During hard reset, TCPM turns off the charging path. The spec provides an option for Sink to either drop to vSafe5V or vSafe0V.
>From USB_PD_R3_0 2.6.2 Sink Operation .. Serious errors are handled by Hard Reset Signaling issued by either Port Partner. A Hard Reset: resets protocol as for a Soft Reset but also returns the power supply to USB Default Operation (vSafe0V or vSafe5V output) in order to protect the Sink. Add a config option to tcpc_dev and let the device specific driver decide what needs to be done. Signed-off-by: Badhri Jagan Sridharan <[email protected]> --- drivers/usb/typec/tcpm.c | 7 ++++++- include/linux/usb/tcpm.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c index a4e0c027a2a9..350d1a7c4543 100644 --- a/drivers/usb/typec/tcpm.c +++ b/drivers/usb/typec/tcpm.c @@ -3269,7 +3269,12 @@ static void run_state_machine(struct tcpm_port *port) case SNK_HARD_RESET_SINK_OFF: memset(&port->pps_data, 0, sizeof(port->pps_data)); tcpm_set_vconn(port, false); - tcpm_set_charge(port, false); + if (port->tcpc->config->vsafe_5v_hard_reset) + tcpm_set_current_limit(port, + tcpm_get_current_limit(port), + 5000); + else + tcpm_set_charge(port, false); if (port->tcpc->config->self_powered) tcpm_set_roles(port, true, TYPEC_SINK, TYPEC_DEVICE); diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h index 50c74a77db55..c6e3ccecba70 100644 --- a/include/linux/usb/tcpm.h +++ b/include/linux/usb/tcpm.h @@ -90,6 +90,7 @@ struct tcpc_config { enum typec_role default_role; bool try_role_hw; /* try.{src,snk} implemented in hardware */ bool self_powered; /* port belongs to a self powered device */ + bool vsafe_5v_hard_reset; /* Maintain VSAFE5V during hard reset */ const struct typec_altmode_desc *alt_modes; }; -- 2.19.0.397.gdd90340f6a-goog
