drm/i915: Add rotation support for cursor plane (v5)

The cursor plane also supports 180 degree rotation. Add a new
"cursor-rotation" property on the crtc which controls this.

Unlike sprites, the cursor has a fixed size, so if you have a small
cursor image with the rest of the bo filled by transparent pixels,
simply flipping the rotation property will cause the visible part
of the cursor to shift. This is something to keep in mind when
using cursor rotation.

v2: Fix gen4/vlv by offsetting the base address appropriately

v3: Removing cursor-rotation property and using rotation property on cursor
plane.
v4: Changing the author name back to Ville.

v5 (by Matt Roper): Slight tweaking to apply against latest di-nightly
codebase.

Cc: Sagar Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Tested-by (IVB): Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -4208,6 +4208,7 @@ enum punit_power_well {
 #define   MCURSOR_PIPE_A	0x00
 #define   MCURSOR_PIPE_B	(1 << 28)
 #define   MCURSOR_GAMMA_ENABLE  (1 << 26)
+#define   CURSOR_ROTATE_180	(1<<15)
 #define   CURSOR_TRICKLE_FEED_DISABLE	(1 << 14)
 #define _CURABASE		0x70084
 #define _CURAPOS		0x70088

drivers/gpu/drm/i915/intel_display.c

@@ -8343,6 +8343,9 @@ static void i9xx_update_cursor(struct drm_crtc *crtc, u32 base)
 			cntl |= CURSOR_PIPE_CSC_ENABLE;
 	}
 
+	if (to_intel_plane(crtc->cursor)->rotation == BIT(DRM_ROTATE_180))
+		cntl |= CURSOR_ROTATE_180;
+
 	if (intel_crtc->cursor_cntl != cntl) {
 		I915_WRITE(CURCNTR(pipe), cntl);
 		POSTING_READ(CURCNTR(pipe));
@@ -8400,6 +8403,13 @@ static void intel_crtc_update_cursor(struct drm_crtc *crtc,
 
 	I915_WRITE(CURPOS(pipe), pos);
 
+	/* ILK+ do this automagically */
+	if (HAS_GMCH_DISPLAY(dev) &&
+		to_intel_plane(crtc->cursor)->rotation == BIT(DRM_ROTATE_180)) {
+		base += (intel_crtc->cursor_height *
+			intel_crtc->cursor_width - 1) * 4;
+	}
+
 	if (IS_845G(dev) || IS_I865G(dev))
 		i845_update_cursor(crtc, base);
 	else
@@ -12010,6 +12020,7 @@ static const struct drm_plane_funcs intel_cursor_plane_funcs = {
 	.update_plane = intel_cursor_plane_update,
 	.disable_plane = intel_cursor_plane_disable,
 	.destroy = intel_plane_destroy,
+	.set_property = intel_plane_set_property,
 };
 
 static struct drm_plane *intel_cursor_plane_create(struct drm_device *dev,
@@ -12025,12 +12036,26 @@ static struct drm_plane *intel_cursor_plane_create(struct drm_device *dev,
 	cursor->max_downscale = 1;
 	cursor->pipe = pipe;
 	cursor->plane = pipe;
+	cursor->rotation = BIT(DRM_ROTATE_0);
 
 	drm_universal_plane_init(dev, &cursor->base, 0,
 				 &intel_cursor_plane_funcs,
 				 intel_cursor_formats,
 				 ARRAY_SIZE(intel_cursor_formats),
 				 DRM_PLANE_TYPE_CURSOR);
+
+	if (INTEL_INFO(dev)->gen >= 4) {
+		if (!dev->mode_config.rotation_property)
+			dev->mode_config.rotation_property =
+				drm_mode_create_rotation_property(dev,
+							BIT(DRM_ROTATE_0) |
+							BIT(DRM_ROTATE_180));
+		if (dev->mode_config.rotation_property)
+			drm_object_attach_property(&cursor->base.base,
+				dev->mode_config.rotation_property,
+				cursor->rotation);
+	}
+
 	return &cursor->base;
 }