phy: sun4i-usb: Fix PHY0 routing and passby configuration for MUSB

Recent Allwinner platforms (starting with the H3) only use the MUSB
controller for peripheral mode and use HCI for host mode. As a result,
extra steps need to be taken to properly route USB signals to one or
the other. More precisely, the following is required:
* Routing the pins to either HCI/MUSB (controlled by PHY);
* Enabling USB PHY passby in HCI mode (controlled by PMU).

The current code will enable passby for each PHY and reroute PHY0 to
MUSB, which is inconsistent and results in broken USB peripheral support.

Passby on PHY0 must only be enabled when we want to use HCI. Since
host/device mode detection is not available from the PHY code and
because U-Boot does not support changing the mode dynamically anyway,
we can just mux the controller to MUSB if it is enabled and mux it to
HCI otherwise.

This fixes USB peripheral support for platforms with PHY0 dual-route,
especially H3/H5 and V3s.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>

diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
index 5723c98..82713b8 100644 (file)
--- a/drivers/phy/allwinner/phy-sun4i-usb.c
+++ b/drivers/phy/allwinner/phy-sun4i-usb.c
@@ -313,9 +313,21 @@ static int sun4i_usb_phy_init(struct phy *phy)
                                    data->cfg->disc_thresh, PHY_DISCON_TH_LEN);
        }
 
+#ifdef CONFIG_USB_MUSB_SUNXI
+       /* Needed for HCI and conflicts with MUSB, keep PHY0 on MUSB */
+       if (usb_phy->id != 0)
+               sun4i_usb_phy_passby(phy, true);
+
+       /* Route PHY0 to MUSB to allow USB gadget */
+       if (data->cfg->phy0_dual_route)
+               sun4i_usb_phy0_reroute(data, true);
+#else
        sun4i_usb_phy_passby(phy, true);
 
-       sun4i_usb_phy0_reroute(data, true);
+       /* Route PHY0 to HCI to allow USB host */
+       if (data->cfg->phy0_dual_route)
+               sun4i_usb_phy0_reroute(data, false);
+#endif
 
        return 0;
 }