>
> On the Renesas R8A7791 SoC based boards there's MAX3355 USB OTG chip and
> mini-AB USB connector corresponding to USB port 0 driven either by EHCI/OHCI
> or Renesas USBHS gadget controller. And we'd like the host/gadget drivers to
> work based on the cable type connected. An 'extcon' driver for MAX3355 has
> been written, so we only need to bind to it via device tree which I'm doing in
> this patch.
>
> I wasn't able to find a solution better than checking the cable type at the host
> driver probe time and refusing to drive a host if B-cable is connected.
>
You may need a dual-role/otg driver to do it, which can enable host/device function
according to ID pin.
Peter
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
>
> ---
> The patch is against the 'usb-next' branch of Greg KH's 'usb.git' repo.
> It needs the recent 'extcon' core in order to properly handle probe deferral.
>
> drivers/usb/core/hcd.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> Index: usb/drivers/usb/core/hcd.c
> ============================================================
> =======
> --- usb.orig/drivers/usb/core/hcd.c
> +++ usb/drivers/usb/core/hcd.c
> @@ -42,6 +42,7 @@
> #include <linux/pm_runtime.h>
> #include <linux/types.h>
>
> +#include <linux/extcon.h>
> #include <linux/phy/phy.h>
> #include <linux/usb.h>
> #include <linux/usb/hcd.h>
> @@ -2632,6 +2633,23 @@ int usb_add_hcd(struct usb_hcd *hcd,
> int retval;
> struct usb_device *rhdev;
>
> + if (IS_ENABLED(CONFIG_EXTCON) &&
> + of_property_read_bool(hcd->self.controller->of_node, "extcon")) {
> + struct extcon_dev *edev;
> +
> + edev = extcon_get_edev_by_phandle(hcd->self.controller, 0);
> + if (IS_ERR(edev))
> + return PTR_ERR(edev);
> +
> + retval = extcon_get_cable_state(edev, "USB-HOST");
> + if (!retval) {
> + dev_err(hcd->self.controller,
> + "OTG B-cable plugged in, host driver won't
> load\n");
> + return -EINVAL;
> + } else if (retval < 0)
> + return retval;
> + }
> +
> if (IS_ENABLED(CONFIG_USB_PHY) && !hcd->usb_phy) {
> struct usb_phy *phy = usb_get_phy_dev(hcd->self.controller,
> 0);
>
>
> --
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