[PATCH v12 06/10] usb: typec: tcpci_maxim: Fix vbus stuck on upon diconnecting sink

[Badhri Jagan Sridharan]

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 <bad...@google.com>
Reviewed-by: Heikki Krogerus <heikki.kroge...@linux.intel.com>
---
v9 is the first version of this patch. Added to fix
occasional bug of vbus turning back on when disconnecting the FRS accessory
after disconnect. No changes since v9.

Changes since v10:
Added Reviewed-by: Heikki Krogerus

Changes since v11:
none
---
 drivers/usb/typec/tcpm/tcpci_maxim.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpci_maxim.c 
b/drivers/usb/typec/tcpm/tcpci_maxim.c
index a5014c3b51d5..dd6171604362 100644
--- 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);
-- 
2.29.1.341.ge80a0c044ae-goog