xHCI: Set link state support

This patch adds support for Set Port Feature(PORT_LINK_STATE) request.

The most significant byte (bits 15..8) of the wIndex field specifies
the U state the host software wants to put the link connected to the
port into. This request is only valid when the PORT_ENABLE bit is set
and the PORT_LINK_STATE should not be above value '5' (Rx.Detect).

This request will be later used to replace the set/clear suspend USB3
protocol ports in hub driver.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index f3bafba4b5c6..b87535442386 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -387,6 +387,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
         __le32 __iomem **port_array;
         int slot_id;
         struct xhci_bus_state *bus_state;
+        u16 link_state = 0;
 
         if (hcd->speed == HCD_USB3) {
                 ports = xhci->num_usb3_ports;
@@ -497,6 +498,8 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                 put_unaligned(cpu_to_le32(status), (__le32 *) buf);
                 break;
         case SetPortFeature:
+                if (wValue == USB_PORT_FEAT_LINK_STATE)
+                        link_state = (wIndex & 0xff00) >> 3;
                 wIndex &= 0xff;
                 if (!wIndex || wIndex > ports)
                         goto error;
@@ -545,6 +548,44 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                         temp = xhci_readl(xhci, port_array[wIndex]);
                         bus_state->suspended_ports |= 1 << wIndex;
                         break;
+                case USB_PORT_FEAT_LINK_STATE:
+                        temp = xhci_readl(xhci, port_array[wIndex]);
+                        /* Software should not attempt to set
+                         * port link state above '5' (Rx.Detect) and the port
+                         * must be enabled.
+                         */
+                        if ((temp & PORT_PE) == 0 ||
+                                (link_state > USB_SS_PORT_LS_RX_DETECT)) {
+                                xhci_warn(xhci, "Cannot set link state.\n");
+                                goto error;
+                        }
+
+                        if (link_state == USB_SS_PORT_LS_U3) {
+                                slot_id = xhci_find_slot_id_by_port(hcd, xhci,
+                                                wIndex + 1);
+                                if (slot_id) {
+                                        /* unlock to execute stop endpoint
+                                         * commands */
+                                        spin_unlock_irqrestore(&xhci->lock,
+                                                                flags);
+                                        xhci_stop_device(xhci, slot_id, 1);
+                                        spin_lock_irqsave(&xhci->lock, flags);
+                                }
+                        }
+
+                        temp = xhci_port_state_to_neutral(temp);
+                        temp &= ~PORT_PLS_MASK;
+                        temp |= PORT_LINK_STROBE | link_state;
+                        xhci_writel(xhci, temp, port_array[wIndex]);
+
+                        spin_unlock_irqrestore(&xhci->lock, flags);
+                        msleep(20); /* wait device to enter */
+                        spin_lock_irqsave(&xhci->lock, flags);
+
+                        temp = xhci_readl(xhci, port_array[wIndex]);
+                        if (link_state == USB_SS_PORT_LS_U3)
+                                bus_state->suspended_ports |= 1 << wIndex;
+                        break;
                 case USB_PORT_FEAT_POWER:
                         /*
                          * Turn on ports, even if there isn't per-port switching.