usb: musb: introduce struct musb_platform_ops

This will be passed to musb_core by platform glue
layer in order to make it easier to compile support
for several HW glue layers.

Later patches will come using this structure and
also moving HW glue layers to its own platform
driver; the idea is to be able to handle platform
peculiarities in a manner which doesn't affect one
another.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/musb/musb_core.h

@@ -253,6 +253,34 @@ enum musb_g_ep0_state {
 
 /******************************** TYPES *************************************/
 
+/**
+ * struct musb_platform_ops - Operations passed to musb_core by HW glue layer
+ * @init:	turns on clocks, sets up platform-specific registers, etc
+ * @exit:	undoes @init
+ * @suspend:	platform-specific suspend, e.g. context save
+ * @resume:	platform-specific resume, e.g. context restore
+ * @set_mode:	forcefully changes operating mode
+ * @try_ilde:	tries to idle the IP
+ * @vbus_status: returns vbus status if possible
+ * @set_vbus:	forces vbus status
+ */
+struct musb_platform_ops {
+	int	(*init)(struct musb *musb);
+	int	(*exit)(struct musb *musb);
+
+	int	(*suspend)(struct musb *musb);
+	int	(*resume)(struct musb *musb);
+
+	void	(*enable)(struct musb *musb);
+	void	(*disable)(struct musb *musb);
+
+	int	(*set_mode)(struct musb *musb, u8 mode);
+	void	(*try_idle)(struct musb *musb, unsigned long timeout);
+
+	int	(*vbus_status)(struct musb *musb);
+	void	(*set_vbus)(struct musb *musb, int on);
+};
+
 /*
  * struct musb_hw_ep - endpoint hardware (bidirectional)
  *