[PATCH v4 0/7] Revise Meta Yosemite5 devicetree

[PATCH v4 0/7] Revise Meta Yosemite5 devicetree

[Kevin Tung]

Summary:
Revise linux device tree entry related to Meta (Facebook) Yosemite5.

Changes in v4:
- Add PDB IO expander device node
- Add GPIO to bypass OCP debug card commands
- Expand commit message explaining the shunt resistor correction
- Link to v3: https://lore.kernel.org/r/20251219-yv5_revise_dts-v3-0-ca1d5a382013@gmail.com

Changes in v3:
- Correct power monitor shunt resistor
- Revert the previous SGPIO P0_I3C_APML_ALERT_L renaming change
- Add new SGPIO line names and rename signal
- Retitle Update sensor configuration for more clarity
- Link to v2: https://lore.kernel.org/r/20251120-yv5_revise_dts-v2-0-4d7de701c5be@gmail.com

Changes in v2:
- Add ipmb node for OCP debug card
- Link to v1: https://lore.kernel.org/r/20251118-yv5_revise_dts-v1-0-fcd6b44b4497@gmail.com

Changes in v1:
- Increase i2c4/i2c12 bus speed to 400 kHz
- Update sensor configuration
- Rename sgpio P0_I3C_APML_ALERT_L

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
Kevin Tung (7):
      ARM: dts: aspeed: yosemite5: Increase i2c4/i2c12 bus speed to 400 kHz
      ARM: dts: aspeed: yosemite5: Remove ambiguous power monitor DTS nodes
      ARM: dts: aspeed: yosemite5: Add new SGPIO line names and rename signal
      ARM: dts: aspeed: yosemite5: Add ipmb node for OCP debug card
      ARM: dts: aspeed: yosemite5: Correct power monitor shunt resistor
      ARM: dts: aspeed: yosemite5: Add PDB IO expander
      ARM: dts: aspeed: yosemite5: Add debug card bypass GPIO

 .../dts/aspeed/aspeed-bmc-facebook-yosemite5.dts   | 92 +++++++++++++++-------
 1 file changed, 64 insertions(+), 28 deletions(-)
---
base-commit: 2a6ff9a25bf681302d29ec93c6b90dbe4b3ad591
change-id: 20251118-yv5_revise_dts-12e10edd95d6

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

[PATCH v4 1/7] ARM: dts: aspeed: yosemite5: Increase i2c4/i2c12 bus speed to 400 kHz

[Kevin Tung]

Configure i2c4 and i2c12 to operate at 400 kHz instead of 100 kHz.
This update aligns the bus settings with the hardware capabilities
and improves MCTP communication performance.

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
 arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 2 ++
 1 file changed, 2 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..7991e9360847532cff9aad4ad4ed57d4c30668a0 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
@@ -231,6 +231,7 @@ sbtsi@4c {
 &i2c4 {
 	multi-master;
 	mctp-controller;
+	clock-frequency = <400000>;
 	status = "okay";
 
 	mctp@10 {
@@ -782,6 +783,7 @@ adc@4b {
 &i2c12 {
 	multi-master;
 	mctp-controller;
+	clock-frequency = <400000>;
 	status = "okay";
 
 	mctp@10 {

-- 
2.52.0

[PATCH v4 2/7] ARM: dts: aspeed: yosemite5: Remove ambiguous power monitor DTS nodes

[Kevin Tung]

Two different power monitor devices, using different drivers, reuse
I2C addresses 0x40 and 0x45 on bus 10 across Yosemite5 board variants.
Defining these devices statically in the DTS can lead to incorrect
driver binding on newer boards when the wrong device is instantiated.

Therefore, remove 10-0040 and 10-0045 device nodes, and let the driver
selection is instead handled in user space by the OpenBMC Entity
Manager based on the actual board configuration.

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
 arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 14 --------------
 1 file changed, 14 deletions(-)

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 7991e9360847532cff9aad4ad4ed57d4c30668a0..45b8ac2e8c65a4f672e64571631b7f6944f26213 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
@@ -674,20 +674,6 @@ gpio-expander@22 {
 			"PWRGD_P3V3_AUX","ALERT_TEMP";
 	};
 
-	power-sensor@40 {
-		compatible = "ti,ina233";
-		reg = <0x40>;
-		shunt-resistor = <2000>;
-		ti,maximum-expected-current-microamp = <32768000>;
-	};
-
-	power-sensor@45 {
-		compatible = "ti,ina233";
-		reg = <0x45>;
-		shunt-resistor = <2000>;
-		ti,maximum-expected-current-microamp = <32768000>;
-	};
-
 	adc@48 {
 		compatible = "ti,ads7830";
 		reg = <0x48>;

-- 
2.52.0

[PATCH v4 3/7] ARM: dts: aspeed: yosemite5: Add new SGPIO line names and rename signal

[Kevin Tung]

Add new SGPIO line names for user space monitoring and event logging.

Also rename PADDLE_BD_IOEXP_INT to ALERT_IRQ_PMBUS_PWR2_N to match
hardware naming. The original PADDLE_BD_IOEXP_INT is unused, so this
change does not affect current system functionality.

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
 .../dts/aspeed/aspeed-bmc-facebook-yosemite5.dts   | 31 ++++++++++++++++++----
 1 file changed, 26 insertions(+), 5 deletions(-)

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 45b8ac2e8c65a4f672e64571631b7f6944f26213..983aebc394d9159c7e3db2e7c39e963f7b64c855 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
@@ -978,7 +978,7 @@ &sgpiom0 {
 	"E1S_0_BD_IOEXP","",
 	"E1S_1_BD_IOEXP","",
 	/*bit88-bit95*/
-	"PADDLE_BD_IOEXP_INT","",
+	"ALERT_IRQ_PMBUS_PWR2_N","",
 	"FM_BOARD_REV_ID0","",
 	"FM_BOARD_REV_ID1","",
 	"FM_BOARD_REV_ID2","",
@@ -991,16 +991,37 @@ &sgpiom0 {
 	"PRSNT_BOOT_N_FF","",
 	"PRSNT_MCIO1A_N_FF","",
 	"NIC_PRSNT_N","",
-	"","",
+	"FM_CPU_BMC_RST_N","",
 	"","",
 	"","",
 	"","",
 	/*bit104-bit111*/
-	"","","","","","","","","","","","","","","","",
+	"MASTER_PWR_EN","",
+	"MASTER_PWR2_EN","",
+	"PRSNT_MCIO0A_E1S0_N","",
+	"","",
+	"PRSNT_MCIO0A_E1S1_N","",
+	"","",
+	"","",
+	"Fault","",
 	/*bit112-bit119*/
-	"","","","","","","","","","","","","","","","",
+	"FM_CPLD_RSVD_MCIO0A_SB1","",
+	"FM_CPLD_RSVD_MCIO0A_SB2","",
+	"","",
+	"","",
+	"","",
+	"","",
+	"","",
+	"","",
 	/*bit120-bit127*/
-	"","","","","","","","","","","","","","","","";
+	"","",
+	"","",
+	"","",
+	"","",
+	"","",
+	"","",
+	"","",
+	"","";
 	status = "okay";
 };
 

-- 
2.52.0

[PATCH v4 4/7] ARM: dts: aspeed: yosemite5: Add ipmb node for OCP debug card

[Kevin Tung]

Add the device tree node to enable the IPMB interface used by
the OCP debug card.

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
 arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 7 +++++++
 1 file changed, 7 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 983aebc394d9159c7e3db2e7c39e963f7b64c855..84d3731b17f7c7c87338672bbcc859de2b89b722 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
@@ -365,7 +365,14 @@ i2c6mux0ch3: i2c@3 {
 
 /* SCM CPLD I2C */
 &i2c7 {
+	multi-master;
 	status = "okay";
+
+	ipmb@10 {
+		compatible = "ipmb-dev";
+		reg = <(0x10 | I2C_OWN_SLAVE_ADDRESS)>;
+		i2c-protocol;
+	};
 };
 
 &i2c8 {

-- 
2.52.0

[PATCH v4 5/7] ARM: dts: aspeed: yosemite5: Correct power monitor shunt resistor

[Kevin Tung]

The shunt resistor value defined in the DTS was incorrect and did not
reflect the resistor value populated on the board. As a result, power
and current readings derived from this value were inaccurate.

This change updates the DTS to use the correct shunt resistor value
according to the hardware design, restoring accurate power and current
measurements.

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
 arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

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 84d3731b17f7c7c87338672bbcc859de2b89b722..524597a81365ef10cd03b67d35eeb88a965cbe0a 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
@@ -415,7 +415,7 @@ power-sensor@42 {
 	power-monitor@43 {
 		compatible = "lltc,ltc4287";
 		reg = <0x43>;
-		shunt-resistor-micro-ohms = <250>;
+		shunt-resistor-micro-ohms = <100>;
 	};
 
 	power-sensor@44 {
@@ -461,25 +461,25 @@ eeprom@57 {
 	power-monitor@58 {
 		compatible = "renesas,isl28022";
 		reg = <0x58>;
-		shunt-resistor-micro-ohms = <1000>;
+		shunt-resistor-micro-ohms = <10000>;
 	};
 
 	power-monitor@59 {
 		compatible = "renesas,isl28022";
 		reg = <0x59>;
-		shunt-resistor-micro-ohms = <1000>;
+		shunt-resistor-micro-ohms = <10000>;
 	};
 
 	power-monitor@5a {
 		compatible = "renesas,isl28022";
 		reg = <0x5a>;
-		shunt-resistor-micro-ohms = <1000>;
+		shunt-resistor-micro-ohms = <10000>;
 	};
 
 	power-monitor@5b {
 		compatible = "renesas,isl28022";
 		reg = <0x5b>;
-		shunt-resistor-micro-ohms = <1000>;
+		shunt-resistor-micro-ohms = <10000>;
 	};
 
 	psu@5c {
@@ -723,13 +723,13 @@ gpio-expander@21 {
 	power-sensor@40 {
 		compatible = "ti,ina230";
 		reg = <0x40>;
-		shunt-resistor = <2000>;
+		shunt-resistor = <1000>;
 	};
 
 	power-sensor@41 {
 		compatible = "ti,ina230";
 		reg = <0x41>;
-		shunt-resistor = <2000>;
+		shunt-resistor = <1000>;
 	};
 
 	power-sensor@42 {

-- 
2.52.0

[PATCH v4 6/7] ARM: dts: aspeed: yosemite5: Add PDB IO expander

[Kevin Tung]

The new hardware design adds an IO expander on the PDB to support
fan presence detection and HSC fault monitoring. So Add the PDB
IO expander device node to the DTS.

The IO expander interrupt is connected to SGPIO92, which was
previously named ALERT_PADDLE2_SMB_N and not used by the system.
This pin is now repurposed and renamed to FM_IOE_ALT_N to reflect
its function as the PDB IO expander interrupt.

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
 .../dts/aspeed/aspeed-bmc-facebook-yosemite5.dts    | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

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 524597a81365ef10cd03b67d35eeb88a965cbe0a..48f864b52d1a22b12f8a39ba9703a90349ed930d 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
@@ -389,6 +389,25 @@ adc@1d {
 		ti,mode = /bits/ 8 <1>;
 	};
 
+	/* PDB IOEXP */
+	gpio-expander@24 {
+		compatible = "nxp,pca9555";
+		reg = <0x24>;
+		interrupt-parent = <&sgpiom0>;
+		interrupts = <92 IRQ_TYPE_LEVEL_LOW>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		gpio-line-names =
+			"FM_P52V_AUX_FLT_N", "FM_P12V_AUX_PWRGD",
+			"FM_SLOTX_HSC_FAULT_N_FF", "",
+			"","",
+			"","",
+			"PRSNT_FAN0","PRSNT_FAN1",
+			"PRSNT_FAN2","PRSNT_FAN3",
+			"","",
+			"","";
+	};
+
 	power-sensor@40 {
 		compatible = "ti,ina238";
 		reg = <0x40>;
@@ -937,7 +956,7 @@ &sgpiom0 {
 	"ALERT_OC_PADDLE2_N","",
 	"ALERT_OC_PWR2_N","",
 	"ALERT_OC_PWR11_N","",
-	"ALERT_PADDLE2_SMB_N","",
+	"FM_IOE_ALT_N","",
 	"ALERT_PWR14_SB2_LEAK_DETECT_N","",
 	/*bit48-bit55*/
 	"ALERT_PWR14_SB3_LEAK_DETECT_N","",

-- 
2.52.0

[PATCH v4 7/7] ARM: dts: aspeed: yosemite5: Add debug card bypass GPIO

[Kevin Tung]

On Yv5, the SCM CPLD bypass OCP debug card commands to the BMC.
These commands share the same I2C bus used by the BMC to access the
SCM CPLD for firmware updates, which can cause bus conflicts.

To avoid this, the SCM CPLD provides a bypass control GPIO connected
to GPIOO7. When asserted by the BMC, this GPIO isolates debug card
commands and prevents conflicts during SCM CPLD access.

Add the DEBUG_CARD_BYPASS GPIO to support this behavior.

Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
---
 arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

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 48f864b52d1a22b12f8a39ba9703a90349ed930d..61e78d5e712ff45e1a0691979b9b36408404cd2d 100644
--- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
+++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
@@ -166,7 +166,8 @@ &gpio0 {
 			"led-postcode-3","led-postcode-4","led-postcode-5",
 			"led-postcode-6","led-postcode-7",
 	/*O0-O7*/	"RUN_POWER_PG","PWR_BRAKE","CHASSIS_AC_LOSS","BSM_PRSNT_N",
-			"PSU_SMB_ALERT","FM_TPM_PRSNT_0_N","PSU_FW_UPDATING_N","",
+			"PSU_SMB_ALERT","FM_TPM_PRSNT_0_N",
+			"PSU_FW_UPDATING_N","DEBUG_CARD_BYPASS",
 	/*P0-P7*/	"PWR_BTN_BMC_N","IPEX_CABLE_PRSNT","ID_RST_BTN_BMC_N",
 			"RST_BMC_RSTBTN_OUT_N","BMC_PWR_LED","RUN_POWER_EN","SHDN_FORCE","",
 	/*Q0-Q7*/	"IRQ_PCH_TPM_SPI_LV3_N","USB_OC0_REAR_N","UART_MUX_SEL",

-- 
2.52.0

Re: [PATCH v4 5/7] ARM: dts: aspeed: yosemite5: Correct power monitor shunt resistor

[Andrew Jeffery]

Hi Kevin,

On Fri, 2026-01-30 at 16:20 +0800, Kevin Tung wrote:
> The shunt resistor value defined in the DTS was incorrect and did not
> reflect the resistor value populated on the board. As a result, power
> and current readings derived from this value were inaccurate.

Okay, but how did it come to be incorrect in the devicetree? Was the
documentation wrong and so someone entered the wrong value? Was the
documentation correct but there was a misunderstanding? Did the
hardware design change and the devicetree is now just inappropriate for
your needs?

Essentially, what's preventing this from happening again?

> 
> This change 
> 

I'd rather you rephrase this to avoid using "This change ...".
Hopefully the commit message always refers to its change.

Generally, please write in the imperative mood (see [1])

[1]: https://docs.kernel.org/process/submitting-patches.html#describe-your-changes

> updates the DTS to use the correct shunt resistor value
> according to the hardware design, restoring accurate power and current
> measurements.
> 
> Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
> ---
>  arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 14 +++++++-------
>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> 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 84d3731b17f7c7c87338672bbcc859de2b89b722..524597a81365ef10cd03b67d35eeb88a965cbe0a 100644
> --- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> +++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> @@ -415,7 +415,7 @@ power-sensor@42 {
>  	power-monitor@43 {
>  		compatible = "lltc,ltc4287";
>  		reg = <0x43>;
> -		shunt-resistor-micro-ohms = <250>;
> +		shunt-resistor-micro-ohms = <100>;
>  	};
>  
>  	power-sensor@44 {
> @@ -461,25 +461,25 @@ eeprom@57 {
>  	power-monitor@58 {
>  		compatible = "renesas,isl28022";
>  		reg = <0x58>;
> -		shunt-resistor-micro-ohms = <1000>;
> +		shunt-resistor-micro-ohms = <10000>;
>  	};
>  
>  	power-monitor@59 {
>  		compatible = "renesas,isl28022";
>  		reg = <0x59>;
> -		shunt-resistor-micro-ohms = <1000>;
> +		shunt-resistor-micro-ohms = <10000>;
>  	};
>  
>  	power-monitor@5a {
>  		compatible = "renesas,isl28022";
>  		reg = <0x5a>;
> -		shunt-resistor-micro-ohms = <1000>;
> +		shunt-resistor-micro-ohms = <10000>;
>  	};
>  
>  	power-monitor@5b {
>  		compatible = "renesas,isl28022";
>  		reg = <0x5b>;
> -		shunt-resistor-micro-ohms = <1000>;
> +		shunt-resistor-micro-ohms = <10000>;
>  	};
>  
>  	psu@5c {
> @@ -723,13 +723,13 @@ gpio-expander@21 {
>  	power-sensor@40 {
>  		compatible = "ti,ina230";
>  		reg = <0x40>;
> -		shunt-resistor = <2000>;
> +		shunt-resistor = <1000>;
>  	};
>  
>  	power-sensor@41 {
>  		compatible = "ti,ina230";
>  		reg = <0x41>;
> -		shunt-resistor = <2000>;
> +		shunt-resistor = <1000>;
>  	};
>  
>  	power-sensor@42 {

The way the commit message is written suggests it was just one shunt
resistor, but that's clearly not the case.

Andrew

Re: [PATCH v4 4/7] ARM: dts: aspeed: yosemite5: Add ipmb node for OCP debug card

[Andrew Jeffery]

On Fri, 2026-01-30 at 16:20 +0800, Kevin Tung wrote:
> Add the device tree node to enable the IPMB interface used by

Here in the patch description you use (capitalised) "IPMB" but in the
patch subject you've used (uncapitalised) "ipmb". Can you please be
consistent and use capitalisation for acronyms.

I wouldn't normally mind and would just fix it up, but I've other
feedback on this series and have fixed the same problem a few patches
already today, so it's a growing source of irritation :)

Andrew

> the OCP debug card.
> 
> Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
> ---
>  arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 7 +++++++
>  1 file changed, 7 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 983aebc394d9159c7e3db2e7c39e963f7b64c855..84d3731b17f7c7c87338672bbcc859de2b89b722 100644
> --- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> +++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> @@ -365,7 +365,14 @@ i2c6mux0ch3: i2c@3 {
>  
>  /* SCM CPLD I2C */
>  &i2c7 {
> +	multi-master;
>  	status = "okay";
> +
> +	ipmb@10 {
> +		compatible = "ipmb-dev";
> +		reg = <(0x10 | I2C_OWN_SLAVE_ADDRESS)>;
> +		i2c-protocol;
> +	};
>  };
>  
>  &i2c8 {

Re: [PATCH v4 6/7] ARM: dts: aspeed: yosemite5: Add PDB IO expander

[Andrew Jeffery]

On Fri, 2026-01-30 at 16:20 +0800, Kevin Tung wrote:
> The new hardware design adds an IO expander on the PDB
> 

What does "PDB" mean? Can you please expand this in the commit message?

>  to support
> fan presence detection and HSC
> 

What does "HSC" mean? Can you please expand this in the commit message?

>  fault monitoring. So Add the PDB
> IO expander device node to the DTS.
> 
> The IO expander interrupt is connected to SGPIO92, which was
> previously named ALERT_PADDLE2_SMB_N and not used by the system.
> This pin is now repurposed and renamed to FM_IOE_ALT_N to reflect
> its function as the PDB IO expander interrupt.
> 
> Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
> ---
>  .../dts/aspeed/aspeed-bmc-facebook-yosemite5.dts    | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> 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 524597a81365ef10cd03b67d35eeb88a965cbe0a..48f864b52d1a22b12f8a39ba9703a90349ed930d 100644
> --- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> +++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> @@ -389,6 +389,25 @@ adc@1d {
>  		ti,mode = /bits/ 8 <1>;
>  	};
>  
> +	/* PDB IOEXP */
> +	gpio-expander@24 {
> +		compatible = "nxp,pca9555";
> +		reg = <0x24>;
> +		interrupt-parent = <&sgpiom0>;
> +		interrupts = <92 IRQ_TYPE_LEVEL_LOW>;
> +		gpio-controller;
> +		#gpio-cells = <2>;
> +		gpio-line-names =
> +			"FM_P52V_AUX_FLT_N", "FM_P12V_AUX_PWRGD",
> +			"FM_SLOTX_HSC_FAULT_N_FF", "",
> +			"","",
> +			"","",
> +			"PRSNT_FAN0","PRSNT_FAN1",
> +			"PRSNT_FAN2","PRSNT_FAN3",
> +			"","",
> +			"","";
> +	};
> +
>  	power-sensor@40 {
>  		compatible = "ti,ina238";
>  		reg = <0x40>;
> @@ -937,7 +956,7 @@ &sgpiom0 {
>  	"ALERT_OC_PADDLE2_N","",
>  	"ALERT_OC_PWR2_N","",
>  	"ALERT_OC_PWR11_N","",
> -	"ALERT_PADDLE2_SMB_N","",
> +	"FM_IOE_ALT_N","",
>  	"ALERT_PWR14_SB2_LEAK_DETECT_N","",
>  	/*bit48-bit55*/
>  	"ALERT_PWR14_SB3_LEAK_DETECT_N","",

Re: [PATCH v4 5/7] ARM: dts: aspeed: yosemite5: Correct power monitor shunt resistor

[Kevin Tung]

On Mon, Feb 9, 2026 at 2:21 PM Andrew Jeffery
<andrew@codeconstruct.com.au> wrote:
>
> Hi Kevin,
>
> On Fri, 2026-01-30 at 16:20 +0800, Kevin Tung wrote:
> > The shunt resistor value defined in the DTS was incorrect and did not
> > reflect the resistor value populated on the board. As a result, power
> > and current readings derived from this value were inaccurate.
>
> Okay, but how did it come to be incorrect in the devicetree? Was the
> documentation wrong and so someone entered the wrong value? Was the
> documentation correct but there was a misunderstanding? Did the
> hardware design change and the devicetree is now just inappropriate for
> your needs?
>
> Essentially, what's preventing this from happening again?
>

Hi Andrew,

The root cause is a hardware design change, which made the previous
devicetree configuration is inappropriate for our needs.
I have updated the commit message to reflect this.

The changes have been confirmed by our power team, verifying that the
power readings now match the latest hardware design.

> >
> > This change
> >
>
> I'd rather you rephrase this to avoid using "This change ...".
> Hopefully the commit message always refers to its change.
>
> Generally, please write in the imperative mood (see [1])
>
> [1]: https://docs.kernel.org/process/submitting-patches.html#describe-your-changes
>

Updated commit message to use imperative mood, thanks for the reference.

Kevin

> > updates the DTS to use the correct shunt resistor value
> > according to the hardware design, restoring accurate power and current
> > measurements.
> >
> > Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
> > ---
> >  arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 14 +++++++-------
> >  1 file changed, 7 insertions(+), 7 deletions(-)
> >
> > 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 84d3731b17f7c7c87338672bbcc859de2b89b722..524597a81365ef10cd03b67d35eeb88a965cbe0a 100644
> > --- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> > +++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> > @@ -415,7 +415,7 @@ power-sensor@42 {
> >       power-monitor@43 {
> >               compatible = "lltc,ltc4287";
> >               reg = <0x43>;
> > -             shunt-resistor-micro-ohms = <250>;
> > +             shunt-resistor-micro-ohms = <100>;
> >       };
> >
> >       power-sensor@44 {
> > @@ -461,25 +461,25 @@ eeprom@57 {
> >       power-monitor@58 {
> >               compatible = "renesas,isl28022";
> >               reg = <0x58>;
> > -             shunt-resistor-micro-ohms = <1000>;
> > +             shunt-resistor-micro-ohms = <10000>;
> >       };
> >
> >       power-monitor@59 {
> >               compatible = "renesas,isl28022";
> >               reg = <0x59>;
> > -             shunt-resistor-micro-ohms = <1000>;
> > +             shunt-resistor-micro-ohms = <10000>;
> >       };
> >
> >       power-monitor@5a {
> >               compatible = "renesas,isl28022";
> >               reg = <0x5a>;
> > -             shunt-resistor-micro-ohms = <1000>;
> > +             shunt-resistor-micro-ohms = <10000>;
> >       };
> >
> >       power-monitor@5b {
> >               compatible = "renesas,isl28022";
> >               reg = <0x5b>;
> > -             shunt-resistor-micro-ohms = <1000>;
> > +             shunt-resistor-micro-ohms = <10000>;
> >       };
> >
> >       psu@5c {
> > @@ -723,13 +723,13 @@ gpio-expander@21 {
> >       power-sensor@40 {
> >               compatible = "ti,ina230";
> >               reg = <0x40>;
> > -             shunt-resistor = <2000>;
> > +             shunt-resistor = <1000>;
> >       };
> >
> >       power-sensor@41 {
> >               compatible = "ti,ina230";
> >               reg = <0x41>;
> > -             shunt-resistor = <2000>;
> > +             shunt-resistor = <1000>;
> >       };
> >
> >       power-sensor@42 {
>
> The way the commit message is written suggests it was just one shunt
> resistor, but that's clearly not the case.
>
> Andrew

Re: [PATCH v4 4/7] ARM: dts: aspeed: yosemite5: Add ipmb node for OCP debug card

[Kevin Tung]

On Mon, Feb 9, 2026 at 2:25 PM Andrew Jeffery
<andrew@codeconstruct.com.au> wrote:
>
> On Fri, 2026-01-30 at 16:20 +0800, Kevin Tung wrote:
> > Add the device tree node to enable the IPMB interface used by
>
> Here in the patch description you use (capitalised) "IPMB" but in the
> patch subject you've used (uncapitalised) "ipmb". Can you please be
> consistent and use capitalisation for acronyms.
>
> I wouldn't normally mind and would just fix it up, but I've other
> feedback on this series and have fixed the same problem a few patches
> already today, so it's a growing source of irritation :)
>
> Andrew
>

Hi Andrew,

Got it. Updated them for consistency in v5, thanks.

Kevin

> > the OCP debug card.
> >
> > Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
> > ---
> >  arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts | 7 +++++++
> >  1 file changed, 7 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 983aebc394d9159c7e3db2e7c39e963f7b64c855..84d3731b17f7c7c87338672bbcc859de2b89b722 100644
> > --- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> > +++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> > @@ -365,7 +365,14 @@ i2c6mux0ch3: i2c@3 {
> >
> >  /* SCM CPLD I2C */
> >  &i2c7 {
> > +     multi-master;
> >       status = "okay";
> > +
> > +     ipmb@10 {
> > +             compatible = "ipmb-dev";
> > +             reg = <(0x10 | I2C_OWN_SLAVE_ADDRESS)>;
> > +             i2c-protocol;
> > +     };
> >  };
> >
> >  &i2c8 {

Re: [PATCH v4 6/7] ARM: dts: aspeed: yosemite5: Add PDB IO expander

[Kevin Tung]

On Mon, Feb 9, 2026 at 2:27 PM Andrew Jeffery
<andrew@codeconstruct.com.au> wrote:
>
> On Fri, 2026-01-30 at 16:20 +0800, Kevin Tung wrote:
> > The new hardware design adds an IO expander on the PDB
> >
>
> What does "PDB" mean? Can you please expand this in the commit message?
>
> >  to support
> > fan presence detection and HSC
> >
>
> What does "HSC" mean? Can you please expand this in the commit message?
>
Hi Andrew,

Sure, I have expanded both abbreviations in the commit message as requested.

Kevin

> >  fault monitoring. So Add the PDB
> > IO expander device node to the DTS.
> >
> > The IO expander interrupt is connected to SGPIO92, which was
> > previously named ALERT_PADDLE2_SMB_N and not used by the system.
> > This pin is now repurposed and renamed to FM_IOE_ALT_N to reflect
> > its function as the PDB IO expander interrupt.
> >
> > Signed-off-by: Kevin Tung <kevin.tung.openbmc@gmail.com>
> > ---
> >  .../dts/aspeed/aspeed-bmc-facebook-yosemite5.dts    | 21 ++++++++++++++++++++-
> >  1 file changed, 20 insertions(+), 1 deletion(-)
> >
> > 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 524597a81365ef10cd03b67d35eeb88a965cbe0a..48f864b52d1a22b12f8a39ba9703a90349ed930d 100644
> > --- a/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> > +++ b/arch/arm/boot/dts/aspeed/aspeed-bmc-facebook-yosemite5.dts
> > @@ -389,6 +389,25 @@ adc@1d {
> >               ti,mode = /bits/ 8 <1>;
> >       };
> >
> > +     /* PDB IOEXP */
> > +     gpio-expander@24 {
> > +             compatible = "nxp,pca9555";
> > +             reg = <0x24>;
> > +             interrupt-parent = <&sgpiom0>;
> > +             interrupts = <92 IRQ_TYPE_LEVEL_LOW>;
> > +             gpio-controller;
> > +             #gpio-cells = <2>;
> > +             gpio-line-names =
> > +                     "FM_P52V_AUX_FLT_N", "FM_P12V_AUX_PWRGD",
> > +                     "FM_SLOTX_HSC_FAULT_N_FF", "",
> > +                     "","",
> > +                     "","",
> > +                     "PRSNT_FAN0","PRSNT_FAN1",
> > +                     "PRSNT_FAN2","PRSNT_FAN3",
> > +                     "","",
> > +                     "","";
> > +     };
> > +
> >       power-sensor@40 {
> >               compatible = "ti,ina238";
> >               reg = <0x40>;
> > @@ -937,7 +956,7 @@ &sgpiom0 {
> >       "ALERT_OC_PADDLE2_N","",
> >       "ALERT_OC_PWR2_N","",
> >       "ALERT_OC_PWR11_N","",
> > -     "ALERT_PADDLE2_SMB_N","",
> > +     "FM_IOE_ALT_N","",
> >       "ALERT_PWR14_SB2_LEAK_DETECT_N","",
> >       /*bit48-bit55*/
> >       "ALERT_PWR14_SB3_LEAK_DETECT_N","",