usb: dwc2: Add clock gating entering flow by system suspend
If not hibernation nor partial power down are supported,
clock gating is used to save power.
Adds a new flow of entering clock gating when PC is
suspended.
Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Link: https://lore.kernel.org/r/20210413073716.30C13A0094@mailhost.synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 31d6a1b..09dcd37 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -4372,6 +4372,15 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd)
break;
case DWC2_POWER_DOWN_PARAM_HIBERNATION:
case DWC2_POWER_DOWN_PARAM_NONE:
+ /*
+ * If not hibernation nor partial power down are supported,
+ * clock gating is used to save power.
+ */
+ dwc2_host_enter_clock_gating(hsotg);
+
+ /* After entering suspend, hardware is not accessible */
+ clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+ break;
default:
goto skip_power_saving;
}
