usb: dwc3: core: Suspend PHYs on runtime suspend in host mode

Some PHY drivers (e.g. for Qualcomm QUSB2 and QMP PHYs) support
runtime PM to reduce PHY power consumption during bus_suspend.
Add changes to let core auto-suspend PHYs on host bus-suspend
using GUSB2PHYCFG register if needed for a platform. Also perform
PHYs runtime suspend/resume and let platform glue drivers e.g.
dwc3-qcom handle remote wakeup during bus suspend by waking up
devices on receiving wakeup event from PHY.

Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index a15648d25e30c46eb6eaa3336375a545980ec1e3..449a0982111b9f169ad6db0a7f87818f0e266dac 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1394,6 +1394,7 @@ static int dwc3_remove(struct platform_device *pdev)
 static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
 {
        unsigned long   flags;
+       u32 reg;
 
        switch (dwc->current_dr_role) {
        case DWC3_GCTL_PRTCAP_DEVICE:
@@ -1403,9 +1404,25 @@ static int dwc3_suspend_common(struct dwc3 *dwc, pm_message_t msg)
                dwc3_core_exit(dwc);
                break;
        case DWC3_GCTL_PRTCAP_HOST:
-               /* do nothing during host runtime_suspend */
-               if (!PMSG_IS_AUTO(msg))
+               if (!PMSG_IS_AUTO(msg)) {
                        dwc3_core_exit(dwc);
+                       break;
+               }
+
+               /* Let controller to suspend HSPHY before PHY driver suspends */
+               if (dwc->dis_u2_susphy_quirk ||
+                   dwc->dis_enblslpm_quirk) {
+                       reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+                       reg |=  DWC3_GUSB2PHYCFG_ENBLSLPM |
+                               DWC3_GUSB2PHYCFG_SUSPHY;
+                       dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+
+                       /* Give some time for USB2 PHY to suspend */
+                       usleep_range(5000, 6000);
+               }
+
+               phy_pm_runtime_put_sync(dwc->usb2_generic_phy);
+               phy_pm_runtime_put_sync(dwc->usb3_generic_phy);
                break;
        case DWC3_GCTL_PRTCAP_OTG:
                /* do nothing during runtime_suspend */
@@ -1433,6 +1450,7 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
 {
        unsigned long   flags;
        int             ret;
+       u32             reg;
 
        switch (dwc->current_dr_role) {
        case DWC3_GCTL_PRTCAP_DEVICE:
@@ -1446,13 +1464,25 @@ static int dwc3_resume_common(struct dwc3 *dwc, pm_message_t msg)
                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;
                        dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
+                       break;
                }
+               /* Restore GUSB2PHYCFG bits that were modified in suspend */
+               reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
+               if (dwc->dis_u2_susphy_quirk)
+                       reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+
+               if (dwc->dis_enblslpm_quirk)
+                       reg &= ~DWC3_GUSB2PHYCFG_ENBLSLPM;
+
+               dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
+
+               phy_pm_runtime_get_sync(dwc->usb2_generic_phy);
+               phy_pm_runtime_get_sync(dwc->usb3_generic_phy);
                break;
        case DWC3_GCTL_PRTCAP_OTG:
                /* nothing to do on runtime_resume */