Re: [PATCH v2] usb: typec: qcom: Add support for per port VBUS detection

[Bryan O'Donoghue]

On 12/03/2026 06:16, Alexander Koskovich wrote:
> This is required for devices (e.g. ASUS ROG Phone 3) where more than
> one USB port can act as a sink and both share a single USBIN input on
> the PMIC.
>
> Because the PM8150B uses USBIN to determine VBUS presence, a charger
> connected to one port causes the PMIC to falsely detect VBUS on the
> other port, preventing it from entering source mode.
>
> For example, plugging a charger into one port prevents using the other
> port for a flash drive.
>
> Fix this by adding support for the vbus-gpios connector binding so the
> driver can use an external GPIO for per-port VBUS presence detection
> instead of the shared USBIN register.
>
> Signed-off-by: Alexander Koskovich <akoskovich@xxxxx>
> ---
> Changes in v2:
> - Dropped RFC prefix
> - Remove redundant vbus-detect-gpios, instead use existing vbus-gpios from usb-connector (Dmitry)
> - Updated cover to better describe scenario where this change is relevant
> - Update comment for EN_TRY_SRC to make more sense
> - Skip vSafe5V poll too not just vSafe0V
> - return gpiod_get_value_cansleep (Konrad)
> - regmap_update_bits -> regmap_set_bits (Konrad)
> - Get vbus-gpios per connector (Konrad)
> - Add bracket to if (IS_ERR(pmic_typec_port->vbus_detect_gpio)) (Bryan)
> - Link to v1: https://lore.kernel.org/r/20260308-qcom-typec-shared-vbus-v1-0-7d574b91052a@xxxxx
> ---
>   drivers/usb/typec/tcpm/qcom/qcom_pmic_typec_port.c | 53 +++++++++++++++++++++-
>   1 file changed, 52 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/tcpm/qcom/qcom_pmic_typec_port.c b/drivers/usb/typec/tcpm/qcom/qcom_pmic_typec_port.c
> index 8051eaa46991..a8f6687a3522 100644
> --- a/drivers/usb/typec/tcpm/qcom/qcom_pmic_typec_port.c
> +++ b/drivers/usb/typec/tcpm/qcom/qcom_pmic_typec_port.c
> @@ -5,6 +5,7 @@
>   
>   #include <linux/delay.h>
>   #include <linux/err.h>
> +#include <linux/gpio/consumer.h>
>   #include <linux/interrupt.h>
>   #include <linux/kernel.h>
>   #include <linux/mod_devicetable.h>
> @@ -176,6 +177,8 @@ struct pmic_typec_port {
>   	bool				vbus_enabled;
>   	struct mutex			vbus_lock;		/* VBUS state serialization */
>   
> +	struct gpio_desc		*vbus_detect_gpio;
> +
>   	int				cc;
>   	bool				debouncing_cc;
>   	struct delayed_work		cc_debounce_dwork;
> @@ -279,6 +282,9 @@ static int qcom_pmic_typec_port_vbus_detect(struct pmic_typec_port *pmic_typec_p
>   	unsigned int misc;
>   	int ret;
>   
> +	if (pmic_typec_port->vbus_detect_gpio)
> +		return gpiod_get_value_cansleep(pmic_typec_port->vbus_detect_gpio);
> +
>   	ret = regmap_read(pmic_typec_port->regmap,
>   			  pmic_typec_port->base + TYPEC_MISC_STATUS_REG,
>   			  &misc);
> @@ -310,6 +316,13 @@ static int qcom_pmic_typec_port_vbus_toggle(struct pmic_typec_port *pmic_typec_p
>   		val = TYPEC_SM_VBUS_VSAFE0V;
>   	}
>   
> +	/*
> +	 * On devices with multiple ports sharing USBIN, VBUS from another
> +	 * port makes the USBIN-based vsafe polls unreliable.
> +	 */
> +	if (pmic_typec_port->vbus_detect_gpio)
> +		return 0;
> +
>   	/* Poll waiting for transition to required vSafe5V or vSafe0V */
>   	ret = regmap_read_poll_timeout(pmic_typec_port->regmap,
>   				       pmic_typec_port->base + TYPEC_SM_STATUS_REG,
> @@ -589,7 +602,15 @@ static int qcom_pmic_typec_port_start_toggling(struct tcpc_dev *tcpc,
>   		mode = EN_SNK_ONLY;
>   		break;
>   	case TYPEC_PORT_DRP:
> -		mode = EN_TRY_SNK;
> +		/*
> +		 * With VBUS present on USBIN from another port, EN_TRY_SNK
> +		 * keeps the port in sink mode. Use EN_TRY_SRC so the port
> +		 * tries to source first.
> +		 */
> +		if (pmic_typec_port->vbus_detect_gpio)
> +			mode = EN_TRY_SRC;
> +		else
> +			mode = EN_TRY_SNK;
>   		break;
>   	}
>   
> @@ -677,6 +698,19 @@ static int qcom_pmic_typec_port_start(struct pmic_typec *tcpm,
>   	if (ret)
>   		goto done;
>   
> +	/*
> +	 * On devices with multiple USB-C ports sharing USBIN, bypass
> +	 * VSAFE0V so SRC attachment can complete despite VBUS being
> +	 * present on USBIN from another port.
> +	 */
> +	if (pmic_typec_port->vbus_detect_gpio) {
> +		ret = regmap_set_bits(pmic_typec_port->regmap,
> +				     pmic_typec_port->base + TYPEC_EXIT_STATE_CFG_REG,
> +				     BYPASS_VSAFE0V_DURING_ROLE_SWAP);

off-by-one

once fixed:
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>