drm: Add drm_rect_debug_print()

Add a debug function to print the rectangle in a human readable format.

v2: Renamed drm_region to drm_rect, the function from drm_region_debug
    to drm_rect_debug_print(), and use %+d instead of +%d in the format.
v3: Use %d format for width/height in the non fixed point case as well

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Dave Airlie <airlied@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_rect.c

@@ -24,6 +24,7 @@
 #include <linux/errno.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
+#include <drm/drmP.h>
 #include <drm/drm_rect.h>
 
 /**
@@ -271,3 +272,24 @@ int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
 	return vscale;
 }
 EXPORT_SYMBOL(drm_rect_calc_vscale_relaxed);
+
+/**
+ * drm_rect_debug_print - print the rectangle information
+ * @r: rectangle to print
+ * @fixed_point: rectangle is in 16.16 fixed point format
+ */
+void drm_rect_debug_print(const struct drm_rect *r, bool fixed_point)
+{
+	int w = drm_rect_width(r);
+	int h = drm_rect_height(r);
+
+	if (fixed_point)
+		DRM_DEBUG_KMS("%d.%06ux%d.%06u%+d.%06u%+d.%06u\n",
+			      w >> 16, ((w & 0xffff) * 15625) >> 10,
+			      h >> 16, ((h & 0xffff) * 15625) >> 10,
+			      r->x1 >> 16, ((r->x1 & 0xffff) * 15625) >> 10,
+			      r->y1 >> 16, ((r->y1 & 0xffff) * 15625) >> 10);
+	else
+		DRM_DEBUG_KMS("%dx%d%+d%+d\n", w, h, r->x1, r->y1);
+}
+EXPORT_SYMBOL(drm_rect_debug_print);

include/drm/drm_rect.h

@@ -140,5 +140,6 @@ int drm_rect_calc_hscale_relaxed(struct drm_rect *src,
 int drm_rect_calc_vscale_relaxed(struct drm_rect *src,
 				 struct drm_rect *dst,
 				 int min_vscale, int max_vscale);
+void drm_rect_debug_print(const struct drm_rect *r, bool fixed_point);
 
 #endif