Hi Sebastian,

I am having difficulty articulating my thoughts clearly right now;
please bear with me as I try to explain.

On Sat, 10 Jan 2026 at 04:41, Sebastian Reichel
[off-list ref] wrote:

Hi,

On Thu, Jan 08, 2026 at 12:24:50PM +0530, Anand Moon wrote:

quoted

Hi Sebastian,

Thanks for your review comments.

On Sat, 3 Jan 2026 at 19:23, Sebastian Reichel
[off-list ref] wrote:

quoted

Hi,

On Sat, Jan 03, 2026 at 02:01:17PM +0530, Anand Moon wrote:

quoted

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 <redacted>
Fixes: 67b2c15d8fb3 ("arm64: dts: rockchip: add USB-C support for ROCK 5B/5B+/5T")
Signed-off-by: Anand Moon <redacted>
---
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.

I don't understand what you want to say here.

I'm sorry for not being clear here. Well, while investigating the bug crash,
I was looking for some more details on this issue.

Here is the datasheet for fuse302. It shares the interrupt pin details

[1} https://www.onsemi.com/download/data-sheet/pdf/fusb302b-d.pdf

SCL     Input                          I2C serial clock signal to be
connected to the phone-based I2C master.
SDA    Open-Drain I/O          I2C serial data signal to be connected
to the phone-based I2C master
INT_N Open-Drain Output    Active LOW open drain interrupt output used
to prompt the processor to
                                             read the I2C register bits.

quoted

quoted

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.

as I try to say it does not depend on pinctrl configuration for any
of the GPIOs you are touching. The pull resistors for them exist as
components on the board.

I understand this correctly, but these registers utilize a high-to-low
state change specifically
to prevent subthreshold leakage current.

Please check the RK3588 Datasheet V0.1-20210727.pdf  (3.4 Electrical
Characteristics for General IO)
[2] https://gitlab.com/rock-chips/rk3588/rk3588-doc/-/raw/master/RK3588%20Datasheet%20V0.1-20210727.pdf?ref_type=heads&inline=true

quoted

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?

This is missing gpios-states, but I also see no point in testing
that. Having one state as 0 effectively means this is a complicated
version of regulator-fixed. The switch from "gpio" to "gpios" is
valid though, since "gpio" is deprecated.

Typically, a regulator-fixed GPIO input pin is used as EN to enable
the regulator.

However, in this case, TYPEC5V_PWREN_H is being used to signal on/off
to the FUSB302.
As the GPIO-controlled interrupt pin is used to enable or disable i2C
controller.
This is the reason I want to switch from regulator-fixed to regulator-gpio.
ok I will add gpios-states= <1>;

That’s why I requested these changes to be reviewed and tested.

[2] https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/regulator/gpio-regulator.yaml

Please let me know if these adjustments are incorrect; if so, we can
discard them.
Currently, I'm not making the desired progress.

Greetings,

-- Sebastian

Thanks
-Anand

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