usb: chipidea: add support for roles

Add some generic code for roles and implement simple role switching
based on ID pin state and/or a sysfs file. At this, we also rename
the device to ci_hdrc, which is what it is.

The "manual" switch is made into a sysfs file and not debugfs, because
it might be useful even in non-debug context. For some boards, like
sheevaplug, it seems to be the only way to switch roles without modifying
the hardware, since the ID pin is always grounded.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/chipidea/udc.h b/drivers/usb/chipidea/udc.h
index 82c9e3e..3a9e669 100644
--- a/drivers/usb/chipidea/udc.h
+++ b/drivers/usb/chipidea/udc.h
@@ -71,26 +71,16 @@
 };
 
 #ifdef CONFIG_USB_CHIPIDEA_UDC
-irqreturn_t udc_irq(int irq, void *data);
-int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
-	      void __iomem *regs, struct ci13xxx **_udc);
-void udc_remove(struct ci13xxx *udc);
+
+int ci_hdrc_gadget_init(struct ci13xxx *ci);
+
 #else
-static inline irqreturn_t udc_irq(int irq, void *data)
+
+static inline int ci_hdrc_gadget_init(struct ci13xxx *ci)
 {
-	return IRQ_NONE;
+	return -ENXIO;
 }
 
-static inline
-int udc_probe(struct ci13xxx_udc_driver *driver, struct device *dev,
-	      void __iomem *regs, struct ci13xxx **_udc)
-{
-	return -ENODEV;
-}
-
-static inline void udc_remove(struct ci13xxx *udc)
-{
-}
 #endif
 
 #endif /* __DRIVERS_USB_CHIPIDEA_UDC_H */