usb: dwc3: qcom: Keep power domain on to retain controller status

If dwc3 is wakeup capable, keep the power domain always ON so that
wakeup from system suspend can be supported. Otherwise, keep the
power domain ON only during runtime suspend to support wakeup from
runtime suspend.
Reviewed-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Link: https://lore.kernel.org/r/1655094654-24052-6-git-send-email-quic_kriskura@quicinc.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/dwc3-qcom.c

@@ -17,6 +17,7 @@
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
+#include <linux/pm_domain.h>
 #include <linux/usb/of.h>
 #include <linux/reset.h>
 #include <linux/iopoll.h>
@@ -756,12 +757,13 @@ dwc3_qcom_create_urs_usb_platdev(struct device *dev)
 
 static int dwc3_qcom_probe(struct platform_device *pdev)
 {
-	struct device_node	*np = pdev->dev.of_node;
-	struct device		*dev = &pdev->dev;
-	struct dwc3_qcom	*qcom;
-	struct resource		*res, *parent_res = NULL;
-	int			ret, i;
-	bool			ignore_pipe_clk;
+	struct device_node *np = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	struct dwc3_qcom *qcom;
+	struct resource	*res, *parent_res = NULL;
+	int ret, i;
+	bool ignore_pipe_clk;
+	struct generic_pm_domain *genpd;
 
 	qcom = devm_kzalloc(&pdev->dev, sizeof(*qcom), GFP_KERNEL);
 	if (!qcom)
@@ -770,6 +772,8 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, qcom);
 	qcom->dev = &pdev->dev;
 
+	genpd = pd_to_genpd(qcom->dev->pm_domain);
+
 	if (has_acpi_companion(dev)) {
 		qcom->acpi_pdata = acpi_device_get_match_data(dev);
 		if (!qcom->acpi_pdata) {
@@ -877,7 +881,17 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
 	if (ret)
 		goto interconnect_exit;
 
-	device_init_wakeup(&pdev->dev, 1);
+	if (device_can_wakeup(&qcom->dwc3->dev)) {
+		/*
+		 * Setting GENPD_FLAG_ALWAYS_ON flag takes care of keeping
+		 * genpd on in both runtime suspend and system suspend cases.
+		 */
+		genpd->flags |= GENPD_FLAG_ALWAYS_ON;
+		device_init_wakeup(&pdev->dev, true);
+	} else {
+		genpd->flags |= GENPD_FLAG_RPM_ALWAYS_ON;
+	}
+
 	qcom->is_suspended = false;
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);