USB: phy: nop: Defer probe if device needs VCC/RESET

Add 2 flags, needs_vcc and needs_reset to platform data.
If the flag is set and the regulator couldn't be found
then we bail out with -EPROBE_DEFER.

For device tree boot we depend on presensce of vcc-supply/
reset-supply properties to decide if we should bail out
with -EPROBE_DEFER or just continue in case the regulator
can't be found.

This is required for proper functionality in cases where the
regulator is needed but is probed later than the PHY device.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/otg/nop-usb-xceiv.c

@@ -147,6 +147,8 @@ static int nop_usb_xceiv_probe(struct platform_device *pdev)
 	enum usb_phy_type	type = USB_PHY_TYPE_USB2;
 	int err;
 	u32 clk_rate = 0;
+	bool needs_vcc = false;
+	bool needs_reset = false;
 
 	nop = devm_kzalloc(&pdev->dev, sizeof(*nop), GFP_KERNEL);
 	if (!nop)
@@ -163,9 +165,14 @@ static int nop_usb_xceiv_probe(struct platform_device *pdev)
 		if (of_property_read_u32(node, "clock-frequency", &clk_rate))
 			clk_rate = 0;
 
+		needs_vcc = of_property_read_bool(node, "vcc-supply");
+		needs_reset = of_property_read_bool(node, "reset-supply");
+
 	} else if (pdata) {
 		type = pdata->type;
 		clk_rate = pdata->clk_rate;
+		needs_vcc = pdata->needs_vcc;
+		needs_reset = pdata->needs_reset;
 	}
 
 	nop->clk = devm_clk_get(&pdev->dev, "main_clk");
@@ -194,12 +201,16 @@ static int nop_usb_xceiv_probe(struct platform_device *pdev)
 	if (IS_ERR(nop->vcc)) {
 		dev_dbg(&pdev->dev, "Error getting vcc regulator: %ld\n",
 					PTR_ERR(nop->vcc));
+		if (needs_vcc)
+			return -EPROBE_DEFER;
 	}
 
 	nop->reset = devm_regulator_get(&pdev->dev, "reset");
 	if (IS_ERR(nop->reset)) {
 		dev_dbg(&pdev->dev, "Error getting reset regulator: %ld\n",
 					PTR_ERR(nop->reset));
+		if (needs_reset)
+			return -EPROBE_DEFER;
 	}
 
 	nop->dev		= &pdev->dev;