drm/imx: ipuv3-plane: add function to query atomic update status

This function allows upper layer to check if a requested atomic update
to the plane has been applied or is still pending.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
[p.zabel@pengutronix.de: inverted logic: done -> pending]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/imx/ipuv3-plane.c

@@ -582,6 +582,7 @@ static void ipu_plane_atomic_update(struct drm_plane *plane,
 		active = ipu_idmac_get_current_buffer(ipu_plane->ipu_ch);
 		ipu_cpmem_set_buffer(ipu_plane->ipu_ch, !active, eba);
 		ipu_idmac_select_buffer(ipu_plane->ipu_ch, !active);
+		ipu_plane->next_buf = !active;
 		if (ipu_plane_separate_alpha(ipu_plane)) {
 			active = ipu_idmac_get_current_buffer(ipu_plane->alpha_ch);
 			ipu_cpmem_set_buffer(ipu_plane->alpha_ch, !active,
@@ -709,6 +710,7 @@ static void ipu_plane_atomic_update(struct drm_plane *plane,
 	ipu_cpmem_set_buffer(ipu_plane->ipu_ch, 1, eba);
 	ipu_idmac_lock_enable(ipu_plane->ipu_ch, num_bursts);
 	ipu_plane_enable(ipu_plane);
+	ipu_plane->next_buf = -1;
 }
 
 static const struct drm_plane_helper_funcs ipu_plane_helper_funcs = {
@@ -718,6 +720,24 @@ static const struct drm_plane_helper_funcs ipu_plane_helper_funcs = {
 	.atomic_update = ipu_plane_atomic_update,
 };
 
+bool ipu_plane_atomic_update_pending(struct drm_plane *plane)
+{
+	struct ipu_plane *ipu_plane = to_ipu_plane(plane);
+	struct drm_plane_state *state = plane->state;
+	struct ipu_plane_state *ipu_state = to_ipu_plane_state(state);
+
+	/* disabled crtcs must not block the update */
+	if (!state->crtc)
+		return false;
+
+	if (ipu_state->use_pre)
+		return ipu_prg_channel_configure_pending(ipu_plane->ipu_ch);
+	else if (ipu_plane->next_buf >= 0)
+		return ipu_idmac_get_current_buffer(ipu_plane->ipu_ch) !=
+		       ipu_plane->next_buf;
+
+	return false;
+}
 int ipu_planes_assign_pre(struct drm_device *dev,
 			  struct drm_atomic_state *state)
 {

drivers/gpu/drm/imx/ipuv3-plane.h

@@ -27,6 +27,7 @@ struct ipu_plane {
 	int			dp_flow;
 
 	bool			disabling;
+	int			next_buf;
 };
 
 struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
@@ -48,5 +49,6 @@ int ipu_plane_irq(struct ipu_plane *plane);
 
 void ipu_plane_disable(struct ipu_plane *ipu_plane, bool disable_dp_channel);
 void ipu_plane_disable_deferred(struct drm_plane *plane);
+bool ipu_plane_atomic_update_pending(struct drm_plane *plane);
 
 #endif