phy: omap-usb2-phy: disable phy charger detect

AM654x PG1.0 has a silicon bug that D+ is pulled high after POR, which
could cause enumeration failure with some USB hubs.  Disabling the
USB2_PHY Charger Detect function will put D+ into the normal state.

Using property "ti,dis-chg-det-quirk" in the DT usb2-phy node to
enable this workaround for AM654x PG1.0.

Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>

diff --git a/drivers/phy/omap-usb2-phy.c b/drivers/phy/omap-usb2-phy.c
index 0793b97..adc454d 100644 (file)
--- a/drivers/phy/omap-usb2-phy.c
+++ b/drivers/phy/omap-usb2-phy.c
@@ -17,6 +17,7 @@
 #include <linux/err.h>
 
 #define OMAP_USB2_CALIBRATE_FALSE_DISCONNECT   BIT(0)
+#define OMAP_USB2_DISABLE_CHG_DET              BIT(1)
 
 #define OMAP_DEV_PHY_PD                BIT(0)
 #define OMAP_USB2_PHY_PD       BIT(28)
@@ -33,6 +34,10 @@
 #define AM654_USB2_VBUS_DET_EN         BIT(5)
 #define AM654_USB2_VBUSVALID_DET_EN    BIT(4)
 
+#define USB2PHY_CHRG_DET                0x14
+#define USB2PHY_USE_CHG_DET_REG                BIT(29)
+#define USB2PHY_DIS_CHG_DET            BIT(28)
+
 DECLARE_GLOBAL_DATA_PTR;
 
 struct omap_usb2_phy {
@@ -160,6 +165,12 @@ static int omap_usb2_phy_init(struct phy *usb_phy)
                writel(val, priv->phy_base + USB2PHY_ANA_CONFIG1);
        }
 
+       if (priv->flags & OMAP_USB2_DISABLE_CHG_DET) {
+               val = readl(priv->phy_base + USB2PHY_CHRG_DET);
+               val |= USB2PHY_USE_CHG_DET_REG | USB2PHY_DIS_CHG_DET;
+               writel(val, priv->phy_base + USB2PHY_CHRG_DET);
+       }
+
        return 0;
 }
 
@@ -197,13 +208,25 @@ int omap_usb2_phy_probe(struct udevice *dev)
        if (!data)
                return -EINVAL;
 
-       if (data->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
-               priv->phy_base = dev_read_addr_ptr(dev);
+       priv->phy_base = dev_read_addr_ptr(dev);
 
-               if (!priv->phy_base)
-                       return -EINVAL;
+       if (!priv->phy_base)
+               return -EINVAL;
+
+       if (data->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT)
                priv->flags |= OMAP_USB2_CALIBRATE_FALSE_DISCONNECT;
-       }
+
+       /*
+        * AM654x PG1.0 has a silicon bug that D+ is pulled high after
+        * POR, which could cause enumeration failure with some USB hubs.
+        * Disabling the USB2_PHY Charger Detect function will put D+
+        * into the normal state.
+        *
+        * Using property "ti,dis-chg-det-quirk" in the DT usb2-phy node
+        * to enable this workaround for AM654x PG1.0.
+        */
+       if (dev_read_bool(dev, "ti,dis-chg-det-quirk"))
+               priv->flags |= OMAP_USB2_DISABLE_CHG_DET;
 
        regmap = syscon_regmap_lookup_by_phandle(dev, "syscon-phy-power");
        if (!IS_ERR(regmap)) {