Re: [PATCH 2/2] usb: dwc3: Host wake up support from system suspend

Avoiding phy powerdown in host mode so that it can be wake up by devices.
Set usb controller wakeup capable when wakeup capable devices are
connected to the host.

Signed-off-by: Sandeep Maheswaram <redacted>
---
 drivers/usb/dwc3/core.c      | 47 ++++++++++++++++++++++++++-----
 drivers/usb/dwc3/core.h      |  1 +
 drivers/usb/dwc3/dwc3-qcom.c | 66 +++++++++++++++++++++++++++++++++-----------
 3 files changed, 91 insertions(+), 23 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 25c686a7..8370350 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c

@@ -31,15 +31,19 @@
 #include <linux/usb/gadget.h>
 #include <linux/usb/of.h>
 #include <linux/usb/otg.h>
+#include <linux/usb/hcd.h>
 
 #include "core.h"
 #include "gadget.h"
 #include "io.h"
 
 #include "debug.h"
+#include "../host/xhci.h"

+
 /**
  * dwc3_get_dr_mode - Validates and sets dr_mode
  * @dwc: pointer to our context structure

@@ -1627,10 +1631,36 @@ static int dwc3_core_init_for_resume(struct dwc3 *dwc)
 	return ret;
 }
 
+static void dwc3_set_phy_speed_flags(struct dwc3 *dwc)
+{
+
+	int i, num_ports;
+	u32 reg;
+	struct usb_hcd	*hcd = platform_get_drvdata(dwc->xhci);
+	struct xhci_hcd	*xhci_hcd = hcd_to_xhci(hcd);
+
+	dwc->hs_phy_flags &= ~(PHY_MODE_USB_HOST_HS | PHY_MODE_USB_HOST_LS);
+
+	reg = readl(&xhci_hcd->cap_regs->hcs_params1);
+
+	num_ports = HCS_MAX_PORTS(reg);
+	for (i = 0; i < num_ports; i++) {
+		reg = readl(&xhci_hcd->op_regs->port_status_base + i*0x10);
+		if (reg & PORT_PE) {
+			if (DEV_HIGHSPEED(reg) || DEV_FULLSPEED(reg))
+				dwc->hs_phy_flags |= PHY_MODE_USB_HOST_HS;
+			else if (DEV_LOWSPEED(reg))
+				dwc->hs_phy_flags |= PHY_MODE_USB_HOST_LS;
+		}
+	}
+	phy_set_mode(dwc->usb2_generic_phy, dwc->hs_phy_flags);

 static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 {
 	unsigned long	flags;
 	u32 reg;
+	struct usb_hcd  *hcd = platform_get_drvdata(dwc->xhci);
 
 	switch (dwc->current_dr_role) {
 	case DWC3_GCTL_PRTCAP_DEVICE:

@@ -1643,9 +1673,10 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 		dwc3_core_exit(dwc);
 		break;
 	case DWC3_GCTL_PRTCAP_HOST:
+		dwc3_set_phy_speed_flags(dwc);
 		if (!PMSG_IS_AUTO(msg)) {
-			dwc3_core_exit(dwc);
-			break;
+			if (usb_wakeup_enabled_descendants(hcd->self.root_hub))
+				need_phy_for_wakeup = true;

@@ -1705,11 +1736,13 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
 		break;
 	case DWC3_GCTL_PRTCAP_HOST:
 		if (!PMSG_IS_AUTO(msg)) {
-			ret = dwc3_core_init_for_resume(dwc);
-			if (ret)
-				return ret;
-			dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
-			break;
+			if (!need_phy_for_wakeup) {
+				ret = dwc3_core_init_for_resume(dwc);
+				if (ret)
+					return ret;
+				dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
+				break;