include/drm/drm_plane.h

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting documentation, and
 * that the name of the copyright holders not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  The copyright holders make no representations
 * about the suitability of this software for any purpose.  It is provided "as
 * is" without express or implied warranty.
 *
 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
 * OF THIS SOFTWARE.
 */

#ifndef __DRM_PLANE_H__
#define __DRM_PLANE_H__

#include <linux/list.h>
#include <linux/ctype.h>
#include <drm/drm_mode_object.h>
#include <drm/drm_color_mgmt.h>
#include <drm/drm_rect.h>
#include <drm/drm_modeset_lock.h>
#include <drm/drm_util.h>

struct drm_crtc;
struct drm_printer;
struct drm_modeset_acquire_ctx;

/**
 * struct drm_plane_state - mutable plane state
 *
 * Please not that the destination coordinates @crtc_x, @crtc_y, @crtc_h and
 * @crtc_w and the source coordinates @src_x, @src_y, @src_h and @src_w are the
 * raw coordinates provided by userspace. Drivers should use
 * drm_atomic_helper_check_plane_state() and only use the derived rectangles in
 * @src and @dst to program the hardware.
 */
struct drm_plane_state {
	/** @plane: backpointer to the plane */
	struct drm_plane *plane;

	/**
	 * @crtc:
	 *
	 * Currently bound CRTC, NULL if disabled. Do not this write directly,
	 * use drm_atomic_set_crtc_for_plane()
	 */
	struct drm_crtc *crtc;

	/**
	 * @fb:
	 *
	 * Currently bound framebuffer. Do not write this directly, use
	 * drm_atomic_set_fb_for_plane()
	 */
	struct drm_framebuffer *fb;

	/**
	 * @fence:
	 *
	 * Optional fence to wait for before scanning out @fb. The core atomic
	 * code will set this when userspace is using explicit fencing. Do not
	 * write this directly for a driver's implicit fence, use
	 * drm_atomic_set_fence_for_plane() to ensure that an explicit fence is
	 * preserved.
	 *
	 * Drivers should store any implicit fence in this from their
	 * &drm_plane_helper_funcs.prepare_fb callback. See drm_gem_fb_prepare_fb()
	 * and drm_gem_fb_simple_display_pipe_prepare_fb() for suitable helpers.
	 */
	struct dma_fence *fence;

	/**
	 * @crtc_x:
	 *
	 * Left position of visible portion of plane on crtc, signed dest
	 * location allows it to be partially off screen.
	 */

	int32_t crtc_x;
	/**
	 * @crtc_y:
	 *
	 * Upper position of visible portion of plane on crtc, signed dest
	 * location allows it to be partially off screen.
	 */
	int32_t crtc_y;

	/** @crtc_w: width of visible portion of plane on crtc */
	/** @crtc_h: height of visible portion of plane on crtc */
	uint32_t crtc_w, crtc_h;

	/**
	 * @src_x: left position of visible portion of plane within plane (in
	 * 16.16 fixed point).
	 */
	uint32_t src_x;
	/**
	 * @src_y: upper position of visible portion of plane within plane (in
	 * 16.16 fixed point).
	 */
	uint32_t src_y;
	/** @src_w: width of visible portion of plane (in 16.16) */
	/** @src_h: height of visible portion of plane (in 16.16) */
	uint32_t src_h, src_w;

	/**
	 * @alpha:
	 * Opacity of the plane with 0 as completely transparent and 0xffff as
	 * completely opaque. See drm_plane_create_alpha_property() for more
	 * details.
	 */
	u16 alpha;

	/**
	 * @pixel_blend_mode:
	 * The alpha blending equation selection, describing how the pixels from
	 * the current plane are composited with the background. Value can be
	 * one of DRM_MODE_BLEND_*
	 */
	uint16_t pixel_blend_mode;

	/**
	 * @rotation:
	 * Rotation of the plane. See drm_plane_create_rotation_property() for
	 * more details.
	 */
	unsigned int rotation;

	/**
	 * @zpos:
	 * Priority of the given plane on crtc (optional).
	 *
	 * Note that multiple active planes on the same crtc can have an
	 * identical zpos value. The rule to solving the conflict is to compare
	 * the plane object IDs; the plane with a higher ID must be stacked on
	 * top of a plane with a lower ID.
	 *
	 * See drm_plane_create_zpos_property() and
	 * drm_plane_create_zpos_immutable_property() for more details.
	 */
	unsigned int zpos;

	/**
	 * @normalized_zpos:
	 * Normalized value of zpos: unique, range from 0 to N-1 where N is the
	 * number of active planes for given crtc. Note that the driver must set
	 * &drm_mode_config.normalize_zpos or call drm_atomic_normalize_zpos() to
	 * update this before it can be trusted.
	 */
	unsigned int normalized_zpos;

	/**
	 * @color_encoding:
	 *
	 * Color encoding for non RGB formats
	 */
	enum drm_color_encoding color_encoding;

	/**
	 * @color_range:
	 *
	 * Color range for non RGB formats
	 */
	enum drm_color_range color_range;

	/** @src: clipped source coordinates of the plane (in 16.16) */
	/** @dst: clipped destination coordinates of the plane */
	struct drm_rect src, dst;

	/**
	 * @visible:
	 *
	 * Visibility of the plane. This can be false even if fb!=NULL and
	 * crtc!=NULL, due to clipping.
	 */
	bool visible;

	/**
	 * @commit: Tracks the pending commit to prevent use-after-free conditions,
	 * and for async plane updates.
	 *
	 * May be NULL.
	 */
	struct drm_crtc_commit *commit;

	/** @state: backpointer to global drm_atomic_state */
	struct drm_atomic_state *state;
};

static inline struct drm_rect
drm_plane_state_src(const struct drm_plane_state *state)
{
	struct drm_rect src = {
		.x1 = state->src_x,
		.y1 = state->src_y,
		.x2 = state->src_x + state->src_w,
		.y2 = state->src_y + state->src_h,
	};
	return src;
}

static inline struct drm_rect
drm_plane_state_dest(const struct drm_plane_state *state)
{
	struct drm_rect dest = {
		.x1 = state->crtc_x,
		.y1 = state->crtc_y,
		.x2 = state->crtc_x + state->crtc_w,
		.y2 = state->crtc_y + state->crtc_h,
	};
	return dest;
}

/**
 * struct drm_plane_funcs - driver plane control functions
 */
struct drm_plane_funcs {
	/**
	 * @update_plane:
	 *
	 * This is the legacy entry point to enable and configure the plane for
	 * the given CRTC and framebuffer. It is never called to disable the
	 * plane, i.e. the passed-in crtc and fb paramters are never NULL.
	 *
	 * The source rectangle in frame buffer memory coordinates is given by
	 * the src_x, src_y, src_w and src_h parameters (as 16.16 fixed point
	 * values). Devices that don't support subpixel plane coordinates can
	 * ignore the fractional part.
	 *
	 * The destination rectangle in CRTC coordinates is given by the
	 * crtc_x, crtc_y, crtc_w and crtc_h parameters (as integer values).
	 * Devices scale the source rectangle to the destination rectangle. If
	 * scaling is not supported, and the source rectangle size doesn't match
	 * the destination rectangle size, the driver must return a
	 * -<errorname>EINVAL</errorname> error.
	 *
	 * Drivers implementing atomic modeset should use
	 * drm_atomic_helper_update_plane() to implement this hook.
	 *
	 * RETURNS:
	 *
	 * 0 on success or a negative error code on failure.
	 */
	int (*update_plane)(struct drm_plane *plane,
			    struct drm_crtc *crtc, struct drm_framebuffer *fb,
			    int crtc_x, int crtc_y,
			    unsigned int crtc_w, unsigned int crtc_h,
			    uint32_t src_x, uint32_t src_y,
			    uint32_t src_w, uint32_t src_h,
			    struct drm_modeset_acquire_ctx *ctx);

	/**
	 * @disable_plane:
	 *
	 * This is the legacy entry point to disable the plane. The DRM core
	 * calls this method in response to a DRM_IOCTL_MODE_SETPLANE IOCTL call
	 * with the frame buffer ID set to 0.  Disabled planes must not be
	 * processed by the CRTC.
	 *
	 * Drivers implementing atomic modeset should use
	 * drm_atomic_helper_disable_plane() to implement this hook.
	 *
	 * RETURNS:
	 *
	 * 0 on success or a negative error code on failure.
	 */
	int (*disable_plane)(struct drm_plane *plane,
			     struct drm_modeset_acquire_ctx *ctx);

	/**
	 * @destroy:
	 *
	 * Clean up plane resources. This is only called at driver unload time
	 * through drm_mode_config_cleanup() since a plane cannot be hotplugged
	 * in DRM.
	 */
	void (*destroy)(struct drm_plane *plane);

	/**
	 * @reset:
	 *
	 * Reset plane hardware and software state to off. This function isn't
	 * called by the core directly, only through drm_mode_config_reset().
	 * It's not a helper hook only for historical reasons.
	 *
	 * Atomic drivers can use drm_atomic_helper_plane_reset() to reset
	 * atomic state using this hook.
	 */
	void (*reset)(struct drm_plane *plane);

	/**
	 * @set_property:
	 *
	 * This is the legacy entry point to update a property attached to the
	 * plane.
	 *
	 * This callback is optional if the driver does not support any legacy
	 * driver-private properties. For atomic drivers it is not used because
	 * property handling is done entirely in the DRM core.
	 *
	 * RETURNS:
	 *
	 * 0 on success or a negative error code on failure.
	 */
	int (*set_property)(struct drm_plane *plane,
			    struct drm_property *property, uint64_t val);

	/**
	 * @atomic_duplicate_state:
	 *
	 * Duplicate the current atomic state for this plane and return it.
	 * The core and helpers guarantee that any atomic state duplicated with
	 * this hook and still owned by the caller (i.e. not transferred to the
	 * driver by calling &drm_mode_config_funcs.atomic_commit) will be
	 * cleaned up by calling the @atomic_destroy_state hook in this
	 * structure.
	 *
	 * This callback is mandatory for atomic drivers.
	 *
	 * Atomic drivers which don't subclass &struct drm_plane_state should use
	 * drm_atomic_helper_plane_duplicate_state(). Drivers that subclass the
	 * state structure to extend it with driver-private state should use
	 * __drm_atomic_helper_plane_duplicate_state() to make sure shared state is
	 * duplicated in a consistent fashion across drivers.
	 *
	 * It is an error to call this hook before &drm_plane.state has been
	 * initialized correctly.
	 *
	 * NOTE:
	 *
	 * If the duplicate state references refcounted resources this hook must
	 * acquire a reference for each of them. The driver must release these
	 * references again in @atomic_destroy_state.
	 *
	 * RETURNS:
	 *
	 * Duplicated atomic state or NULL when the allocation failed.
	 */
	struct drm_plane_state *(*atomic_duplicate_state)(struct drm_plane *plane);

	/**
	 * @atomic_destroy_state:
	 *
	 * Destroy a state duplicated with @atomic_duplicate_state and release
	 * or unreference all resources it references
	 *
	 * This callback is mandatory for atomic drivers.
	 */
	void (*atomic_destroy_state)(struct drm_plane *plane,
				     struct drm_plane_state *state);

	/**
	 * @atomic_set_property:
	 *
	 * Decode a driver-private property value and store the decoded value
	 * into the passed-in state structure. Since the atomic core decodes all
	 * standardized properties (even for extensions beyond the core set of
	 * properties which might not be implemented by all drivers) this
	 * requires drivers to subclass the state structure.
	 *
	 * Such driver-private properties should really only be implemented for
	 * truly hardware/vendor specific state. Instead it is preferred to
	 * standardize atomic extension and decode the properties used to expose
	 * such an extension in the core.
	 *
	 * Do not call this function directly, use
	 * drm_atomic_plane_set_property() instead.
	 *
	 * This callback is optional if the driver does not support any
	 * driver-private atomic properties.
	 *
	 * NOTE:
	 *
	 * This function is called in the state assembly phase of atomic
	 * modesets, which can be aborted for any reason (including on
	 * userspace's request to just check whether a configuration would be
	 * possible). Drivers MUST NOT touch any persistent state (hardware or
	 * software) or data structures except the passed in @state parameter.
	 *
	 * Also since userspace controls in which order properties are set this
	 * function must not do any input validation (since the state update is
	 * incomplete and hence likely inconsistent). Instead any such input
	 * validation must be done in the various atomic_check callbacks.
	 *
	 * RETURNS:
	 *
	 * 0 if the property has been found, -EINVAL if the property isn't
	 * implemented by the driver (which shouldn't ever happen, the core only
	 * asks for properties attached to this plane). No other validation is
	 * allowed by the driver. The core already checks that the property
	 * value is within the range (integer, valid enum value, ...) the driver
	 * set when registering the property.
	 */
	int (*atomic_set_property)(struct drm_plane *plane,
				   struct drm_plane_state *state,
				   struct drm_property *property,
				   uint64_t val);

	/**
	 * @atomic_get_property:
	 *
	 * Reads out the decoded driver-private property. This is used to
	 * implement the GETPLANE IOCTL.
	 *
	 * Do not call this function directly, use
	 * drm_atomic_plane_get_property() instead.
	 *
	 * This callback is optional if the driver does not support any
	 * driver-private atomic properties.
	 *
	 * RETURNS:
	 *
	 * 0 on success, -EINVAL if the property isn't implemented by the
	 * driver (which should never happen, the core only asks for
	 * properties attached to this plane).
	 */
	int (*atomic_get_property)(struct drm_plane *plane,
				   const struct drm_plane_state *state,
				   struct drm_property *property,
				   uint64_t *val);
	/**
	 * @late_register:
	 *
	 * This optional hook can be used to register additional userspace
	 * interfaces attached to the plane like debugfs interfaces.
	 * It is called late in the driver load sequence from drm_dev_register().
	 * Everything added from this callback should be unregistered in
	 * the early_unregister callback.
	 *
	 * Returns:
	 *
	 * 0 on success, or a negative error code on failure.
	 */
	int (*late_register)(struct drm_plane *plane);

	/**
	 * @early_unregister:
	 *
	 * This optional hook should be used to unregister the additional
	 * userspace interfaces attached to the plane from
	 * @late_register. It is called from drm_dev_unregister(),
	 * early in the driver unload sequence to disable userspace access
	 * before data structures are torndown.
	 */
	void (*early_unregister)(struct drm_plane *plane);

	/**
	 * @atomic_print_state:
	 *
	 * If driver subclasses &struct drm_plane_state, it should implement
	 * this optional hook for printing additional driver specific state.
	 *
	 * Do not call this directly, use drm_atomic_plane_print_state()
	 * instead.
	 */
	void (*atomic_print_state)(struct drm_printer *p,
				   const struct drm_plane_state *state);

	/**
	 * @format_mod_supported:
	 *
	 * This optional hook is used for the DRM to determine if the given
	 * format/modifier combination is valid for the plane. This allows the
	 * DRM to generate the correct format bitmask (which formats apply to
	 * which modifier), and to valdiate modifiers at atomic_check time.
	 *
	 * If not present, then any modifier in the plane's modifier
	 * list is allowed with any of the plane's formats.
	 *
	 * Returns:
	 *
	 * True if the given modifier is valid for that format on the plane.
	 * False otherwise.
	 */
	bool (*format_mod_supported)(struct drm_plane *plane, uint32_t format,
				     uint64_t modifier);
};

/**
 * enum drm_plane_type - uapi plane type enumeration
 *
 * For historical reasons not all planes are made the same. This enumeration is
 * used to tell the different types of planes apart to implement the different
 * uapi semantics for them. For userspace which is universal plane aware and
 * which is using that atomic IOCTL there's no difference between these planes
 * (beyong what the driver and hardware can support of course).
 *
 * For compatibility with legacy userspace, only overlay planes are made
 * available to userspace by default. Userspace clients may set the
 * DRM_CLIENT_CAP_UNIVERSAL_PLANES client capability bit to indicate that they
 * wish to receive a universal plane list containing all plane types. See also
 * drm_for_each_legacy_plane().
 *
 * WARNING: The values of this enum is UABI since they're exposed in the "type"
 * property.
 */
enum drm_plane_type {
	/**
	 * @DRM_PLANE_TYPE_OVERLAY:
	 *
	 * Overlay planes represent all non-primary, non-cursor planes. Some
	 * drivers refer to these types of planes as "sprites" internally.
	 */
	DRM_PLANE_TYPE_OVERLAY,

	/**
	 * @DRM_PLANE_TYPE_PRIMARY:
	 *
	 * Primary planes represent a "main" plane for a CRTC.  Primary planes
	 * are the planes operated upon by CRTC modesetting and flipping
	 * operations described in the &drm_crtc_funcs.page_flip and
	 * &drm_crtc_funcs.set_config hooks.
	 */
	DRM_PLANE_TYPE_PRIMARY,

	/**
	 * @DRM_PLANE_TYPE_CURSOR:
	 *
	 * Cursor planes represent a "cursor" plane for a CRTC.  Cursor planes
	 * are the planes operated upon by the DRM_IOCTL_MODE_CURSOR and
	 * DRM_IOCTL_MODE_CURSOR2 IOCTLs.
	 */
	DRM_PLANE_TYPE_CURSOR,
};


/**
 * struct drm_plane - central DRM plane control structure
 *
 * Planes represent the scanout hardware of a display block. They receive their
 * input data from a &drm_framebuffer and feed it to a &drm_crtc. Planes control
 * the color conversion, see `Plane Composition Properties`_ for more details,
 * and are also involved in the color conversion of input pixels, see `Color
 * Management Properties`_ for details on that.
 */
struct drm_plane {
	/** @dev: DRM device this plane belongs to */
	struct drm_device *dev;

	/**
	 * @head:
	 *
	 * List of all planes on @dev, linked from &drm_mode_config.plane_list.
	 * Invariant over the lifetime of @dev and therefore does not need
	 * locking.
	 */
	struct list_head head;

	/** @name: human readable name, can be overwritten by the driver */
	char *name;

	/**
	 * @mutex:
	 *
	 * Protects modeset plane state, together with the &drm_crtc.mutex of
	 * CRTC this plane is linked to (when active, getting activated or
	 * getting disabled).
	 *
	 * For atomic drivers specifically this protects @state.
	 */
	struct drm_modeset_lock mutex;

	/** @base: base mode object */
	struct drm_mode_object base;

	/**
	 * @possible_crtcs: pipes this plane can be bound to constructed from
	 * drm_crtc_mask()
	 */
	uint32_t possible_crtcs;
	/** @format_types: array of formats supported by this plane */
	uint32_t *format_types;
	/** @format_count: Size of the array pointed at by @format_types. */
	unsigned int format_count;
	/**
	 * @format_default: driver hasn't supplied supported formats for the
	 * plane. Used by the drm_plane_init compatibility wrapper only.
	 */
	bool format_default;

	/** @modifiers: array of modifiers supported by this plane */
	uint64_t *modifiers;
	/** @modifier_count: Size of the array pointed at by @modifier_count. */
	unsigned int modifier_count;

	/**
	 * @crtc:
	 *
	 * Currently bound CRTC, only meaningful for non-atomic drivers. For
	 * atomic drivers this is forced to be NULL, atomic drivers should
	 * instead check &drm_plane_state.crtc.
	 */
	struct drm_crtc *crtc;

	/**
	 * @fb:
	 *
	 * Currently bound framebuffer, only meaningful for non-atomic drivers.
	 * For atomic drivers this is forced to be NULL, atomic drivers should
	 * instead check &drm_plane_state.fb.
	 */
	struct drm_framebuffer *fb;

	/**
	 * @old_fb:
	 *
	 * Temporary tracking of the old fb while a modeset is ongoing. Only
	 * used by non-atomic drivers, forced to be NULL for atomic drivers.
	 */
	struct drm_framebuffer *old_fb;

	/** @funcs: plane control functions */
	const struct drm_plane_funcs *funcs;

	/** @properties: property tracking for this plane */
	struct drm_object_properties properties;

	/** @type: Type of plane, see &enum drm_plane_type for details. */
	enum drm_plane_type type;

	/**
	 * @index: Position inside the mode_config.list, can be used as an array
	 * index. It is invariant over the lifetime of the plane.
	 */
	unsigned index;

	/** @helper_private: mid-layer private data */
	const struct drm_plane_helper_funcs *helper_private;

	/**
	 * @state:
	 *
	 * Current atomic state for this plane.
	 *
	 * This is protected by @mutex. Note that nonblocking atomic commits
	 * access the current plane state without taking locks. Either by going
	 * through the &struct drm_atomic_state pointers, see
	 * for_each_oldnew_plane_in_state(), for_each_old_plane_in_state() and
	 * for_each_new_plane_in_state(). Or through careful ordering of atomic
	 * commit operations as implemented in the atomic helpers, see
	 * &struct drm_crtc_commit.
	 */
	struct drm_plane_state *state;

	/**
	 * @alpha_property:
	 * Optional alpha property for this plane. See
	 * drm_plane_create_alpha_property().
	 */
	struct drm_property *alpha_property;
	/**
	 * @zpos_property:
	 * Optional zpos property for this plane. See
	 * drm_plane_create_zpos_property().
	 */
	struct drm_property *zpos_property;
	/**
	 * @rotation_property:
	 * Optional rotation property for this plane. See
	 * drm_plane_create_rotation_property().
	 */
	struct drm_property *rotation_property;
	/**
	 * @blend_mode_property:
	 * Optional "pixel blend mode" enum property for this plane.
	 * Blend mode property represents the alpha blending equation selection,
	 * describing how the pixels from the current plane are composited with
	 * the background.
	 */
	struct drm_property *blend_mode_property;

	/**
	 * @color_encoding_property:
	 *
	 * Optional "COLOR_ENCODING" enum property for specifying
	 * color encoding for non RGB formats.
	 * See drm_plane_create_color_properties().
	 */
	struct drm_property *color_encoding_property;
	/**
	 * @color_range_property:
	 *
	 * Optional "COLOR_RANGE" enum property for specifying
	 * color range for non RGB formats.
	 * See drm_plane_create_color_properties().
	 */
	struct drm_property *color_range_property;
};

#define obj_to_plane(x) container_of(x, struct drm_plane, base)

__printf(9, 10)
int drm_universal_plane_init(struct drm_device *dev,
			     struct drm_plane *plane,
			     uint32_t possible_crtcs,
			     const struct drm_plane_funcs *funcs,
			     const uint32_t *formats,
			     unsigned int format_count,
			     const uint64_t *format_modifiers,
			     enum drm_plane_type type,
			     const char *name, ...);
int drm_plane_init(struct drm_device *dev,
		   struct drm_plane *plane,
		   uint32_t possible_crtcs,
		   const struct drm_plane_funcs *funcs,
		   const uint32_t *formats, unsigned int format_count,
		   bool is_primary);
void drm_plane_cleanup(struct drm_plane *plane);

/**
 * drm_plane_index - find the index of a registered plane
 * @plane: plane to find index for
 *
 * Given a registered plane, return the index of that plane within a DRM
 * device's list of planes.
 */
static inline unsigned int drm_plane_index(const struct drm_plane *plane)
{
	return plane->index;
}

/**
 * drm_plane_mask - find the mask of a registered plane
 * @plane: plane to find mask for
 */
static inline u32 drm_plane_mask(const struct drm_plane *plane)
{
	return 1 << drm_plane_index(plane);
}

struct drm_plane * drm_plane_from_index(struct drm_device *dev, int idx);
void drm_plane_force_disable(struct drm_plane *plane);

int drm_mode_plane_set_obj_prop(struct drm_plane *plane,
				       struct drm_property *property,
				       uint64_t value);

/**
 * drm_plane_find - find a &drm_plane
 * @dev: DRM device
 * @file_priv: drm file to check for lease against.
 * @id: plane id
 *
 * Returns the plane with @id, NULL if it doesn't exist. Simple wrapper around
 * drm_mode_object_find().
 */
static inline struct drm_plane *drm_plane_find(struct drm_device *dev,
		struct drm_file *file_priv,
		uint32_t id)
{
	struct drm_mode_object *mo;
	mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_PLANE);
	return mo ? obj_to_plane(mo) : NULL;
}

/**
 * drm_for_each_plane_mask - iterate over planes specified by bitmask
 * @plane: the loop cursor
 * @dev: the DRM device
 * @plane_mask: bitmask of plane indices
 *
 * Iterate over all planes specified by bitmask.
 */
#define drm_for_each_plane_mask(plane, dev, plane_mask) \
	list_for_each_entry((plane), &(dev)->mode_config.plane_list, head) \
		for_each_if ((plane_mask) & drm_plane_mask(plane))

/**
 * drm_for_each_legacy_plane - iterate over all planes for legacy userspace
 * @plane: the loop cursor
 * @dev: the DRM device
 *
 * Iterate over all legacy planes of @dev, excluding primary and cursor planes.
 * This is useful for implementing userspace apis when userspace is not
 * universal plane aware. See also &enum drm_plane_type.
 */
#define drm_for_each_legacy_plane(plane, dev) \
	list_for_each_entry(plane, &(dev)->mode_config.plane_list, head) \
		for_each_if (plane->type == DRM_PLANE_TYPE_OVERLAY)

/**
 * drm_for_each_plane - iterate over all planes
 * @plane: the loop cursor
 * @dev: the DRM device
 *
 * Iterate over all planes of @dev, include primary and cursor planes.
 */
#define drm_for_each_plane(plane, dev) \
	list_for_each_entry(plane, &(dev)->mode_config.plane_list, head)


#endif