[PATCHv5 6/7] usb: dwc2: gadget: Do not fail probe if there isn't a clock node

[<dinguyen@opensource.altera.com>]

From: Dinh Nguyen <dinguyen@opensource.altera.com>

Since the dwc2 hcd driver is currently not looking for a clock node during
init, we should not completely fail if there isn't a clock provided.
For dual-role mode, we will only fail init for a non-clock node error. We
then update the HCD to only call gadget funtions if there is a proper clock
node.

Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
---
v5: reworked to not access gadget functions from the hcd.
---
 drivers/usb/dwc2/core.h      |  3 +--
 drivers/usb/dwc2/core_intr.c |  9 ++++++---
 drivers/usb/dwc2/hcd.c       |  3 ++-
 drivers/usb/dwc2/platform.c  | 19 +++++++++++++++----
 4 files changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index ba488ec..8794c08 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -660,6 +660,7 @@ struct dwc2_hsotg {
 #endif
 #endif /* CONFIG_USB_DWC2_HOST || CONFIG_USB_DWC2_DUAL_ROLE */
 
+	struct clk *clk;
 #if IS_ENABLED(CONFIG_USB_DWC2_PERIPHERAL) || IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE)
 	/* Gadget structures */
 	struct usb_gadget_driver *driver;
@@ -667,8 +668,6 @@ struct dwc2_hsotg {
 	struct usb_phy *uphy;
 	struct s3c_hsotg_plat *plat;
 
-	struct clk *clk;
-
 	struct regulator_bulk_data supplies[ARRAY_SIZE(s3c_hsotg_supply_names)];
 
 	u32 phyif;
diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index 1240875..1608037 100644
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -339,7 +339,8 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
 		}
 		/* Change to L0 state */
 		hsotg->lx_state = DWC2_L0;
-		call_gadget(hsotg, resume);
+		if (!IS_ERR(hsotg->clk))
+			call_gadget(hsotg, resume);
 	} else {
 		if (hsotg->lx_state != DWC2_L1) {
 			u32 pcgcctl = readl(hsotg->regs + PCGCTL);
@@ -400,7 +401,8 @@ static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
 			"DSTS.Suspend Status=%d HWCFG4.Power Optimize=%d\n",
 			!!(dsts & DSTS_SUSPSTS),
 			hsotg->hw_params.power_optimized);
-		call_gadget(hsotg, suspend);
+		if (!IS_ERR(hsotg->clk))
+			call_gadget(hsotg, suspend);
 	} else {
 		if (hsotg->op_state == OTG_STATE_A_PERIPHERAL) {
 			dev_dbg(hsotg->dev, "a_peripheral->a_host\n");
@@ -477,7 +479,8 @@ irqreturn_t dwc2_handle_common_intr(int irq, void *dev)
 	spin_lock(&hsotg->lock);
 
 	if (dwc2_is_device_mode(hsotg))
-		retval = s3c_hsotg_irq(irq, dev);
+		if (!IS_ERR(hsotg->clk))
+			retval = s3c_hsotg_irq(irq, dev);
 
 	gintsts = dwc2_read_common_intr(hsotg);
 	if (gintsts & ~GINTSTS_PRTINT)
diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 44c609f..fa49c72 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -1371,7 +1371,8 @@ static void dwc2_conn_id_status_change(struct work_struct *work)
 		hsotg->op_state = OTG_STATE_B_PERIPHERAL;
 		dwc2_core_init(hsotg, false, -1);
 		dwc2_enable_global_interrupts(hsotg);
-		s3c_hsotg_core_init(hsotg);
+		if (!IS_ERR(hsotg->clk))
+			s3c_hsotg_core_init(hsotg);
 	} else {
 		/* A-Device connector (Host Mode) */
 		dev_dbg(hsotg->dev, "connId A\n");
diff --git a/drivers/usb/dwc2/platform.c b/drivers/usb/dwc2/platform.c
index 72f32f7..77c8417 100644
--- a/drivers/usb/dwc2/platform.c
+++ b/drivers/usb/dwc2/platform.c
@@ -217,8 +217,17 @@ static int dwc2_driver_probe(struct platform_device *dev)
 
 	spin_lock_init(&hsotg->lock);
 	retval = dwc2_gadget_init(hsotg, irq);
-	if (retval)
-		return retval;
+	if (retval) {
+		/*
+		 * We will not fail the driver initialization for dual-role
+		 * if no clock node is supplied. However, all gadget
+		 * functionality will be disabled if a clock node is not
+		 * provided. Host functionality will continue.
+		 * TO-DO: make clock node a requirement for the HCD.
+		 */
+		if (!IS_ERR(hsotg->clk))
+			return retval;
+	}
 	retval = dwc2_hcd_init(hsotg, irq, params);
 	if (retval)
 		return retval;
@@ -234,7 +243,8 @@ static int dwc2_suspend(struct device *dev)
 	int ret = 0;
 
 	if (dwc2_is_device_mode(dwc2))
-		ret = s3c_hsotg_suspend(dwc2);
+		if (!IS_ERR(dwc2->clk))
+			ret = s3c_hsotg_suspend(dwc2);
 	return ret;
 }
 
@@ -244,7 +254,8 @@ static int dwc2_resume(struct device *dev)
 	int ret = 0;
 
 	if (dwc2_is_device_mode(dwc2))
-		ret = s3c_hsotg_resume(dwc2);
+		if (!IS_ERR(dwc2->clk))
+			ret = s3c_hsotg_resume(dwc2);
 
 	return ret;
 }
-- 
2.0.3