| Message ID | 20210414142656.63749-2-badhri@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 1373fefc6243cc96b3565f0ffffadfac4ccfb977 |
| Headers | show |
| Series | [v4,1/3] usb: typec: tcpm: Honour pSnkStdby requirement during negotiation | expand |
On Wed, Apr 14, 2021 at 07:26:55AM -0700, Badhri Jagan Sridharan wrote: > When a PD charger advertising Rp-3.0 is connected to a sink port, the > sink port current limit would 3A, during SNK_DISCOVERY, till power > negotiation starts. Once the negotiation starts the power limit needs > to drop down to pSnkStby(500mA @ 5V) and to negotiated current limit > once the explicit contract is in place. Not all charging loops can ramp > up to 3A and drop down to 500mA within tSnkStdby which is 15ms. The port > partner might hard reset if tSnkStdby is not met. > > To solve this problem, this patch introduces slow-charger-loop which > when set makes the port request PD_P_SNK_STDBY_MW upon entering > SNK_DISCOVERY(instead of 3A or the 1.5A during SNK_DISCOVERY) and the > actual currrent limit after RX of PD_CTRL_PSRDY for PD link or during > SNK_READY for non-pd link. > > Signed-off-by: Badhri Jagan Sridharan <badhri@google.com> > Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > Changes since V3: > * Added reviewed-by tag from Heikki No need to add reviewed-by tags, my tools pick that up already. Patches 1 and 2 now queued up. thanks, greg k-h
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index aedc8bb9532a..2ad5e14a6867 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -459,6 +459,12 @@ struct tcpm_port { /* Auto vbus discharge status */ bool auto_vbus_discharge_enabled; + /* + * When set, port requests PD_P_SNK_STDBY_MW upon entering SNK_DISCOVERY and + * the actual currrent limit after RX of PD_CTRL_PSRDY for PD link, + * SNK_READY for non-pd link. + */ + bool slow_charger_loop; #ifdef CONFIG_DEBUG_FS struct dentry *dentry; struct mutex logbuffer_lock; /* log buffer access lock */ @@ -4047,9 +4053,11 @@ static void run_state_machine(struct tcpm_port *port) break; case SNK_DISCOVERY: if (port->vbus_present) { - tcpm_set_current_limit(port, - tcpm_get_current_limit(port), - 5000); + u32 current_lim = tcpm_get_current_limit(port); + + if (port->slow_charger_loop || (current_lim > PD_P_SNK_STDBY_MW / 5)) + current_lim = PD_P_SNK_STDBY_MW / 5; + tcpm_set_current_limit(port, current_lim, 5000); tcpm_set_charge(port, true); tcpm_set_state(port, SNK_WAIT_CAPABILITIES, 0); break; @@ -4161,6 +4169,8 @@ static void run_state_machine(struct tcpm_port *port) port->pwr_opmode = TYPEC_PWR_MODE_PD; } + if (!port->pd_capable && port->slow_charger_loop) + tcpm_set_current_limit(port, tcpm_get_current_limit(port), 5000); tcpm_swap_complete(port, 0); tcpm_typec_connect(port); mod_enable_frs_delayed_work(port, 0); @@ -5763,6 +5773,7 @@ static int tcpm_fw_get_caps(struct tcpm_port *port, port->typec_caps.type = ret; port->port_type = port->typec_caps.type; + port->slow_charger_loop = fwnode_property_read_bool(fwnode, "slow-charger-loop"); if (port->port_type == TYPEC_PORT_SNK) goto sink;