USB: xHCI: PCI power management implementation

This patch implements the PCI suspend/resume.

Please refer to xHCI spec for doing the suspend/resume operation.

For S3, CSS/SRS in USBCMD is used to save/restore the internal state.
However, an error maybe occurs while restoring the internal state.
In this case, it means that HC internal state is wrong and HC will be
re-initialized.

Signed-off-by: Libin Yang <libin.yang@amd.com>
Signed-off-by: Dong Nguyen <dong.nguyen@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>

1 files changed, 33 insertions, 1 deletions

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 3865f8c6f647..bb668a894ab9 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -116,6 +116,30 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
         return xhci_pci_reinit(xhci, pdev);
 }
 
+#ifdef CONFIG_PM
+static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
+{
+        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+        int     retval = 0;
+
+        if (hcd->state != HC_STATE_SUSPENDED)
+                return -EINVAL;
+
+        retval = xhci_suspend(xhci);
+
+        return retval;
+}
+
+static int xhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
+{
+        struct xhci_hcd         *xhci = hcd_to_xhci(hcd);
+        int                     retval = 0;
+
+        retval = xhci_resume(xhci, hibernated);
+        return retval;
+}
+#endif /* CONFIG_PM */
+
 static const struct hc_driver xhci_pci_hc_driver = {
         .description =          hcd_name,
         .product_desc =         "xHCI Host Controller",
@@ -132,7 +156,10 @@ static const struct hc_driver xhci_pci_hc_driver = {
          */
         .reset =                xhci_pci_setup,
         .start =                xhci_run,
-        /* suspend and resume implemented later */
+#ifdef CONFIG_PM
+        .pci_suspend =          xhci_pci_suspend,
+        .pci_resume =           xhci_pci_resume,
+#endif
         .stop =                 xhci_stop,
         .shutdown =             xhci_shutdown,
 
@@ -188,6 +215,11 @@ static struct pci_driver xhci_pci_driver = {
         /* suspend and resume implemented later */
 
         .shutdown =     usb_hcd_pci_shutdown,
+#ifdef CONFIG_PM_SLEEP
+        .driver = {
+                .pm = &usb_hcd_pci_pm_ops
+        },
+#endif
 };
 
 int xhci_register_pci(void)