drm/fsl-dcu: enable TCON bypass mode by default

Do not use encoder disable/enable callbacks to control bypass
mode as this seems to mess with the signals not liked by
displays. This also makes more sense since the encoder is
already defined to be parallel RGB/LVDS at creation time.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Tested-By: Meng Yi <meng.yi@nxp.com>

drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c

@@ -273,6 +273,8 @@ static int fsl_dcu_drm_pm_resume(struct device *dev)
 		goto disable_dcu_clk;
 	}
 
+	if (fsl_dev->tcon)
+		fsl_tcon_bypass_enable(fsl_dev->tcon);
 	fsl_dcu_drm_init_planes(fsl_dev->drm);
 	drm_atomic_helper_resume(fsl_dev->drm, fsl_dev->state);
 

drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_rgb.c

@@ -20,38 +20,6 @@
 #include "fsl_dcu_drm_drv.h"
 #include "fsl_tcon.h"
 
-static int
-fsl_dcu_drm_encoder_atomic_check(struct drm_encoder *encoder,
-				 struct drm_crtc_state *crtc_state,
-				 struct drm_connector_state *conn_state)
-{
-	return 0;
-}
-
-static void fsl_dcu_drm_encoder_disable(struct drm_encoder *encoder)
-{
-	struct drm_device *dev = encoder->dev;
-	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
-
-	if (fsl_dev->tcon)
-		fsl_tcon_bypass_disable(fsl_dev->tcon);
-}
-
-static void fsl_dcu_drm_encoder_enable(struct drm_encoder *encoder)
-{
-	struct drm_device *dev = encoder->dev;
-	struct fsl_dcu_drm_device *fsl_dev = dev->dev_private;
-
-	if (fsl_dev->tcon)
-		fsl_tcon_bypass_enable(fsl_dev->tcon);
-}
-
-static const struct drm_encoder_helper_funcs encoder_helper_funcs = {
-	.atomic_check = fsl_dcu_drm_encoder_atomic_check,
-	.disable = fsl_dcu_drm_encoder_disable,
-	.enable = fsl_dcu_drm_encoder_enable,
-};
-
 static void fsl_dcu_drm_encoder_destroy(struct drm_encoder *encoder)
 {
 	drm_encoder_cleanup(encoder);
@@ -68,13 +36,16 @@ int fsl_dcu_drm_encoder_create(struct fsl_dcu_drm_device *fsl_dev,
 	int ret;
 
 	encoder->possible_crtcs = 1;
+
+	/* Use bypass mode for parallel RGB/LVDS encoder */
+	if (fsl_dev->tcon)
+		fsl_tcon_bypass_enable(fsl_dev->tcon);
+
 	ret = drm_encoder_init(fsl_dev->drm, encoder, &encoder_funcs,
 			       DRM_MODE_ENCODER_LVDS, NULL);
 	if (ret < 0)
 		return ret;
 
-	drm_encoder_helper_add(encoder, &encoder_helper_funcs);
-
 	return 0;
 }