Re: [PATCH v5 5/5] pinctrl: renesas: rzg2l: Add RZ/G3S support for selecting the I3C power source

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Requesting an unsupported 3.3V power source for an I3C pin is silently accepted and misconfigures the hardware to 1.8V.
--

--- Patch [5]: [PATCH v5 5/5] pinctrl: renesas: rzg2l: Add RZ/G3S support for selecting the I3C power source ---
commit 0ea5cf7346d186b66e9a09433c5157725bc0936d
Author: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>

pinctrl: renesas: rzg2l: Add RZ/G3S support for selecting the I3C power source

The Renesas RZ/G3S I3C pins can be powered at either 1.8V or 1.2V. The
pin controller provides a register to select between these two options.
Update the Renesas RZ/G2L pin controller driver to allow selecting the
I3C power source on RZ/G3S SoC.

> diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> index bab7bd73a4328..41ca18aeeb0fa 100644
> --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
[ ... ]
> @@ -463,6 +474,10 @@ struct rzg2l_pinctrl_ps_desc {
>  
>  /* Keep the entries with .caps set in the first positions. */
>  static const struct rzg2l_pinctrl_ps_desc available_ps[] = {
> +	/* I3C I/O domain voltage 1.2V */
> +	RZG2L_PINCTRL_PS_DESC(1200, 1, PIN_CFG_IO_VMC_I3C, RZG2L_IOLH_IDX_NA),
> +	/* I3C I/O domain voltage 1.8V */
> +	RZG2L_PINCTRL_PS_DESC(1800, 0, PIN_CFG_IO_VMC_I3C, RZG2L_IOLH_IDX_NA),
>  	/* Ethernet I/O domain voltage 2.5V */
>  	RZG2L_PINCTRL_PS_DESC(2500, 2, PIN_CFG_IO_VMC_ETH0 | PIN_CFG_IO_VMC_ETH1,
>  			      RZG2L_IOLH_IDX_2V5),
>  	/* I/O domain voltage 1.8V */
>  	RZG2L_PINCTRL_PS_DESC(1800, 1, 0, RZG2L_IOLH_IDX_1V8),
>  	/* I/O domain voltage 3.3V */
>  	RZG2L_PINCTRL_PS_DESC(3300, 0, 0, RZG2L_IOLH_IDX_3V3),
>  };

[Severity: Medium]
If a device tree incorrectly requests a 3.3V power source for an I3C pin,
will this silently accept the configuration and set the hardware to 1.8V
instead of returning an error?

Looking at RZG2L_PINCTRL_PS_DESC_MEMBER_TO_DESC_FUNC(), it treats entries
with .caps == 0 as wildcards:

drivers/pinctrl/renesas/pinctrl-rzg2l.c:RZG2L_PINCTRL_PS_DESC_MEMBER_TO_DESC_FUNC() {
	...
			if (available_ps[i].caps) {
				if (available_ps[i].caps & _caps) {
					desc = &available_ps[i];
					break;
				}
			} else {
				desc = &available_ps[i];
				break;
			}
	...
}

Since the 3.3V entry above has .caps = 0, it seems rzg2l_ps_to_desc() would
match it for an I3C pin requesting 3300mV, returning pwr_reg_val = 0, which
configures the hardware to 1.8V.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260819143553.2478984-1-claudiu.beznea+renesas@tuxon.dev?part=5