USB: musb: sysfs mode updates

Fix three omissions in the "mode" sysfs attribute support:
  (a) inability to report errors;
  (b) no DaVinci support ... just report an error;
  (c) for omap2430, accepting unsupportable values

The 2430 stuff is still odd....

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/omap2430.c

@@ -196,7 +196,7 @@ static int omap_set_power(struct otg_transceiver *x, unsigned mA)
 
 static int musb_platform_resume(struct musb *musb);
 
-void musb_platform_set_mode(struct musb *musb, u8 musb_mode)
+int musb_platform_set_mode(struct musb *musb, u8 musb_mode)
 {
 	u8	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
 
@@ -204,15 +204,24 @@ void musb_platform_set_mode(struct musb *musb, u8 musb_mode)
 	musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
 
 	switch (musb_mode) {
+#ifdef CONFIG_USB_MUSB_HDRC_HCD
 	case MUSB_HOST:
 		otg_set_host(&musb->xceiv, musb->xceiv.host);
 		break;
+#endif
+#ifdef CONFIG_USB_GADGET_MUSB_HDRC
 	case MUSB_PERIPHERAL:
 		otg_set_peripheral(&musb->xceiv, musb->xceiv.gadget);
 		break;
+#endif
+#ifdef CONFIG_USB_MUSB_OTG
 	case MUSB_OTG:
 		break;
+#endif
+	default:
+		return -EINVAL;
 	}
+	return 0;
 }
 
 int __init musb_platform_init(struct musb *musb)