[U-Boot] [linux-sunxi] [PATCH] phy: sun4i-usb: Fix PHY0 routing and passby configuration for MUSB

[Jagan Teki]

On Thu, Mar 14, 2019 at 4:08 PM Paul Kocialkowski
<paul.kocialkowski at bootlin.com> wrote:
>
> 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 at bootlin.com>
> ---
>  drivers/phy/allwinner/phy-sun4i-usb.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/phy/allwinner/phy-sun4i-usb.c b/drivers/phy/allwinner/phy-sun4i-usb.c
> index f206fa3f5d48..4f1c7e519d71 100644
> --- a/drivers/phy/allwinner/phy-sun4i-usb.c
> +++ b/drivers/phy/allwinner/phy-sun4i-usb.c
> @@ -302,9 +302,21 @@ 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

I think we can manage this route and passby dynamically by detecting
id since we have dr_mode verify the MUSB host or peripheral via
usb_get_dr_mode, any chance to try that way?