Merge tag 'du-next-20190608-2' of git://linuxtv.org/pinchartl/media into drm-next

R-Car DU changes for v5.3:

- R8A774A1 SoC support
- LVDS dual-link mode support
- Support for additional formats
- Misc fixes

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190608134652.GE4786@pendragon.ideasonboard.com

7 files changed, 267 insertions, 44 deletions

diff --git a/drivers/gpu/drm/bridge/thc63lvd1024.c b/drivers/gpu/drm/bridge/thc63lvd1024.c
index fd597f58f4e6..3d74129b2995 100644
--- a/drivers/gpu/drm/bridge/thc63lvd1024.c
+++ b/drivers/gpu/drm/bridge/thc63lvd1024.c
@@ -33,6 +33,8 @@ struct thc63_dev {
 
 	struct drm_bridge bridge;
 	struct drm_bridge *next;
+
+	struct drm_bridge_timings timings;
 };
 
 static inline struct thc63_dev *to_thc63(struct drm_bridge *bridge)
@@ -50,15 +52,28 @@ static int thc63_attach(struct drm_bridge *bridge)
 static enum drm_mode_status thc63_mode_valid(struct drm_bridge *bridge,
 					const struct drm_display_mode *mode)
 {
+	struct thc63_dev *thc63 = to_thc63(bridge);
+	unsigned int min_freq;
+	unsigned int max_freq;
+
 	/*
-	 * The THC63LVD1024 clock frequency range is 8 to 135 MHz in single-in
-	 * mode. Note that the limits are different in dual-in, single-out mode,
-	 * and will need to be adjusted accordingly.
+	 * The THC63LVD1024 pixel rate range is 8 to 135 MHz in all modes but
+	 * dual-in, single-out where it is 40 to 150 MHz. As dual-in, dual-out
+	 * isn't supported by the driver yet, simply derive the limits from the
+	 * input mode.
 	 */
-	if (mode->clock < 8000)
+	if (thc63->timings.dual_link) {
+		min_freq = 40000;
+		max_freq = 150000;
+	} else {
+		min_freq = 8000;
+		max_freq = 135000;
+	}
+
+	if (mode->clock < min_freq)
 		return MODE_CLOCK_LOW;
 
-	if (mode->clock > 135000)
+	if (mode->clock > max_freq)
 		return MODE_CLOCK_HIGH;
 
 	return MODE_OK;
@@ -103,19 +118,19 @@ static const struct drm_bridge_funcs thc63_bridge_func = {
 
 static int thc63_parse_dt(struct thc63_dev *thc63)
 {
-	struct device_node *thc63_out;
+	struct device_node *endpoint;
 	struct device_node *remote;
 
-	thc63_out = of_graph_get_endpoint_by_regs(thc63->dev->of_node,
-						  THC63_RGB_OUT0, -1);
-	if (!thc63_out) {
+	endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node,
+						 THC63_RGB_OUT0, -1);
+	if (!endpoint) {
 		dev_err(thc63->dev, "Missing endpoint in port@%u\n",
 			THC63_RGB_OUT0);
 		return -ENODEV;
 	}
 
-	remote = of_graph_get_remote_port_parent(thc63_out);
-	of_node_put(thc63_out);
+	remote = of_graph_get_remote_port_parent(endpoint);
+	of_node_put(endpoint);
 	if (!remote) {
 		dev_err(thc63->dev, "Endpoint in port@%u unconnected\n",
 			THC63_RGB_OUT0);
@@ -134,6 +149,22 @@ static int thc63_parse_dt(struct thc63_dev *thc63)
 	if (!thc63->next)
 		return -EPROBE_DEFER;
 
+	endpoint = of_graph_get_endpoint_by_regs(thc63->dev->of_node,
+						 THC63_LVDS_IN1, -1);
+	if (endpoint) {
+		remote = of_graph_get_remote_port_parent(endpoint);
+		of_node_put(endpoint);
+
+		if (remote) {
+			if (of_device_is_available(remote))
+				thc63->timings.dual_link = true;
+			of_node_put(remote);
+		}
+	}
+
+	dev_dbg(thc63->dev, "operating in %s-link mode\n",
+		thc63->timings.dual_link ? "dual" : "single");
+
 	return 0;
 }
 
@@ -190,6 +221,7 @@ static int thc63_probe(struct platform_device *pdev)
 	thc63->bridge.driver_private = thc63;
 	thc63->bridge.of_node = pdev->dev.of_node;
 	thc63->bridge.funcs = &thc63_bridge_func;
+	thc63->bridge.timings = &thc63->timings;
 
 	drm_bridge_add(&thc63->bridge);
 
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_drv.c b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
index 75ab17af13a9..6df37c2a9678 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_drv.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_drv.c
@@ -102,6 +102,35 @@ static const struct rcar_du_device_info rzg1_du_r8a77470_info = {
 	},
 };
 
+static const struct rcar_du_device_info rcar_du_r8a774a1_info = {
+	.gen = 3,
+	.features = RCAR_DU_FEATURE_CRTC_IRQ_CLOCK
+		  | RCAR_DU_FEATURE_VSP1_SOURCE
+		  | RCAR_DU_FEATURE_INTERLACED
+		  | RCAR_DU_FEATURE_TVM_SYNC,
+	.channels_mask = BIT(2) | BIT(1) | BIT(0),
+	.routes = {
+		/*
+		 * R8A774A1 has one RGB output, one LVDS output and one HDMI
+		 * output.
+		 */
+		[RCAR_DU_OUTPUT_DPAD0] = {
+			.possible_crtcs = BIT(2),
+			.port = 0,
+		},
+		[RCAR_DU_OUTPUT_HDMI0] = {
+			.possible_crtcs = BIT(1),
+			.port = 1,
+		},
+		[RCAR_DU_OUTPUT_LVDS0] = {
+			.possible_crtcs = BIT(0),
+			.port = 2,
+		},
+	},
+	.num_lvds = 1,
+	.dpll_mask =  BIT(1),
+};
+
 static const struct rcar_du_device_info rcar_du_r8a774c0_info = {
 	.gen = 3,
 	.features = RCAR_DU_FEATURE_CRTC_IRQ_CLOCK
@@ -386,6 +415,7 @@ static const struct of_device_id rcar_du_of_table[] = {
 	{ .compatible = "renesas,du-r8a7744", .data = &rzg1_du_r8a7743_info },
 	{ .compatible = "renesas,du-r8a7745", .data = &rzg1_du_r8a7745_info },
 	{ .compatible = "renesas,du-r8a77470", .data = &rzg1_du_r8a77470_info },
+	{ .compatible = "renesas,du-r8a774a1", .data = &rcar_du_r8a774a1_info },
 	{ .compatible = "renesas,du-r8a774c0", .data = &rcar_du_r8a774c0_info },
 	{ .compatible = "renesas,du-r8a7779", .data = &rcar_du_r8a7779_info },
 	{ .compatible = "renesas,du-r8a7790", .data = &rcar_du_r8a7790_info },
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
index 6c91753af7bc..0f00bdfe2366 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
@@ -16,6 +16,7 @@
 #include "rcar_du_drv.h"
 #include "rcar_du_encoder.h"
 #include "rcar_du_kms.h"
+#include "rcar_lvds.h"
 
 /* -----------------------------------------------------------------------------
  * Encoder
@@ -97,6 +98,17 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
 		}
 	}
 
+	/*
+	 * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a
+	 * companion for LVDS0 in dual-link mode.
+	 */
+	if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) {
+		if (rcar_lvds_dual_link(bridge)) {
+			ret = -ENOLINK;
+			goto done;
+		}
+	}
+
 	ret = drm_encoder_init(rcdu->ddev, encoder, &encoder_funcs,
 			       DRM_MODE_ENCODER_NONE, NULL);
 	if (ret < 0)
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
index f8f7fff34dff..2dc9caee8767 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_kms.c
@@ -124,6 +124,66 @@ static const struct rcar_du_format_info rcar_du_format_infos[] = {
 		.bpp = 16,
 		.planes = 1,
 	}, {
+		.fourcc = DRM_FORMAT_RGBA4444,
+		.v4l2 = V4L2_PIX_FMT_RGBA444,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_RGBX4444,
+		.v4l2 = V4L2_PIX_FMT_RGBX444,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_ABGR4444,
+		.v4l2 = V4L2_PIX_FMT_ABGR444,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_XBGR4444,
+		.v4l2 = V4L2_PIX_FMT_XBGR444,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_BGRA4444,
+		.v4l2 = V4L2_PIX_FMT_BGRA444,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_BGRX4444,
+		.v4l2 = V4L2_PIX_FMT_BGRX444,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_RGBA5551,
+		.v4l2 = V4L2_PIX_FMT_RGBA555,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_RGBX5551,
+		.v4l2 = V4L2_PIX_FMT_RGBX555,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_ABGR1555,
+		.v4l2 = V4L2_PIX_FMT_ABGR555,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_XBGR1555,
+		.v4l2 = V4L2_PIX_FMT_XBGR555,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_BGRA5551,
+		.v4l2 = V4L2_PIX_FMT_BGRA555,
+		.bpp = 16,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_BGRX5551,
+		.v4l2 = V4L2_PIX_FMT_BGRX555,
+		.bpp = 16,
+		.planes = 1,
+	}, {
 		.fourcc = DRM_FORMAT_BGR888,
 		.v4l2 = V4L2_PIX_FMT_RGB24,
 		.bpp = 24,
@@ -134,6 +194,26 @@ static const struct rcar_du_format_info rcar_du_format_infos[] = {
 		.bpp = 24,
 		.planes = 1,
 	}, {
+		.fourcc = DRM_FORMAT_RGBA8888,
+		.v4l2 = V4L2_PIX_FMT_BGRA32,
+		.bpp = 32,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_RGBX8888,
+		.v4l2 = V4L2_PIX_FMT_BGRX32,
+		.bpp = 32,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_ABGR8888,
+		.v4l2 = V4L2_PIX_FMT_RGBA32,
+		.bpp = 32,
+		.planes = 1,
+	}, {
+		.fourcc = DRM_FORMAT_XBGR8888,
+		.v4l2 = V4L2_PIX_FMT_RGBX32,
+		.bpp = 32,
+		.planes = 1,
+	}, {
 		.fourcc = DRM_FORMAT_BGRA8888,
 		.v4l2 = V4L2_PIX_FMT_ARGB32,
 		.bpp = 32,
@@ -378,7 +458,7 @@ static int rcar_du_encoders_init_one(struct rcar_du_device *rcdu,
 	}
 
 	ret = rcar_du_encoder_init(rcdu, output, entity);
-	if (ret && ret != -EPROBE_DEFER)
+	if (ret && ret != -EPROBE_DEFER && ret != -ENOLINK)
 		dev_warn(rcdu->dev,
 			 "failed to initialize encoder %pOF on output %u (%d), skipping\n",
 			 entity, output, ret);
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_writeback.c b/drivers/gpu/drm/rcar-du/rcar_du_writeback.c
index 989a0be94131..ae07290bba6a 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_writeback.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_writeback.c
@@ -14,6 +14,7 @@
 #include "rcar_du_crtc.h"
 #include "rcar_du_drv.h"
 #include "rcar_du_kms.h"
+#include "rcar_du_writeback.h"
 
 /**
  * struct rcar_du_wb_conn_state - Driver-specific writeback connector state
diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.c b/drivers/gpu/drm/rcar-du/rcar_lvds.c
index 620b51aab291..fd9e0d36154f 100644
--- a/drivers/gpu/drm/rcar-du/rcar_lvds.c
+++ b/drivers/gpu/drm/rcar-du/rcar_lvds.c
@@ -63,10 +63,12 @@ struct rcar_lvds {
 		struct clk *extal;		/* External clock */
 		struct clk *dotclkin[2];	/* External DU clocks */
 	} clocks;
-	bool enabled;
 
 	struct drm_display_mode display_mode;
 	enum rcar_lvds_mode mode;
+
+	struct drm_bridge *companion;
+	bool dual_link;
 };
 
 #define bridge_to_rcar_lvds(bridge) \
@@ -368,15 +370,12 @@ int rcar_lvds_clk_enable(struct drm_bridge *bridge, unsigned long freq)
 
 	dev_dbg(lvds->dev, "enabling LVDS PLL, freq=%luHz\n", freq);
 
-	WARN_ON(lvds->enabled);
-
 	ret = clk_prepare_enable(lvds->clocks.mod);
 	if (ret < 0)
 		return ret;
 
 	__rcar_lvds_pll_setup_d3_e3(lvds, freq, true);
 
-	lvds->enabled = true;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(rcar_lvds_clk_enable);
@@ -390,13 +389,9 @@ void rcar_lvds_clk_disable(struct drm_bridge *bridge)
 
 	dev_dbg(lvds->dev, "disabling LVDS PLL\n");
 
-	WARN_ON(!lvds->enabled);
-
 	rcar_lvds_write(lvds, LVDPLLCR, 0);
 
 	clk_disable_unprepare(lvds->clocks.mod);
-
-	lvds->enabled = false;
 }
 EXPORT_SYMBOL_GPL(rcar_lvds_clk_disable);
 
@@ -408,21 +403,18 @@ static void rcar_lvds_enable(struct drm_bridge *bridge)
 {
 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
 	const struct drm_display_mode *mode = &lvds->display_mode;
-	/*
-	 * FIXME: We should really retrieve the CRTC through the state, but how
-	 * do we get a state pointer?
-	 */
-	struct drm_crtc *crtc = lvds->bridge.encoder->crtc;
 	u32 lvdhcr;
 	u32 lvdcr0;
 	int ret;
 
-	WARN_ON(lvds->enabled);
-
 	ret = clk_prepare_enable(lvds->clocks.mod);
 	if (ret < 0)
 		return;
 
+	/* Enable the companion LVDS encoder in dual-link mode. */
+	if (lvds->dual_link && lvds->companion)
+		lvds->companion->funcs->enable(lvds->companion);
+
 	/*
 	 * Hardcode the channels and control signals routing for now.
 	 *
@@ -445,17 +437,33 @@ static void rcar_lvds_enable(struct drm_bridge *bridge)
 	rcar_lvds_write(lvds, LVDCHCR, lvdhcr);
 
 	if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK) {
-		/* Disable dual-link mode. */
-		rcar_lvds_write(lvds, LVDSTRIPE, 0);
+		/*
+		 * Configure vertical stripe based on the mode of operation of
+		 * the connected device.
+		 */
+		rcar_lvds_write(lvds, LVDSTRIPE,
+				lvds->dual_link ? LVDSTRIPE_ST_ON : 0);
 	}
 
-	/* PLL clock configuration. */
-	lvds->info->pll_setup(lvds, mode->clock * 1000);
+	/*
+	 * PLL clock configuration on all instances but the companion in
+	 * dual-link mode.
+	 */
+	if (!lvds->dual_link || lvds->companion)
+		lvds->info->pll_setup(lvds, mode->clock * 1000);
 
 	/* Set the LVDS mode and select the input. */
 	lvdcr0 = lvds->mode << LVDCR0_LVMD_SHIFT;
-	if (drm_crtc_index(crtc) == 2)
-		lvdcr0 |= LVDCR0_DUSEL;
+
+	if (lvds->bridge.encoder) {
+		/*
+		 * FIXME: We should really retrieve the CRTC through the state,
+		 * but how do we get a state pointer?
+		 */
+		if (drm_crtc_index(lvds->bridge.encoder->crtc) == 2)
+			lvdcr0 |= LVDCR0_DUSEL;
+	}
+
 	rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 
 	/* Turn all the channels on. */
@@ -507,16 +515,12 @@ static void rcar_lvds_enable(struct drm_bridge *bridge)
 		drm_panel_prepare(lvds->panel);
 		drm_panel_enable(lvds->panel);
 	}
-
-	lvds->enabled = true;
 }
 
 static void rcar_lvds_disable(struct drm_bridge *bridge)
 {
 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
 
-	WARN_ON(!lvds->enabled);
-
 	if (lvds->panel) {
 		drm_panel_disable(lvds->panel);
 		drm_panel_unprepare(lvds->panel);
@@ -526,9 +530,11 @@ static void rcar_lvds_disable(struct drm_bridge *bridge)
 	rcar_lvds_write(lvds, LVDCR1, 0);
 	rcar_lvds_write(lvds, LVDPLLCR, 0);
 
-	clk_disable_unprepare(lvds->clocks.mod);
+	/* Disable the companion LVDS encoder in dual-link mode. */
+	if (lvds->dual_link && lvds->companion)
+		lvds->companion->funcs->disable(lvds->companion);
 
-	lvds->enabled = false;
+	clk_disable_unprepare(lvds->clocks.mod);
 }
 
 static bool rcar_lvds_mode_fixup(struct drm_bridge *bridge,
@@ -592,8 +598,6 @@ static void rcar_lvds_mode_set(struct drm_bridge *bridge,
 {
 	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
 
-	WARN_ON(lvds->enabled);
-
 	lvds->display_mode = *adjusted_mode;
 
 	rcar_lvds_get_lvds_mode(lvds);
@@ -646,10 +650,57 @@ static const struct drm_bridge_funcs rcar_lvds_bridge_ops = {
 	.mode_set = rcar_lvds_mode_set,
 };
 
+bool rcar_lvds_dual_link(struct drm_bridge *bridge)
+{
+	struct rcar_lvds *lvds = bridge_to_rcar_lvds(bridge);
+
+	return lvds->dual_link;
+}
+EXPORT_SYMBOL_GPL(rcar_lvds_dual_link);
+
 /* -----------------------------------------------------------------------------
  * Probe & Remove
  */
 
+static int rcar_lvds_parse_dt_companion(struct rcar_lvds *lvds)
+{
+	const struct of_device_id *match;
+	struct device_node *companion;
+	struct device *dev = lvds->dev;
+	int ret = 0;
+
+	/* Locate the companion LVDS encoder for dual-link operation, if any. */
+	companion = of_parse_phandle(dev->of_node, "renesas,companion", 0);
+	if (!companion) {
+		dev_err(dev, "Companion LVDS encoder not found\n");
+		return -ENXIO;
+	}
+
+	/*
+	 * Sanity check: the companion encoder must have the same compatible
+	 * string.
+	 */
+	match = of_match_device(dev->driver->of_match_table, dev);
+	if (!of_device_is_compatible(companion, match->compatible)) {
+		dev_err(dev, "Companion LVDS encoder is invalid\n");
+		ret = -ENXIO;
+		goto done;
+	}
+
+	lvds->companion = of_drm_find_bridge(companion);
+	if (!lvds->companion) {
+		ret = -EPROBE_DEFER;
+		goto done;
+	}
+
+	dev_dbg(dev, "Found companion encoder %pOF\n", companion);
+
+done:
+	of_node_put(companion);
+
+	return ret;
+}
+
 static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
 {
 	struct device_node *local_output = NULL;
@@ -700,14 +751,26 @@ static int rcar_lvds_parse_dt(struct rcar_lvds *lvds)
 
 	if (is_bridge) {
 		lvds->next_bridge = of_drm_find_bridge(remote);
-		if (!lvds->next_bridge)
+		if (!lvds->next_bridge) {
 			ret = -EPROBE_DEFER;
+			goto done;
+		}
+
+		if (lvds->info->quirks & RCAR_LVDS_QUIRK_DUAL_LINK)
+			lvds->dual_link = lvds->next_bridge->timings
+					? lvds->next_bridge->timings->dual_link
+					: false;
 	} else {
 		lvds->panel = of_drm_find_panel(remote);
-		if (IS_ERR(lvds->panel))
+		if (IS_ERR(lvds->panel)) {
 			ret = PTR_ERR(lvds->panel);
+			goto done;
+		}
 	}
 
+	if (lvds->dual_link)
+		ret = rcar_lvds_parse_dt_companion(lvds);
+
 done:
 	of_node_put(local_output);
 	of_node_put(remote_input);
@@ -793,7 +856,6 @@ static int rcar_lvds_probe(struct platform_device *pdev)
 
 	lvds->dev = &pdev->dev;
 	lvds->info = of_device_get_match_data(&pdev->dev);
-	lvds->enabled = false;
 
 	ret = rcar_lvds_parse_dt(lvds);
 	if (ret < 0)
@@ -866,6 +928,7 @@ static const struct rcar_lvds_device_info rcar_lvds_r8a77995_info = {
 static const struct of_device_id rcar_lvds_of_table[] = {
 	{ .compatible = "renesas,r8a7743-lvds", .data = &rcar_lvds_gen2_info },
 	{ .compatible = "renesas,r8a7744-lvds", .data = &rcar_lvds_gen2_info },
+	{ .compatible = "renesas,r8a774a1-lvds", .data = &rcar_lvds_gen3_info },
 	{ .compatible = "renesas,r8a774c0-lvds", .data = &rcar_lvds_r8a77990_info },
 	{ .compatible = "renesas,r8a7790-lvds", .data = &rcar_lvds_r8a7790_info },
 	{ .compatible = "renesas,r8a7791-lvds", .data = &rcar_lvds_gen2_info },
diff --git a/drivers/gpu/drm/rcar-du/rcar_lvds.h b/drivers/gpu/drm/rcar-du/rcar_lvds.h
index a709cae1bc32..222ec0e60785 100644
--- a/drivers/gpu/drm/rcar-du/rcar_lvds.h
+++ b/drivers/gpu/drm/rcar-du/rcar_lvds.h
@@ -15,6 +15,7 @@ struct drm_bridge;
 #if IS_ENABLED(CONFIG_DRM_RCAR_LVDS)
 int rcar_lvds_clk_enable(struct drm_bridge *bridge, unsigned long freq);
 void rcar_lvds_clk_disable(struct drm_bridge *bridge);
+bool rcar_lvds_dual_link(struct drm_bridge *bridge);
 #else
 static inline int rcar_lvds_clk_enable(struct drm_bridge *bridge,
 				       unsigned long freq)
@@ -22,6 +23,10 @@ static inline int rcar_lvds_clk_enable(struct drm_bridge *bridge,
 	return -ENOSYS;
 }
 static inline void rcar_lvds_clk_disable(struct drm_bridge *bridge) { }
+static inline bool rcar_lvds_dual_link(struct drm_bridge *bridge)
+{
+	return false;
+}
 #endif /* CONFIG_DRM_RCAR_LVDS */
 
 #endif /* __RCAR_LVDS_H__ */