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>

4 files changed, 101 insertions, 6 deletions

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 14b48b261e06..8163f17e7043 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -123,7 +123,7 @@ static unsigned int xhci_port_speed(unsigned int port_status)
  * writing a 0 clears the bit and writing a 1 sets the bit (RWS).
  * For all other types (RW1S, RW1CS, RW, and RZ), writing a '0' has no effect.
  */
-static u32 xhci_port_state_to_neutral(u32 state)
+u32 xhci_port_state_to_neutral(u32 state)
 {
         /* Save read-only status and port state */
         return (state & XHCI_PORT_RO) | (state & XHCI_PORT_RWS);
@@ -132,7 +132,7 @@ static u32 xhci_port_state_to_neutral(u32 state)
 /*
  * find slot id based on port number.
  */
-static int xhci_find_slot_id_by_port(struct xhci_hcd *xhci, u16 port)
+int xhci_find_slot_id_by_port(struct xhci_hcd *xhci, u16 port)
 {
         int slot_id;
         int i;
@@ -210,7 +210,7 @@ command_cleanup:
 /*
  * Ring device, it rings the all doorbells unconditionally.
  */
-static void xhci_ring_device(struct xhci_hcd *xhci, int slot_id)
+void xhci_ring_device(struct xhci_hcd *xhci, int slot_id)
 {
         int i;
 
@@ -276,7 +276,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
         int ports;
         unsigned long flags;
-        u32 temp, status;
+        u32 temp, temp1, status;
         int retval = 0;
         u32 __iomem *addr;
         int slot_id;
@@ -315,6 +315,34 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                 if ((temp & PORT_PLS_MASK) == XDEV_U3
                         && (temp & PORT_POWER))
                         status |= 1 << USB_PORT_FEAT_SUSPEND;
+                if ((temp & PORT_PLS_MASK) == XDEV_RESUME) {
+                        if ((temp & PORT_RESET) || !(temp & PORT_PE))
+                                goto error;
+                        if (!DEV_SUPERSPEED(temp) && time_after_eq(jiffies,
+                                                xhci->resume_done[wIndex])) {
+                                xhci_dbg(xhci, "Resume USB2 port %d\n",
+                                        wIndex + 1);
+                                xhci->resume_done[wIndex] = 0;
+                                temp1 = xhci_port_state_to_neutral(temp);
+                                temp1 &= ~PORT_PLS_MASK;
+                                temp1 |= PORT_LINK_STROBE | XDEV_U0;
+                                xhci_writel(xhci, temp1, addr);
+
+                                xhci_dbg(xhci, "set port %d resume\n",
+                                        wIndex + 1);
+                                slot_id = xhci_find_slot_id_by_port(xhci,
+                                                                 wIndex + 1);
+                                if (!slot_id) {
+                                        xhci_dbg(xhci, "slot_id is zero\n");
+                                        goto error;
+                                }
+                                xhci_ring_device(xhci, slot_id);
+                                xhci->port_c_suspend[wIndex >> 5] |=
+                                                1 << (wIndex & 31);
+                                xhci->suspended_ports[wIndex >> 5] &=
+                                                ~(1 << (wIndex & 31));
+                        }
+                }
                 if ((temp & PORT_PLS_MASK) == XDEV_U0
                         && (temp & PORT_POWER)
                         && (xhci->suspended_ports[wIndex >> 5] &
@@ -500,6 +528,7 @@ int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
 {
         unsigned long flags;
         u32 temp, status;
+        u32 mask;
         int i, retval;
         struct xhci_hcd *xhci = hcd_to_xhci(hcd);
         int ports;
@@ -512,13 +541,18 @@ int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
         memset(buf, 0, retval);
         status = 0;
 
+        mask = PORT_CSC | PORT_PEC | PORT_OCC;
+
         spin_lock_irqsave(&xhci->lock, flags);
         /* For each port, did anything change?  If so, set that bit in buf. */
         for (i = 0; i < ports; i++) {
                 addr = &xhci->op_regs->port_status_base +
                         NUM_PORT_REGS*i;
                 temp = xhci_readl(xhci, addr);
-                if (temp & (PORT_CSC | PORT_PEC | PORT_OCC)) {
+                if ((temp & mask) != 0 ||
+                        (xhci->port_c_suspend[i >> 5] & 1 << (i & 31)) ||
+                        (xhci->resume_done[i] && time_after_eq(
+                            jiffies, xhci->resume_done[i]))) {
                         buf[(i + 1) / 8] |= 1 << (i + 1) % 8;
                         status = 1;
                 }
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 858a82867e1d..fd888bc0422b 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1803,6 +1803,8 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
         init_completion(&xhci->addr_dev);
         for (i = 0; i < MAX_HC_SLOTS; ++i)
                 xhci->devs[i] = NULL;
+        for (i = 0; i < MAX_HC_PORTS; ++i)
+                xhci->resume_done[i] = 0;
 
         if (scratchpad_alloc(xhci, flags))
                 goto fail;
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);
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 73e5db3e89c9..ca4a923dc810 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1215,6 +1215,7 @@ struct xhci_hcd {
         u32                     port_c_suspend[8];      /* port suspend change*/
         u32                     suspended_ports[8];     /* which ports are
                                                            suspended */
+        unsigned long           resume_done[MAX_HC_PORTS];
 };
 
 /* For testing purposes */
@@ -1459,6 +1460,9 @@ void xhci_ring_ep_doorbell(struct xhci_hcd *xhci, unsigned int slot_id,
 int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex,
                 char *buf, u16 wLength);
 int xhci_hub_status_data(struct usb_hcd *hcd, char *buf);
+u32 xhci_port_state_to_neutral(u32 state);
+int xhci_find_slot_id_by_port(struct xhci_hcd *xhci, u16 port);
+void xhci_ring_device(struct xhci_hcd *xhci, int slot_id);
 
 /* xHCI contexts */
 struct xhci_input_control_ctx *xhci_get_input_control_ctx(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx);