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

[Bryan O'Donoghue]

On 19/03/2026 19:57, Dmitry Baryshkov wrote:
> 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.

That's true.

Its quite common in OTG devices to have VBUS detect GPIOs.

---
bod