[PATCH 07/10] drm/mxsfb: Signal mode changed when bpp changed

[Robert Chiras <robert.chiras@nxp.com>]

From: Mirela Rabulea <mirela.rabulea@nxp.com>

Add mxsfb_atomic_helper_check to signal mode changed when bpp changed.
This will trigger the execution of disable/enable on
a modeset with different bpp than the current one.

Signed-off-by: Mirela Rabulea <mirela.rabulea@nxp.com>
---
 drivers/gpu/drm/mxsfb/mxsfb_drv.c | 48 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
index d3fb3a8..f528a37 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
@@ -115,9 +115,55 @@ void mxsfb_disable_axi_clk(struct mxsfb_drm_private *mxsfb)
 		clk_disable_unprepare(mxsfb->clk_axi);
 }
 
+/**
+ * mxsfb_atomic_helper_check - validate state object
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * On top of the drm imlementation drm_atomic_helper_check,
+ * check if the bpp is changed, if so, signal mode_changed,
+ * this will trigger disable/enable
+ *
+ * RETURNS:
+ * Zero for success or -errno
+ */
+static int mxsfb_atomic_helper_check(struct drm_device *dev,
+			    struct drm_atomic_state *state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *crtc_state;
+	int i, ret;
+
+	ret = drm_atomic_helper_check(dev, state);
+	if (ret)
+		return ret;
+
+	for_each_crtc_in_state(state, crtc, crtc_state, i) {
+		struct drm_plane_state *primary_state;
+		int old_bpp = 0;
+		int new_bpp = 0;
+
+		if (!crtc->primary || !crtc->primary->old_fb)
+			continue;
+		primary_state =
+			drm_atomic_get_plane_state(state, crtc->primary);
+		if (!primary_state || !primary_state->fb)
+			continue;
+		old_bpp = crtc->primary->old_fb->format->depth;
+		new_bpp = primary_state->fb->format->depth;
+		if (old_bpp != new_bpp) {
+			crtc_state->mode_changed = true;
+			DRM_DEBUG_ATOMIC(
+				"[CRTC:%d:%s] mode changed, bpp %d->%d\n",
+				crtc->base.id, crtc->name, old_bpp, new_bpp);
+		}
+	}
+	return ret;
+}
+
 static const struct drm_mode_config_funcs mxsfb_mode_config_funcs = {
 	.fb_create		= drm_gem_fb_create,
-	.atomic_check		= drm_atomic_helper_check,
+	.atomic_check		= mxsfb_atomic_helper_check,
 	.atomic_commit		= drm_atomic_helper_commit,
 };
 
-- 
2.7.4