Re: [PATCH v2] usb: typec: qcom: Add support for per port VBUS detection
From: Dmitry Baryshkov
Date: Thu Mar 19 2026 - 16:00:09 EST
On Thu, Mar 19, 2026 at 02:26:00PM +0100, Konrad Dybcio wrote:
> On 3/12/26 7:16 AM, 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;
>
> I'd like for this to include the word 'secondary', since it's not obvious
> that if an external GPIO is at play, we have two ports connected in this
> uhh non-standard fashion
>
> perhaps just secondary_vbus_detect_gpio
In theory it can be used even if we have one port.
--
With best wishes
Dmitry