diff options
Diffstat (limited to 'drivers/usb/host/xhci-hub.c')
| -rw-r--r-- | drivers/usb/host/xhci-hub.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c index 61f083de6e19..d27c30ac17fd 100644 --- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -752,6 +752,42 @@ static int xhci_exit_test_mode(struct xhci_hcd *xhci) return xhci_reset(xhci, XHCI_RESET_SHORT_USEC); } +/** + * xhci_port_is_tunneled() - Check if USB3 connection is tunneled over USB4 + * @xhci: xhci host controller + * @port: USB3 port to be checked. + * + * Some hosts can detect if a USB3 connection is native USB3 or tunneled over + * USB4. Intel hosts expose this via vendor specific extended capability 206 + * eSS PORT registers TUNEN (tunnel enabled) bit. + * + * A USB3 device must be connected to the port to detect the tunnel. + * + * Return: link tunnel mode enum, USB_LINK_UNKNOWN if host is incapable of + * detecting USB3 over USB4 tunnels. USB_LINK_NATIVE or USB_LINK_TUNNELED + * otherwise. + */ +enum usb_link_tunnel_mode xhci_port_is_tunneled(struct xhci_hcd *xhci, + struct xhci_port *port) +{ + void __iomem *base; + u32 offset; + + base = &xhci->cap_regs->hc_capbase; + offset = xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_INTEL_SPR_SHADOW); + + if (offset && offset <= XHCI_INTEL_SPR_ESS_PORT_OFFSET) { + offset = XHCI_INTEL_SPR_ESS_PORT_OFFSET + port->hcd_portnum * 0x20; + + if (readl(base + offset) & XHCI_INTEL_SPR_TUNEN) + return USB_LINK_TUNNELED; + else + return USB_LINK_NATIVE; + } + + return USB_LINK_UNKNOWN; +} + void xhci_set_link_state(struct xhci_hcd *xhci, struct xhci_port *port, u32 link_state) { |