[PATCH] ARM: dts: aspeed: yosemite5: add x4 E1.S expansion board I2C mux

[PATCH] ARM: dts: aspeed: yosemite5: add x4 E1.S expansion board I2C mux

[Kevin Tung]

The new hardware design adds two additional E1.S devices behind an
I2C mux at address 0x73 on bus 10. Add support for this mux in the
DTS device tree.

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
Summary:
Revise linux device tree entry related to Meta (Facebook) Yosemite5.

Changes in v1:
- Add x4 E1.S expansion board I2C mux
---
 .../dts/aspeed/aspeed-bmc-facebook-yosemite5.dts   | 23 ++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
index 2486981f3d6bd36f3fe780b21e834b85242f8aa9..87524892322c1388c146b33ac454018a31dad168 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
@@ -31,6 +31,8 @@ aliases {
 		i2c33 = &i2c30mux0ch1;
 		i2c34 = &i2c30mux0ch2;
 		i2c35 = &i2c30mux0ch3;
+		i2c36 = &i2c10mux0ch0;
+		i2c37 = &i2c10mux0ch1;
 		serial0 = &uart1;
 		serial2 = &uart3;
 		serial3 = &uart4;
@@ -702,6 +704,27 @@ eeprom@54 {
 		compatible = "atmel,24c128";
 		reg = <0x54>;
 	};
+
+	/* I2C MUX on E1S x4 board */
+	i2c-mux@73 {
+		compatible = "nxp,pca9543";
+		reg = <0x73>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		i2c-mux-idle-disconnect;
+
+		i2c10mux0ch0: i2c@0 {
+			reg = <0>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+
+		i2c10mux0ch1: i2c@1 {
+			reg = <1>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+		};
+	};
 };
 
 &i2c11 {

---
base-commit: 9448598b22c50c8a5bb77a9103e2d49f134c9578
change-id: 20251222-yv5_add_dvt_e1s_ioexp-14930e048043

Best regards,
-- 
Kevin Tung <kevin.tung.openbmc@gmail.com>

Re: [PATCH] ARM: dts: aspeed: yosemite5: add x4 E1.S expansion board I2C mux

[Andrew Jeffery]

On Mon, 2025-12-22 at 19:25 +0800, Kevin Tung wrote:
> The new hardware design adds two additional E1.S devices behind an
> I2C mux at address 0x73 on bus 10. Add support for this mux in the
> DTS device tree.

Out of curiosity, you're monitoring them with the NVMe-MI basic
management command and not NVMe-MI over MCTP, or is there something
else going on which motivates describing empty mux legs?

Andrew

Re: [PATCH] ARM: dts: aspeed: yosemite5: add x4 E1.S expansion board I2C mux

[Kevin Tung]

On Thu, Jan 8, 2026 at 12:46 PM Andrew Jeffery
<andrew@codeconstruct.com.au> wrote:
>
> On Mon, 2025-12-22 at 19:25 +0800, Kevin Tung wrote:
> > The new hardware design adds two additional E1.S devices behind an
> > I2C mux at address 0x73 on bus 10. Add support for this mux in the
> > DTS device tree.
>
> Out of curiosity, you're monitoring them with the NVMe-MI basic
> management command and not NVMe-MI over MCTP, or is there something
> else going on which motivates describing empty mux legs?
>
> Andrew

Hi Andrew,

We’re monitoring them using the NVMe-MI basic management commands
directly, which is why the empty mux legs are described.

Kevin