectly mark it
as active-high. With an active-low GPIO, gpiod_set_value(1) drives the
line low (assert reset) and gpiod_set_value(0) drives it high (deassert).

Update all affected DTS files to explicitly use GPIO_ACTIVE_LOW so that
the reset polarity matches the hardware design.

Additionally, adjust the mt7530 driver reset sequence to correctly assert
reset by driving the GPIO low first, wait for the reset interval, and
then deassert reset by driving the GPIO high.

Boards fixed:
 - mt7622-bananapi-bpi-r64
 - mt7622-rfb1
 - mt7986a-bananapi-bpi-r3
 - mt7986a-rfb
 - mt7986b-rfb

This ensures the MT7531 receives a proper low-to-high active-low reset
pulse and initializes reliably.

Signed-off-by: Chen Minqiang <ptpt52@gmail.com>
---
 arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts | 2 +-
 arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts             | 2 +-
 arch/arm64/boot/dts/mediatek/mt7986a-bananapi-bpi-r3.dts | 2 +-
 arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts             | 2 +-
 arch/arm64/boot/dts/mediatek/mt7986b-rfb.dts             | 2 +-
 drivers/net/dsa/mt7530.c                                 | 4 ++--
 6 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts b/arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts
index 9f100b18a676..6f29ce828fdb 100644
--- a/arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts
@@ -155,7 +155,7 @@
 			interrupt-controller;
 			#interrupt-cells = <1>;
 			interrupts-extended = <&pio 53 IRQ_TYPE_LEVEL_HIGH>;
-			reset-gpios = <&pio 54 0>;
+			reset-gpios = <&pio 54 GPIO_ACTIVE_LOW>;
 
 			ports {
 				#address-cells = <1>;
diff --git a/arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts b/arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts
index 8c3e2e2578bc..6600f06ccebf 100644
--- a/arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts
@@ -137,7 +137,7 @@
 		switch@0 {
 			compatible = "mediatek,mt7531";
 			reg = <0>;
-			reset-gpios = <&pio 54 0>;
+			reset-gpios = <&pio 54 GPIO_ACTIVE_LOW>;
 
 			ports {
 				#address-cells = <1>;
diff --git a/arch/arm64/boot/dts/mediatek/mt7986a-bananapi-bpi-r3.dts b/arch/arm64/boot/dts/mediatek/mt7986a-bananapi-bpi-r3.dts
index e7654dc9a1c9..8ec2ec78ee46 100644
--- a/arch/arm64/boot/dts/mediatek/mt7986a-bananapi-bpi-r3.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7986a-bananapi-bpi-r3.dts
@@ -203,7 +203,7 @@
 		interrupt-parent = <&pio>;
 		interrupts = <66 IRQ_TYPE_LEVEL_HIGH>;
 		#interrupt-cells = <1>;
-		reset-gpios = <&pio 5 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&pio 5 GPIO_ACTIVE_LOW>;
 	};
 };
 
diff --git a/arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts b/arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts
index 5d8e3d3f6c20..732dc4f5244f 100644
--- a/arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts
@@ -87,7 +87,7 @@
 	switch: switch@0 {
 		compatible = "mediatek,mt7531";
 		reg = <31>;
-		reset-gpios = <&pio 5 0>;
+		reset-gpios = <&pio 5 GPIO_ACTIVE_LOW>;
 	};
 };
 
diff --git a/arch/arm64/boot/dts/mediatek/mt7986b-rfb.dts b/arch/arm64/boot/dts/mediatek/mt7986b-rfb.dts
index 58f77d932429..91809cdb4499 100644
--- a/arch/arm64/boot/dts/mediatek/mt7986b-rfb.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7986b-rfb.dts
@@ -64,7 +64,7 @@
 		switch@0 {
 			compatible = "mediatek,mt7531";
 			reg = <31>;
-			reset-gpios = <&pio 5 0>;
+			reset-gpios = <&pio 5 GPIO_ACTIVE_LOW>;
 
 			ports {
 				#address-cells = <1>;
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 548b85befbf4..e4caedc3eee5 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2405,9 +2405,9 @@ mt7530_setup(struct dsa_switch *ds)
 		usleep_range(5000, 5100);
 		reset_control_deassert(priv->rstc);
 	} else {
-		gpiod_set_value_cansleep(priv->reset, 0);
-		usleep_range(5000, 5100);
 		gpiod_set_value_cansleep(priv->reset, 1);
+		usleep_range(5000, 5100);
+		gpiod_set_value_cansleep(priv->reset, 0);
 	}
 
 	/* Waiting for MT7530 got to stable */
-- 
2.17.1



             reply	other threads:[~2025-11-20 16:23 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-11-20 16:22 Chen Minqiang [this message]
2025-11-20 16:45 ` [PATCH] ARM64: dts: mediatek: fix MT7531 reset polarity and reset sequence Jakub Kicinski
2025-11-20 21:09 ` Andrew Lunn

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