drivers/gpu/drm/vc4/vc4_plane.c - kernel/msm-4.19 - Gitiles

 /*
  * Copyright (C) 2015 Broadcom
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 /**
  * DOC: VC4 plane module
  *
  * Each DRM plane is a layer of pixels being scanned out by the HVS.
  *
  * At atomic modeset check time, we compute the HVS display element
  * state that would be necessary for displaying the plane (giving us a
  * chance to figure out if a plane configuration is invalid), then at
  * atomic flush time the CRTC will ask us to write our element state
  * into the region of the HVS that it has allocated for us.
  */

 #include "vc4_drv.h"
 #include "vc4_regs.h"
 #include "drm_atomic_helper.h"
 #include "drm_fb_cma_helper.h"
 #include "drm_plane_helper.h"

 struct vc4_plane_state {
 	struct drm_plane_state base;
 	u32 *dlist;
 	u32 dlist_size; /* Number of dwords in allocated for the display list */
 	u32 dlist_count; /* Number of used dwords in the display list. */

 	/* Offset in the dlist to pointer word 0. */
 	u32 pw0_offset;

 	/* Offset where the plane's dlist was last stored in the
 	   hardware at vc4_crtc_atomic_flush() time.
 	*/
 	u32 *hw_dlist;
 };

 static inline struct vc4_plane_state *
 to_vc4_plane_state(struct drm_plane_state *state)
 {
 	return (struct vc4_plane_state *)state;
 }

 static const struct hvs_format {
 	u32 drm; /* DRM_FORMAT_* */
 	u32 hvs; /* HVS_FORMAT_* */
 	u32 pixel_order;
 	bool has_alpha;
 } hvs_formats[] = {
 	{
 		.drm = DRM_FORMAT_XRGB8888, .hvs = HVS_PIXEL_FORMAT_RGBA8888,
 		.pixel_order = HVS_PIXEL_ORDER_ABGR, .has_alpha = false,
 	},
 	{
 		.drm = DRM_FORMAT_ARGB8888, .hvs = HVS_PIXEL_FORMAT_RGBA8888,
 		.pixel_order = HVS_PIXEL_ORDER_ABGR, .has_alpha = true,
 	},
 };

 static const struct hvs_format *vc4_get_hvs_format(u32 drm_format)
 {
 	unsigned i;

 	for (i = 0; i < ARRAY_SIZE(hvs_formats); i++) {
 		if (hvs_formats[i].drm == drm_format)
 			return &hvs_formats[i];
 	}

 	return NULL;
 }

 static bool plane_enabled(struct drm_plane_state *state)
 {
 	return state->fb && state->crtc;
 }

 static struct drm_plane_state *vc4_plane_duplicate_state(struct drm_plane *plane)
 {
 	struct vc4_plane_state *vc4_state;

 	if (WARN_ON(!plane->state))
 		return NULL;

 	vc4_state = kmemdup(plane->state, sizeof(*vc4_state), GFP_KERNEL);
 	if (!vc4_state)
 		return NULL;

 	__drm_atomic_helper_plane_duplicate_state(plane, &vc4_state->base);

 	if (vc4_state->dlist) {
 		vc4_state->dlist = kmemdup(vc4_state->dlist,
 					   vc4_state->dlist_count * 4,
 					   GFP_KERNEL);
 		if (!vc4_state->dlist) {
 			kfree(vc4_state);
 			return NULL;
 		}
 		vc4_state->dlist_size = vc4_state->dlist_count;
 	}

 	return &vc4_state->base;
 }

 static void vc4_plane_destroy_state(struct drm_plane *plane,
 				    struct drm_plane_state *state)
 {
 	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);

 	kfree(vc4_state->dlist);
 	__drm_atomic_helper_plane_destroy_state(plane, &vc4_state->base);
 	kfree(state);
 }

 /* Called during init to allocate the plane's atomic state. */
 static void vc4_plane_reset(struct drm_plane *plane)
 {
 	struct vc4_plane_state *vc4_state;

 	WARN_ON(plane->state);

 	vc4_state = kzalloc(sizeof(*vc4_state), GFP_KERNEL);
 	if (!vc4_state)
 		return;

 	plane->state = &vc4_state->base;
 	vc4_state->base.plane = plane;
 }

 static void vc4_dlist_write(struct vc4_plane_state *vc4_state, u32 val)
 {
 	if (vc4_state->dlist_count == vc4_state->dlist_size) {
 		u32 new_size = max(4u, vc4_state->dlist_count * 2);
 		u32 *new_dlist = kmalloc(new_size * 4, GFP_KERNEL);

 		if (!new_dlist)
 			return;
 		memcpy(new_dlist, vc4_state->dlist, vc4_state->dlist_count * 4);

 		kfree(vc4_state->dlist);
 		vc4_state->dlist = new_dlist;
 		vc4_state->dlist_size = new_size;
 	}

 	vc4_state->dlist[vc4_state->dlist_count++] = val;
 }

 /* Writes out a full display list for an active plane to the plane's
  * private dlist state.
  */
 static int vc4_plane_mode_set(struct drm_plane *plane,
 			      struct drm_plane_state *state)
 {
 	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);
 	struct drm_framebuffer *fb = state->fb;
 	struct drm_gem_cma_object *bo = drm_fb_cma_get_gem_obj(fb, 0);
 	u32 ctl0_offset = vc4_state->dlist_count;
 	const struct hvs_format *format = vc4_get_hvs_format(fb->pixel_format);
 	uint32_t offset = fb->offsets[0];
 	int crtc_x = state->crtc_x;
 	int crtc_y = state->crtc_y;
 	int crtc_w = state->crtc_w;
 	int crtc_h = state->crtc_h;

 	if (state->crtc_w << 16 != state->src_w ||
 	    state->crtc_h << 16 != state->src_h) {
 		/* We don't support scaling yet, which involves
 		 * allocating the LBM memory for scaling temporary
 		 * storage, and putting filter kernels in the HVS
 		 * context.
 		 */
 		return -EINVAL;
 	}

 	if (crtc_x < 0) {
 		offset += drm_format_plane_cpp(fb->pixel_format, 0) * -crtc_x;
 		crtc_w += crtc_x;
 		crtc_x = 0;
 	}

 	if (crtc_y < 0) {
 		offset += fb->pitches[0] * -crtc_y;
 		crtc_h += crtc_y;
 		crtc_y = 0;
 	}

 	vc4_dlist_write(vc4_state,
 			SCALER_CTL0_VALID |
 			(format->pixel_order << SCALER_CTL0_ORDER_SHIFT) |
 			(format->hvs << SCALER_CTL0_PIXEL_FORMAT_SHIFT) |
 			SCALER_CTL0_UNITY);

 	/* Position Word 0: Image Positions and Alpha Value */
 	vc4_dlist_write(vc4_state,
 			VC4_SET_FIELD(0xff, SCALER_POS0_FIXED_ALPHA) |
 			VC4_SET_FIELD(crtc_x, SCALER_POS0_START_X) |
 			VC4_SET_FIELD(crtc_y, SCALER_POS0_START_Y));

 	/* Position Word 1: Scaled Image Dimensions.
 	 * Skipped due to SCALER_CTL0_UNITY scaling.
 	 */

 	/* Position Word 2: Source Image Size, Alpha Mode */
 	vc4_dlist_write(vc4_state,
 			VC4_SET_FIELD(format->has_alpha ?
 				      SCALER_POS2_ALPHA_MODE_PIPELINE :
 				      SCALER_POS2_ALPHA_MODE_FIXED,
 				      SCALER_POS2_ALPHA_MODE) |
 			VC4_SET_FIELD(crtc_w, SCALER_POS2_WIDTH) |
 			VC4_SET_FIELD(crtc_h, SCALER_POS2_HEIGHT));

 	/* Position Word 3: Context.  Written by the HVS. */
 	vc4_dlist_write(vc4_state, 0xc0c0c0c0);

 	vc4_state->pw0_offset = vc4_state->dlist_count;

 	/* Pointer Word 0: RGB / Y Pointer */
 	vc4_dlist_write(vc4_state, bo->paddr + offset);

 	/* Pointer Context Word 0: Written by the HVS */
 	vc4_dlist_write(vc4_state, 0xc0c0c0c0);

 	/* Pitch word 0: Pointer 0 Pitch */
 	vc4_dlist_write(vc4_state,
 			VC4_SET_FIELD(fb->pitches[0], SCALER_SRC_PITCH));

 	vc4_state->dlist[ctl0_offset] |=
 		VC4_SET_FIELD(vc4_state->dlist_count, SCALER_CTL0_SIZE);

 	return 0;
 }

 /* If a modeset involves changing the setup of a plane, the atomic
  * infrastructure will call this to validate a proposed plane setup.
  * However, if a plane isn't getting updated, this (and the
  * corresponding vc4_plane_atomic_update) won't get called.  Thus, we
  * compute the dlist here and have all active plane dlists get updated
  * in the CRTC's flush.
  */
 static int vc4_plane_atomic_check(struct drm_plane *plane,
 				  struct drm_plane_state *state)
 {
 	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);

 	vc4_state->dlist_count = 0;

 	if (plane_enabled(state))
 		return vc4_plane_mode_set(plane, state);
 	else
 		return 0;
 }

 static void vc4_plane_atomic_update(struct drm_plane *plane,
 				    struct drm_plane_state *old_state)
 {
 	/* No contents here.  Since we don't know where in the CRTC's
 	 * dlist we should be stored, our dlist is uploaded to the
 	 * hardware with vc4_plane_write_dlist() at CRTC atomic_flush
 	 * time.
 	 */
 }

 u32 vc4_plane_write_dlist(struct drm_plane *plane, u32 __iomem *dlist)
 {
 	struct vc4_plane_state *vc4_state = to_vc4_plane_state(plane->state);
 	int i;

 	vc4_state->hw_dlist = dlist;

 	/* Can't memcpy_toio() because it needs to be 32-bit writes. */
 	for (i = 0; i < vc4_state->dlist_count; i++)
 		writel(vc4_state->dlist[i], &dlist[i]);

 	return vc4_state->dlist_count;
 }

 u32 vc4_plane_dlist_size(struct drm_plane_state *state)
 {
 	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);

 	return vc4_state->dlist_count;
 }

 /* Updates the plane to immediately (well, once the FIFO needs
  * refilling) scan out from at a new framebuffer.
  */
 void vc4_plane_async_set_fb(struct drm_plane *plane, struct drm_framebuffer *fb)
 {
 	struct vc4_plane_state *vc4_state = to_vc4_plane_state(plane->state);
 	struct drm_gem_cma_object *bo = drm_fb_cma_get_gem_obj(fb, 0);
 	uint32_t addr;

 	/* We're skipping the address adjustment for negative origin,
 	 * because this is only called on the primary plane.
 	 */
 	WARN_ON_ONCE(plane->state->crtc_x < 0 || plane->state->crtc_y < 0);
 	addr = bo->paddr + fb->offsets[0];

 	/* Write the new address into the hardware immediately.  The
 	 * scanout will start from this address as soon as the FIFO
 	 * needs to refill with pixels.
 	 */
 	writel(addr, &vc4_state->hw_dlist[vc4_state->pw0_offset]);

 	/* Also update the CPU-side dlist copy, so that any later
 	 * atomic updates that don't do a new modeset on our plane
 	 * also use our updated address.
 	 */
 	vc4_state->dlist[vc4_state->pw0_offset] = addr;
 }

 static const struct drm_plane_helper_funcs vc4_plane_helper_funcs = {
 	.prepare_fb = NULL,
 	.cleanup_fb = NULL,
 	.atomic_check = vc4_plane_atomic_check,
 	.atomic_update = vc4_plane_atomic_update,
 };

 static void vc4_plane_destroy(struct drm_plane *plane)
 {
 	drm_plane_helper_disable(plane);
 	drm_plane_cleanup(plane);
 }

 static const struct drm_plane_funcs vc4_plane_funcs = {
 	.update_plane = drm_atomic_helper_update_plane,
 	.disable_plane = drm_atomic_helper_disable_plane,
 	.destroy = vc4_plane_destroy,
 	.set_property = NULL,
 	.reset = vc4_plane_reset,
 	.atomic_duplicate_state = vc4_plane_duplicate_state,
 	.atomic_destroy_state = vc4_plane_destroy_state,
 };

 struct drm_plane *vc4_plane_init(struct drm_device *dev,
 				 enum drm_plane_type type)
 {
 	struct drm_plane *plane = NULL;
 	struct vc4_plane *vc4_plane;
 	u32 formats[ARRAY_SIZE(hvs_formats)];
 	int ret = 0;
 	unsigned i;

 	vc4_plane = devm_kzalloc(dev->dev, sizeof(*vc4_plane),
 				 GFP_KERNEL);
 	if (!vc4_plane) {
 		ret = -ENOMEM;
 		goto fail;
 	}

 	for (i = 0; i < ARRAY_SIZE(hvs_formats); i++)
 		formats[i] = hvs_formats[i].drm;
 	plane = &vc4_plane->base;
 	ret = drm_universal_plane_init(dev, plane, 0xff,
 				       &vc4_plane_funcs,
 				       formats, ARRAY_SIZE(formats),
 				       type, NULL);

 	drm_plane_helper_add(plane, &vc4_plane_helper_funcs);

 	return plane;
 fail:
 	if (plane)
 		vc4_plane_destroy(plane);

 	return ERR_PTR(ret);
 }
	/*
	* Copyright (C) 2015 Broadcom
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	/**
	* DOC: VC4 plane module
	*
	* Each DRM plane is a layer of pixels being scanned out by the HVS.
	*
	* At atomic modeset check time, we compute the HVS display element
	* state that would be necessary for displaying the plane (giving us a
	* chance to figure out if a plane configuration is invalid), then at
	* atomic flush time the CRTC will ask us to write our element state
	* into the region of the HVS that it has allocated for us.
	*/

	#include "vc4_drv.h"
	#include "vc4_regs.h"
	#include "drm_atomic_helper.h"
	#include "drm_fb_cma_helper.h"
	#include "drm_plane_helper.h"

	struct vc4_plane_state {
	struct drm_plane_state base;
	u32 *dlist;
	u32 dlist_size; /* Number of dwords in allocated for the display list */
	u32 dlist_count; /* Number of used dwords in the display list. */

	/* Offset in the dlist to pointer word 0. */
	u32 pw0_offset;

	/* Offset where the plane's dlist was last stored in the
	hardware at vc4_crtc_atomic_flush() time.
	*/
	u32 *hw_dlist;
	};

	static inline struct vc4_plane_state *
	to_vc4_plane_state(struct drm_plane_state *state)
	{
	return (struct vc4_plane_state *)state;
	}

	static const struct hvs_format {
	u32 drm; /* DRM_FORMAT_* */
	u32 hvs; /* HVS_FORMAT_* */
	u32 pixel_order;
	bool has_alpha;
	} hvs_formats[] = {
	{
	.drm = DRM_FORMAT_XRGB8888, .hvs = HVS_PIXEL_FORMAT_RGBA8888,
	.pixel_order = HVS_PIXEL_ORDER_ABGR, .has_alpha = false,
	},
	{
	.drm = DRM_FORMAT_ARGB8888, .hvs = HVS_PIXEL_FORMAT_RGBA8888,
	.pixel_order = HVS_PIXEL_ORDER_ABGR, .has_alpha = true,
	},
	};

	static const struct hvs_format *vc4_get_hvs_format(u32 drm_format)
	{
	unsigned i;

	for (i = 0; i < ARRAY_SIZE(hvs_formats); i++) {
	if (hvs_formats[i].drm == drm_format)
	return &hvs_formats[i];
	}

	return NULL;
	}

	static bool plane_enabled(struct drm_plane_state *state)
	{
	return state->fb && state->crtc;
	}

	static struct drm_plane_state vc4_plane_duplicate_state(struct drm_plane plane)
	{
	struct vc4_plane_state *vc4_state;

	if (WARN_ON(!plane->state))
	return NULL;

	vc4_state = kmemdup(plane->state, sizeof(*vc4_state), GFP_KERNEL);
	if (!vc4_state)
	return NULL;

	__drm_atomic_helper_plane_duplicate_state(plane, &vc4_state->base);

	if (vc4_state->dlist) {
	vc4_state->dlist = kmemdup(vc4_state->dlist,
	vc4_state->dlist_count * 4,
	GFP_KERNEL);
	if (!vc4_state->dlist) {
	kfree(vc4_state);
	return NULL;
	}
	vc4_state->dlist_size = vc4_state->dlist_count;
	}

	return &vc4_state->base;
	}

	static void vc4_plane_destroy_state(struct drm_plane *plane,
	struct drm_plane_state *state)
	{
	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);

	kfree(vc4_state->dlist);
	__drm_atomic_helper_plane_destroy_state(plane, &vc4_state->base);
	kfree(state);
	}

	/* Called during init to allocate the plane's atomic state. */
	static void vc4_plane_reset(struct drm_plane *plane)
	{
	struct vc4_plane_state *vc4_state;

	WARN_ON(plane->state);

	vc4_state = kzalloc(sizeof(*vc4_state), GFP_KERNEL);
	if (!vc4_state)
	return;

	plane->state = &vc4_state->base;
	vc4_state->base.plane = plane;
	}

	static void vc4_dlist_write(struct vc4_plane_state *vc4_state, u32 val)
	{
	if (vc4_state->dlist_count == vc4_state->dlist_size) {
	u32 new_size = max(4u, vc4_state->dlist_count * 2);
	u32 new_dlist = kmalloc(new_size 4, GFP_KERNEL);

	if (!new_dlist)
	return;
	memcpy(new_dlist, vc4_state->dlist, vc4_state->dlist_count * 4);

	kfree(vc4_state->dlist);
	vc4_state->dlist = new_dlist;
	vc4_state->dlist_size = new_size;
	}

	vc4_state->dlist[vc4_state->dlist_count++] = val;
	}

	/* Writes out a full display list for an active plane to the plane's
	* private dlist state.
	*/
	static int vc4_plane_mode_set(struct drm_plane *plane,
	struct drm_plane_state *state)
	{
	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);
	struct drm_framebuffer *fb = state->fb;
	struct drm_gem_cma_object *bo = drm_fb_cma_get_gem_obj(fb, 0);
	u32 ctl0_offset = vc4_state->dlist_count;
	const struct hvs_format *format = vc4_get_hvs_format(fb->pixel_format);
	uint32_t offset = fb->offsets[0];
	int crtc_x = state->crtc_x;
	int crtc_y = state->crtc_y;
	int crtc_w = state->crtc_w;
	int crtc_h = state->crtc_h;

	if (state->crtc_w << 16 != state->src_w \|\|
	state->crtc_h << 16 != state->src_h) {
	/* We don't support scaling yet, which involves
	* allocating the LBM memory for scaling temporary
	* storage, and putting filter kernels in the HVS
	* context.
	*/
	return -EINVAL;
	}

	if (crtc_x < 0) {
	offset += drm_format_plane_cpp(fb->pixel_format, 0) * -crtc_x;
	crtc_w += crtc_x;
	crtc_x = 0;
	}

	if (crtc_y < 0) {
	offset += fb->pitches[0] * -crtc_y;
	crtc_h += crtc_y;
	crtc_y = 0;
	}

	vc4_dlist_write(vc4_state,
	SCALER_CTL0_VALID \|
	(format->pixel_order << SCALER_CTL0_ORDER_SHIFT) \|
	(format->hvs << SCALER_CTL0_PIXEL_FORMAT_SHIFT) \|
	SCALER_CTL0_UNITY);

	/* Position Word 0: Image Positions and Alpha Value */
	vc4_dlist_write(vc4_state,
	VC4_SET_FIELD(0xff, SCALER_POS0_FIXED_ALPHA) \|
	VC4_SET_FIELD(crtc_x, SCALER_POS0_START_X) \|
	VC4_SET_FIELD(crtc_y, SCALER_POS0_START_Y));

	/* Position Word 1: Scaled Image Dimensions.
	* Skipped due to SCALER_CTL0_UNITY scaling.
	*/

	/* Position Word 2: Source Image Size, Alpha Mode */
	vc4_dlist_write(vc4_state,
	VC4_SET_FIELD(format->has_alpha ?
	SCALER_POS2_ALPHA_MODE_PIPELINE :
	SCALER_POS2_ALPHA_MODE_FIXED,
	SCALER_POS2_ALPHA_MODE) \|
	VC4_SET_FIELD(crtc_w, SCALER_POS2_WIDTH) \|
	VC4_SET_FIELD(crtc_h, SCALER_POS2_HEIGHT));

	/* Position Word 3: Context. Written by the HVS. */
	vc4_dlist_write(vc4_state, 0xc0c0c0c0);

	vc4_state->pw0_offset = vc4_state->dlist_count;

	/* Pointer Word 0: RGB / Y Pointer */
	vc4_dlist_write(vc4_state, bo->paddr + offset);

	/* Pointer Context Word 0: Written by the HVS */
	vc4_dlist_write(vc4_state, 0xc0c0c0c0);

	/* Pitch word 0: Pointer 0 Pitch */
	vc4_dlist_write(vc4_state,
	VC4_SET_FIELD(fb->pitches[0], SCALER_SRC_PITCH));

	vc4_state->dlist[ctl0_offset] \|=
	VC4_SET_FIELD(vc4_state->dlist_count, SCALER_CTL0_SIZE);

	return 0;
	}

	/* If a modeset involves changing the setup of a plane, the atomic
	* infrastructure will call this to validate a proposed plane setup.
	* However, if a plane isn't getting updated, this (and the
	* corresponding vc4_plane_atomic_update) won't get called. Thus, we
	* compute the dlist here and have all active plane dlists get updated
	* in the CRTC's flush.
	*/
	static int vc4_plane_atomic_check(struct drm_plane *plane,
	struct drm_plane_state *state)
	{
	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);

	vc4_state->dlist_count = 0;

	if (plane_enabled(state))
	return vc4_plane_mode_set(plane, state);
	else
	return 0;
	}

	static void vc4_plane_atomic_update(struct drm_plane *plane,
	struct drm_plane_state *old_state)
	{
	/* No contents here. Since we don't know where in the CRTC's
	* dlist we should be stored, our dlist is uploaded to the
	* hardware with vc4_plane_write_dlist() at CRTC atomic_flush
	* time.
	*/
	}

	u32 vc4_plane_write_dlist(struct drm_plane plane, u32 __iomem dlist)
	{
	struct vc4_plane_state *vc4_state = to_vc4_plane_state(plane->state);
	int i;

	vc4_state->hw_dlist = dlist;

	/* Can't memcpy_toio() because it needs to be 32-bit writes. */
	for (i = 0; i < vc4_state->dlist_count; i++)
	writel(vc4_state->dlist[i], &dlist[i]);

	return vc4_state->dlist_count;
	}

	u32 vc4_plane_dlist_size(struct drm_plane_state *state)
	{
	struct vc4_plane_state *vc4_state = to_vc4_plane_state(state);

	return vc4_state->dlist_count;
	}

	/* Updates the plane to immediately (well, once the FIFO needs
	* refilling) scan out from at a new framebuffer.
	*/
	void vc4_plane_async_set_fb(struct drm_plane plane, struct drm_framebuffer fb)
	{
	struct vc4_plane_state *vc4_state = to_vc4_plane_state(plane->state);
	struct drm_gem_cma_object *bo = drm_fb_cma_get_gem_obj(fb, 0);
	uint32_t addr;

	/* We're skipping the address adjustment for negative origin,
	* because this is only called on the primary plane.
	*/
	WARN_ON_ONCE(plane->state->crtc_x < 0 \|\| plane->state->crtc_y < 0);
	addr = bo->paddr + fb->offsets[0];

	/* Write the new address into the hardware immediately. The
	* scanout will start from this address as soon as the FIFO
	* needs to refill with pixels.
	*/
	writel(addr, &vc4_state->hw_dlist[vc4_state->pw0_offset]);

	/* Also update the CPU-side dlist copy, so that any later
	* atomic updates that don't do a new modeset on our plane
	* also use our updated address.
	*/
	vc4_state->dlist[vc4_state->pw0_offset] = addr;
	}

	static const struct drm_plane_helper_funcs vc4_plane_helper_funcs = {
	.prepare_fb = NULL,
	.cleanup_fb = NULL,
	.atomic_check = vc4_plane_atomic_check,
	.atomic_update = vc4_plane_atomic_update,
	};

	static void vc4_plane_destroy(struct drm_plane *plane)
	{
	drm_plane_helper_disable(plane);
	drm_plane_cleanup(plane);
	}

	static const struct drm_plane_funcs vc4_plane_funcs = {
	.update_plane = drm_atomic_helper_update_plane,
	.disable_plane = drm_atomic_helper_disable_plane,
	.destroy = vc4_plane_destroy,
	.set_property = NULL,
	.reset = vc4_plane_reset,
	.atomic_duplicate_state = vc4_plane_duplicate_state,
	.atomic_destroy_state = vc4_plane_destroy_state,
	};

	struct drm_plane vc4_plane_init(struct drm_device dev,
	enum drm_plane_type type)
	{
	struct drm_plane *plane = NULL;
	struct vc4_plane *vc4_plane;
	u32 formats[ARRAY_SIZE(hvs_formats)];
	int ret = 0;
	unsigned i;

	vc4_plane = devm_kzalloc(dev->dev, sizeof(*vc4_plane),
	GFP_KERNEL);
	if (!vc4_plane) {
	ret = -ENOMEM;
	goto fail;
	}

	for (i = 0; i < ARRAY_SIZE(hvs_formats); i++)
	formats[i] = hvs_formats[i].drm;
	plane = &vc4_plane->base;
	ret = drm_universal_plane_init(dev, plane, 0xff,
	&vc4_plane_funcs,
	formats, ARRAY_SIZE(formats),
	type, NULL);

	drm_plane_helper_add(plane, &vc4_plane_helper_funcs);

	return plane;
	fail:
	if (plane)
	vc4_plane_destroy(plane);

	return ERR_PTR(ret);
	}