[PATCH v2 10/12] usb: dwc2: Add clock gating entering flow by system suspend

[Artur Petrosyan]

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.petros...@synopsys.com>
---
 Changes in v2:
 - None

 drivers/usb/dwc2/hcd.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 31d6a1b87228..09dcd37b9ef8 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;
        }
-- 
2.25.1