sun4i/drm: backend: use mode_set engine callback

Newly introduced mode_set callback in engine structure is a much better
place for setting backend output size and interlace mode for following
reasons:
1. Aforementioned properties change only when mode changes, so it's
   enough to be set only once per mode set. Currently it's done whenever
   properties of primary plane are changed.
2. It's assumed that primary plane will always cover whole screen. While
   this is true most of the time, it's not always. Planes are universal.
   There is no reason to add artificial limitation to primary plane.

Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
[Samuel: drop unused 'interlaced' variable]
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220424162633.12369-8-samuel@sholland.org

drivers/gpu/drm/sun4i/sun4i_backend.c

@@ -172,14 +172,6 @@ int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
 
 	DRM_DEBUG_DRIVER("Updating layer %d\n", layer);
 
-	if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
-		DRM_DEBUG_DRIVER("Primary layer, updating global size W: %u H: %u\n",
-				 state->crtc_w, state->crtc_h);
-		regmap_write(backend->engine.regs, SUN4I_BACKEND_DISSIZE_REG,
-			     SUN4I_BACKEND_DISSIZE(state->crtc_w,
-						   state->crtc_h));
-	}
-
 	/* Set height and width */
 	DRM_DEBUG_DRIVER("Layer size W: %u H: %u\n",
 			 state->crtc_w, state->crtc_h);
@@ -259,7 +251,6 @@ int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,
 {
 	struct drm_plane_state *state = plane->state;
 	struct drm_framebuffer *fb = state->fb;
-	bool interlaced = false;
 	u32 val;
 	int ret;
 
@@ -267,17 +258,6 @@ int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,
 	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_ATTCTL_REG0(layer),
 			   SUN4I_BACKEND_ATTCTL_REG0_LAY_YUVEN, 0);
 
-	if (plane->state->crtc)
-		interlaced = plane->state->crtc->state->adjusted_mode.flags
-			& DRM_MODE_FLAG_INTERLACE;
-
-	regmap_update_bits(backend->engine.regs, SUN4I_BACKEND_MODCTL_REG,
-			   SUN4I_BACKEND_MODCTL_ITLMOD_EN,
-			   interlaced ? SUN4I_BACKEND_MODCTL_ITLMOD_EN : 0);
-
-	DRM_DEBUG_DRIVER("Switching display backend interlaced mode %s\n",
-			 interlaced ? "on" : "off");
-
 	val = SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA(state->alpha >> 8);
 	if (state->alpha != DRM_BLEND_ALPHA_OPAQUE)
 		val |= SUN4I_BACKEND_ATTCTL_REG0_LAY_GLBALPHA_EN;
@@ -654,6 +634,25 @@ static void sun4i_backend_vblank_quirk(struct sunxi_engine *engine)
 	spin_unlock(&backend->frontend_lock);
 };
 
+static void sun4i_backend_mode_set(struct sunxi_engine *engine,
+				   const struct drm_display_mode *mode)
+{
+	bool interlaced = !!(mode->flags & DRM_MODE_FLAG_INTERLACE);
+
+	DRM_DEBUG_DRIVER("Updating global size W: %u H: %u\n",
+			 mode->hdisplay, mode->vdisplay);
+
+	regmap_write(engine->regs, SUN4I_BACKEND_DISSIZE_REG,
+		     SUN4I_BACKEND_DISSIZE(mode->hdisplay, mode->vdisplay));
+
+	regmap_update_bits(engine->regs, SUN4I_BACKEND_MODCTL_REG,
+			   SUN4I_BACKEND_MODCTL_ITLMOD_EN,
+			   interlaced ? SUN4I_BACKEND_MODCTL_ITLMOD_EN : 0);
+
+	DRM_DEBUG_DRIVER("Switching display backend interlaced mode %s\n",
+			 interlaced ? "on" : "off");
+}
+
 static int sun4i_backend_init_sat(struct device *dev) {
 	struct sun4i_backend *backend = dev_get_drvdata(dev);
 	int ret;
@@ -765,6 +764,7 @@ static const struct sunxi_engine_ops sun4i_backend_engine_ops = {
 	.apply_color_correction		= sun4i_backend_apply_color_correction,
 	.disable_color_correction	= sun4i_backend_disable_color_correction,
 	.vblank_quirk			= sun4i_backend_vblank_quirk,
+	.mode_set			= sun4i_backend_mode_set,
 };
 
 static const struct regmap_config sun4i_backend_regmap_config = {