[RFC PATCH v2 01/13] drm/atomic-helper: split not-scaling part of drm_atomic_helper_check_plane_state

[Dmitry Baryshkov]

The helper drm_atomic_helper_check_plane_state() runs several checks on
plane src and dst rectangles, including the check whether required
scaling fits into the required margins. The msm driver would benefit
from having a function that does all these checks except the scaling
one. Split them into a new helper called
drm_atomic_helper_check_plane_noscale().

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
---
 drivers/gpu/drm/drm_atomic_helper.c | 85 ++++++++++++++++++++++-------
 include/drm/drm_atomic_helper.h     |  4 ++
 2 files changed, 68 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index d579fd8f7cb8..86c5e19c7bdb 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -825,11 +825,9 @@ drm_atomic_helper_check_wb_encoder_state(struct drm_encoder *encoder,
 EXPORT_SYMBOL(drm_atomic_helper_check_wb_encoder_state);
 
 /**
- * drm_atomic_helper_check_plane_state() - Check plane state for validity
+ * drm_atomic_helper_check_plane_noscale() - Check plane state for validity
  * @plane_state: plane state to check
  * @crtc_state: CRTC state to check
- * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
- * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
  * @can_position: is it legal to position the plane such that it
  *                doesn't cover the entire CRTC?  This will generally
  *                only be false for primary planes.
@@ -845,19 +843,16 @@ EXPORT_SYMBOL(drm_atomic_helper_check_wb_encoder_state);
  * RETURNS:
  * Zero if update appears valid, error code on failure
  */
-int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
-					const struct drm_crtc_state *crtc_state,
-					int min_scale,
-					int max_scale,
-					bool can_position,
-					bool can_update_disabled)
+int drm_atomic_helper_check_plane_noscale(struct drm_plane_state *plane_state,
+					  const struct drm_crtc_state *crtc_state,
+					  bool can_position,
+					  bool can_update_disabled)
 {
 	struct drm_framebuffer *fb = plane_state->fb;
 	struct drm_rect *src = &plane_state->src;
 	struct drm_rect *dst = &plane_state->dst;
 	unsigned int rotation = plane_state->rotation;
 	struct drm_rect clip = {};
-	int hscale, vscale;
 
 	WARN_ON(plane_state->crtc && plane_state->crtc != crtc_state->crtc);
 
@@ -883,17 +878,6 @@ int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
 
 	drm_rect_rotate(src, fb->width << 16, fb->height << 16, rotation);
 
-	/* Check scaling */
-	hscale = drm_rect_calc_hscale(src, dst, min_scale, max_scale);
-	vscale = drm_rect_calc_vscale(src, dst, min_scale, max_scale);
-	if (hscale < 0 || vscale < 0) {
-		drm_dbg_kms(plane_state->plane->dev,
-			    "Invalid scaling of plane\n");
-		drm_rect_debug_print("src: ", &plane_state->src, true);
-		drm_rect_debug_print("dst: ", &plane_state->dst, false);
-		return -ERANGE;
-	}
-
 	if (crtc_state->enable)
 		drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
 
@@ -921,6 +905,65 @@ int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
 
 	return 0;
 }
+EXPORT_SYMBOL(drm_atomic_helper_check_plane_noscale);
+
+/**
+ * drm_atomic_helper_check_plane_state() - Check plane state for validity
+ * @plane_state: plane state to check
+ * @crtc_state: CRTC state to check
+ * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
+ * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
+ * @can_position: is it legal to position the plane such that it
+ *                doesn't cover the entire CRTC?  This will generally
+ *                only be false for primary planes.
+ * @can_update_disabled: can the plane be updated while the CRTC
+ *                       is disabled?
+ *
+ * Checks that a desired plane update is valid, and updates various
+ * bits of derived state (clipped coordinates etc.). Drivers that provide
+ * their own plane handling rather than helper-provided implementations may
+ * still wish to call this function to avoid duplication of error checking
+ * code.
+ *
+ * RETURNS:
+ * Zero if update appears valid, error code on failure
+ */
+int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
+					const struct drm_crtc_state *crtc_state,
+					int min_scale,
+					int max_scale,
+					bool can_position,
+					bool can_update_disabled)
+{
+	struct drm_framebuffer *fb = plane_state->fb;
+	struct drm_rect src;
+	struct drm_rect dst;
+	int hscale, vscale, ret;
+
+	ret = drm_atomic_helper_check_plane_noscale(plane_state, crtc_state, can_position, can_update_disabled);
+	if (ret < 0)
+		return ret;
+
+	if (!plane_state->visible)
+		return 0;
+
+	src = drm_plane_state_src(plane_state);
+	dst = drm_plane_state_dest(plane_state);
+
+	drm_rect_rotate(&src, fb->width << 16, fb->height << 16, plane_state->rotation);
+
+	hscale = drm_rect_calc_hscale(&src, &dst, min_scale, max_scale);
+	vscale = drm_rect_calc_vscale(&src, &dst, min_scale, max_scale);
+	if (hscale < 0 || vscale < 0) {
+		drm_dbg_kms(plane_state->plane->dev,
+			    "Invalid scaling of plane\n");
+		drm_rect_debug_print("src: ", &plane_state->src, true);
+		drm_rect_debug_print("dst: ", &plane_state->dst, false);
+		return -ERANGE;
+	}
+
+	return 0;
+}
 EXPORT_SYMBOL(drm_atomic_helper_check_plane_state);
 
 /**
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 33f982cd1a27..ebf95437431d 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -52,6 +52,10 @@ int drm_atomic_helper_check_modeset(struct drm_device *dev,
 int
 drm_atomic_helper_check_wb_encoder_state(struct drm_encoder *encoder,
 					 struct drm_connector_state *conn_state);
+int drm_atomic_helper_check_plane_noscale(struct drm_plane_state *plane_state,
+					  const struct drm_crtc_state *crtc_state,
+					  bool can_position,
+					  bool can_update_disabled);
 int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
 					const struct drm_crtc_state *crtc_state,
 					int min_scale,
-- 
2.30.2