drm/tegra: rgb: Restore DPMS

In order to restore DPMS with atomic mode-setting, move all code from
the ->mode_set() callback into ->enable(). At the same time, rename the
->prepare() callback to ->disable() to use the names preferred by atomic
mode-setting. This simplifies the calling sequence and will allow DPMS
code to use runtime PM in subsequent patches.

While at it, remove the enabled field that hasn't been used since the
demidlayering of the output drivers done in preparation for the atomic
mode-setting conversion.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/rgb.c b/drivers/gpu/drm/tegra/rgb.c
index 7cd833f..bc9735b 100644
--- a/drivers/gpu/drm/tegra/rgb.c
+++ b/drivers/gpu/drm/tegra/rgb.c
@@ -18,7 +18,6 @@
 struct tegra_rgb {
 	struct tegra_output output;
 	struct tegra_dc *dc;
-	bool enabled;
 
 	struct clk *clk_parent;
 	struct clk *clk;
@@ -88,13 +87,8 @@
 		tegra_dc_writel(dc, table[i].value, table[i].offset);
 }
 
-static void tegra_rgb_connector_dpms(struct drm_connector *connector,
-				     int mode)
-{
-}
-
 static const struct drm_connector_funcs tegra_rgb_connector_funcs = {
-	.dpms = tegra_rgb_connector_dpms,
+	.dpms = drm_atomic_helper_connector_dpms,
 	.reset = drm_atomic_helper_connector_reset,
 	.detect = tegra_output_connector_detect,
 	.fill_modes = drm_helper_probe_single_connector_modes,
@@ -125,21 +119,22 @@
 	.destroy = tegra_output_encoder_destroy,
 };
 
-static void tegra_rgb_encoder_dpms(struct drm_encoder *encoder, int mode)
+static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
 {
+	struct tegra_output *output = encoder_to_output(encoder);
+	struct tegra_rgb *rgb = to_rgb(output);
+
+	if (output->panel)
+		drm_panel_disable(output->panel);
+
+	tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
+	tegra_dc_commit(rgb->dc);
+
+	if (output->panel)
+		drm_panel_unprepare(output->panel);
 }
 
-static void tegra_rgb_encoder_prepare(struct drm_encoder *encoder)
-{
-}
-
-static void tegra_rgb_encoder_commit(struct drm_encoder *encoder)
-{
-}
-
-static void tegra_rgb_encoder_mode_set(struct drm_encoder *encoder,
-				       struct drm_display_mode *mode,
-				       struct drm_display_mode *adjusted)
+static void tegra_rgb_encoder_enable(struct drm_encoder *encoder)
 {
 	struct tegra_output *output = encoder_to_output(encoder);
 	struct tegra_rgb *rgb = to_rgb(output);
@@ -174,21 +169,6 @@
 		drm_panel_enable(output->panel);
 }
 
-static void tegra_rgb_encoder_disable(struct drm_encoder *encoder)
-{
-	struct tegra_output *output = encoder_to_output(encoder);
-	struct tegra_rgb *rgb = to_rgb(output);
-
-	if (output->panel)
-		drm_panel_disable(output->panel);
-
-	tegra_dc_write_regs(rgb->dc, rgb_disable, ARRAY_SIZE(rgb_disable));
-	tegra_dc_commit(rgb->dc);
-
-	if (output->panel)
-		drm_panel_unprepare(output->panel);
-}
-
 static int
 tegra_rgb_encoder_atomic_check(struct drm_encoder *encoder,
 			       struct drm_crtc_state *crtc_state,
@@ -231,11 +211,8 @@
 }
 
 static const struct drm_encoder_helper_funcs tegra_rgb_encoder_helper_funcs = {
-	.dpms = tegra_rgb_encoder_dpms,
-	.prepare = tegra_rgb_encoder_prepare,
-	.commit = tegra_rgb_encoder_commit,
-	.mode_set = tegra_rgb_encoder_mode_set,
 	.disable = tegra_rgb_encoder_disable,
+	.enable = tegra_rgb_encoder_enable,
 	.atomic_check = tegra_rgb_encoder_atomic_check,
 };