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

[Andrew Jeffery <andrew@codeconstruct.com.au>]

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","",