OMAPDSS: VRFB: add omap_vrfb_supported()

Add an exported function omap_vrfb_supported() which returns true if the
vrfb driver has been loaded succesfully. This can be used to decide if
VRFB can be used or not.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/vrfb.c

@@ -77,6 +77,8 @@ static void __iomem *vrfb_base;
 static int num_ctxs;
 static struct vrfb_ctx *ctxs;
 
+static bool vrfb_loaded;
+
 static void omap2_sms_write_rot_control(u32 val, unsigned ctx)
 {
 	__raw_writel(val, vrfb_base + SMS_ROT_CONTROL(ctx));
@@ -336,6 +338,12 @@ int omap_vrfb_request_ctx(struct vrfb *vrfb)
 }
 EXPORT_SYMBOL(omap_vrfb_request_ctx);
 
+bool omap_vrfb_supported(void)
+{
+	return vrfb_loaded;
+}
+EXPORT_SYMBOL(omap_vrfb_supported);
+
 static int __init vrfb_probe(struct platform_device *pdev)
 {
 	struct resource *mem;
@@ -375,11 +383,19 @@ static int __init vrfb_probe(struct platform_device *pdev)
 		ctxs[i].base = mem->start;
 	}
 
+	vrfb_loaded = true;
+
 	return 0;
 }
 
+static void __exit vrfb_remove(struct platform_device *pdev)
+{
+	vrfb_loaded = false;
+}
+
 static struct platform_driver vrfb_driver = {
 	.driver.name	= "omapvrfb",
+	.remove		= __exit_p(vrfb_remove),
 };
 
 static int __init vrfb_init(void)

include/video/omapvrfb.h

@@ -36,6 +36,7 @@ struct vrfb {
 };
 
 #ifdef CONFIG_OMAP2_VRFB
+extern bool omap_vrfb_supported(void);
 extern int omap_vrfb_request_ctx(struct vrfb *vrfb);
 extern void omap_vrfb_release_ctx(struct vrfb *vrfb);
 extern void omap_vrfb_adjust_size(u16 *width, u16 *height,
@@ -49,6 +50,7 @@ extern int omap_vrfb_map_angle(struct vrfb *vrfb, u16 height, u8 rot);
 extern void omap_vrfb_restore_context(void);
 
 #else
+static inline bool omap_vrfb_supported(void) { return false; }
 static inline int omap_vrfb_request_ctx(struct vrfb *vrfb) { return 0; }
 static inline void omap_vrfb_release_ctx(struct vrfb *vrfb) {}
 static inline void omap_vrfb_adjust_size(u16 *width, u16 *height,