OMAP: DSS2: Functions to request/release DSI VCs

Introduce functions which request and release VC's. This will be used in panel
drivers in their probes.

omap_dsi_request_vc() takes in the pointer to the omap_dss_device, the VC_ID
parameter which goes into the header of the DSI packets, and returns a Virtual
channel number (or virtual channel register set) which it can use.

omap_dsi_set_vc_id() takes the omap_dss_device pointer, the Virtual Channel
number and the VC_ID that needs to be set for the specifed Virtual Channel.

omap_dsi_release_vc() takes the omap_dss_device pointer and the Virtual Channel
number that needs to be made free.

Initialisation of VC parameters is done in dsi_init().

Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/arch/arm/plat-omap/include/plat/display.h b/arch/arm/plat-omap/include/plat/display.h
index 3765824..e81ca66 100644
--- a/arch/arm/plat-omap/include/plat/display.h
+++ b/arch/arm/plat-omap/include/plat/display.h
@@ -562,6 +562,9 @@
 		int channel,
 		u16 x, u16 y, u16 w, u16 h,
 		void (*callback)(int, void *), void *data);
+int omap_dsi_request_vc(struct omap_dss_device *dssdev, int *channel);
+int omap_dsi_set_vc_id(struct omap_dss_device *dssdev, int channel, int vc_id);
+void omap_dsi_release_vc(struct omap_dss_device *dssdev, int channel);
 
 int omapdss_dsi_display_enable(struct omap_dss_device *dssdev);
 void omapdss_dsi_display_disable(struct omap_dss_device *dssdev);