xHCI: set USB2 hardware LPM

If the device pass the USB2 software LPM and the host supports hardware
LPM, enable hardware LPM for the device to let the host decide when to
put the link into lower power state.

If hardware LPM is enabled for a port and driver wants to put it into
suspend, it must first disable hardware LPM, resume the port into U0,
and then suspend the port.

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, 14 insertions, 0 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index 14b83f2a4e87..adf5ca8a2396 100644
--- a/drivers/usb/core/driver.c
+++ b/drivers/usb/core/driver.c
@@ -1700,6 +1700,20 @@ int usb_runtime_idle(struct device *dev)
         return 0;
 }
 
+int usb_set_usb2_hardware_lpm(struct usb_device *udev, int enable)
+{
+        struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+        int ret = -EPERM;
+
+        if (hcd->driver->set_usb2_hw_lpm) {
+                ret = hcd->driver->set_usb2_hw_lpm(hcd, udev, enable);
+                if (!ret)
+                        udev->usb2_hw_lpm_enabled = enable;
+        }
+
+        return ret;
+}
+
 #endif /* CONFIG_USB_SUSPEND */
 
 struct bus_type usb_bus_type = {