Merge tag 'imx-drm-next-20160301' of git://git.pengutronix.de/git/pza/linux into drm-next

imx-drm vblank IRQ control, fence support, and of endpoint helpers

- Add and make use of drm_of_active_endpoint helpers
- Silence a noisy dev_info into a dev_dbg
- Stop touching primary fb on pageflips
- Track flip state explicitly
- Keep GEM buffer objects referenced while scanout is active
- Implement fence sync by deferring flips to a workqueue for
  dma-bufs with pending fences
- Actually disable vblank IRQs while they are not needed

* tag 'imx-drm-next-20160301' of git://git.pengutronix.de/git/pza/linux:
  drm/imx: only enable vblank IRQs when needed
  drm/imx: implement fence sync
  drm/imx: keep GEM object referenced as long as scanout is active
  drm/imx: track flip state explicitly
  drm/imx: don't touch primary fb on pageflip
  drm/imx: ipuv3 plane: Replace dev_info with dev_dbg if a plane's CRTC changes
  gpu: ipu-v3: ipu-dc: Simplify display controller microcode setup
  drm/rockchip: remove rockchip_drm_encoder_get_mux_id
  drm/imx: remove imx_drm_encoder_get_mux_id
  drm: add drm_of_encoder_active_endpoint helpers

drivers/gpu/drm/drm_of.c

@@ -149,3 +149,37 @@ int drm_of_component_probe(struct device *dev,
 	return component_master_add_with_match(dev, m_ops, match);
 }
 EXPORT_SYMBOL(drm_of_component_probe);
+
+/*
+ * drm_of_encoder_active_endpoint - return the active encoder endpoint
+ * @node: device tree node containing encoder input ports
+ * @encoder: drm_encoder
+ *
+ * Given an encoder device node and a drm_encoder with a connected crtc,
+ * parse the encoder endpoint connecting to the crtc port.
+ */
+int drm_of_encoder_active_endpoint(struct device_node *node,
+				   struct drm_encoder *encoder,
+				   struct of_endpoint *endpoint)
+{
+	struct device_node *ep;
+	struct drm_crtc *crtc = encoder->crtc;
+	struct device_node *port;
+	int ret;
+
+	if (!node || !crtc)
+		return -EINVAL;
+
+	for_each_endpoint_of_node(node, ep) {
+		port = of_graph_get_remote_port(ep);
+		of_node_put(port);
+		if (port == crtc->port) {
+			ret = of_graph_parse_endpoint(ep, endpoint);
+			of_node_put(ep);
+			return ret;
+		}
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(drm_of_encoder_active_endpoint);

drivers/gpu/drm/imx/dw_hdmi-imx.c

@@ -118,7 +118,7 @@ static void dw_hdmi_imx_encoder_mode_set(struct drm_encoder *encoder,
 static void dw_hdmi_imx_encoder_commit(struct drm_encoder *encoder)
 {
 	struct imx_hdmi *hdmi = container_of(encoder, struct imx_hdmi, encoder);
-	int mux = imx_drm_encoder_get_mux_id(hdmi->dev->of_node, encoder);
+	int mux = drm_of_encoder_active_port_id(hdmi->dev->of_node, encoder);
 
 	regmap_update_bits(hdmi->regmap, IOMUXC_GPR3,
 			   IMX6Q_GPR3_HDMI_MUX_CTL_MASK,

drivers/gpu/drm/imx/imx-drm-core.c

@@ -17,7 +17,6 @@
 #include <linux/device.h>
 #include <linux/fb.h>
 #include <linux/module.h>
-#include <linux/of_graph.h>
 #include <linux/platform_device.h>
 #include <drm/drmP.h>
 #include <drm/drm_fb_helper.h>
@@ -412,36 +411,6 @@ int imx_drm_encoder_parse_of(struct drm_device *drm,
 }
 EXPORT_SYMBOL_GPL(imx_drm_encoder_parse_of);
 
-/*
- * @node: device tree node containing encoder input ports
- * @encoder: drm_encoder
- */
-int imx_drm_encoder_get_mux_id(struct device_node *node,
-			       struct drm_encoder *encoder)
-{
-	struct imx_drm_crtc *imx_crtc = imx_drm_find_crtc(encoder->crtc);
-	struct device_node *ep;
-	struct of_endpoint endpoint;
-	struct device_node *port;
-	int ret;
-
-	if (!node || !imx_crtc)
-		return -EINVAL;
-
-	for_each_endpoint_of_node(node, ep) {
-		port = of_graph_get_remote_port(ep);
-		of_node_put(port);
-		if (port == imx_crtc->crtc->port) {
-			ret = of_graph_parse_endpoint(ep, &endpoint);
-			of_node_put(ep);
-			return ret ? ret : endpoint.port;
-		}
-	}
-
-	return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(imx_drm_encoder_get_mux_id);
-
 static const struct drm_ioctl_desc imx_drm_ioctls[] = {
 	/* none so far */
 };

drivers/gpu/drm/imx/imx-drm.h

@@ -46,8 +46,6 @@ int imx_drm_set_bus_format_pins(struct drm_encoder *encoder,
 int imx_drm_set_bus_format(struct drm_encoder *encoder,
 		u32 bus_format);
 
-int imx_drm_encoder_get_mux_id(struct device_node *node,
-		struct drm_encoder *encoder);
 int imx_drm_encoder_parse_of(struct drm_device *drm,
 	struct drm_encoder *encoder, struct device_node *np);
 

drivers/gpu/drm/imx/imx-ldb.c

@@ -19,6 +19,7 @@
 #include <drm/drmP.h>
 #include <drm/drm_fb_helper.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_of.h>
 #include <drm/drm_panel.h>
 #include <linux/mfd/syscon.h>
 #include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
@@ -208,7 +209,7 @@ static void imx_ldb_encoder_commit(struct drm_encoder *encoder)
 	struct imx_ldb_channel *imx_ldb_ch = enc_to_imx_ldb_ch(encoder);
 	struct imx_ldb *ldb = imx_ldb_ch->ldb;
 	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
-	int mux = imx_drm_encoder_get_mux_id(imx_ldb_ch->child, encoder);
+	int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder);
 
 	drm_panel_prepare(imx_ldb_ch->panel);
 
@@ -258,7 +259,7 @@ static void imx_ldb_encoder_mode_set(struct drm_encoder *encoder,
 	int dual = ldb->ldb_ctrl & LDB_SPLIT_MODE_EN;
 	unsigned long serial_clk;
 	unsigned long di_clk = mode->clock * 1000;
-	int mux = imx_drm_encoder_get_mux_id(imx_ldb_ch->child, encoder);
+	int mux = drm_of_encoder_active_port_id(imx_ldb_ch->child, encoder);
 
 	if (mode->clock > 170000) {
 		dev_warn(ldb->dev,

drivers/gpu/drm/imx/ipuv3-crtc.c

@@ -22,6 +22,8 @@
 #include <linux/fb.h>
 #include <linux/clk.h>
 #include <linux/errno.h>
+#include <linux/reservation.h>
+#include <linux/dma-buf.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_fb_cma_helper.h>
 
@@ -31,6 +33,23 @@
 
 #define DRIVER_DESC		"i.MX IPUv3 Graphics"
 
+enum ipu_flip_status {
+	IPU_FLIP_NONE,
+	IPU_FLIP_PENDING,
+	IPU_FLIP_SUBMITTED,
+};
+
+struct ipu_flip_work {
+	struct work_struct		unref_work;
+	struct drm_gem_object		*bo;
+	struct drm_pending_vblank_event *page_flip_event;
+	struct work_struct		fence_work;
+	struct ipu_crtc			*crtc;
+	struct fence			*excl;
+	unsigned			shared_count;
+	struct fence			**shared;
+};
+
 struct ipu_crtc {
 	struct device		*dev;
 	struct drm_crtc		base;
@@ -42,8 +61,9 @@ struct ipu_crtc {
 	struct ipu_dc		*dc;
 	struct ipu_di		*di;
 	int			enabled;
-	struct drm_pending_vblank_event *page_flip_event;
-	struct drm_framebuffer	*newfb;
+	enum ipu_flip_status	flip_state;
+	struct workqueue_struct *flip_queue;
+	struct ipu_flip_work	*flip_work;
 	int			irq;
 	u32			bus_format;
 	int			di_hsync_pin;
@@ -102,15 +122,45 @@ static void ipu_crtc_dpms(struct drm_crtc *crtc, int mode)
 	}
 }
 
+static void ipu_flip_unref_work_func(struct work_struct *__work)
+{
+	struct ipu_flip_work *work =
+			container_of(__work, struct ipu_flip_work, unref_work);
+
+	drm_gem_object_unreference_unlocked(work->bo);
+	kfree(work);
+}
+
+static void ipu_flip_fence_work_func(struct work_struct *__work)
+{
+	struct ipu_flip_work *work =
+			container_of(__work, struct ipu_flip_work, fence_work);
+	int i;
+
+	/* wait for all fences attached to the FB obj to signal */
+	if (work->excl) {
+		fence_wait(work->excl, false);
+		fence_put(work->excl);
+	}
+	for (i = 0; i < work->shared_count; i++) {
+		fence_wait(work->shared[i], false);
+		fence_put(work->shared[i]);
+	}
+
+	work->crtc->flip_state = IPU_FLIP_SUBMITTED;
+}
+
 static int ipu_page_flip(struct drm_crtc *crtc,
 		struct drm_framebuffer *fb,
 		struct drm_pending_vblank_event *event,
 		uint32_t page_flip_flags)
 {
+	struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
 	struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
+	struct ipu_flip_work *flip_work;
 	int ret;
 
-	if (ipu_crtc->newfb)
+	if (ipu_crtc->flip_state != IPU_FLIP_NONE)
 		return -EBUSY;
 
 	ret = imx_drm_crtc_vblank_get(ipu_crtc->imx_crtc);
@@ -121,11 +171,58 @@ static int ipu_page_flip(struct drm_crtc *crtc,
 		return ret;
 	}
 
-	ipu_crtc->newfb = fb;
-	ipu_crtc->page_flip_event = event;
-	crtc->primary->fb = fb;
+	flip_work = kzalloc(sizeof *flip_work, GFP_KERNEL);
+	if (!flip_work) {
+		ret = -ENOMEM;
+		goto put_vblank;
+	}
+	INIT_WORK(&flip_work->unref_work, ipu_flip_unref_work_func);
+	flip_work->page_flip_event = event;
+
+	/* get BO backing the old framebuffer and take a reference */
+	flip_work->bo = &drm_fb_cma_get_gem_obj(crtc->primary->fb, 0)->base;
+	drm_gem_object_reference(flip_work->bo);
+
+	ipu_crtc->flip_work = flip_work;
+	/*
+	 * If the object has a DMABUF attached, we need to wait on its fences
+	 * if there are any.
+	 */
+	if (cma_obj->base.dma_buf) {
+		INIT_WORK(&flip_work->fence_work, ipu_flip_fence_work_func);
+		flip_work->crtc = ipu_crtc;
+
+		ret = reservation_object_get_fences_rcu(
+				cma_obj->base.dma_buf->resv, &flip_work->excl,
+				&flip_work->shared_count, &flip_work->shared);
+
+		if (unlikely(ret)) {
+			DRM_ERROR("failed to get fences for buffer\n");
+			goto free_flip_work;
+		}
+
+		/* No need to queue the worker if the are no fences */
+		if (!flip_work->excl && !flip_work->shared_count) {
+			ipu_crtc->flip_state = IPU_FLIP_SUBMITTED;
+		} else {
+			ipu_crtc->flip_state = IPU_FLIP_PENDING;
+			queue_work(ipu_crtc->flip_queue,
+				   &flip_work->fence_work);
+		}
+	} else {
+		ipu_crtc->flip_state = IPU_FLIP_SUBMITTED;
+	}
 
 	return 0;
+
+free_flip_work:
+	drm_gem_object_unreference_unlocked(flip_work->bo);
+	kfree(flip_work);
+	ipu_crtc->flip_work = NULL;
+put_vblank:
+	imx_drm_crtc_vblank_put(ipu_crtc->imx_crtc);
+
+	return ret;
 }
 
 static const struct drm_crtc_funcs ipu_crtc_funcs = {
@@ -209,12 +306,12 @@ static void ipu_crtc_handle_pageflip(struct ipu_crtc *ipu_crtc)
 {
 	unsigned long flags;
 	struct drm_device *drm = ipu_crtc->base.dev;
+	struct ipu_flip_work *work = ipu_crtc->flip_work;
 
 	spin_lock_irqsave(&drm->event_lock, flags);
-	if (ipu_crtc->page_flip_event)
+	if (work->page_flip_event)
 		drm_crtc_send_vblank_event(&ipu_crtc->base,
-					   ipu_crtc->page_flip_event);
-	ipu_crtc->page_flip_event = NULL;
+					   work->page_flip_event);
 	imx_drm_crtc_vblank_put(ipu_crtc->imx_crtc);
 	spin_unlock_irqrestore(&drm->event_lock, flags);
 }
@@ -225,13 +322,15 @@ static irqreturn_t ipu_irq_handler(int irq, void *dev_id)
 
 	imx_drm_handle_vblank(ipu_crtc->imx_crtc);
 
-	if (ipu_crtc->newfb) {
+	if (ipu_crtc->flip_state == IPU_FLIP_SUBMITTED) {
 		struct ipu_plane *plane = ipu_crtc->plane[0];
 
-		ipu_crtc->newfb = NULL;
 		ipu_plane_set_base(plane, ipu_crtc->base.primary->fb,
 				   plane->x, plane->y);
 		ipu_crtc_handle_pageflip(ipu_crtc);
+		queue_work(ipu_crtc->flip_queue,
+			   &ipu_crtc->flip_work->unref_work);
+		ipu_crtc->flip_state = IPU_FLIP_NONE;
 	}
 
 	return IRQ_HANDLED;
@@ -280,11 +379,18 @@ static const struct drm_crtc_helper_funcs ipu_helper_funcs = {
 
 static int ipu_enable_vblank(struct drm_crtc *crtc)
 {
+	struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
+
+	enable_irq(ipu_crtc->irq);
+
 	return 0;
 }
 
 static void ipu_disable_vblank(struct drm_crtc *crtc)
 {
+	struct ipu_crtc *ipu_crtc = to_ipu_crtc(crtc);
+
+	disable_irq_nosync(ipu_crtc->irq);
 }
 
 static int ipu_set_interface_pix_fmt(struct drm_crtc *crtc,
@@ -395,6 +501,10 @@ static int ipu_crtc_init(struct ipu_crtc *ipu_crtc,
 		dev_err(ipu_crtc->dev, "irq request failed with %d.\n", ret);
 		goto err_put_plane_res;
 	}
+	/* Only enable IRQ when we actually need it to trigger work. */
+	disable_irq(ipu_crtc->irq);
+
+	ipu_crtc->flip_queue = create_singlethread_workqueue("ipu-crtc-flip");
 
 	return 0;
 
@@ -437,6 +547,7 @@ static void ipu_drm_unbind(struct device *dev, struct device *master,
 
 	imx_drm_remove_crtc(ipu_crtc->imx_crtc);
 
+	destroy_workqueue(ipu_crtc->flip_queue);
 	ipu_plane_put_resources(ipu_crtc->plane[0]);
 	ipu_put_resources(ipu_crtc);
 }

drivers/gpu/drm/imx/ipuv3-plane.c

@@ -338,7 +338,7 @@ static int ipu_update_plane(struct drm_plane *plane, struct drm_crtc *crtc,
 	}
 
 	if (crtc != plane->crtc)
-		dev_info(plane->dev->dev, "crtc change: %p -> %p\n",
+		dev_dbg(plane->dev->dev, "crtc change: %p -> %p\n",
 				plane->crtc, crtc);
 	plane->crtc = crtc;
 

drivers/gpu/drm/rockchip/dw-mipi-dsi.c

@@ -878,7 +878,7 @@ static void dw_mipi_dsi_encoder_disable(struct drm_encoder *encoder)
 static void dw_mipi_dsi_encoder_commit(struct drm_encoder *encoder)
 {
 	struct dw_mipi_dsi *dsi = encoder_to_dsi(encoder);
-	int mux  = rockchip_drm_encoder_get_mux_id(dsi->dev->of_node, encoder);
+	int mux = drm_of_encoder_active_endpoint_id(dsi->dev->of_node, encoder);
 	u32 interface_pix_fmt;
 	u32 val;
 

drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c

@@ -204,7 +204,7 @@ static void dw_hdmi_rockchip_encoder_enable(struct drm_encoder *encoder)
 	rockchip_drm_crtc_mode_config(encoder->crtc, DRM_MODE_CONNECTOR_HDMIA,
 				      ROCKCHIP_OUT_MODE_AAAA);
 
-	mux = rockchip_drm_encoder_get_mux_id(hdmi->dev->of_node, encoder);
+	mux = drm_of_encoder_active_endpoint_id(hdmi->dev->of_node, encoder);
 	if (mux)
 		val = HDMI_SEL_VOP_LIT | (HDMI_SEL_VOP_LIT << 16);
 	else

drivers/gpu/drm/rockchip/rockchip_drm_drv.c

@@ -384,36 +384,6 @@ static const struct dev_pm_ops rockchip_drm_pm_ops = {
 				rockchip_drm_sys_resume)
 };
 
-/*
- * @node: device tree node containing encoder input ports
- * @encoder: drm_encoder
- */
-int rockchip_drm_encoder_get_mux_id(struct device_node *node,
-				    struct drm_encoder *encoder)
-{
-	struct device_node *ep;
-	struct drm_crtc *crtc = encoder->crtc;
-	struct of_endpoint endpoint;
-	struct device_node *port;
-	int ret;
-
-	if (!node || !crtc)
-		return -EINVAL;
-
-	for_each_endpoint_of_node(node, ep) {
-		port = of_graph_get_remote_port(ep);
-		of_node_put(port);
-		if (port == crtc->port) {
-			ret = of_graph_parse_endpoint(ep, &endpoint);
-			of_node_put(ep);
-			return ret ?: endpoint.id;
-		}
-	}
-
-	return -EINVAL;
-}
-EXPORT_SYMBOL_GPL(rockchip_drm_encoder_get_mux_id);
-
 static int compare_of(struct device *dev, void *data)
 {
 	struct device_node *np = data;

drivers/gpu/drm/rockchip/rockchip_drm_drv.h

@@ -67,8 +67,6 @@ void rockchip_drm_atomic_work(struct work_struct *work);
 int rockchip_register_crtc_funcs(struct drm_crtc *crtc,
 				 const struct rockchip_crtc_funcs *crtc_funcs);
 void rockchip_unregister_crtc_funcs(struct drm_crtc *crtc);
-int rockchip_drm_encoder_get_mux_id(struct device_node *node,
-				    struct drm_encoder *encoder);
 int rockchip_drm_crtc_mode_config(struct drm_crtc *crtc, int connector_type,
 				  int out_mode);
 int rockchip_drm_dma_attach_device(struct drm_device *drm_dev,

drivers/gpu/ipu-v3/ipu-dc.c

@@ -171,6 +171,7 @@ int ipu_dc_init_sync(struct ipu_dc *dc, struct ipu_di *di, bool interlaced,
 		u32 bus_format, u32 width)
 {
 	struct ipu_dc_priv *priv = dc->priv;
+	int addr, sync;
 	u32 reg = 0;
 	int map;
 
@@ -182,41 +183,39 @@ int ipu_dc_init_sync(struct ipu_dc *dc, struct ipu_di *di, bool interlaced,
 		return map;
 	}
 
-	if (interlaced) {
-		int addr;
-
-		if (dc->di)
-			addr = 1;
-		else
-			addr = 0;
+	/*
+	 * In interlaced mode we need more counters to create the asymmetric
+	 * per-field VSYNC signals. The pixel active signal synchronising DC
+	 * to DI moves to signal generator #6 (see ipu-di.c). In progressive
+	 * mode counter #5 is used.
+	 */
+	sync = interlaced ? 6 : 5;
+
+	/* Reserve 5 microcode template words for each DI */
+	if (dc->di)
+		addr = 5;
+	else
+		addr = 0;
 
+	if (interlaced) {
 		dc_link_event(dc, DC_EVT_NL, addr, 3);
 		dc_link_event(dc, DC_EVT_EOL, addr, 2);
 		dc_link_event(dc, DC_EVT_NEW_DATA, addr, 1);
 
 		/* Init template microcode */
-		dc_write_tmpl(dc, addr, WROD(0), 0, map, SYNC_WAVE, 0, 6, 1);
+		dc_write_tmpl(dc, addr, WROD(0), 0, map, SYNC_WAVE, 0, sync, 1);
 	} else {
-		if (dc->di) {
-			dc_link_event(dc, DC_EVT_NL, 2, 3);
-			dc_link_event(dc, DC_EVT_EOL, 3, 2);
-			dc_link_event(dc, DC_EVT_NEW_DATA, 1, 1);
-			/* Init template microcode */
-			dc_write_tmpl(dc, 2, WROD(0), 0, map, SYNC_WAVE, 8, 5, 1);
-			dc_write_tmpl(dc, 3, WROD(0), 0, map, SYNC_WAVE, 4, 5, 0);
-			dc_write_tmpl(dc, 4, WRG, 0, map, NULL_WAVE, 0, 0, 1);
-			dc_write_tmpl(dc, 1, WROD(0), 0, map, SYNC_WAVE, 0, 5, 1);
-		} else {
-			dc_link_event(dc, DC_EVT_NL, 5, 3);
-			dc_link_event(dc, DC_EVT_EOL, 6, 2);
-			dc_link_event(dc, DC_EVT_NEW_DATA, 8, 1);
-			/* Init template microcode */
-			dc_write_tmpl(dc, 5, WROD(0), 0, map, SYNC_WAVE, 8, 5, 1);
-			dc_write_tmpl(dc, 6, WROD(0), 0, map, SYNC_WAVE, 4, 5, 0);
-			dc_write_tmpl(dc, 7, WRG, 0, map, NULL_WAVE, 0, 0, 1);
-			dc_write_tmpl(dc, 8, WROD(0), 0, map, SYNC_WAVE, 0, 5, 1);
-		}
+		dc_link_event(dc, DC_EVT_NL, addr + 2, 3);
+		dc_link_event(dc, DC_EVT_EOL, addr + 3, 2);
+		dc_link_event(dc, DC_EVT_NEW_DATA, addr + 1, 1);
+
+		/* Init template microcode */
+		dc_write_tmpl(dc, addr + 2, WROD(0), 0, map, SYNC_WAVE, 8, sync, 1);
+		dc_write_tmpl(dc, addr + 3, WROD(0), 0, map, SYNC_WAVE, 4, sync, 0);
+		dc_write_tmpl(dc, addr + 4, WRG, 0, map, NULL_WAVE, 0, 0, 1);
+		dc_write_tmpl(dc, addr + 1, WROD(0), 0, map, SYNC_WAVE, 0, sync, 1);
 	}
+
 	dc_link_event(dc, DC_EVT_NF, 0, 0);
 	dc_link_event(dc, DC_EVT_NFIELD, 0, 0);
 	dc_link_event(dc, DC_EVT_EOF, 0, 0);

include/drm/drm_of.h

@@ -1,9 +1,12 @@
 #ifndef __DRM_OF_H__
 #define __DRM_OF_H__
 
+#include <linux/of_graph.h>
+
 struct component_master_ops;
 struct device;
 struct drm_device;
+struct drm_encoder;
 struct device_node;
 
 #ifdef CONFIG_OF
@@ -12,6 +15,9 @@ extern uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
 extern int drm_of_component_probe(struct device *dev,
 				  int (*compare_of)(struct device *, void *),
 				  const struct component_master_ops *m_ops);
+extern int drm_of_encoder_active_endpoint(struct device_node *node,
+					  struct drm_encoder *encoder,
+					  struct of_endpoint *endpoint);
 #else
 static inline uint32_t drm_of_find_possible_crtcs(struct drm_device *dev,
 						  struct device_node *port)
@@ -26,6 +32,33 @@ drm_of_component_probe(struct device *dev,
 {
 	return -EINVAL;
 }
+
+static inline int drm_of_encoder_active_endpoint(struct device_node *node,
+						 struct drm_encoder *encoder,
+						 struct of_endpoint *endpoint)
+{
+	return -EINVAL;
+}
 #endif
 
+static inline int drm_of_encoder_active_endpoint_id(struct device_node *node,
+						    struct drm_encoder *encoder)
+{
+	struct of_endpoint endpoint;
+	int ret = drm_of_encoder_active_endpoint(node, encoder,
+						 &endpoint);
+
+	return ret ?: endpoint.id;
+}
+
+static inline int drm_of_encoder_active_port_id(struct device_node *node,
+						struct drm_encoder *encoder)
+{
+	struct of_endpoint endpoint;
+	int ret = drm_of_encoder_active_endpoint(node, encoder,
+						 &endpoint);
+
+	return ret ?: endpoint.port;
+}
+
 #endif /* __DRM_OF_H__ */