usb: dwc2: gadget: Add functionality to exit from LPM L1 state

Add a function which will be called if device is in L1 sleep state
and Resume/Remote Wakeup Detected interrupt is asserted.

Signed-off-by: Sevak Arakelyan <sevaka@synopsys.com>
Signed-off-by: Grigor Tovmasyan <tovmasya@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index ab3fa16..6baa0c9 100644 (file)
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -335,6 +335,53 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
        }
 }
 
+/**
+ * dwc2_wakeup_from_lpm_l1 - Exit the device from LPM L1 state
+ *
+ * @hsotg: Programming view of DWC_otg controller
+ *
+ */
+static void dwc2_wakeup_from_lpm_l1(struct dwc2_hsotg *hsotg)
+{
+       u32 glpmcfg;
+       u32 i = 0;
+
+       if (hsotg->lx_state != DWC2_L1) {
+               dev_err(hsotg->dev, "Core isn't in DWC2_L1 state\n");
+               return;
+       }
+
+       glpmcfg = dwc2_readl(hsotg->regs + GLPMCFG);
+       if (dwc2_is_device_mode(hsotg)) {
+               dev_dbg(hsotg->dev, "Exit from L1 state\n");
+               glpmcfg &= ~GLPMCFG_ENBLSLPM;
+               glpmcfg &= ~GLPMCFG_HIRD_THRES_EN;
+               dwc2_writel(glpmcfg, hsotg->regs + GLPMCFG);
+
+               do {
+                       glpmcfg = dwc2_readl(hsotg->regs + GLPMCFG);
+
+                       if (!(glpmcfg & (GLPMCFG_COREL1RES_MASK |
+                                        GLPMCFG_L1RESUMEOK | GLPMCFG_SLPSTS)))
+                               break;
+
+                       udelay(1);
+               } while (++i < 200);
+
+               if (i == 200) {
+                       dev_err(hsotg->dev, "Failed to exit L1 sleep state in 200us.\n");
+                       return;
+               }
+       } else {
+               /* TODO */
+               dev_err(hsotg->dev, "Host side LPM is not supported.\n");
+               return;
+       }
+
+       /* Change to L0 state */
+       hsotg->lx_state = DWC2_L0;
+}
+
 /*
  * This interrupt indicates that the DWC_otg controller has detected a
  * resume or remote wakeup sequence. If the DWC_otg controller is in
@@ -352,6 +399,11 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
        dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
        dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
 
+       if (hsotg->lx_state == DWC2_L1) {
+               dwc2_wakeup_from_lpm_l1(hsotg);
+               return;
+       }
+
        if (dwc2_is_device_mode(hsotg)) {
                dev_dbg(hsotg->dev, "DSTS=0x%0x\n",
                        dwc2_readl(hsotg->regs + DSTS));