usb: dwc3: core: Power-off core/PHYs on system_suspend in host mode

Commit 689bf72 ("usb: dwc3: Don't reinitialize core during
host bus-suspend/resume") updated suspend/resume routines to not
power_off and reinit PHYs/core for host mode.
It broke platforms that rely on DWC3 core to power_off PHYs to
enter low power state on system suspend.

Perform dwc3_core_exit/init only during host mode system_suspend/
resume to addresses power regression from above mentioned patch
and also allow USB session to stay connected across
runtime_suspend/resume in host mode. While at it also replace
existing checks for HOST only dr_mode with current_dr_role to
have similar core driver behavior for both Host-only and DRD+Host
configurations.

Fixes: 689bf72 ("usb: dwc3: Don't reinitialize core during host bus-suspend/resume")
Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/core.c

@@ -100,6 +100,8 @@ static void dwc3_set_prtcap(struct dwc3 *dwc, u32 mode)
 	reg &= ~(DWC3_GCTL_PRTCAPDIR(DWC3_GCTL_PRTCAP_OTG));
 	reg |= DWC3_GCTL_PRTCAPDIR(mode);
 	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
+
+	dwc->current_dr_role = mode;
 }
 
 static void __dwc3_set_mode(struct work_struct *work)
@@ -133,8 +135,6 @@ static void __dwc3_set_mode(struct work_struct *work)
 
 	dwc3_set_prtcap(dwc, dwc->desired_dr_role);
 
-	dwc->current_dr_role = dwc->desired_dr_role;
-
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
 	switch (dwc->desired_dr_role) {
@@ -219,7 +219,7 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
 	 * XHCI driver will reset the host block. If dwc3 was configured for
 	 * host-only mode, then we can return early.
 	 */
-	if (dwc->dr_mode == USB_DR_MODE_HOST)
+	if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_HOST)
 		return 0;
 
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
@@ -919,7 +919,6 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
 
 	switch (dwc->dr_mode) {
 	case USB_DR_MODE_PERIPHERAL:
-		dwc->current_dr_role = DWC3_GCTL_PRTCAP_DEVICE;
 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_DEVICE);
 
 		if (dwc->usb2_phy)
@@ -935,7 +934,6 @@ static int dwc3_core_init_mode(struct dwc3 *dwc)
 		}
 		break;
 	case USB_DR_MODE_HOST:
-		dwc->current_dr_role = DWC3_GCTL_PRTCAP_HOST;
 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
 
 		if (dwc->usb2_phy)
@@ -1287,7 +1285,7 @@ static int dwc3_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM
-static int dwc3_suspend_common(struct dwc3 *dwc)
+static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 {
 	unsigned long	flags;
 
@@ -1299,6 +1297,10 @@ static int dwc3_suspend_common(struct dwc3 *dwc)
 		dwc3_core_exit(dwc);
 		break;
 	case DWC3_GCTL_PRTCAP_HOST:
+		/* do nothing during host runtime_suspend */
+		if (!PMSG_IS_AUTO(msg))
+			dwc3_core_exit(dwc);
+		break;
 	default:
 		/* do nothing */
 		break;
@@ -1307,7 +1309,7 @@ static int dwc3_suspend_common(struct dwc3 *dwc)
 	return 0;
 }
 
-static int dwc3_resume_common(struct dwc3 *dwc)
+static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
 {
 	unsigned long	flags;
 	int		ret;
@@ -1323,6 +1325,13 @@ static int dwc3_resume_common(struct dwc3 *dwc)
 		spin_unlock_irqrestore(&dwc->lock, flags);
 		break;
 	case DWC3_GCTL_PRTCAP_HOST:
+		/* nothing to do on host runtime_resume */
+		if (!PMSG_IS_AUTO(msg)) {
+			ret = dwc3_core_init(dwc);
+			if (ret)
+				return ret;
+		}
+		break;
 	default:
 		/* do nothing */
 		break;
@@ -1334,12 +1343,11 @@ static int dwc3_resume_common(struct dwc3 *dwc)
 static int dwc3_runtime_checks(struct dwc3 *dwc)
 {
 	switch (dwc->current_dr_role) {
-	case USB_DR_MODE_PERIPHERAL:
-	case USB_DR_MODE_OTG:
+	case DWC3_GCTL_PRTCAP_DEVICE:
 		if (dwc->connected)
 			return -EBUSY;
 		break;
-	case USB_DR_MODE_HOST:
+	case DWC3_GCTL_PRTCAP_HOST:
 	default:
 		/* do nothing */
 		break;
@@ -1356,7 +1364,7 @@ static int dwc3_runtime_suspend(struct device *dev)
 	if (dwc3_runtime_checks(dwc))
 		return -EBUSY;
 
-	ret = dwc3_suspend_common(dwc);
+	ret = dwc3_suspend_common(dwc, PMSG_AUTO_SUSPEND);
 	if (ret)
 		return ret;
 
@@ -1372,7 +1380,7 @@ static int dwc3_runtime_resume(struct device *dev)
 
 	device_init_wakeup(dev, false);
 
-	ret = dwc3_resume_common(dwc);
+	ret = dwc3_resume_common(dwc, PMSG_AUTO_RESUME);
 	if (ret)
 		return ret;
 
@@ -1419,7 +1427,7 @@ static int dwc3_suspend(struct device *dev)
 	struct dwc3	*dwc = dev_get_drvdata(dev);
 	int		ret;
 
-	ret = dwc3_suspend_common(dwc);
+	ret = dwc3_suspend_common(dwc, PMSG_SUSPEND);
 	if (ret)
 		return ret;
 
@@ -1435,7 +1443,7 @@ static int dwc3_resume(struct device *dev)
 
 	pinctrl_pm_select_default_state(dev);
 
-	ret = dwc3_resume_common(dwc);
+	ret = dwc3_resume_common(dwc, PMSG_RESUME);
 	if (ret)
 		return ret;