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

[Xu Yang <xu.yang_2@nxp.com>]

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>
---
 drivers/usb/typec/tcpm/tcpm.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 829d75ebab42..4f7e4c50e847 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4301,7 +4301,12 @@ 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);
+
+			if (pdo_max_current(port->snk_pdo[0]))
+				tcpm_set_charge(port, true);
+			else
+				tcpm_log(port, "Not require power from Source");
+
 			if (!port->pd_supported)
 				tcpm_set_state(port, SNK_READY, 0);
 			else
@@ -4582,7 +4587,10 @@ 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);
+			if (pdo_max_current(port->snk_pdo[0]))
+				tcpm_set_charge(port, true);
+			else
+				tcpm_log(port, "Not require power from Source");
 		}
 		if (port->ams == HARD_RESET)
 			tcpm_ams_finish(port);
-- 
2.34.1