usb: dwc3: qcom: Configure wakeup interrupts during suspend

Configure DP/DM line interrupts based on the USB2 device attached to
the root hub port. When HS/FS device is connected, configure the DP line
as falling edge to detect both disconnect and remote wakeup scenarios. When
LS device is connected, configure DM line as falling edge to detect both
disconnect and remote wakeup. When no device is connected, configure both
DP and DM lines as rising edge to detect HS/HS/LS device connect scenario.

Reviewed-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
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/1655094654-24052-5-git-send-email-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/dwc3-qcom.c

@@ -20,7 +20,8 @@
 #include <linux/usb/of.h>
 #include <linux/reset.h>
 #include <linux/iopoll.h>
-
+#include <linux/usb/hcd.h>
+#include <linux/usb.h>
 #include "core.h"
 
 /* USB QSCRATCH Hardware registers */
@@ -76,6 +77,7 @@ struct dwc3_qcom {
 	int			dp_hs_phy_irq;
 	int			dm_hs_phy_irq;
 	int			ss_phy_irq;
+	enum usb_device_speed	usb2_speed;
 
 	struct extcon_dev	*edev;
 	struct extcon_dev	*host_edev;
@@ -296,11 +298,34 @@ static void dwc3_qcom_interconnect_exit(struct dwc3_qcom *qcom)
 	icc_put(qcom->icc_path_apps);
 }
 
-static void dwc3_qcom_enable_wakeup_irq(int irq)
+static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
+{
+	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
+	struct usb_hcd *hcd = platform_get_drvdata(dwc->xhci);
+	struct usb_device *udev;
+
+	/*
+	 * It is possible to query the speed of all children of
+	 * USB2.0 root hub via usb_hub_for_each_child(). DWC3 code
+	 * currently supports only 1 port per controller. So
+	 * this is sufficient.
+	 */
+	udev = usb_hub_find_child(hcd->self.root_hub, 1);
+
+	if (!udev)
+		return USB_SPEED_UNKNOWN;
+
+	return udev->speed;
+}
+
+static void dwc3_qcom_enable_wakeup_irq(int irq, unsigned int polarity)
 {
 	if (!irq)
 		return;
 
+	if (polarity)
+		irq_set_irq_type(irq, polarity);
+
 	enable_irq(irq);
 	enable_irq_wake(irq);
 }
@@ -318,22 +343,47 @@ static void dwc3_qcom_disable_interrupts(struct dwc3_qcom *qcom)
 {
 	dwc3_qcom_disable_wakeup_irq(qcom->hs_phy_irq);
 
-	dwc3_qcom_disable_wakeup_irq(qcom->dp_hs_phy_irq);
-
-	dwc3_qcom_disable_wakeup_irq(qcom->dm_hs_phy_irq);
+	if (qcom->usb2_speed == USB_SPEED_LOW) {
+		dwc3_qcom_disable_wakeup_irq(qcom->dm_hs_phy_irq);
+	} else if ((qcom->usb2_speed == USB_SPEED_HIGH) ||
+			(qcom->usb2_speed == USB_SPEED_FULL)) {
+		dwc3_qcom_disable_wakeup_irq(qcom->dp_hs_phy_irq);
+	} else {
+		dwc3_qcom_disable_wakeup_irq(qcom->dp_hs_phy_irq);
+		dwc3_qcom_disable_wakeup_irq(qcom->dm_hs_phy_irq);
+	}
 
 	dwc3_qcom_disable_wakeup_irq(qcom->ss_phy_irq);
 }
 
 static void dwc3_qcom_enable_interrupts(struct dwc3_qcom *qcom)
 {
-	dwc3_qcom_enable_wakeup_irq(qcom->hs_phy_irq);
+	dwc3_qcom_enable_wakeup_irq(qcom->hs_phy_irq, 0);
 
-	dwc3_qcom_enable_wakeup_irq(qcom->dp_hs_phy_irq);
+	/*
+	 * Configure DP/DM line interrupts based on the USB2 device attached to
+	 * the root hub port. When HS/FS device is connected, configure the DP line
+	 * as falling edge to detect both disconnect and remote wakeup scenarios. When
+	 * LS device is connected, configure DM line as falling edge to detect both
+	 * disconnect and remote wakeup. When no device is connected, configure both
+	 * DP and DM lines as rising edge to detect HS/HS/LS device connect scenario.
+	 */
 
-	dwc3_qcom_enable_wakeup_irq(qcom->dm_hs_phy_irq);
+	if (qcom->usb2_speed == USB_SPEED_LOW) {
+		dwc3_qcom_enable_wakeup_irq(qcom->dm_hs_phy_irq,
+						IRQ_TYPE_EDGE_FALLING);
+	} else if ((qcom->usb2_speed == USB_SPEED_HIGH) ||
+			(qcom->usb2_speed == USB_SPEED_FULL)) {
+		dwc3_qcom_enable_wakeup_irq(qcom->dp_hs_phy_irq,
+						IRQ_TYPE_EDGE_FALLING);
+	} else {
+		dwc3_qcom_enable_wakeup_irq(qcom->dp_hs_phy_irq,
+						IRQ_TYPE_EDGE_RISING);
+		dwc3_qcom_enable_wakeup_irq(qcom->dm_hs_phy_irq,
+						IRQ_TYPE_EDGE_RISING);
+	}
 
-	dwc3_qcom_enable_wakeup_irq(qcom->ss_phy_irq);
+	dwc3_qcom_enable_wakeup_irq(qcom->ss_phy_irq, 0);
 }
 
 static int dwc3_qcom_suspend(struct dwc3_qcom *qcom)
@@ -355,8 +405,10 @@ static int dwc3_qcom_suspend(struct dwc3_qcom *qcom)
 	if (ret)
 		dev_warn(qcom->dev, "failed to disable interconnect: %d\n", ret);
 
-	if (device_may_wakeup(qcom->dev))
+	if (device_may_wakeup(qcom->dev)) {
+		qcom->usb2_speed = dwc3_qcom_read_usb2_speed(qcom);
 		dwc3_qcom_enable_interrupts(qcom);
+	}
 
 	qcom->is_suspended = true;