[PATCH 1/2] arm64: dts: mediatek: mt7622: set PHY address of MT7531 switch to 0x1f

From: "Arınç ÜNAL via B4 Relay" <devnull+arinc.unal.arinc9.com@kernel.org>
To: Rob Herring <robh+dt@kernel.org>,
	 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	 Conor Dooley <conor+dt@kernel.org>,
	 Matthias Brugger <matthias.bgg@gmail.com>,
	 AngeloGioacchino Del Regno
	<angelogioacchino.delregno@collabora.com>
Cc: mithat.guner@xeront.com, erkin.bozoglu@xeront.com,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org,
	"Arınç ÜNAL" <arinc.unal@arinc9.com>
Subject: [PATCH 1/2] arm64: dts: mediatek: mt7622: set PHY address of MT7531 switch to 0x1f
Date: Thu, 14 Mar 2024 15:20:04 +0300	[thread overview]
Message-ID: <20240314-for-mediatek-mt7531-phy-address-v1-1-52f58db01acd@arinc9.com> (raw)
In-Reply-To: <20240314-for-mediatek-mt7531-phy-address-v1-0-52f58db01acd@arinc9.com>

From: Arınç ÜNAL <arinc.unal@arinc9.com>

The MT7531 switch listens on PHY address 0x1f on an MDIO bus. I've got two
findings that support this. There's no bootstrapping option to change the
PHY address of the switch. The Linux driver hardcodes 0x1f as the PHY
address of the switch. So the reg property on the device tree is currently
ignored by the Linux driver.

Therefore, describe the correct PHY address on boards that have this
switch.

Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
---
 arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts | 4 ++--
 arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts             | 4 ++--
 2 files changed, 4 insertions(+), 4 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 224bb289660c..811b227d6f50 100644
--- a/arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts
@@ -149,9 +149,9 @@ mdio: mdio-bus {
 		#address-cells = <1>;
 		#size-cells = <0>;
 
-		switch@0 {
+		switch@1f {
 			compatible = "mediatek,mt7531";
-			reg = <0>;
+			reg = <0x1f>;
 			interrupt-controller;
 			#interrupt-cells = <1>;
 			interrupts-extended = <&pio 53 IRQ_TYPE_LEVEL_HIGH>;
diff --git a/arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts b/arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts
index 41629769bdc8..3c2423cb38fd 100644
--- a/arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts
+++ b/arch/arm64/boot/dts/mediatek/mt7622-rfb1.dts
@@ -134,9 +134,9 @@ mdio-bus {
 		#address-cells = <1>;
 		#size-cells = <0>;
 
-		switch@0 {
+		switch@1f {
 			compatible = "mediatek,mt7531";
-			reg = <0>;
+			reg = <0x1f>;
 			reset-gpios = <&pio 54 0>;
 
 			ports {

-- 
2.40.1

