diff options
| -rw-r--r-- | drivers/usb/typec/tcpm/tcpm.c | 17 | ||||
| -rw-r--r-- | include/linux/usb/pd.h | 2 |
2 files changed, 19 insertions, 0 deletions
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 1c32bdf62852..aedc8bb9532a 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -4131,6 +4131,23 @@ static void run_state_machine(struct tcpm_port *port) } break; case SNK_TRANSITION_SINK: + /* From the USB PD spec: + * "The Sink Shall transition to Sink Standby before a positive or + * negative voltage transition of VBUS. During Sink Standby + * the Sink Shall reduce its power draw to pSnkStdby." + * + * This is not applicable to PPS though as the port can continue + * to draw negotiated power without switching to standby. + */ + if (port->supply_voltage != port->req_supply_voltage && !port->pps_data.active && + port->current_limit * port->supply_voltage / 1000 > PD_P_SNK_STDBY_MW) { + u32 stdby_ma = PD_P_SNK_STDBY_MW * 1000 / port->supply_voltage; + + tcpm_log(port, "Setting standby current %u mV @ %u mA", + port->supply_voltage, stdby_ma); + tcpm_set_current_limit(port, stdby_ma, port->supply_voltage); + } + fallthrough; case SNK_TRANSITION_SINK_VBUS: tcpm_set_state(port, hard_reset_state(port), PD_T_PS_TRANSITION); diff --git a/include/linux/usb/pd.h b/include/linux/usb/pd.h index 70d681918d01..bf00259493e0 100644 --- a/include/linux/usb/pd.h +++ b/include/linux/usb/pd.h @@ -493,4 +493,6 @@ static inline unsigned int rdo_max_power(u32 rdo) #define PD_N_CAPS_COUNT (PD_T_NO_RESPONSE / PD_T_SEND_SOURCE_CAP) #define PD_N_HARD_RESET_COUNT 2 +#define PD_P_SNK_STDBY_MW 2500 /* 2500 mW */ + #endif /* __LINUX_USB_PD_H */ |