usb: typec: tcpci_maxim: Fix vbus stuck on upon diconnecting sink

Occasionally, POWER_STATUS.sourcing_vbus takes a while to clear after
writing to  MAX_BUCK_BOOST_OP register. This causes vbus to turn back
on while disconnecting the sink. Overcome this issue by writing into
MAX_BUCK_BOOST_OP during frs while sourcing vbu, instead of always
into the register whenever POWER_STATUS.sourcing_vbus is set.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20201029063138.1429760-7-badhri@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c b/drivers/usb/typec/tcpm/tcpci_maxim.c
index 723d7dd..43dcad9 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpci_maxim.c
+++ b/drivers/usb/typec/tcpm/tcpci_maxim.c
@@ -238,23 +238,22 @@ static void process_power_status(struct max_tcpci_chip *chip)
        if (ret < 0)
                return;
 
-       if (pwr_status == 0xff) {
+       if (pwr_status == 0xff)
                max_tcpci_init_regs(chip);
-       } else if (pwr_status & TCPC_POWER_STATUS_SOURCING_VBUS) {
+       else if (pwr_status & TCPC_POWER_STATUS_SOURCING_VBUS)
                tcpm_sourcing_vbus(chip->port);
-               /*
-                * Alawys re-enable boost here.
-                * In normal case, when say an headset is attached, TCPM would
-                * have instructed to TCPC to enable boost, so the call is a
-                * no-op.
-                * But for Fast Role Swap case, Boost turns on autonomously without
-                * AP intervention, but, needs AP to enable source mode explicitly
-                * for AP to regain control.
-                */
-               max_tcpci_set_vbus(chip->tcpci, &chip->data, true, false);
-       } else {
+       else
                tcpm_vbus_change(chip->port);
-       }
+}
+
+static void max_tcpci_frs_sourcing_vbus(struct tcpci *tcpci, struct tcpci_data *tdata)
+{
+       /*
+        * For Fast Role Swap case, Boost turns on autonomously without
+        * AP intervention, but, needs AP to enable source mode explicitly
+        * for AP to regain control.
+        */
+       max_tcpci_set_vbus(tcpci, tdata, true, false);
 }
 
 static void process_tx(struct max_tcpci_chip *chip, u16 status)
@@ -441,6 +440,7 @@ static int max_tcpci_probe(struct i2c_client *client, const struct i2c_device_id
        chip->data.start_drp_toggling = max_tcpci_start_toggling;
        chip->data.TX_BUF_BYTE_x_hidden = true;
        chip->data.init = tcpci_init;
+       chip->data.frs_sourcing_vbus = max_tcpci_frs_sourcing_vbus;
 
        max_tcpci_init_regs(chip);
        chip->tcpci = tcpci_register_port(chip->dev, &chip->data);