drm: Add helper iterator functions for plane fb_damage_clips blob

 *

 * Drivers that are interested in damage interface for plane should enable

 * FB_DAMAGE_CLIPS property by calling drm_plane_enable_fb_damage_clips().

 * Drivers implementing damage can use drm_atomic_helper_damage_iter_init() and

 * drm_atomic_helper_damage_iter_next() helper iterator function to get damage

 * rectangles clipped to &drm_plane_state.src.

 */

/**

	}

}

EXPORT_SYMBOL(drm_atomic_helper_check_plane_damage);

/**

 * drm_atomic_helper_damage_iter_init - Initialize the damage iterator.

 * @iter: The iterator to initialize.

 * @old_state: Old plane state for validation.

 * @new_state: Plane state from which to iterate the damage clips.

 *

 * Initialize an iterator, which clips plane damage

 * &drm_plane_state.fb_damage_clips to plane &drm_plane_state.src. This iterator

 * returns full plane src in case damage is not present because either

 * user-space didn't sent or driver discarded it (it want to do full plane

 * update). Currently this iterator returns full plane src in case plane src

 * changed but that can be changed in future to return damage.

 *

 * For the case when plane is not visible or plane update should not happen the

 * first call to iter_next will return false. Note that this helper use clipped

 * &drm_plane_state.src, so driver calling this helper should have called

 * drm_atomic_helper_check_plane_state() earlier.

 */

void

drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,

				   const struct drm_plane_state *old_state,

				   const struct drm_plane_state *state)

{

	memset(iter, 0, sizeof(*iter));

	if (!state || !state->crtc || !state->fb || !state->visible)

		return;

	iter->clips = drm_helper_get_plane_damage_clips(state);

	iter->num_clips = drm_plane_get_damage_clips_count(state);

	/* Round down for x1/y1 and round up for x2/y2 to catch all pixels */

	iter->plane_src.x1 = state->src.x1 >> 16;

	iter->plane_src.y1 = state->src.y1 >> 16;

	iter->plane_src.x2 = (state->src.x2 >> 16) + !!(state->src.x2 & 0xFFFF);

	iter->plane_src.y2 = (state->src.y2 >> 16) + !!(state->src.y2 & 0xFFFF);

	if (!iter->clips || !drm_rect_equals(&state->src, &old_state->src)) {

		iter->clips = 0;

		iter->num_clips = 0;

		iter->full_update = true;

	}

}

EXPORT_SYMBOL(drm_atomic_helper_damage_iter_init);

/**

 * drm_atomic_helper_damage_iter_next - Advance the damage iterator.

 * @iter: The iterator to advance.

 * @rect: Return a rectangle in fb coordinate clipped to plane src.

 *

 * Since plane src is in 16.16 fixed point and damage clips are whole number,

 * this iterator round off clips that intersect with plane src. Round down for

 * x1/y1 and round up for x2/y2 for the intersected coordinate. Similar rounding

 * off for full plane src, in case it's returned as damage. This iterator will

 * skip damage clips outside of plane src.

 *

 * Return: True if the output is valid, false if reached the end.

 *

 * If the first call to iterator next returns false then it means no need to

 * update the plane.

 */

bool

drm_atomic_helper_damage_iter_next(struct drm_atomic_helper_damage_iter *iter,

				   struct drm_rect *rect)

{

	bool ret = false;

	if (iter->full_update) {

		*rect = iter->plane_src;

		iter->full_update = false;

		return true;

	}

	while (iter->curr_clip < iter->num_clips) {

		*rect = iter->clips[iter->curr_clip];

		iter->curr_clip++;

		if (drm_rect_intersect(rect, &iter->plane_src)) {

			ret = true;

			break;

		}

	}

	return ret;

}

EXPORT_SYMBOL(drm_atomic_helper_damage_iter_next);

#include <drm/drm_atomic_helper.h>

/**

 * drm_atomic_for_each_plane_damage - Iterator macro for plane damage.

 * @iter: The iterator to advance.

 * @rect: Return a rectangle in fb coordinate clipped to plane src.

 *

 * Note that if the first call to iterator macro return false then no need to do

 * plane update. Iterator will return full plane src when damage is not passed

 * by user-space.

 */

#define drm_atomic_for_each_plane_damage(iter, rect) \

	while (drm_atomic_helper_damage_iter_next(iter, rect))

/**

 * struct drm_atomic_helper_damage_iter - Closure structure for damage iterator.

 *

 * This structure tracks state needed to walk the list of plane damage clips.

 */

struct drm_atomic_helper_damage_iter {

	/* private: Plane src in whole number. */

	struct drm_rect plane_src;

	/* private: Rectangles in plane damage blob. */

	const struct drm_rect *clips;

	/* private: Number of rectangles in plane damage blob. */

	uint32_t num_clips;

	/* private: Current clip iterator is advancing on. */

	uint32_t curr_clip;

	/* private: Whether need full plane update. */

	bool full_update;

};

void drm_plane_enable_fb_damage_clips(struct drm_plane *plane);

void drm_atomic_helper_check_plane_damage(struct drm_atomic_state *state,

					  struct drm_plane_state *plane_state);

void

drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,

				   const struct drm_plane_state *old_state,

				   const struct drm_plane_state *new_state);

bool

drm_atomic_helper_damage_iter_next(struct drm_atomic_helper_damage_iter *iter,

				   struct drm_rect *rect);

/**

 * drm_helper_get_plane_damage_clips - Returns damage clips in &drm_rect.

 * @state: Plane state.

 *

 * Returns plane damage rectangles in internal &drm_rect. Currently &drm_rect

 * can be obtained by simply typecasting &drm_mode_rect. This is because both

 * are signed 32 and during drm_atomic_check_only() it is verified that damage

 * clips are inside fb.

 *

 * Return: Clips in plane fb_damage_clips blob property.

 */

static inline struct drm_rect *

drm_helper_get_plane_damage_clips(const struct drm_plane_state *state)

{

	return (struct drm_rect *)drm_plane_get_damage_clips(state);

}

#endif

 * drm_plane_get_damage_clips - Returns damage clips.

 * @state: Plane state.

 *

 * Note that this function returns uapi type &drm_mode_rect.

 * Note that this function returns uapi type &drm_mode_rect. Drivers might

 * instead be interested in internal &drm_rect which can be obtained by calling

 * drm_helper_get_plane_damage_clips().

 *

 * Return: Damage clips in plane fb_damage_clips blob property.

 */