usb: musb: fix dependency on transceiver driver

This patch let glue driver return -EPROBE_DEFER if the transceiver
is not readly, so we can support defer probe on musb to fix the
below error on 3.7-rc5 if transceiver drivers are built as module:

[   19.052490] unable to find transceiver of type USB2 PHY
[   19.072052] HS USB OTG: no transceiver configured
[   19.076995] musb-hdrc musb-hdrc.0.auto: musb_init_controller failed with status -19
[   19.089355] musb-hdrc: probe of musb-hdrc.0.auto rejects match -19
[   19.096771] driver: 'musb-omap2430': driver_bound: bound to device 'musb-omap2430'
[   19.105194] bus: 'platform': really_probe: bound device musb-omap2430 to driver musb-omap2430
[   19.174407] bus: 'platform': add driver twl4030_usb
[   19.179656] bus: 'platform': driver_probe_device: matched device twl4030_usb with driver twl4030_usb
[   19.202270] bus: 'platform': really_probe: probing driver twl4030_usb with device twl4030_usb
[   19.214172] twl4030_usb twl4030_usb: HW_CONDITIONS 0xc0/192; link 3
[   19.239624] musb-omap2430 musb-omap2430: musb core is not yet ready
[   19.246765] twl4030_usb twl4030_usb: Initialized TWL4030 USB module
[   19.254516] driver: 'twl4030_usb': driver_bound: bound to device 'twl4030_usb'
[   19.263580] bus: 'platform': really_probe: bound device twl4030_usb to driver twl4030_usb

Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Cc: <stable@vger.kernel.org> v3.8
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/musb/am35x.c

@@ -365,7 +365,7 @@ static int am35x_musb_init(struct musb *musb)
 	usb_nop_xceiv_register();
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
 	if (IS_ERR_OR_NULL(musb->xceiv))
-		return -ENODEV;
+		return -EPROBE_DEFER;
 
 	setup_timer(&otg_workaround, otg_timer, (unsigned long) musb);
 

drivers/usb/musb/blackfin.c

@@ -406,7 +406,7 @@ static int bfin_musb_init(struct musb *musb)
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
 	if (IS_ERR_OR_NULL(musb->xceiv)) {
 		gpio_free(musb->config->gpio_vrsel);
-		return -ENODEV;
+		return -EPROBE_DEFER;
 	}
 
 	bfin_musb_reg_init(musb);

drivers/usb/musb/da8xx.c

@@ -410,6 +410,7 @@ static int da8xx_musb_init(struct musb *musb)
 {
 	void __iomem *reg_base = musb->ctrl_base;
 	u32 rev;
+	int ret = -ENODEV;
 
 	musb->mregs += DA8XX_MENTOR_CORE_OFFSET;
 
@@ -420,8 +421,10 @@ static int da8xx_musb_init(struct musb *musb)
 
 	usb_nop_xceiv_register();
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
-	if (IS_ERR_OR_NULL(musb->xceiv))
+	if (IS_ERR_OR_NULL(musb->xceiv)) {
+		ret = -EPROBE_DEFER;
 		goto fail;
+	}
 
 	setup_timer(&otg_workaround, otg_timer, (unsigned long)musb);
 
@@ -441,7 +444,7 @@ static int da8xx_musb_init(struct musb *musb)
 	musb->isr = da8xx_musb_interrupt;
 	return 0;
 fail:
-	return -ENODEV;
+	return ret;
 }
 
 static int da8xx_musb_exit(struct musb *musb)

drivers/usb/musb/davinci.c

@@ -380,11 +380,14 @@ static int davinci_musb_init(struct musb *musb)
 {
 	void __iomem	*tibase = musb->ctrl_base;
 	u32		revision;
+	int 		ret = -ENODEV;
 
 	usb_nop_xceiv_register();
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
-	if (IS_ERR_OR_NULL(musb->xceiv))
+	if (IS_ERR_OR_NULL(musb->xceiv)) {
+		ret = -EPROBE_DEFER;
 		goto unregister;
+	}
 
 	musb->mregs += DAVINCI_BASE_OFFSET;
 
@@ -438,7 +441,7 @@ static int davinci_musb_init(struct musb *musb)
 	usb_put_phy(musb->xceiv);
 unregister:
 	usb_nop_xceiv_unregister();
-	return -ENODEV;
+	return ret;
 }
 
 static int davinci_musb_exit(struct musb *musb)

drivers/usb/musb/musb_dsps.c

@@ -413,7 +413,7 @@ static int dsps_musb_init(struct musb *musb)
 	usb_nop_xceiv_register();
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
 	if (IS_ERR_OR_NULL(musb->xceiv))
-		return -ENODEV;
+		return -EPROBE_DEFER;
 
 	/* Returns zero if e.g. not clocked */
 	rev = dsps_readl(reg_base, wrp->revision);

drivers/usb/musb/omap2430.c

@@ -369,7 +369,7 @@ static int omap2430_musb_init(struct musb *musb)
 	musb->xceiv = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
 	if (IS_ERR_OR_NULL(musb->xceiv)) {
 		pr_err("HS USB OTG: no transceiver configured\n");
-		return -ENODEV;
+		return -EPROBE_DEFER;
 	}
 
 	musb->isr = omap2430_musb_interrupt;

drivers/usb/musb/tusb6010.c

@@ -1069,7 +1069,7 @@ static int tusb_musb_init(struct musb *musb)
 	usb_nop_xceiv_register();
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
 	if (IS_ERR_OR_NULL(musb->xceiv))
-		return -ENODEV;
+		return -EPROBE_DEFER;
 
 	pdev = to_platform_device(musb->controller);
 

drivers/usb/musb/ux500.c

@@ -61,7 +61,7 @@ static int ux500_musb_init(struct musb *musb)
 	musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
 	if (IS_ERR_OR_NULL(musb->xceiv)) {
 		pr_err("HS USB OTG: no transceiver configured\n");
-		return -ENODEV;
+		return -EPROBE_DEFER;
 	}
 
 	musb->isr = ux500_musb_interrupt;