USB: xHCI: bus power management implementation

This patch implements xHCI bus suspend/resume function hook.

In the patch it goes through all the ports and suspend/resume
the ports if needed.

If any port is in remote wakeup, abort bus suspend as what ehci/ohci do.

Signed-off-by: Libin Yang <libin.yang@amd.com>
Signed-off-by: Crane Cai <crane.cai@amd.com>
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, 200 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 8163f17e7043..7f2f63cb6c53 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -24,6 +24,10 @@
 
 #include "xhci.h"
 
+#define PORT_WAKE_BITS  (PORT_WKOC_E | PORT_WKDISC_E | PORT_WKCONN_E)
+#define PORT_RWC_BITS   (PORT_CSC | PORT_PEC | PORT_WRC | PORT_OCC | \
+                         PORT_RC | PORT_PLC | PORT_PE)
+
 static void xhci_hub_descriptor(struct xhci_hcd *xhci,
                 struct usb_hub_descriptor *desc)
 {
@@ -560,3 +564,187 @@ int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
         spin_unlock_irqrestore(&xhci->lock, flags);
         return status ? retval : 0;
 }
+
+#ifdef CONFIG_PM
+
+int xhci_bus_suspend(struct usb_hcd *hcd)
+{
+        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+        int port;
+        unsigned long flags;
+
+        xhci_dbg(xhci, "suspend root hub\n");
+
+        spin_lock_irqsave(&xhci->lock, flags);
+
+        if (hcd->self.root_hub->do_remote_wakeup) {
+                port = HCS_MAX_PORTS(xhci->hcs_params1);
+                while (port--) {
+                        if (xhci->resume_done[port] != 0) {
+                                spin_unlock_irqrestore(&xhci->lock, flags);
+                                xhci_dbg(xhci, "suspend failed because "
+                                                "port %d is resuming\n",
+                                                port + 1);
+                                return -EBUSY;
+                        }
+                }
+        }
+
+        port = HCS_MAX_PORTS(xhci->hcs_params1);
+        xhci->bus_suspended = 0;
+        while (port--) {
+                /* suspend the port if the port is not suspended */
+                u32 __iomem *addr;
+                u32 t1, t2;
+                int slot_id;
+
+                addr = &xhci->op_regs->port_status_base +
+                        NUM_PORT_REGS * (port & 0xff);
+                t1 = xhci_readl(xhci, addr);
+                t2 = xhci_port_state_to_neutral(t1);
+
+                if ((t1 & PORT_PE) && !(t1 & PORT_PLS_MASK)) {
+                        xhci_dbg(xhci, "port %d not suspended\n", port);
+                        slot_id = xhci_find_slot_id_by_port(xhci, port + 1);
+                        if (slot_id) {
+                                spin_unlock_irqrestore(&xhci->lock, flags);
+                                xhci_stop_device(xhci, slot_id, 1);
+                                spin_lock_irqsave(&xhci->lock, flags);
+                        }
+                        t2 &= ~PORT_PLS_MASK;
+                        t2 |= PORT_LINK_STROBE | XDEV_U3;
+                        set_bit(port, &xhci->bus_suspended);
+                }
+                if (hcd->self.root_hub->do_remote_wakeup) {
+                        if (t1 & PORT_CONNECT) {
+                                t2 |= PORT_WKOC_E | PORT_WKDISC_E;
+                                t2 &= ~PORT_WKCONN_E;
+                        } else {
+                                t2 |= PORT_WKOC_E | PORT_WKCONN_E;
+                                t2 &= ~PORT_WKDISC_E;
+                        }
+                } else
+                        t2 &= ~PORT_WAKE_BITS;
+
+                t1 = xhci_port_state_to_neutral(t1);
+                if (t1 != t2)
+                        xhci_writel(xhci, t2, addr);
+
+                if (DEV_HIGHSPEED(t1)) {
+                        /* enable remote wake up for USB 2.0 */
+                        u32 __iomem *addr;
+                        u32 tmp;
+
+                        addr = &xhci->op_regs->port_power_base +
+                                NUM_PORT_REGS * (port & 0xff);
+                        tmp = xhci_readl(xhci, addr);
+                        tmp |= PORT_RWE;
+                        xhci_writel(xhci, tmp, addr);
+                }
+        }
+        hcd->state = HC_STATE_SUSPENDED;
+        xhci->next_statechange = jiffies + msecs_to_jiffies(10);
+        spin_unlock_irqrestore(&xhci->lock, flags);
+        return 0;
+}
+
+int xhci_bus_resume(struct usb_hcd *hcd)
+{
+        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+        int port;
+        u32 temp;
+        unsigned long flags;
+
+        xhci_dbg(xhci, "resume root hub\n");
+
+        if (time_before(jiffies, xhci->next_statechange))
+                msleep(5);
+
+        spin_lock_irqsave(&xhci->lock, flags);
+        if (!HCD_HW_ACCESSIBLE(hcd)) {
+                spin_unlock_irqrestore(&xhci->lock, flags);
+                return -ESHUTDOWN;
+        }
+
+        /* delay the irqs */
+        temp = xhci_readl(xhci, &xhci->op_regs->command);
+        temp &= ~CMD_EIE;
+        xhci_writel(xhci, temp, &xhci->op_regs->command);
+
+        port = HCS_MAX_PORTS(xhci->hcs_params1);
+        while (port--) {
+                /* Check whether need resume ports. If needed
+                   resume port and disable remote wakeup */
+                u32 __iomem *addr;
+                u32 temp;
+                int slot_id;
+
+                addr = &xhci->op_regs->port_status_base +
+                        NUM_PORT_REGS * (port & 0xff);
+                temp = xhci_readl(xhci, addr);
+                if (DEV_SUPERSPEED(temp))
+                        temp &= ~(PORT_RWC_BITS | PORT_CEC | PORT_WAKE_BITS);
+                else
+                        temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
+                if (test_bit(port, &xhci->bus_suspended) &&
+                    (temp & PORT_PLS_MASK)) {
+                        if (DEV_SUPERSPEED(temp)) {
+                                temp = xhci_port_state_to_neutral(temp);
+                                temp &= ~PORT_PLS_MASK;
+                                temp |= PORT_LINK_STROBE | XDEV_U0;
+                                xhci_writel(xhci, temp, addr);
+                        } else {
+                                temp = xhci_port_state_to_neutral(temp);
+                                temp &= ~PORT_PLS_MASK;
+                                temp |= PORT_LINK_STROBE | XDEV_RESUME;
+                                xhci_writel(xhci, temp, addr);
+
+                                spin_unlock_irqrestore(&xhci->lock, flags);
+                                msleep(20);
+                                spin_lock_irqsave(&xhci->lock, flags);
+
+                                temp = xhci_readl(xhci, addr);
+                                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 + 1);
+                        if (slot_id)
+                                xhci_ring_device(xhci, slot_id);
+                } else
+                        xhci_writel(xhci, temp, addr);
+
+                if (DEV_HIGHSPEED(temp)) {
+                        /* disable remote wake up for USB 2.0 */
+                        u32 __iomem *addr;
+                        u32 tmp;
+
+                        addr = &xhci->op_regs->port_power_base +
+                                NUM_PORT_REGS * (port & 0xff);
+                        tmp = xhci_readl(xhci, addr);
+                        tmp &= ~PORT_RWE;
+                        xhci_writel(xhci, tmp, addr);
+                }
+        }
+
+        (void) xhci_readl(xhci, &xhci->op_regs->command);
+
+        xhci->next_statechange = jiffies + msecs_to_jiffies(5);
+        hcd->state = HC_STATE_RUNNING;
+        /* re-enable irqs */
+        temp = xhci_readl(xhci, &xhci->op_regs->command);
+        temp |= CMD_EIE;
+        xhci_writel(xhci, temp, &xhci->op_regs->command);
+        temp = xhci_readl(xhci, &xhci->op_regs->command);
+
+        spin_unlock_irqrestore(&xhci->lock, flags);
+        return 0;
+}
+
+#else
+
+#define xhci_bus_suspend        NULL
+#define xhci_bus_resume         NULL
+
+#endif
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index fd888bc0422b..202770676da3 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1445,6 +1445,7 @@ void xhci_mem_cleanup(struct xhci_hcd *xhci)
         scratchpad_free(xhci);
         xhci->page_size = 0;
         xhci->page_shift = 0;
+        xhci->bus_suspended = 0;
 }
 
 static int xhci_test_trb_in_td(struct xhci_hcd *xhci,
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index aefc3496376a..3865f8c6f647 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -162,6 +162,8 @@ static const struct hc_driver xhci_pci_hc_driver = {
         /* Root hub support */
         .hub_control =          xhci_hub_control,
         .hub_status_data =      xhci_hub_status_data,
+        .bus_suspend =          xhci_bus_suspend,
+        .bus_resume =           xhci_bus_resume,
 };
 
 /*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index ca4a923dc810..196e21fb36ff 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -357,6 +357,8 @@ struct xhci_op_regs {
 #define PORT_U2_TIMEOUT(p)      (((p) & 0xff) << 8)
 /* Bits 24:31 for port testing */
 
+/* USB2 Protocol PORTSPMSC */
+#define PORT_RWE        (1 << 0x3)
 
 /**
  * struct xhci_intr_reg - Interrupt Register Set
@@ -1191,6 +1193,11 @@ struct xhci_hcd {
 #endif
         /* Host controller watchdog timer structures */
         unsigned int            xhc_state;
+
+        unsigned long           bus_suspended;
+        unsigned long           next_statechange;
+
+        u32                     command;
 /* Host controller is dying - not responding to commands. "I'm not dead yet!"
  *
  * xHC interrupts have been disabled and a watchdog timer will (or has already)
@@ -1460,6 +1467,8 @@ 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);
+int xhci_bus_suspend(struct usb_hcd *hcd);
+int xhci_bus_resume(struct usb_hcd *hcd);
 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);