USB: xHCI: port remote wakeup implementation

This commit implements port remote wakeup.

When a port is in U3 state and resume signaling is detected from a device,
the port transitions to the Resume state, and the xHC generates a Port Status
Change Event.

For USB3 port, software write a '0' to the PLS field to complete the resume
signaling. For USB2 port, the resume should be signaling for at least 20ms,
irq handler set a timer for port remote wakeup, and then finishes process in
hub_control GetPortStatus.

Some codes are borrowed from EHCI code.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 56 insertions, 1 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index b18e00ecb468..9f3115e729b1 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1165,17 +1165,72 @@ static void handle_vendor_event(struct xhci_hcd *xhci,
 static void handle_port_status(struct xhci_hcd *xhci,
                 union xhci_trb *event)
 {
+        struct usb_hcd *hcd = xhci_to_hcd(xhci);
         u32 port_id;
+        u32 temp, temp1;
+        u32 __iomem *addr;
+        int ports;
+        int slot_id;
 
         /* Port status change events always have a successful completion code */
         if (GET_COMP_CODE(event->generic.field[2]) != COMP_SUCCESS) {
                 xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
                 xhci->error_bitmask |= 1 << 8;
         }
-        /* FIXME: core doesn't care about all port link state changes yet */
         port_id = GET_PORT_ID(event->generic.field[0]);
         xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
 
+        ports = HCS_MAX_PORTS(xhci->hcs_params1);
+        if ((port_id <= 0) || (port_id > ports)) {
+                xhci_warn(xhci, "Invalid port id %d\n", port_id);
+                goto cleanup;
+        }
+
+        addr = &xhci->op_regs->port_status_base + NUM_PORT_REGS * (port_id - 1);
+        temp = xhci_readl(xhci, addr);
+        if ((temp & PORT_CONNECT) && (hcd->state == HC_STATE_SUSPENDED)) {
+                xhci_dbg(xhci, "resume root hub\n");
+                usb_hcd_resume_root_hub(hcd);
+        }
+
+        if ((temp & PORT_PLC) && (temp & PORT_PLS_MASK) == XDEV_RESUME) {
+                xhci_dbg(xhci, "port resume event for port %d\n", port_id);
+
+                temp1 = xhci_readl(xhci, &xhci->op_regs->command);
+                if (!(temp1 & CMD_RUN)) {
+                        xhci_warn(xhci, "xHC is not running.\n");
+                        goto cleanup;
+                }
+
+                if (DEV_SUPERSPEED(temp)) {
+                        xhci_dbg(xhci, "resume SS port %d\n", port_id);
+                        temp = xhci_port_state_to_neutral(temp);
+                        temp &= ~PORT_PLS_MASK;
+                        temp |= PORT_LINK_STROBE | XDEV_U0;
+                        xhci_writel(xhci, temp, addr);
+                        slot_id = xhci_find_slot_id_by_port(xhci, port_id);
+                        if (!slot_id) {
+                                xhci_dbg(xhci, "slot_id is zero\n");
+                                goto cleanup;
+                        }
+                        xhci_ring_device(xhci, slot_id);
+                        xhci_dbg(xhci, "resume SS port %d finished\n", port_id);
+                        /* Clear PORT_PLC */
+                        temp = xhci_readl(xhci, addr);
+                        temp = xhci_port_state_to_neutral(temp);
+                        temp |= PORT_PLC;
+                        xhci_writel(xhci, temp, addr);
+                } else {
+                        xhci_dbg(xhci, "resume HS port %d\n", port_id);
+                        xhci->resume_done[port_id - 1] = jiffies +
+                                msecs_to_jiffies(20);
+                        mod_timer(&hcd->rh_timer,
+                                  xhci->resume_done[port_id - 1]);
+                        /* Do the rest in GetPortStatus */
+                }
+        }
+
+cleanup:
         /* Update event ring dequeue pointer before dropping the lock */
         inc_deq(xhci, xhci->event_ring, true);