usb: typec: tcpm: not sink vbus if operational current is 0mA

PD3.0 Spec 6.4.1.3.1 said:
For a Sink requiring no power from the Source, the Voltage (B19-10)
shall be set to 5V and the Operational Current Shall be set to 0mA.

Therefore, we can keep sink path closed if the operational current of
the first fixed PDO is 0mA.

Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230801070110.1653394-1-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 9c496b8..5a7d8cc 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4231,7 +4231,9 @@ static void run_state_machine(struct tcpm_port *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);
+                       /* Not sink vbus if operational current is 0mA */
+                       tcpm_set_charge(port, !!pdo_max_current(port->snk_pdo[0]));
+
                        if (!port->pd_supported)
                                tcpm_set_state(port, SNK_READY, 0);
                        else
@@ -4512,7 +4514,8 @@ static void run_state_machine(struct tcpm_port *port)
                        tcpm_set_current_limit(port,
                                               tcpm_get_current_limit(port),
                                               5000);
-                       tcpm_set_charge(port, true);
+                       /* Not sink vbus if operational current is 0mA */
+                       tcpm_set_charge(port, !!pdo_max_current(port->snk_pdo[0]));
                }
                if (port->ams == HARD_RESET)
                        tcpm_ams_finish(port);