usb: phy: twl4030-usb: check if vbus is driven by twl itself

At least on pandora, STS_VBUS gets set even when VBUS is driven by twl
itself. Reporting VBUS in this case confuses OMAP musb glue and charger
driver, so check if OTG VBUS charge pump is on before reporting VBUS
event to avoid this problem.

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/phy/phy-twl4030-usb.c b/drivers/usb/phy/phy-twl4030-usb.c
index 61fe7e29c9c3a16bb648c2ec9657761bd4dd09a8..3f9858fbebc2f1cc9861ff1366c3f70f610bf886 100644 (file)
--- a/drivers/usb/phy/phy-twl4030-usb.c
+++ b/drivers/usb/phy/phy-twl4030-usb.c
@@ -248,6 +248,25 @@ twl4030_usb_clear_bits(struct twl4030_usb *twl, u8 reg, u8 bits)
 
 /*-------------------------------------------------------------------------*/
 
+static bool twl4030_is_driving_vbus(struct twl4030_usb *twl)
+{
+       int ret;
+
+       ret = twl4030_usb_read(twl, PHY_CLK_CTRL_STS);
+       if (ret < 0 || !(ret & PHY_DPLL_CLK))
+               /*
+                * if clocks are off, registers are not updated,
+                * but we can assume we don't drive VBUS in this case
+                */
+               return false;
+
+       ret = twl4030_usb_read(twl, ULPI_OTG_CTRL);
+       if (ret < 0)
+               return false;
+
+       return (ret & (ULPI_OTG_DRVVBUS | ULPI_OTG_CHRGVBUS)) ? true : false;
+}
+
 static enum omap_musb_vbus_id_status
        twl4030_usb_linkstat(struct twl4030_usb *twl)
 {
@@ -270,13 +289,19 @@ static enum omap_musb_vbus_id_status
        if (status < 0)
                dev_err(twl->dev, "USB link status err %d\n", status);
        else if (status & (BIT(7) | BIT(2))) {
-               if (status & (BIT(7)))
-                        twl->vbus_supplied = true;
+               if (status & BIT(7)) {
+                       if (twl4030_is_driving_vbus(twl))
+                               status &= ~BIT(7);
+                       else
+                               twl->vbus_supplied = true;
+               }
 
                if (status & BIT(2))
                        linkstat = OMAP_MUSB_ID_GROUND;
-               else
+               else if (status & BIT(7))
                        linkstat = OMAP_MUSB_VBUS_VALID;
+               else
+                       linkstat = OMAP_MUSB_VBUS_OFF;
        } else {
                if (twl->linkstat != OMAP_MUSB_UNKNOWN)
                        linkstat = OMAP_MUSB_VBUS_OFF;