linux-kernel - Re: [PATCH v1 1/3] arm64: dts: rockchip: rk3588-rock-5b-5bp-5t: Correct Type-C pin bias settings

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Message-ID: <CANAwSgSd0TLrkxpnS5qdot8B7vkd4wH76-g8hAixqfbEtH4LyA@mail.gmail.com>
Date: Thu, 8 Jan 2026 12:24:50 +0530
From: Anand Moon <linux.amoon@...il.com>
To: Sebastian Reichel <sebastian.reichel@...labora.com>
Cc: Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, 
	Conor Dooley <conor+dt@...nel.org>, Heiko Stuebner <heiko@...ech.de>, 
	Heikki Krogerus <heikki.krogerus@...ux.intel.com>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, 
	Nicolas Frattaroli <nicolas.frattaroli@...labora.com>, FUKAUMI Naoki <naoki@...xa.com>, 
	Diederik de Haas <didi.debian@...ow.org>, Yongbo Zhang <giraffesnn123@...il.com>, 
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" <devicetree@...r.kernel.org>, 
	"moderated list:ARM/Rockchip SoC support" <linux-arm-kernel@...ts.infradead.org>, 
	"open list:ARM/Rockchip SoC support" <linux-rockchip@...ts.infradead.org>, 
	open list <linux-kernel@...r.kernel.org>, 
	"open list:USB TYPEC CLASS" <linux-usb@...r.kernel.org>
Subject: Re: [PATCH v1 1/3] arm64: dts: rockchip: rk3588-rock-5b-5bp-5t:
 Correct Type-C pin bias settings

Hi Sebastian,

Thanks for your review comments.

On Sat, 3 Jan 2026 at 19:23, Sebastian Reichel
<sebastian.reichel@...labora.com> wrote:
>
> Hi,
>
> On Sat, Jan 03, 2026 at 02:01:17PM +0530, Anand Moon wrote:
> > As pre FUSB302 datasheet interrupt line (INT_N) is an open-drain,
> > active-low signal. It requires a pull-up resistor to maintain a stable
> > high state when deasserted. Similarly, the TYPEC5V_PWREN_H enable signal
> > requires a pull-down resistor to ensure it defaults to a low state,
> > preventing unintended power delivery during the boot sequence.
> >
> > Update the pinctrl entries to use pcfg_pull_up for usbc0_int and
> > pcfg_pull_down for vbus5v0_typec_en to align with the hardware's
> > electrical requirements.
> >
> > Cc: Sebastian Reichel <sebastian.reichel@...labora.com>
> > Fixes: 67b2c15d8fb3 ("arm64: dts: rockchip: add USB-C support for ROCK 5B/5B+/5T")
> > Signed-off-by: Anand Moon <linux.amoon@...il.com>
> > ---
> > v1: As per the shematics CC_INT_L interrupt pin is GPIO3_B4_u
> >     As per the shematics TYPEC5V_PWREN_H pin is GPIO2_B6_d
> > ---
>
> Checking the schematics:
>
> 5B v1.45 - CC_INT_L - R2613 10K pull-up resistor
> 5B v1.45 - TYPEC5V_PWREN_H - GPIO is effectively unused because R95035 is NC
>
> 5B+ v1.2 - CC_INT_L - R2613 10K pull-up resistor
> 5B+ v1.2 - TYPEC5V_PWREN_H - R163 100K pull-down resistor
>
> 5T v1.2 - CC_INT_L - R2613 10K pull-up resistor
> 5T v1.2 - TYPEC5V_PWREN_H - R163 100K pull-down resistor
>
CC_INT_L is gpio interrupt pin to enable the I2C read operation.

As per FUSB302 datasheet, here is the updated version of the commit message

Configure CC_INT_L as an active-low, open-drain output. Per the hardware design,
this pin utilizes an external pull-up and is driven LOW by the Type-C
controller to
signal the processor to perform I2C register reads.

The TYPEC5V_PWREN_H pull-down resistor is turned on as a signal to
the Type-C regulator, which has an active-enable-high property. In this context,
the regulator is used to set the polarity of the GPIO used to enable or disable
the regulator.

> TLDR: All GPIOs have pull resistors in discrete hardware and do not
> need them muxed in the SoC.
>
It depends on the GPIO, pinctrl PMU configuration.

I was thinking of converting the vbus5v0_typec regulator to 'regulator-gpio.'
to better reflect the hardware schematics. The TYPEC5V_PWREN_H signal
(GPIO2_B6_d) acts as a state controller rather than a simple enable pin,
and this change ensures the device tree aligns with that design

[1] https://dl.radxa.com/rock5/5b/docs/hw/radxa_rock_5b_v1450_schematic.pdf
(page 28)

$ git diff arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi
diff --git a/arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi
b/arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi
index 5f58e339a052..387ff009ec76 100644
--- a/arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk3588-rock-5b-5bp-5t.dtsi
@@ -57,9 +57,10 @@ rfkill-bt {
        };

        vbus5v0_typec: vbus5v0-typec {
-               compatible = "regulator-fixed";
+               compatible = "regulator-gpio";
                enable-active-high;
-               gpio = <&gpio2 RK_PB6 GPIO_ACTIVE_HIGH>;
+               gpios = <&gpio2 RK_PB6 GPIO_ACTIVE_HIGH>;
+               states = <5000000 0x1>, <0 0x0>;
                pinctrl-names = "default";
                pinctrl-0 = <&vbus5v0_typec_en>;
                regulator-name = "vbus5v0_typec";

Could you please try this at your end?

Thanks
-Anand