Re: [PATCH v2 4/5] riscv: dts: thead: Add IO labels for the IO expansion on I2C1

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The `gpio-line-names` array added for `ioexp2` incorrectly labels pin 4 as `wl_host_wake` and pin 7 as `bt_host_wake`. This is physically and logically incorrect because the PCA9557 IO expander lacks interrupt output capability, meaning it cannot be used to receive asynchronous wake signals from peripherals to wake the host. Furthermore, pin 4 is already configured in the base device tree as a `reset-gpios` output for the `wifi_pwrseq` node, directly contradicting the input nature of a host wake signal.
--

--- Patch [4]: [PATCH v2 4/5] riscv: dts: thead: Add IO labels for the IO expansion on I2C1 ---
commit 0fffc115b12752f1a08b3dcb530cafc2d17759f7
Author: Emil Renner Berthing <emil.renner.berthing@canonical.com>

riscv: dts: thead: Add IO labels for the IO expansion on I2C1

This commit adds labels for GPIOs on the IO expansion chip on the I2C1 bus.

> diff --git a/arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts b/arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts
> index 74b120c6b063a..78f5979a56c14 100644
> --- a/arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts
> +++ b/arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts
> @@ -128,6 +128,14 @@ ioexp2: gpio@18 {
>  		reg = <0x18>;
>  		gpio-controller;
>  		#gpio-cells = <2>;
> +		gpio-line-names = "",
> +				  "cam0_reset",
> +				  "cam1_reset",
> +				  "cam2_reset",
> +				  "wl_host_wake",
> +				  "bt_resetn",
> +				  "",
> +				  "bt_host_wake";

[Severity: Low]
The PCA9557 IO expander lacks interrupt output capability, meaning it cannot
receive asynchronous wake signals from peripherals to wake the host.

Additionally, pin 4 is already configured as a reset output in the base
device tree for the wifi_pwrseq node:

arch/riscv/boot/dts/thead/th1520-lichee-pi-4a.dts:
	wifi_pwrseq: wifi-pwrseq {
		...
		reset-gpios = <&ioexp2 4 GPIO_ACTIVE_LOW>;
	};

This configuration contradicts the input nature of a host wake signal.

Are the labels wl_host_wake and bt_host_wake correct for this IO expander?

>  	};
>  };

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260714074515.1959352-1-zhengxingda@iscas.ac.cn?part=4