usb: typec: tcpm: Update vbus_vsafe0v on init

During init, vbus_vsafe0v does not get updated till the first
connect as a sink. This causes TCPM to be stuck in SRC_ATTACH_WAIT
state while booting with a sink (For instance: a headset) connected.

[    1.429168] Start toggling
[    1.439907] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[    1.445242] CC1: 0 -> 0, CC2: 0 -> 0 [state TOGGLING, polarity 0, disconnected]
[   53.358528] CC1: 0 -> 0, CC2: 0 -> 2 [state TOGGLING, polarity 0, connected]
[   53.358564] state change TOGGLING -> SRC_ATTACH_WAIT [rev1 NONE_AMS]

Fix this by updating vbus_vsafe0v based on vbus_present status
on boot.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20201211071911.2205197-1-badhri@google.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 36b6ce8..6326a8f 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4804,6 +4804,24 @@ static void tcpm_init(struct tcpm_port *port)
        if (port->vbus_present)
                port->vbus_never_low = true;
 
+       /*
+        * 1. When vbus_present is true, voltage on VBUS is already at VSAFE5V.
+        * So implicitly vbus_vsafe0v = false.
+        *
+        * 2. When vbus_present is false and TCPC does NOT support querying
+        * vsafe0v status, then, it's best to assume vbus is at VSAFE0V i.e.
+        * vbus_vsafe0v is true.
+        *
+        * 3. When vbus_present is false and TCPC does support querying vsafe0v,
+        * then, query tcpc for vsafe0v status.
+        */
+       if (port->vbus_present)
+               port->vbus_vsafe0v = false;
+       else if (!port->tcpc->is_vbus_vsafe0v)
+               port->vbus_vsafe0v = true;
+       else
+               port->vbus_vsafe0v = port->tcpc->is_vbus_vsafe0v(port->tcpc);
+
        tcpm_set_state(port, tcpm_default_state(port), 0);
 
        if (port->tcpc->get_cc(port->tcpc, &cc1, &cc2) == 0)