Merge branch 'drm-atmel-hlcdc-devel' of https://github.com/bbrezillon/linux-at91 into drm-next

This PR contains several improvement and cleanup patches for the
atmel-hlcdc driver to be applied on drm-next (targeting 4.7).

* 'drm-atmel-hlcdc-devel' of https://github.com/bbrezillon/linux-at91:
  drm: atmel-hlcdc: route DMA accesses through AHB interfaces
  drm: atmel-hlcdc: check display mode validity in crtc->mode_fixup()
  drm: atmel-hlcdc: rework the output code to support drm bridges
  drm: atmel-hlcdc: move output mode selection in CRTC implementation
  drm: atmel-hlcdc: support extended timing ranges on sama5d4 and sama5d2
  drm: atmel-hlcdc: remove leftovers from atomic mode setting migration
  drm: atmel-hlcdc: fix connector and encoder types
  drm: atmel-hlcdc: support asynchronous atomic commit operations
  drm: atmel-hlcdc: add a ->cleanup_fb() operation

5 files changed, 481 insertions, 159 deletions

diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index 58c4f785cf84..8df0aaf98725 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -32,6 +32,23 @@
 #include "atmel_hlcdc_dc.h"
 
 /**
+ * Atmel HLCDC CRTC state structure
+ *
+ * @base: base CRTC state
+ * @output_mode: RGBXXX output mode
+ */
+struct atmel_hlcdc_crtc_state {
+	struct drm_crtc_state base;
+	unsigned int output_mode;
+};
+
+static inline struct atmel_hlcdc_crtc_state *
+drm_crtc_state_to_atmel_hlcdc_crtc_state(struct drm_crtc_state *state)
+{
+	return container_of(state, struct atmel_hlcdc_crtc_state, base);
+}
+
+/**
  * Atmel HLCDC CRTC structure
  *
  * @base: base DRM CRTC structure
@@ -59,6 +76,7 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
 	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
 	struct regmap *regmap = crtc->dc->hlcdc->regmap;
 	struct drm_display_mode *adj = &c->state->adjusted_mode;
+	struct atmel_hlcdc_crtc_state *state;
 	unsigned long mode_rate;
 	struct videomode vm;
 	unsigned long prate;
@@ -112,15 +130,27 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
 	if (adj->flags & DRM_MODE_FLAG_NHSYNC)
 		cfg |= ATMEL_HLCDC_HSPOL;
 
+	state = drm_crtc_state_to_atmel_hlcdc_crtc_state(c->state);
+	cfg |= state->output_mode << 8;
+
 	regmap_update_bits(regmap, ATMEL_HLCDC_CFG(5),
 			   ATMEL_HLCDC_HSPOL | ATMEL_HLCDC_VSPOL |
 			   ATMEL_HLCDC_VSPDLYS | ATMEL_HLCDC_VSPDLYE |
 			   ATMEL_HLCDC_DISPPOL | ATMEL_HLCDC_DISPDLY |
 			   ATMEL_HLCDC_VSPSU | ATMEL_HLCDC_VSPHO |
-			   ATMEL_HLCDC_GUARDTIME_MASK,
+			   ATMEL_HLCDC_GUARDTIME_MASK | ATMEL_HLCDC_MODE_MASK,
 			   cfg);
 }
 
+static bool atmel_hlcdc_crtc_mode_fixup(struct drm_crtc *c,
+					const struct drm_display_mode *mode,
+					struct drm_display_mode *adjusted_mode)
+{
+	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
+
+	return atmel_hlcdc_dc_mode_valid(crtc->dc, adjusted_mode) == MODE_OK;
+}
+
 static void atmel_hlcdc_crtc_disable(struct drm_crtc *c)
 {
 	struct drm_device *dev = c->dev;
@@ -221,15 +251,79 @@ void atmel_hlcdc_crtc_resume(struct drm_crtc *c)
 	}
 }
 
+#define ATMEL_HLCDC_RGB444_OUTPUT	BIT(0)
+#define ATMEL_HLCDC_RGB565_OUTPUT	BIT(1)
+#define ATMEL_HLCDC_RGB666_OUTPUT	BIT(2)
+#define ATMEL_HLCDC_RGB888_OUTPUT	BIT(3)
+#define ATMEL_HLCDC_OUTPUT_MODE_MASK	GENMASK(3, 0)
+
+static int atmel_hlcdc_crtc_select_output_mode(struct drm_crtc_state *state)
+{
+	unsigned int output_fmts = ATMEL_HLCDC_OUTPUT_MODE_MASK;
+	struct atmel_hlcdc_crtc_state *hstate;
+	struct drm_connector_state *cstate;
+	struct drm_connector *connector;
+	struct atmel_hlcdc_crtc *crtc;
+	int i;
+
+	crtc = drm_crtc_to_atmel_hlcdc_crtc(state->crtc);
+
+	for_each_connector_in_state(state->state, connector, cstate, i) {
+		struct drm_display_info *info = &connector->display_info;
+		unsigned int supported_fmts = 0;
+		int j;
+
+		if (!cstate->crtc)
+			continue;
+
+		for (j = 0; j < info->num_bus_formats; j++) {
+			switch (info->bus_formats[j]) {
+			case MEDIA_BUS_FMT_RGB444_1X12:
+				supported_fmts |= ATMEL_HLCDC_RGB444_OUTPUT;
+				break;
+			case MEDIA_BUS_FMT_RGB565_1X16:
+				supported_fmts |= ATMEL_HLCDC_RGB565_OUTPUT;
+				break;
+			case MEDIA_BUS_FMT_RGB666_1X18:
+				supported_fmts |= ATMEL_HLCDC_RGB666_OUTPUT;
+				break;
+			case MEDIA_BUS_FMT_RGB888_1X24:
+				supported_fmts |= ATMEL_HLCDC_RGB888_OUTPUT;
+				break;
+			default:
+				break;
+			}
+		}
+
+		if (crtc->dc->desc->conflicting_output_formats)
+			output_fmts &= supported_fmts;
+		else
+			output_fmts |= supported_fmts;
+	}
+
+	if (!output_fmts)
+		return -EINVAL;
+
+	hstate = drm_crtc_state_to_atmel_hlcdc_crtc_state(state);
+	hstate->output_mode = fls(output_fmts) - 1;
+
+	return 0;
+}
+
 static int atmel_hlcdc_crtc_atomic_check(struct drm_crtc *c,
 					 struct drm_crtc_state *s)
 {
-	struct atmel_hlcdc_crtc *crtc = drm_crtc_to_atmel_hlcdc_crtc(c);
+	int ret;
 
-	if (atmel_hlcdc_dc_mode_valid(crtc->dc, &s->adjusted_mode) != MODE_OK)
-		return -EINVAL;
+	ret = atmel_hlcdc_crtc_select_output_mode(s);
+	if (ret)
+		return ret;
+
+	ret = atmel_hlcdc_plane_prepare_disc_area(s);
+	if (ret)
+		return ret;
 
-	return atmel_hlcdc_plane_prepare_disc_area(s);
+	return atmel_hlcdc_plane_prepare_ahb_routing(s);
 }
 
 static void atmel_hlcdc_crtc_atomic_begin(struct drm_crtc *c,
@@ -254,6 +348,7 @@ static void atmel_hlcdc_crtc_atomic_flush(struct drm_crtc *crtc,
 }
 
 static const struct drm_crtc_helper_funcs lcdc_crtc_helper_funcs = {
+	.mode_fixup = atmel_hlcdc_crtc_mode_fixup,
 	.mode_set = drm_helper_crtc_mode_set,
 	.mode_set_nofb = atmel_hlcdc_crtc_mode_set_nofb,
 	.mode_set_base = drm_helper_crtc_mode_set_base,
@@ -292,13 +387,60 @@ void atmel_hlcdc_crtc_irq(struct drm_crtc *c)
 	atmel_hlcdc_crtc_finish_page_flip(drm_crtc_to_atmel_hlcdc_crtc(c));
 }
 
+void atmel_hlcdc_crtc_reset(struct drm_crtc *crtc)
+{
+	struct atmel_hlcdc_crtc_state *state;
+
+	if (crtc->state && crtc->state->mode_blob)
+		drm_property_unreference_blob(crtc->state->mode_blob);
+
+	if (crtc->state) {
+		state = drm_crtc_state_to_atmel_hlcdc_crtc_state(crtc->state);
+		kfree(state);
+	}
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	if (state) {
+		crtc->state = &state->base;
+		crtc->state->crtc = crtc;
+	}
+}
+
+static struct drm_crtc_state *
+atmel_hlcdc_crtc_duplicate_state(struct drm_crtc *crtc)
+{
+	struct atmel_hlcdc_crtc_state *state, *cur;
+
+	if (WARN_ON(!crtc->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_crtc_duplicate_state(crtc, &state->base);
+
+	cur = drm_crtc_state_to_atmel_hlcdc_crtc_state(crtc->state);
+	state->output_mode = cur->output_mode;
+
+	return &state->base;
+}
+
+static void atmel_hlcdc_crtc_destroy_state(struct drm_crtc *crtc,
+					   struct drm_crtc_state *s)
+{
+	struct atmel_hlcdc_crtc_state *state;
+
+	state = drm_crtc_state_to_atmel_hlcdc_crtc_state(s);
+	__drm_atomic_helper_crtc_destroy_state(crtc, s);
+	kfree(state);
+}
+
 static const struct drm_crtc_funcs atmel_hlcdc_crtc_funcs = {
 	.page_flip = drm_atomic_helper_page_flip,
 	.set_config = drm_atomic_helper_set_config,
 	.destroy = atmel_hlcdc_crtc_destroy,
-	.reset = drm_atomic_helper_crtc_reset,
-	.atomic_duplicate_state =  drm_atomic_helper_crtc_duplicate_state,
-	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+	.reset = atmel_hlcdc_crtc_reset,
+	.atomic_duplicate_state =  atmel_hlcdc_crtc_duplicate_state,
+	.atomic_destroy_state = atmel_hlcdc_crtc_destroy_state,
 };
 
 int atmel_hlcdc_crtc_create(struct drm_device *dev)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
index 9907dd1ef4d0..8ded7645747e 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.c
@@ -50,6 +50,10 @@ static const struct atmel_hlcdc_dc_desc atmel_hlcdc_dc_at91sam9n12 = {
 	.min_height = 0,
 	.max_width = 1280,
 	.max_height = 860,
+	.max_spw = 0x3f,
+	.max_vpw = 0x3f,
+	.max_hpw = 0xff,
+	.conflicting_output_formats = true,
 	.nlayers = ARRAY_SIZE(atmel_hlcdc_at91sam9n12_layers),
 	.layers = atmel_hlcdc_at91sam9n12_layers,
 };
@@ -134,6 +138,10 @@ static const struct atmel_hlcdc_dc_desc atmel_hlcdc_dc_at91sam9x5 = {
 	.min_height = 0,
 	.max_width = 800,
 	.max_height = 600,
+	.max_spw = 0x3f,
+	.max_vpw = 0x3f,
+	.max_hpw = 0xff,
+	.conflicting_output_formats = true,
 	.nlayers = ARRAY_SIZE(atmel_hlcdc_at91sam9x5_layers),
 	.layers = atmel_hlcdc_at91sam9x5_layers,
 };
@@ -237,6 +245,10 @@ static const struct atmel_hlcdc_dc_desc atmel_hlcdc_dc_sama5d3 = {
 	.min_height = 0,
 	.max_width = 2048,
 	.max_height = 2048,
+	.max_spw = 0x3f,
+	.max_vpw = 0x3f,
+	.max_hpw = 0x1ff,
+	.conflicting_output_formats = true,
 	.nlayers = ARRAY_SIZE(atmel_hlcdc_sama5d3_layers),
 	.layers = atmel_hlcdc_sama5d3_layers,
 };
@@ -320,6 +332,9 @@ static const struct atmel_hlcdc_dc_desc atmel_hlcdc_dc_sama5d4 = {
 	.min_height = 0,
 	.max_width = 2048,
 	.max_height = 2048,
+	.max_spw = 0xff,
+	.max_vpw = 0xff,
+	.max_hpw = 0x3ff,
 	.nlayers = ARRAY_SIZE(atmel_hlcdc_sama5d4_layers),
 	.layers = atmel_hlcdc_sama5d4_layers,
 };
@@ -358,19 +373,19 @@ int atmel_hlcdc_dc_mode_valid(struct atmel_hlcdc_dc *dc,
 	int hback_porch = mode->htotal - mode->hsync_end;
 	int hsync_len = mode->hsync_end - mode->hsync_start;
 
-	if (hsync_len > 0x40 || hsync_len < 1)
+	if (hsync_len > dc->desc->max_spw + 1 || hsync_len < 1)
 		return MODE_HSYNC;
 
-	if (vsync_len > 0x40 || vsync_len < 1)
+	if (vsync_len > dc->desc->max_spw + 1 || vsync_len < 1)
 		return MODE_VSYNC;
 
-	if (hfront_porch > 0x200 || hfront_porch < 1 ||
-	    hback_porch > 0x200 || hback_porch < 1 ||
+	if (hfront_porch > dc->desc->max_hpw + 1 || hfront_porch < 1 ||
+	    hback_porch > dc->desc->max_hpw + 1 || hback_porch < 1 ||
 	    mode->hdisplay < 1)
 		return MODE_H_ILLEGAL;
 
-	if (vfront_porch > 0x40 || vfront_porch < 1 ||
-	    vback_porch > 0x40 || vback_porch < 0 ||
+	if (vfront_porch > dc->desc->max_vpw + 1 || vfront_porch < 1 ||
+	    vback_porch > dc->desc->max_vpw || vback_porch < 0 ||
 	    mode->vdisplay < 1)
 		return MODE_V_ILLEGAL;
 
@@ -427,11 +442,102 @@ static void atmel_hlcdc_fb_output_poll_changed(struct drm_device *dev)
 	}
 }
 
+struct atmel_hlcdc_dc_commit {
+	struct work_struct work;
+	struct drm_device *dev;
+	struct drm_atomic_state *state;
+};
+
+static void
+atmel_hlcdc_dc_atomic_complete(struct atmel_hlcdc_dc_commit *commit)
+{
+	struct drm_device *dev = commit->dev;
+	struct atmel_hlcdc_dc *dc = dev->dev_private;
+	struct drm_atomic_state *old_state = commit->state;
+
+	/* Apply the atomic update. */
+	drm_atomic_helper_commit_modeset_disables(dev, old_state);
+	drm_atomic_helper_commit_planes(dev, old_state, false);
+	drm_atomic_helper_commit_modeset_enables(dev, old_state);
+
+	drm_atomic_helper_wait_for_vblanks(dev, old_state);
+
+	drm_atomic_helper_cleanup_planes(dev, old_state);
+
+	drm_atomic_state_free(old_state);
+
+	/* Complete the commit, wake up any waiter. */
+	spin_lock(&dc->commit.wait.lock);
+	dc->commit.pending = false;
+	wake_up_all_locked(&dc->commit.wait);
+	spin_unlock(&dc->commit.wait.lock);
+
+	kfree(commit);
+}
+
+static void atmel_hlcdc_dc_atomic_work(struct work_struct *work)
+{
+	struct atmel_hlcdc_dc_commit *commit =
+		container_of(work, struct atmel_hlcdc_dc_commit, work);
+
+	atmel_hlcdc_dc_atomic_complete(commit);
+}
+
+static int atmel_hlcdc_dc_atomic_commit(struct drm_device *dev,
+					struct drm_atomic_state *state,
+					bool async)
+{
+	struct atmel_hlcdc_dc *dc = dev->dev_private;
+	struct atmel_hlcdc_dc_commit *commit;
+	int ret;
+
+	ret = drm_atomic_helper_prepare_planes(dev, state);
+	if (ret)
+		return ret;
+
+	/* Allocate the commit object. */
+	commit = kzalloc(sizeof(*commit), GFP_KERNEL);
+	if (!commit) {
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	INIT_WORK(&commit->work, atmel_hlcdc_dc_atomic_work);
+	commit->dev = dev;
+	commit->state = state;
+
+	spin_lock(&dc->commit.wait.lock);
+	ret = wait_event_interruptible_locked(dc->commit.wait,
+					      !dc->commit.pending);
+	if (ret == 0)
+		dc->commit.pending = true;
+	spin_unlock(&dc->commit.wait.lock);
+
+	if (ret) {
+		kfree(commit);
+		goto error;
+	}
+
+	/* Swap the state, this is the point of no return. */
+	drm_atomic_helper_swap_state(dev, state);
+
+	if (async)
+		queue_work(dc->wq, &commit->work);
+	else
+		atmel_hlcdc_dc_atomic_complete(commit);
+
+	return 0;
+
+error:
+	drm_atomic_helper_cleanup_planes(dev, state);
+	return ret;
+}
+
 static const struct drm_mode_config_funcs mode_config_funcs = {
 	.fb_create = atmel_hlcdc_fb_create,
 	.output_poll_changed = atmel_hlcdc_fb_output_poll_changed,
 	.atomic_check = drm_atomic_helper_check,
-	.atomic_commit = drm_atomic_helper_commit,
+	.atomic_commit = atmel_hlcdc_dc_atomic_commit,
 };
 
 static int atmel_hlcdc_dc_modeset_init(struct drm_device *dev)
@@ -445,7 +551,7 @@ static int atmel_hlcdc_dc_modeset_init(struct drm_device *dev)
 
 	ret = atmel_hlcdc_create_outputs(dev);
 	if (ret) {
-		dev_err(dev->dev, "failed to create panel: %d\n", ret);
+		dev_err(dev->dev, "failed to create HLCDC outputs: %d\n", ret);
 		return ret;
 	}
 
@@ -509,6 +615,7 @@ static int atmel_hlcdc_dc_load(struct drm_device *dev)
 	if (!dc->wq)
 		return -ENOMEM;
 
+	init_waitqueue_head(&dc->commit.wait);
 	dc->desc = match->data;
 	dc->hlcdc = dev_get_drvdata(dev->dev->parent);
 	dev->dev_private = dc;
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
index fed517f297da..7a47f8c094d0 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_dc.h
@@ -50,6 +50,11 @@
  * @min_height: minimum height supported by the Display Controller
  * @max_width: maximum width supported by the Display Controller
  * @max_height: maximum height supported by the Display Controller
+ * @max_spw: maximum vertical/horizontal pulse width
+ * @max_vpw: maximum vertical back/front porch width
+ * @max_hpw: maximum horizontal back/front porch width
+ * @conflicting_output_formats: true if RGBXXX output formats conflict with
+ *				each other.
  * @layers: a layer description table describing available layers
  * @nlayers: layer description table size
  */
@@ -58,6 +63,10 @@ struct atmel_hlcdc_dc_desc {
 	int min_height;
 	int max_width;
 	int max_height;
+	int max_spw;
+	int max_vpw;
+	int max_hpw;
+	bool conflicting_output_formats;
 	const struct atmel_hlcdc_layer_desc *layers;
 	int nlayers;
 };
@@ -128,6 +137,7 @@ struct atmel_hlcdc_planes {
  * @planes: instantiated planes
  * @layers: active HLCDC layer
  * @wq: display controller workqueue
+ * @commit: used for async commit handling
  */
 struct atmel_hlcdc_dc {
 	const struct atmel_hlcdc_dc_desc *desc;
@@ -137,6 +147,10 @@ struct atmel_hlcdc_dc {
 	struct atmel_hlcdc_planes *planes;
 	struct atmel_hlcdc_layer *layers[ATMEL_HLCDC_MAX_LAYERS];
 	struct workqueue_struct *wq;
+	struct {
+		wait_queue_head_t wait;
+		bool pending;
+	} commit;
 };
 
 extern struct atmel_hlcdc_formats atmel_hlcdc_plane_rgb_formats;
@@ -149,6 +163,7 @@ struct atmel_hlcdc_planes *
 atmel_hlcdc_create_planes(struct drm_device *dev);
 
 int atmel_hlcdc_plane_prepare_disc_area(struct drm_crtc_state *c_state);
+int atmel_hlcdc_plane_prepare_ahb_routing(struct drm_crtc_state *c_state);
 
 void atmel_hlcdc_crtc_irq(struct drm_crtc *c);
 
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
index 0f7ec016e7a9..39802c0539b6 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c
@@ -27,16 +27,6 @@
 #include "atmel_hlcdc_dc.h"
 
 /**
- * Atmel HLCDC RGB output mode
- */
-enum atmel_hlcdc_connector_rgb_mode {
-	ATMEL_HLCDC_CONNECTOR_RGB444,
-	ATMEL_HLCDC_CONNECTOR_RGB565,
-	ATMEL_HLCDC_CONNECTOR_RGB666,
-	ATMEL_HLCDC_CONNECTOR_RGB888,
-};
-
-/**
  * Atmel HLCDC RGB connector structure
  *
  * This structure stores RGB slave device information.
@@ -44,13 +34,13 @@ enum atmel_hlcdc_connector_rgb_mode {
  * @connector: DRM connector
  * @encoder: DRM encoder
  * @dc: pointer to the atmel_hlcdc_dc structure
- * @dpms: current DPMS mode
+ * @panel: panel connected on the RGB output
  */
 struct atmel_hlcdc_rgb_output {
 	struct drm_connector connector;
 	struct drm_encoder encoder;
 	struct atmel_hlcdc_dc *dc;
-	int dpms;
+	struct drm_panel *panel;
 };
 
 static inline struct atmel_hlcdc_rgb_output *
@@ -66,91 +56,31 @@ drm_encoder_to_atmel_hlcdc_rgb_output(struct drm_encoder *encoder)
 	return container_of(encoder, struct atmel_hlcdc_rgb_output, encoder);
 }
 
-/**
- * Atmel HLCDC Panel device structure
- *
- * This structure is specialization of the slave device structure to
- * interface with drm panels.
- *
- * @base: base slave device fields
- * @panel: drm panel attached to this slave device
- */
-struct atmel_hlcdc_panel {
-	struct atmel_hlcdc_rgb_output base;
-	struct drm_panel *panel;
-};
-
-static inline struct atmel_hlcdc_panel *
-atmel_hlcdc_rgb_output_to_panel(struct atmel_hlcdc_rgb_output *output)
-{
-	return container_of(output, struct atmel_hlcdc_panel, base);
-}
-
-static void atmel_hlcdc_panel_encoder_enable(struct drm_encoder *encoder)
+static void atmel_hlcdc_rgb_encoder_enable(struct drm_encoder *encoder)
 {
 	struct atmel_hlcdc_rgb_output *rgb =
 			drm_encoder_to_atmel_hlcdc_rgb_output(encoder);
-	struct atmel_hlcdc_panel *panel = atmel_hlcdc_rgb_output_to_panel(rgb);
 
-	drm_panel_enable(panel->panel);
+	if (rgb->panel) {
+		drm_panel_prepare(rgb->panel);
+		drm_panel_enable(rgb->panel);
+	}
 }
 
-static void atmel_hlcdc_panel_encoder_disable(struct drm_encoder *encoder)
+static void atmel_hlcdc_rgb_encoder_disable(struct drm_encoder *encoder)
 {
 	struct atmel_hlcdc_rgb_output *rgb =
 			drm_encoder_to_atmel_hlcdc_rgb_output(encoder);
-	struct atmel_hlcdc_panel *panel = atmel_hlcdc_rgb_output_to_panel(rgb);
 
-	drm_panel_disable(panel->panel);
-}
-
-static bool
-atmel_hlcdc_panel_encoder_mode_fixup(struct drm_encoder *encoder,
-				     const struct drm_display_mode *mode,
-				     struct drm_display_mode *adjusted)
-{
-	return true;
-}
-
-static void
-atmel_hlcdc_rgb_encoder_mode_set(struct drm_encoder *encoder,
-				 struct drm_display_mode *mode,
-				 struct drm_display_mode *adjusted)
-{
-	struct atmel_hlcdc_rgb_output *rgb =
-			drm_encoder_to_atmel_hlcdc_rgb_output(encoder);
-	struct drm_display_info *info = &rgb->connector.display_info;
-	unsigned int cfg;
-
-	cfg = 0;
-
-	if (info->num_bus_formats) {
-		switch (info->bus_formats[0]) {
-		case MEDIA_BUS_FMT_RGB565_1X16:
-			cfg |= ATMEL_HLCDC_CONNECTOR_RGB565 << 8;
-			break;
-		case MEDIA_BUS_FMT_RGB666_1X18:
-			cfg |= ATMEL_HLCDC_CONNECTOR_RGB666 << 8;
-			break;
-		case MEDIA_BUS_FMT_RGB888_1X24:
-			cfg |= ATMEL_HLCDC_CONNECTOR_RGB888 << 8;
-			break;
-		case MEDIA_BUS_FMT_RGB444_1X12:
-		default:
-			break;
-		}
+	if (rgb->panel) {
+		drm_panel_disable(rgb->panel);
+		drm_panel_unprepare(rgb->panel);
 	}
-
-	regmap_update_bits(rgb->dc->hlcdc->regmap, ATMEL_HLCDC_CFG(5),
-			   ATMEL_HLCDC_MODE_MASK,
-			   cfg);
 }
 
 static const struct drm_encoder_helper_funcs atmel_hlcdc_panel_encoder_helper_funcs = {
-	.mode_fixup = atmel_hlcdc_panel_encoder_mode_fixup,
-	.mode_set = atmel_hlcdc_rgb_encoder_mode_set,
-	.disable = atmel_hlcdc_panel_encoder_disable,
-	.enable = atmel_hlcdc_panel_encoder_enable,
+	.disable = atmel_hlcdc_rgb_encoder_disable,
+	.enable = atmel_hlcdc_rgb_encoder_enable,
 };
 
 static void atmel_hlcdc_rgb_encoder_destroy(struct drm_encoder *encoder)
@@ -167,9 +97,11 @@ static int atmel_hlcdc_panel_get_modes(struct drm_connector *connector)
 {
 	struct atmel_hlcdc_rgb_output *rgb =
 			drm_connector_to_atmel_hlcdc_rgb_output(connector);
-	struct atmel_hlcdc_panel *panel = atmel_hlcdc_rgb_output_to_panel(rgb);
 
-	return panel->panel->funcs->get_modes(panel->panel);
+	if (rgb->panel)
+		return rgb->panel->funcs->get_modes(rgb->panel);
+
+	return 0;
 }
 
 static int atmel_hlcdc_rgb_mode_valid(struct drm_connector *connector,
@@ -201,7 +133,13 @@ static const struct drm_connector_helper_funcs atmel_hlcdc_panel_connector_helpe
 static enum drm_connector_status
 atmel_hlcdc_panel_connector_detect(struct drm_connector *connector, bool force)
 {
-	return connector_status_connected;
+	struct atmel_hlcdc_rgb_output *rgb =
+			drm_connector_to_atmel_hlcdc_rgb_output(connector);
+
+	if (rgb->panel)
+		return connector_status_connected;
+
+	return connector_status_disconnected;
 }
 
 static void
@@ -209,9 +147,10 @@ atmel_hlcdc_panel_connector_destroy(struct drm_connector *connector)
 {
 	struct atmel_hlcdc_rgb_output *rgb =
 			drm_connector_to_atmel_hlcdc_rgb_output(connector);
-	struct atmel_hlcdc_panel *panel = atmel_hlcdc_rgb_output_to_panel(rgb);
 
-	drm_panel_detach(panel->panel);
+	if (rgb->panel)
+		drm_panel_detach(rgb->panel);
+
 	drm_connector_cleanup(connector);
 }
 
@@ -225,88 +164,122 @@ static const struct drm_connector_funcs atmel_hlcdc_panel_connector_funcs = {
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
 };
 
-static int atmel_hlcdc_create_panel_output(struct drm_device *dev,
-					   struct of_endpoint *ep)
+static int atmel_hlcdc_check_endpoint(struct drm_device *dev,
+				      const struct of_endpoint *ep)
 {
-	struct atmel_hlcdc_dc *dc = dev->dev_private;
 	struct device_node *np;
-	struct drm_panel *p = NULL;
-	struct atmel_hlcdc_panel *panel;
-	int ret;
+	void *obj;
 
 	np = of_graph_get_remote_port_parent(ep->local_node);
-	if (!np)
-		return -EINVAL;
 
-	p = of_drm_find_panel(np);
+	obj = of_drm_find_panel(np);
+	if (!obj)
+		obj = of_drm_find_bridge(np);
+
 	of_node_put(np);
 
-	if (!p)
-		return -EPROBE_DEFER;
+	return obj ? 0 : -EPROBE_DEFER;
+}
 
-	panel = devm_kzalloc(dev->dev, sizeof(*panel), GFP_KERNEL);
-	if (!panel)
-		return -EINVAL;
+static int atmel_hlcdc_attach_endpoint(struct drm_device *dev,
+				       const struct of_endpoint *ep)
+{
+	struct atmel_hlcdc_dc *dc = dev->dev_private;
+	struct atmel_hlcdc_rgb_output *output;
+	struct device_node *np;
+	struct drm_panel *panel;
+	struct drm_bridge *bridge;
+	int ret;
 
-	panel->base.dpms = DRM_MODE_DPMS_OFF;
+	output = devm_kzalloc(dev->dev, sizeof(*output), GFP_KERNEL);
+	if (!output)
+		return -EINVAL;
 
-	panel->base.dc = dc;
+	output->dc = dc;
 
-	drm_encoder_helper_add(&panel->base.encoder,
+	drm_encoder_helper_add(&output->encoder,
 			       &atmel_hlcdc_panel_encoder_helper_funcs);
-	ret = drm_encoder_init(dev, &panel->base.encoder,
+	ret = drm_encoder_init(dev, &output->encoder,
 			       &atmel_hlcdc_panel_encoder_funcs,
-			       DRM_MODE_ENCODER_LVDS, NULL);
+			       DRM_MODE_ENCODER_NONE, NULL);
 	if (ret)
 		return ret;
 
-	panel->base.connector.dpms = DRM_MODE_DPMS_OFF;
-	panel->base.connector.polled = DRM_CONNECTOR_POLL_CONNECT;
-	drm_connector_helper_add(&panel->base.connector,
-				 &atmel_hlcdc_panel_connector_helper_funcs);
-	ret = drm_connector_init(dev, &panel->base.connector,
-				 &atmel_hlcdc_panel_connector_funcs,
-				 DRM_MODE_CONNECTOR_LVDS);
-	if (ret)
-		goto err_encoder_cleanup;
+	output->encoder.possible_crtcs = 0x1;
+
+	np = of_graph_get_remote_port_parent(ep->local_node);
 
-	drm_mode_connector_attach_encoder(&panel->base.connector,
-					  &panel->base.encoder);
-	panel->base.encoder.possible_crtcs = 0x1;
+	ret = -EPROBE_DEFER;
+
+	panel = of_drm_find_panel(np);
+	if (panel) {
+		of_node_put(np);
+		output->connector.dpms = DRM_MODE_DPMS_OFF;
+		output->connector.polled = DRM_CONNECTOR_POLL_CONNECT;
+		drm_connector_helper_add(&output->connector,
+				&atmel_hlcdc_panel_connector_helper_funcs);
+		ret = drm_connector_init(dev, &output->connector,
+					 &atmel_hlcdc_panel_connector_funcs,
+					 DRM_MODE_CONNECTOR_Unknown);
+		if (ret)
+			goto err_encoder_cleanup;
+
+		drm_mode_connector_attach_encoder(&output->connector,
+						  &output->encoder);
+
+		ret = drm_panel_attach(panel, &output->connector);
+		if (ret) {
+			drm_connector_cleanup(&output->connector);
+			goto err_encoder_cleanup;
+		}
 
-	drm_panel_attach(p, &panel->base.connector);
-	panel->panel = p;
+		output->panel = panel;
 
-	return 0;
+		return 0;
+	}
+
+	bridge = of_drm_find_bridge(np);
+	of_node_put(np);
+
+	if (bridge) {
+		output->encoder.bridge = bridge;
+		bridge->encoder = &output->encoder;
+		ret = drm_bridge_attach(dev, bridge);
+		if (!ret)
+			return 0;
+	}
 
 err_encoder_cleanup:
-	drm_encoder_cleanup(&panel->base.encoder);
+	drm_encoder_cleanup(&output->encoder);
 
 	return ret;
 }
 
 int atmel_hlcdc_create_outputs(struct drm_device *dev)
 {
-	struct device_node *port_np, *np;
+	struct device_node *ep_np = NULL;
 	struct of_endpoint ep;
 	int ret;
 
-	port_np = of_get_child_by_name(dev->dev->of_node, "port");
-	if (!port_np)
-		return -EINVAL;
-
-	np = of_get_child_by_name(port_np, "endpoint");
-	of_node_put(port_np);
+	for_each_endpoint_of_node(dev->dev->of_node, ep_np) {
+		ret = of_graph_parse_endpoint(ep_np, &ep);
+		if (!ret)
+			ret = atmel_hlcdc_check_endpoint(dev, &ep);
 
-	if (!np)
-		return -EINVAL;
+		of_node_put(ep_np);
+		if (ret)
+			return ret;
+	}
 
-	ret = of_graph_parse_endpoint(np, &ep);
-	of_node_put(port_np);
+	for_each_endpoint_of_node(dev->dev->of_node, ep_np) {
+		ret = of_graph_parse_endpoint(ep_np, &ep);
+		if (!ret)
+			ret = atmel_hlcdc_attach_endpoint(dev, &ep);
 
-	if (ret)
-		return ret;
+		of_node_put(ep_np);
+		if (ret)
+			return ret;
+	}
 
-	/* We currently only support panel output */
-	return atmel_hlcdc_create_panel_output(dev, &ep);
+	return 0;
 }
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
index d65dcaee3832..aef3ca8a81fa 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
@@ -37,6 +37,7 @@
  * @xstride: value to add to the pixel pointer between each line
  * @pstride: value to add to the pixel pointer between each pixel
  * @nplanes: number of planes (deduced from pixel_format)
+ * @prepared: plane update has been prepared
  */
 struct atmel_hlcdc_plane_state {
 	struct drm_plane_state base;
@@ -58,12 +59,15 @@ struct atmel_hlcdc_plane_state {
 	int disc_w;
 	int disc_h;
 
+	int ahb_id;
+
 	/* These fields are private and should not be touched */
 	int bpp[ATMEL_HLCDC_MAX_PLANES];
 	unsigned int offsets[ATMEL_HLCDC_MAX_PLANES];
 	int xstride[ATMEL_HLCDC_MAX_PLANES];
 	int pstride[ATMEL_HLCDC_MAX_PLANES];
 	int nplanes;
+	bool prepared;
 };
 
 static inline struct atmel_hlcdc_plane_state *
@@ -359,8 +363,10 @@ atmel_hlcdc_plane_update_general_settings(struct atmel_hlcdc_plane *plane,
 
 	atmel_hlcdc_layer_update_cfg(&plane->layer,
 				     ATMEL_HLCDC_LAYER_DMA_CFG_ID,
-				     ATMEL_HLCDC_LAYER_DMA_BLEN_MASK,
-				     ATMEL_HLCDC_LAYER_DMA_BLEN_INCR16);
+				     ATMEL_HLCDC_LAYER_DMA_BLEN_MASK |
+				     ATMEL_HLCDC_LAYER_DMA_SIF,
+				     ATMEL_HLCDC_LAYER_DMA_BLEN_INCR16 |
+				     state->ahb_id);
 
 	atmel_hlcdc_layer_update_cfg(&plane->layer, layout->general_config,
 				     ATMEL_HLCDC_LAYER_ITER2BL |
@@ -435,6 +441,41 @@ static void atmel_hlcdc_plane_update_buffers(struct atmel_hlcdc_plane *plane,
 	}
 }
 
+int atmel_hlcdc_plane_prepare_ahb_routing(struct drm_crtc_state *c_state)
+{
+	unsigned int ahb_load[2] = { };
+	struct drm_plane *plane;
+
+	drm_atomic_crtc_state_for_each_plane(plane, c_state) {
+		struct atmel_hlcdc_plane_state *plane_state;
+		struct drm_plane_state *plane_s;
+		unsigned int pixels, load = 0;
+		int i;
+
+		plane_s = drm_atomic_get_plane_state(c_state->state, plane);
+		if (IS_ERR(plane_s))
+			return PTR_ERR(plane_s);
+
+		plane_state =
+			drm_plane_state_to_atmel_hlcdc_plane_state(plane_s);
+
+		pixels = (plane_state->src_w * plane_state->src_h) -
+			 (plane_state->disc_w * plane_state->disc_h);
+
+		for (i = 0; i < plane_state->nplanes; i++)
+			load += pixels * plane_state->bpp[i];
+
+		if (ahb_load[0] <= ahb_load[1])
+			plane_state->ahb_id = 0;
+		else
+			plane_state->ahb_id = 1;
+
+		ahb_load[plane_state->ahb_id] += load;
+	}
+
+	return 0;
+}
+
 int
 atmel_hlcdc_plane_prepare_disc_area(struct drm_crtc_state *c_state)
 {
@@ -714,12 +755,54 @@ static int atmel_hlcdc_plane_atomic_check(struct drm_plane *p,
 static int atmel_hlcdc_plane_prepare_fb(struct drm_plane *p,
 					const struct drm_plane_state *new_state)
 {
+	/*
+	 * FIXME: we should avoid this const -> non-const cast but it's
+	 * currently the only solution we have to modify the ->prepared
+	 * state and rollback the update request.
+	 * Ideally, we should rework the code to attach all the resources
+	 * to atmel_hlcdc_plane_state (including the DMA desc allocation),
+	 * but this require a complete rework of the atmel_hlcdc_layer
+	 * code.
+	 */
+	struct drm_plane_state *s = (struct drm_plane_state *)new_state;
+	struct atmel_hlcdc_plane *plane = drm_plane_to_atmel_hlcdc_plane(p);
+	struct atmel_hlcdc_plane_state *state =
+			drm_plane_state_to_atmel_hlcdc_plane_state(s);
+	int ret;
+
+	ret = atmel_hlcdc_layer_update_start(&plane->layer);
+	if (!ret)
+		state->prepared = true;
+
+	return ret;
+}
+
+static void atmel_hlcdc_plane_cleanup_fb(struct drm_plane *p,
+				const struct drm_plane_state *old_state)
+{
+	/*
+	 * FIXME: we should avoid this const -> non-const cast but it's
+	 * currently the only solution we have to modify the ->prepared
+	 * state and rollback the update request.
+	 * Ideally, we should rework the code to attach all the resources
+	 * to atmel_hlcdc_plane_state (including the DMA desc allocation),
+	 * but this require a complete rework of the atmel_hlcdc_layer
+	 * code.
+	 */
+	struct drm_plane_state *s = (struct drm_plane_state *)old_state;
 	struct atmel_hlcdc_plane *plane = drm_plane_to_atmel_hlcdc_plane(p);
+	struct atmel_hlcdc_plane_state *state =
+			drm_plane_state_to_atmel_hlcdc_plane_state(s);
 
-	if (!new_state->fb)
-		return 0;
+	/*
+	 * The Request has already been applied or cancelled, nothing to do
+	 * here.
+	 */
+	if (!state->prepared)
+		return;
 
-	return atmel_hlcdc_layer_update_start(&plane->layer);
+	atmel_hlcdc_layer_update_rollback(&plane->layer);
+	state->prepared = false;
 }
 
 static void atmel_hlcdc_plane_atomic_update(struct drm_plane *p,
@@ -844,6 +927,7 @@ static void atmel_hlcdc_plane_init_properties(struct atmel_hlcdc_plane *plane,
 
 static struct drm_plane_helper_funcs atmel_hlcdc_layer_plane_helper_funcs = {
 	.prepare_fb = atmel_hlcdc_plane_prepare_fb,
+	.cleanup_fb = atmel_hlcdc_plane_cleanup_fb,
 	.atomic_check = atmel_hlcdc_plane_atomic_check,
 	.atomic_update = atmel_hlcdc_plane_atomic_update,
 	.atomic_disable = atmel_hlcdc_plane_atomic_disable,
@@ -883,6 +967,7 @@ atmel_hlcdc_plane_atomic_duplicate_state(struct drm_plane *p)
 		return NULL;
 
 	copy->disc_updated = false;
+	copy->prepared = false;
 
 	if (copy->base.fb)
 		drm_framebuffer_reference(copy->base.fb);