[PATCH] [RFC] usb: dwc3: removal of assumption that usb3 phy always present

[Ruchika Kharwar <ruchika-l0cyMroinI0@public.gmane.org>]

DRA7XX has several USB OTG subsystems. USB_OTG_SS1 includes a USB1 and USB2
phy. USB_OTG_SS2 includes only a USB2 phy.
This patch allows the dwc3 probe to continue if a usb3_phy is not found.

This patch currently works for DRA7XX and submitted in the interim a nicer
method emerges.

Signed-off-by: Ruchika Kharwar <ruchika-l0cyMroinI0@public.gmane.org>
---
 drivers/usb/dwc3/core.c   |   38 ++++++++++++++++++++------------------
 drivers/usb/dwc3/gadget.c |   11 ++++++++---
 2 files changed, 28 insertions(+), 21 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 358375e..feea92d 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -100,7 +100,10 @@ static void dwc3_core_soft_reset(struct dwc3 *dwc)
 	dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
 
 	usb_phy_init(dwc->usb2_phy);
-	usb_phy_init(dwc->usb3_phy);
+
+	if (!IS_ERR(dwc->usb3_phy))
+		usb_phy_init(dwc->usb3_phy);
+
 	mdelay(100);
 
 	/* Clear USB3 PHY reset */
@@ -360,7 +363,9 @@ err0:
 static void dwc3_core_exit(struct dwc3 *dwc)
 {
 	usb_phy_shutdown(dwc->usb2_phy);
-	usb_phy_shutdown(dwc->usb3_phy);
+
+	if (!IS_ERR(dwc->usb3_phy))
+		usb_phy_shutdown(dwc->usb3_phy);
 }
 
 #define DWC3_ALIGN_MASK		(16 - 1)
@@ -450,22 +455,13 @@ static int dwc3_probe(struct platform_device *pdev)
 	}
 
 	if (IS_ERR(dwc->usb3_phy)) {
-		ret = PTR_ERR(dwc->usb3_phy);
-
-		/*
-		 * if -ENXIO is returned, it means PHY layer wasn't
-		 * enabled, so it makes no sense to return -EPROBE_DEFER
-		 * in that case, since no PHY driver will ever probe.
-		 */
-		if (ret == -ENXIO)
-			return ret;
-
-		dev_err(dev, "no usb3 phy configured\n");
-		return -EPROBE_DEFER;
+		dev_dbg(dev, "no usb3 phy configured, possibly absent\n");
 	}
 
 	usb_phy_set_suspend(dwc->usb2_phy, 0);
-	usb_phy_set_suspend(dwc->usb3_phy, 0);
+
+	if (!IS_ERR(dwc->usb3_phy))
+		usb_phy_set_suspend(dwc->usb3_phy, 0);
 
 	spin_lock_init(&dwc->lock);
 	platform_set_drvdata(pdev, dwc);
@@ -604,7 +600,9 @@ static int dwc3_remove(struct platform_device *pdev)
 	struct dwc3	*dwc = platform_get_drvdata(pdev);
 
 	usb_phy_set_suspend(dwc->usb2_phy, 1);
-	usb_phy_set_suspend(dwc->usb3_phy, 1);
+
+	if (!IS_ERR(dwc->usb3_phy))
+		usb_phy_set_suspend(dwc->usb3_phy, 1);
 
 	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
@@ -700,7 +698,9 @@ static int dwc3_suspend(struct device *dev)
 	dwc->gctl = dwc3_readl(dwc->regs, DWC3_GCTL);
 	spin_unlock_irqrestore(&dwc->lock, flags);
 
-	usb_phy_shutdown(dwc->usb3_phy);
+	if (!IS_ERR(dwc->usb3_phy))
+		usb_phy_shutdown(dwc->usb3_phy);
+
 	usb_phy_shutdown(dwc->usb2_phy);
 
 	return 0;
@@ -711,7 +711,9 @@ static int dwc3_resume(struct device *dev)
 	struct dwc3	*dwc = dev_get_drvdata(dev);
 	unsigned long	flags;
 
-	usb_phy_init(dwc->usb3_phy);
+	if (!IS_ERR(dwc->usb3_phy))
+		usb_phy_init(dwc->usb3_phy);
+
 	usb_phy_init(dwc->usb2_phy);
 	msleep(100);
 
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index b5e5b35..7ca3745 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -2176,7 +2176,9 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
 	if (dwc->revision < DWC3_REVISION_194A) {
 		/* Resume PHYs */
 		dwc3_gadget_usb2_phy_suspend(dwc, false);
-		dwc3_gadget_usb3_phy_suspend(dwc, false);
+
+		if (!IS_ERR(dwc->usb3_phy))
+			dwc3_gadget_usb3_phy_suspend(dwc, false);
 	}
 
 	if (dwc->gadget.speed != USB_SPEED_UNKNOWN)
@@ -2231,7 +2233,8 @@ static void dwc3_gadget_phy_suspend(struct dwc3 *dwc, u8 speed)
 	case USB_SPEED_HIGH:
 	case USB_SPEED_FULL:
 	case USB_SPEED_LOW:
-		dwc3_gadget_usb3_phy_suspend(dwc, true);
+		if (!IS_ERR(dwc->usb3_phy))
+			dwc3_gadget_usb3_phy_suspend(dwc, true);
 		break;
 	}
 }
@@ -2649,7 +2652,9 @@ int dwc3_gadget_init(struct dwc3 *dwc)
 	/* Enable USB2 LPM and automatic phy suspend only on recent versions */
 	if (dwc->revision >= DWC3_REVISION_194A) {
 		dwc3_gadget_usb2_phy_suspend(dwc, false);
-		dwc3_gadget_usb3_phy_suspend(dwc, false);
+
+		if (!IS_ERR(dwc->usb3_phy))
+			dwc3_gadget_usb3_phy_suspend(dwc, false);
 	}
 
 	ret = usb_add_gadget_udc(dwc->dev, &dwc->gadget);
-- 
1.7.9.5

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