diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
index 983ae476c203..93161b98e22a 100644
--- a/drivers/gpu/drm/vc4/vc4_crtc.c
+++ b/drivers/gpu/drm/vc4/vc4_crtc.c
@@ -206,48 +206,6 @@ static void vc4_crtc_destroy(struct drm_crtc *crtc)
 	drm_crtc_cleanup(crtc);
 }
 
-static void
-vc4_crtc_lut_load(struct drm_crtc *crtc)
-{
-	struct drm_device *dev = crtc->dev;
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
-	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
-	struct vc4_crtc_state *vc4_crtc_state = to_vc4_crtc_state(crtc->state);
-	u32 i;
-
-	/* The LUT memory is laid out with each HVS channel in order,
-	 * each of which takes 256 writes for R, 256 for G, then 256
-	 * for B.
-	 */
-	HVS_WRITE(SCALER_GAMADDR,
-		  SCALER_GAMADDR_AUTOINC |
-		  (vc4_crtc_state->assigned_channel * 3 * crtc->gamma_size));
-
-	for (i = 0; i < crtc->gamma_size; i++)
-		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_r[i]);
-	for (i = 0; i < crtc->gamma_size; i++)
-		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_g[i]);
-	for (i = 0; i < crtc->gamma_size; i++)
-		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_b[i]);
-}
-
-static void
-vc4_crtc_update_gamma_lut(struct drm_crtc *crtc)
-{
-	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
-	struct drm_color_lut *lut = crtc->state->gamma_lut->data;
-	u32 length = drm_color_lut_size(crtc->state->gamma_lut);
-	u32 i;
-
-	for (i = 0; i < length; i++) {
-		vc4_crtc->lut_r[i] = drm_color_lut_extract(lut[i].red, 8);
-		vc4_crtc->lut_g[i] = drm_color_lut_extract(lut[i].green, 8);
-		vc4_crtc->lut_b[i] = drm_color_lut_extract(lut[i].blue, 8);
-	}
-
-	vc4_crtc_lut_load(crtc);
-}
-
 static u32 vc4_get_fifo_full_level(struct vc4_crtc *vc4_crtc, u32 format)
 {
 	u32 fifo_len_bytes = vc4_crtc->data->fifo_depth;
@@ -403,12 +361,8 @@ static void vc4_crtc_config_pv(struct drm_crtc *crtc)
 
 static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc)
 {
-	struct drm_device *dev = crtc->dev;
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
-	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
-	bool interlace = mode->flags & DRM_MODE_FLAG_INTERLACE;
 	bool debug_dump_regs = false;
 
 	if (debug_dump_regs) {
@@ -418,42 +372,10 @@ static void vc4_crtc_mode_set_nofb(struct drm_crtc *crtc)
 		drm_print_regset32(&p, &vc4_crtc->regset);
 	}
 
-	if (vc4_crtc->data->hvs_output == 2) {
-		u32 dispctrl;
-		u32 dsp3_mux;
-
-		/*
-		 * SCALER_DISPCTRL_DSP3 = X, where X < 2 means 'connect DSP3 to
-		 * FIFO X'.
-		 * SCALER_DISPCTRL_DSP3 = 3 means 'disable DSP 3'.
-		 *
-		 * DSP3 is connected to FIFO2 unless the transposer is
-		 * enabled. In this case, FIFO 2 is directly accessed by the
-		 * TXP IP, and we need to disable the FIFO2 -> pixelvalve1
-		 * route.
-		 */
-		if (vc4_state->feed_txp)
-			dsp3_mux = VC4_SET_FIELD(3, SCALER_DISPCTRL_DSP3_MUX);
-		else
-			dsp3_mux = VC4_SET_FIELD(2, SCALER_DISPCTRL_DSP3_MUX);
-
-		dispctrl = HVS_READ(SCALER_DISPCTRL) &
-			   ~SCALER_DISPCTRL_DSP3_MUX_MASK;
-		HVS_WRITE(SCALER_DISPCTRL, dispctrl | dsp3_mux);
-	}
-
 	if (!vc4_state->feed_txp)
 		vc4_crtc_config_pv(crtc);
 
-	HVS_WRITE(SCALER_DISPBKGNDX(vc4_state->assigned_channel),
-		  SCALER_DISPBKGND_AUTOHS |
-		  ((!vc4->hvs->hvs5) ? SCALER_DISPBKGND_GAMMA : 0) |
-		  (interlace ? SCALER_DISPBKGND_INTERLACE : 0));
-
-	/* Reload the LUT, since the SRAMs would have been disabled if
-	 * all CRTCs had SCALER_DISPBKGND_GAMMA unset at once.
-	 */
-	vc4_crtc_lut_load(crtc);
+	vc4_hvs_mode_set_nofb(crtc);
 
 	if (debug_dump_regs) {
 		struct drm_printer p = drm_info_printer(&vc4_crtc->pdev->dev);
@@ -475,11 +397,9 @@ static void vc4_crtc_atomic_disable(struct drm_crtc *crtc,
 				    struct drm_crtc_state *old_state)
 {
 	struct drm_device *dev = crtc->dev;
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
-	struct vc4_crtc_state *vc4_crtc_state = to_vc4_crtc_state(old_state);
-	u32 chan = vc4_crtc_state->assigned_channel;
 	int ret;
+
 	require_hvs_enabled(dev);
 
 	/* Disable vblank irq handling before crtc is disabled. */
@@ -492,28 +412,7 @@ static void vc4_crtc_atomic_disable(struct drm_crtc *crtc,
 
 	CRTC_WRITE(PV_CONTROL, CRTC_READ(PV_CONTROL) & ~PV_CONTROL_EN);
 
-	if (HVS_READ(SCALER_DISPCTRLX(chan)) &
-	    SCALER_DISPCTRLX_ENABLE) {
-		HVS_WRITE(SCALER_DISPCTRLX(chan),
-			  SCALER_DISPCTRLX_RESET);
-
-		/* While the docs say that reset is self-clearing, it
-		 * seems it doesn't actually.
-		 */
-		HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
-	}
-
-	/* Once we leave, the scaler should be disabled and its fifo empty. */
-
-	WARN_ON_ONCE(HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_RESET);
-
-	WARN_ON_ONCE(VC4_GET_FIELD(HVS_READ(SCALER_DISPSTATX(chan)),
-				   SCALER_DISPSTATX_MODE) !=
-		     SCALER_DISPSTATX_MODE_DISABLED);
-
-	WARN_ON_ONCE((HVS_READ(SCALER_DISPSTATX(chan)) &
-		      (SCALER_DISPSTATX_FULL | SCALER_DISPSTATX_EMPTY)) !=
-		     SCALER_DISPSTATX_EMPTY);
+	vc4_hvs_atomic_disable(crtc, old_state);
 
 	/*
 	 * Make sure we issue a vblank event after disabling the CRTC if
@@ -536,46 +435,12 @@ void vc4_crtc_txp_armed(struct drm_crtc_state *state)
 	vc4_state->txp_armed = true;
 }
 
-static void vc4_crtc_update_dlist(struct drm_crtc *crtc)
-{
-	struct drm_device *dev = crtc->dev;
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
-	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
-	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
-
-	if (crtc->state->event) {
-		unsigned long flags;
-
-		crtc->state->event->pipe = drm_crtc_index(crtc);
-
-		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
-
-		spin_lock_irqsave(&dev->event_lock, flags);
-
-		if (!vc4_state->feed_txp || vc4_state->txp_armed) {
-			vc4_crtc->event = crtc->state->event;
-			crtc->state->event = NULL;
-		}
-
-		HVS_WRITE(SCALER_DISPLISTX(vc4_state->assigned_channel),
-			  vc4_state->mm.start);
-
-		spin_unlock_irqrestore(&dev->event_lock, flags);
-	} else {
-		HVS_WRITE(SCALER_DISPLISTX(vc4_state->assigned_channel),
-			  vc4_state->mm.start);
-	}
-}
-
 static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,
 				   struct drm_crtc_state *old_state)
 {
 	struct drm_device *dev = crtc->dev;
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
-	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
-	u32 dispctrl;
 
 	require_hvs_enabled(dev);
 
@@ -587,31 +452,8 @@ static void vc4_crtc_atomic_enable(struct drm_crtc *crtc,
 	 * drm_crtc_get_vblank() fails in vc4_crtc_update_dlist().
 	 */
 	drm_crtc_vblank_on(crtc);
-	vc4_crtc_update_dlist(crtc);
-
-	/* Turn on the scaler, which will wait for vstart to start
-	 * compositing.
-	 * When feeding the transposer, we should operate in oneshot
-	 * mode.
-	 */
-	dispctrl = SCALER_DISPCTRLX_ENABLE;
-
-	if (!vc4->hvs->hvs5)
-		dispctrl |= VC4_SET_FIELD(mode->hdisplay,
-					  SCALER_DISPCTRLX_WIDTH) |
-			    VC4_SET_FIELD(mode->vdisplay,
-					  SCALER_DISPCTRLX_HEIGHT) |
-			    (vc4_state->feed_txp ?
-					SCALER_DISPCTRLX_ONESHOT : 0);
-	else
-		dispctrl |= VC4_SET_FIELD(mode->hdisplay,
-					  SCALER5_DISPCTRLX_WIDTH) |
-			    VC4_SET_FIELD(mode->vdisplay,
-					  SCALER5_DISPCTRLX_HEIGHT) |
-			    (vc4_state->feed_txp ?
-					SCALER5_DISPCTRLX_ONESHOT : 0);
 
-	HVS_WRITE(SCALER_DISPCTRLX(vc4_state->assigned_channel), dispctrl);
+	vc4_hvs_atomic_enable(crtc, old_state);
 
 	/* When feeding the transposer block the pixelvalve is unneeded and
 	 * should not be enabled.
@@ -669,31 +511,11 @@ static int vc4_crtc_atomic_check(struct drm_crtc *crtc,
 				 struct drm_crtc_state *state)
 {
 	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(state);
-	struct drm_device *dev = crtc->dev;
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
-	struct drm_plane *plane;
-	unsigned long flags;
-	const struct drm_plane_state *plane_state;
 	struct drm_connector *conn;
 	struct drm_connector_state *conn_state;
-	u32 dlist_count = 0;
 	int ret, i;
 
-	/* The pixelvalve can only feed one encoder (and encoders are
-	 * 1:1 with connectors.)
-	 */
-	if (hweight32(state->connector_mask) > 1)
-		return -EINVAL;
-
-	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, state)
-		dlist_count += vc4_plane_dlist_size(plane_state);
-
-	dlist_count++; /* Account for SCALER_CTL0_END. */
-
-	spin_lock_irqsave(&vc4->hvs->mm_lock, flags);
-	ret = drm_mm_insert_node(&vc4->hvs->dlist_mm, &vc4_state->mm,
-				 dlist_count);
-	spin_unlock_irqrestore(&vc4->hvs->mm_lock, flags);
+	ret = vc4_hvs_atomic_check(crtc, state);
 	if (ret)
 		return ret;
 
@@ -722,88 +544,6 @@ static int vc4_crtc_atomic_check(struct drm_crtc *crtc,
 	return 0;
 }
 
-static void vc4_crtc_atomic_flush(struct drm_crtc *crtc,
-				  struct drm_crtc_state *old_state)
-{
-	struct drm_device *dev = crtc->dev;
-	struct vc4_dev *vc4 = to_vc4_dev(dev);
-	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
-	struct drm_plane *plane;
-	struct vc4_plane_state *vc4_plane_state;
-	bool debug_dump_regs = false;
-	bool enable_bg_fill = false;
-	u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start;
-	u32 __iomem *dlist_next = dlist_start;
-
-	if (debug_dump_regs) {
-		DRM_INFO("CRTC %d HVS before:\n", drm_crtc_index(crtc));
-		vc4_hvs_dump_state(dev);
-	}
-
-	/* Copy all the active planes' dlist contents to the hardware dlist. */
-	drm_atomic_crtc_for_each_plane(plane, crtc) {
-		/* Is this the first active plane? */
-		if (dlist_next == dlist_start) {
-			/* We need to enable background fill when a plane
-			 * could be alpha blending from the background, i.e.
-			 * where no other plane is underneath. It suffices to
-			 * consider the first active plane here since we set
-			 * needs_bg_fill such that either the first plane
-			 * already needs it or all planes on top blend from
-			 * the first or a lower plane.
-			 */
-			vc4_plane_state = to_vc4_plane_state(plane->state);
-			enable_bg_fill = vc4_plane_state->needs_bg_fill;
-		}
-
-		dlist_next += vc4_plane_write_dlist(plane, dlist_next);
-	}
-
-	writel(SCALER_CTL0_END, dlist_next);
-	dlist_next++;
-
-	WARN_ON_ONCE(dlist_next - dlist_start != vc4_state->mm.size);
-
-	if (enable_bg_fill)
-		/* This sets a black background color fill, as is the case
-		 * with other DRM drivers.
-		 */
-		HVS_WRITE(SCALER_DISPBKGNDX(vc4_state->assigned_channel),
-			  HVS_READ(SCALER_DISPBKGNDX(vc4_state->assigned_channel)) |
-			  SCALER_DISPBKGND_FILL);
-
-	/* Only update DISPLIST if the CRTC was already running and is not
-	 * being disabled.
-	 * vc4_crtc_enable() takes care of updating the dlist just after
-	 * re-enabling VBLANK interrupts and before enabling the engine.
-	 * If the CRTC is being disabled, there's no point in updating this
-	 * information.
-	 */
-	if (crtc->state->active && old_state->active)
-		vc4_crtc_update_dlist(crtc);
-
-	if (crtc->state->color_mgmt_changed) {
-		u32 dispbkgndx = HVS_READ(SCALER_DISPBKGNDX(vc4_state->assigned_channel));
-
-		if (crtc->state->gamma_lut) {
-			vc4_crtc_update_gamma_lut(crtc);
-			dispbkgndx |= SCALER_DISPBKGND_GAMMA;
-		} else {
-			/* Unsetting DISPBKGND_GAMMA skips the gamma lut step
-			 * in hardware, which is the same as a linear lut that
-			 * DRM expects us to use in absence of a user lut.
-			 */
-			dispbkgndx &= ~SCALER_DISPBKGND_GAMMA;
-		}
-		HVS_WRITE(SCALER_DISPBKGNDX(vc4_state->assigned_channel), dispbkgndx);
-	}
-
-	if (debug_dump_regs) {
-		DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc));
-		vc4_hvs_dump_state(dev);
-	}
-}
-
 static int vc4_enable_vblank(struct drm_crtc *crtc)
 {
 	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
@@ -1080,7 +820,7 @@ static const struct drm_crtc_helper_funcs vc4_crtc_helper_funcs = {
 	.mode_set_nofb = vc4_crtc_mode_set_nofb,
 	.mode_valid = vc4_crtc_mode_valid,
 	.atomic_check = vc4_crtc_atomic_check,
-	.atomic_flush = vc4_crtc_atomic_flush,
+	.atomic_flush = vc4_hvs_atomic_flush,
 	.atomic_enable = vc4_crtc_atomic_enable,
 	.atomic_disable = vc4_crtc_atomic_disable,
 	.get_scanout_position = vc4_crtc_get_scanout_position,
diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
index 974cda3c5292..5520a22f8126 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.h
+++ b/drivers/gpu/drm/vc4/vc4_drv.h
@@ -872,6 +872,11 @@ void vc4_irq_reset(struct drm_device *dev);
 
 /* vc4_hvs.c */
 extern struct platform_driver vc4_hvs_driver;
+int vc4_hvs_atomic_check(struct drm_crtc *crtc, struct drm_crtc_state *state);
+void vc4_hvs_atomic_enable(struct drm_crtc *crtc, struct drm_crtc_state *old_state);
+void vc4_hvs_atomic_disable(struct drm_crtc *crtc, struct drm_crtc_state *old_state);
+void vc4_hvs_atomic_flush(struct drm_crtc *crtc, struct drm_crtc_state *state);
+void vc4_hvs_mode_set_nofb(struct drm_crtc *crtc);
 void vc4_hvs_dump_state(struct drm_device *dev);
 void vc4_hvs_unmask_underrun(struct drm_device *dev, int channel);
 void vc4_hvs_mask_underrun(struct drm_device *dev, int channel);
diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index f4942667355b..0cd63d817a7e 100644
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -24,6 +24,7 @@
 #include <linux/platform_device.h>
 
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_vblank.h>
 
 #include "vc4_drv.h"
 #include "vc4_regs.h"
@@ -155,6 +156,303 @@ static int vc4_hvs_upload_linear_kernel(struct vc4_hvs *hvs,
 	return 0;
 }
 
+static void vc4_hvs_lut_load(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	struct vc4_crtc_state *vc4_crtc_state = to_vc4_crtc_state(crtc->state);
+	u32 i;
+
+	/* The LUT memory is laid out with each HVS channel in order,
+	 * each of which takes 256 writes for R, 256 for G, then 256
+	 * for B.
+	 */
+	HVS_WRITE(SCALER_GAMADDR,
+		  SCALER_GAMADDR_AUTOINC |
+		  (vc4_crtc_state->assigned_channel * 3 * crtc->gamma_size));
+
+	for (i = 0; i < crtc->gamma_size; i++)
+		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_r[i]);
+	for (i = 0; i < crtc->gamma_size; i++)
+		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_g[i]);
+	for (i = 0; i < crtc->gamma_size; i++)
+		HVS_WRITE(SCALER_GAMDATA, vc4_crtc->lut_b[i]);
+}
+
+static void vc4_hvs_update_gamma_lut(struct drm_crtc *crtc)
+{
+	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	struct drm_color_lut *lut = crtc->state->gamma_lut->data;
+	u32 length = drm_color_lut_size(crtc->state->gamma_lut);
+	u32 i;
+
+	for (i = 0; i < length; i++) {
+		vc4_crtc->lut_r[i] = drm_color_lut_extract(lut[i].red, 8);
+		vc4_crtc->lut_g[i] = drm_color_lut_extract(lut[i].green, 8);
+		vc4_crtc->lut_b[i] = drm_color_lut_extract(lut[i].blue, 8);
+	}
+
+	vc4_hvs_lut_load(crtc);
+}
+
+int vc4_hvs_atomic_check(struct drm_crtc *crtc,
+			 struct drm_crtc_state *state)
+{
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(state);
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct drm_plane *plane;
+	unsigned long flags;
+	const struct drm_plane_state *plane_state;
+	u32 dlist_count = 0;
+	int ret;
+
+	/* The pixelvalve can only feed one encoder (and encoders are
+	 * 1:1 with connectors.)
+	 */
+	if (hweight32(state->connector_mask) > 1)
+		return -EINVAL;
+
+	drm_atomic_crtc_state_for_each_plane_state(plane, plane_state, state)
+		dlist_count += vc4_plane_dlist_size(plane_state);
+
+	dlist_count++; /* Account for SCALER_CTL0_END. */
+
+	spin_lock_irqsave(&vc4->hvs->mm_lock, flags);
+	ret = drm_mm_insert_node(&vc4->hvs->dlist_mm, &vc4_state->mm,
+				 dlist_count);
+	spin_unlock_irqrestore(&vc4->hvs->mm_lock, flags);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void vc4_hvs_update_dlist(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
+
+	if (crtc->state->event) {
+		unsigned long flags;
+
+		crtc->state->event->pipe = drm_crtc_index(crtc);
+
+		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
+
+		spin_lock_irqsave(&dev->event_lock, flags);
+
+		if (!vc4_state->feed_txp || vc4_state->txp_armed) {
+			vc4_crtc->event = crtc->state->event;
+			crtc->state->event = NULL;
+		}
+
+		HVS_WRITE(SCALER_DISPLISTX(vc4_state->assigned_channel),
+			  vc4_state->mm.start);
+
+		spin_unlock_irqrestore(&dev->event_lock, flags);
+	} else {
+		HVS_WRITE(SCALER_DISPLISTX(vc4_state->assigned_channel),
+			  vc4_state->mm.start);
+	}
+}
+
+void vc4_hvs_atomic_enable(struct drm_crtc *crtc,
+			   struct drm_crtc_state *old_state)
+{
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
+	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+	bool oneshot = vc4_state->feed_txp;
+	u32 dispctrl;
+
+	vc4_hvs_update_dlist(crtc);
+
+	/* Turn on the scaler, which will wait for vstart to start
+	 * compositing.
+	 * When feeding the transposer, we should operate in oneshot
+	 * mode.
+	 */
+	dispctrl = SCALER_DISPCTRLX_ENABLE;
+
+	if (!vc4->hvs->hvs5)
+		dispctrl |= VC4_SET_FIELD(mode->hdisplay,
+					  SCALER_DISPCTRLX_WIDTH) |
+			    VC4_SET_FIELD(mode->vdisplay,
+					  SCALER_DISPCTRLX_HEIGHT) |
+			    (oneshot ? SCALER_DISPCTRLX_ONESHOT : 0);
+	else
+		dispctrl |= VC4_SET_FIELD(mode->hdisplay,
+					  SCALER5_DISPCTRLX_WIDTH) |
+			    VC4_SET_FIELD(mode->vdisplay,
+					  SCALER5_DISPCTRLX_HEIGHT) |
+			    (oneshot ? SCALER5_DISPCTRLX_ONESHOT : 0);
+
+	HVS_WRITE(SCALER_DISPCTRLX(vc4_state->assigned_channel), dispctrl);
+}
+
+void vc4_hvs_atomic_disable(struct drm_crtc *crtc,
+			    struct drm_crtc_state *old_state)
+{
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_crtc_state *vc4_crtc_state = to_vc4_crtc_state(old_state);
+	u32 chan = vc4_crtc_state->assigned_channel;
+
+	if (HVS_READ(SCALER_DISPCTRLX(chan)) &
+	    SCALER_DISPCTRLX_ENABLE) {
+		HVS_WRITE(SCALER_DISPCTRLX(chan),
+			  SCALER_DISPCTRLX_RESET);
+
+		/* While the docs say that reset is self-clearing, it
+		 * seems it doesn't actually.
+		 */
+		HVS_WRITE(SCALER_DISPCTRLX(chan), 0);
+	}
+
+	/* Once we leave, the scaler should be disabled and its fifo empty. */
+
+	WARN_ON_ONCE(HVS_READ(SCALER_DISPCTRLX(chan)) & SCALER_DISPCTRLX_RESET);
+
+	WARN_ON_ONCE(VC4_GET_FIELD(HVS_READ(SCALER_DISPSTATX(chan)),
+				   SCALER_DISPSTATX_MODE) !=
+		     SCALER_DISPSTATX_MODE_DISABLED);
+
+	WARN_ON_ONCE((HVS_READ(SCALER_DISPSTATX(chan)) &
+		      (SCALER_DISPSTATX_FULL | SCALER_DISPSTATX_EMPTY)) !=
+		     SCALER_DISPSTATX_EMPTY);
+}
+
+void vc4_hvs_atomic_flush(struct drm_crtc *crtc,
+			  struct drm_crtc_state *old_state)
+{
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
+	struct drm_plane *plane;
+	struct vc4_plane_state *vc4_plane_state;
+	bool debug_dump_regs = false;
+	bool enable_bg_fill = false;
+	u32 __iomem *dlist_start = vc4->hvs->dlist + vc4_state->mm.start;
+	u32 __iomem *dlist_next = dlist_start;
+
+	if (debug_dump_regs) {
+		DRM_INFO("CRTC %d HVS before:\n", drm_crtc_index(crtc));
+		vc4_hvs_dump_state(dev);
+	}
+
+	/* Copy all the active planes' dlist contents to the hardware dlist. */
+	drm_atomic_crtc_for_each_plane(plane, crtc) {
+		/* Is this the first active plane? */
+		if (dlist_next == dlist_start) {
+			/* We need to enable background fill when a plane
+			 * could be alpha blending from the background, i.e.
+			 * where no other plane is underneath. It suffices to
+			 * consider the first active plane here since we set
+			 * needs_bg_fill such that either the first plane
+			 * already needs it or all planes on top blend from
+			 * the first or a lower plane.
+			 */
+			vc4_plane_state = to_vc4_plane_state(plane->state);
+			enable_bg_fill = vc4_plane_state->needs_bg_fill;
+		}
+
+		dlist_next += vc4_plane_write_dlist(plane, dlist_next);
+	}
+
+	writel(SCALER_CTL0_END, dlist_next);
+	dlist_next++;
+
+	WARN_ON_ONCE(dlist_next - dlist_start != vc4_state->mm.size);
+
+	if (enable_bg_fill)
+		/* This sets a black background color fill, as is the case
+		 * with other DRM drivers.
+		 */
+		HVS_WRITE(SCALER_DISPBKGNDX(vc4_state->assigned_channel),
+			  HVS_READ(SCALER_DISPBKGNDX(vc4_state->assigned_channel)) |
+			  SCALER_DISPBKGND_FILL);
+
+	/* Only update DISPLIST if the CRTC was already running and is not
+	 * being disabled.
+	 * vc4_crtc_enable() takes care of updating the dlist just after
+	 * re-enabling VBLANK interrupts and before enabling the engine.
+	 * If the CRTC is being disabled, there's no point in updating this
+	 * information.
+	 */
+	if (crtc->state->active && old_state->active)
+		vc4_hvs_update_dlist(crtc);
+
+	if (crtc->state->color_mgmt_changed) {
+		u32 dispbkgndx = HVS_READ(SCALER_DISPBKGNDX(vc4_state->assigned_channel));
+
+		if (crtc->state->gamma_lut) {
+			vc4_hvs_update_gamma_lut(crtc);
+			dispbkgndx |= SCALER_DISPBKGND_GAMMA;
+		} else {
+			/* Unsetting DISPBKGND_GAMMA skips the gamma lut step
+			 * in hardware, which is the same as a linear lut that
+			 * DRM expects us to use in absence of a user lut.
+			 */
+			dispbkgndx &= ~SCALER_DISPBKGND_GAMMA;
+		}
+		HVS_WRITE(SCALER_DISPBKGNDX(vc4_state->assigned_channel), dispbkgndx);
+	}
+
+	if (debug_dump_regs) {
+		DRM_INFO("CRTC %d HVS after:\n", drm_crtc_index(crtc));
+		vc4_hvs_dump_state(dev);
+	}
+}
+
+void vc4_hvs_mode_set_nofb(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+	struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+	struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc->state);
+	struct drm_display_mode *mode = &crtc->state->adjusted_mode;
+	bool interlace = mode->flags & DRM_MODE_FLAG_INTERLACE;
+
+	if (vc4_crtc->data->hvs_output == 2) {
+		u32 dispctrl;
+		u32 dsp3_mux;
+
+		/*
+		 * SCALER_DISPCTRL_DSP3 = X, where X < 2 means 'connect DSP3 to
+		 * FIFO X'.
+		 * SCALER_DISPCTRL_DSP3 = 3 means 'disable DSP 3'.
+		 *
+		 * DSP3 is connected to FIFO2 unless the transposer is
+		 * enabled. In this case, FIFO 2 is directly accessed by the
+		 * TXP IP, and we need to disable the FIFO2 -> pixelvalve1
+		 * route.
+		 */
+		if (vc4_state->feed_txp)
+			dsp3_mux = VC4_SET_FIELD(3, SCALER_DISPCTRL_DSP3_MUX);
+		else
+			dsp3_mux = VC4_SET_FIELD(2, SCALER_DISPCTRL_DSP3_MUX);
+
+		dispctrl = HVS_READ(SCALER_DISPCTRL) &
+			   ~SCALER_DISPCTRL_DSP3_MUX_MASK;
+		HVS_WRITE(SCALER_DISPCTRL, dispctrl | dsp3_mux);
+	}
+
+	HVS_WRITE(SCALER_DISPBKGNDX(vc4_state->assigned_channel),
+		  SCALER_DISPBKGND_AUTOHS |
+		  ((!vc4->hvs->hvs5) ? SCALER_DISPBKGND_GAMMA : 0) |
+		  (interlace ? SCALER_DISPBKGND_INTERLACE : 0));
+
+	/* Reload the LUT, since the SRAMs would have been disabled if
+	 * all CRTCs had SCALER_DISPBKGND_GAMMA unset at once.
+	 */
+	vc4_hvs_lut_load(crtc);
+}
+
 void vc4_hvs_mask_underrun(struct drm_device *dev, int channel)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
