Downstream has a flag called qcom,dp-manual-pullup which informs the
downstream driver if it should toggle ULPI_MISC_A_VBUSVLDEXTSEL and
ULPI_MISC_A_VBUSVLDEXT.

Downstream states:

"qcom,dp-manual-pullup: If present, vbus is not routed to USB
        controller/phy and controller driver therefore enables pull-up
        explicitly before starting controller using usbcmd run/stop bit."

Working with a type-c controller which handles VBUS entirely means there's
a need to replicate similar logic in upstream.

The current PHY code waggles these bits if an extcon associated with VBUS
exists but, that is not the case when using a full-fat type-c controller
i.e. there's no VBUS line routed to a SoC pad to sense.

This patch enables and disables the VBUS pullup bits on PHY power_on and
power_off respectively if the DT has declared the bool
"qcom,enable-vbus-pullup".

Cc: Andy Gross <[email protected]>
Cc: Bjorn Andersson <[email protected]>
Cc: Kishon Vijay Abraham I <[email protected]>
Cc: Vinod Koul <[email protected]>
Cc: Philipp Zabel <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Stephen Boyd <[email protected]>
Signed-off-by: Bryan O'Donoghue <[email protected]>
---
 drivers/phy/qualcomm/phy-qcom-usb-hs.c | 36 ++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/phy/qualcomm/phy-qcom-usb-hs.c 
b/drivers/phy/qualcomm/phy-qcom-usb-hs.c
index 61054272a7c8..578a4e1fc539 100644
--- a/drivers/phy/qualcomm/phy-qcom-usb-hs.c
+++ b/drivers/phy/qualcomm/phy-qcom-usb-hs.c
@@ -37,6 +37,7 @@ struct qcom_usb_hs_phy {
        struct ulpi_seq *init_seq;
        struct extcon_dev *vbus_edev;
        struct notifier_block vbus_notify;
+       u8 enable_vbus_pullup:1;
 };
 
 static int qcom_usb_hs_phy_set_mode(struct phy *phy,
@@ -104,6 +105,23 @@ qcom_usb_hs_phy_vbus_notifier(struct notifier_block *nb, 
unsigned long event,
        return ulpi_write(uphy->ulpi, addr, ULPI_MISC_A_VBUSVLDEXT);
 }
 
+static int qcom_usb_hs_phy_enable_vbus_pullup(struct ulpi *ulpi, bool enable)
+{
+       u8 addr;
+       int ret;
+
+       if (enable)
+               addr = ULPI_SET(ULPI_MISC_A);
+       else
+               addr = ULPI_CLR(ULPI_MISC_A);
+
+       ret = ulpi_write(ulpi, addr, ULPI_MISC_A_VBUSVLDEXTSEL);
+       if (ret)
+               return ret;
+
+       return ulpi_write(ulpi, addr, ULPI_MISC_A_VBUSVLDEXT);
+}
+
 static int qcom_usb_hs_phy_power_on(struct phy *phy)
 {
        struct qcom_usb_hs_phy *uphy = phy_get_drvdata(phy);
@@ -153,6 +171,12 @@ static int qcom_usb_hs_phy_power_on(struct phy *phy)
                        goto err_ulpi;
        }
 
+       if (uphy->enable_vbus_pullup) {
+               ret = qcom_usb_hs_phy_enable_vbus_pullup(ulpi, true);
+               if (ret)
+                       goto err_ulpi;
+       }
+
        if (uphy->vbus_edev) {
                state = extcon_get_state(uphy->vbus_edev, EXTCON_USB);
                /* setup initial state */
@@ -179,10 +203,19 @@ static int qcom_usb_hs_phy_power_on(struct phy *phy)
 static int qcom_usb_hs_phy_power_off(struct phy *phy)
 {
        struct qcom_usb_hs_phy *uphy = phy_get_drvdata(phy);
+       struct ulpi *ulpi = uphy->ulpi;
+       int ret;
 
        if (uphy->vbus_edev)
                extcon_unregister_notifier(uphy->vbus_edev, EXTCON_USB,
                                           &uphy->vbus_notify);
+
+       if (uphy->enable_vbus_pullup) {
+               ret = qcom_usb_hs_phy_enable_vbus_pullup(ulpi, false);
+               if (ret)
+                       return ret;
+       }
+
        regulator_disable(uphy->v3p3);
        regulator_disable(uphy->v1p8);
        clk_disable_unprepare(uphy->sleep_clk);
@@ -228,6 +261,9 @@ static int qcom_usb_hs_phy_probe(struct ulpi *ulpi)
        /* NUL terminate */
        uphy->init_seq[size / 2].addr = uphy->init_seq[size / 2].val = 0;
 
+       if (of_property_read_bool(ulpi->dev.of_node, "qcom,enable-vbus-pullup"))
+               uphy->enable_vbus_pullup = 1;
+
        uphy->ref_clk = clk = devm_clk_get(&ulpi->dev, "ref");
        if (IS_ERR(clk))
                return PTR_ERR(clk);
-- 
2.25.1

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