usb: dwc2: Add clock gating exiting flow by system resume

If not hibernation nor partial power down are supported,
port resume is done using the clock gating programming flow.

Adds a new flow of exiting clock gating when PC is
resumed.

Signed-off-by: Artur Petrosyan <Arthur.Petrosyan@synopsys.com>
Link: https://lore.kernel.org/r/20210413073723.BA0FEA022E@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 09dcd37..04a1b53 100644 (file)
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -4445,6 +4445,28 @@ static int _dwc2_hcd_resume(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,
+                * port resume is done using the clock gating programming flow.
+                */
+               spin_unlock_irqrestore(&hsotg->lock, flags);
+               dwc2_host_exit_clock_gating(hsotg, 0);
+
+               /*
+                * Initialize the Core for Host mode, as after system resume
+                * the global interrupts are disabled.
+                */
+               dwc2_core_init(hsotg, false);
+               dwc2_enable_global_interrupts(hsotg);
+               dwc2_hcd_reinit(hsotg);
+               spin_lock_irqsave(&hsotg->lock, flags);
+
+               /*
+                * Set HW accessible bit before powering on the controller
+                * since an interrupt may rise.
+                */
+               set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+               break;
        default:
                hsotg->lx_state = DWC2_L0;
                goto unlock;