// SPDX-License-Identifier: GPL-2.0+

#include <linux/iosys-map.h>

#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_blend.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>

#include "vkms_drv.h"
#include "vkms_formats.h"

static const u32 vkms_formats[] = {
	DRM_FORMAT_ARGB8888,
	DRM_FORMAT_XRGB8888,
	DRM_FORMAT_XRGB16161616,
	DRM_FORMAT_ARGB16161616,
	DRM_FORMAT_RGB565
};

static struct drm_plane_state *
vkms_plane_duplicate_state(struct drm_plane *plane)
{
	struct vkms_plane_state *vkms_state;
	struct vkms_frame_info *frame_info;

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

	frame_info = kzalloc(sizeof(*frame_info), GFP_KERNEL);
	if (!frame_info) {
		DRM_DEBUG_KMS("Couldn't allocate frame_info\n");
		kfree(vkms_state);
		return NULL;
	}

	vkms_state->frame_info = frame_info;

	__drm_gem_duplicate_shadow_plane_state(plane, &vkms_state->base);

	return &vkms_state->base.base;
}

static void vkms_plane_destroy_state(struct drm_plane *plane,
				     struct drm_plane_state *old_state)
{
	struct vkms_plane_state *vkms_state = to_vkms_plane_state(old_state);
	struct drm_crtc *crtc = vkms_state->base.base.crtc;

	if (crtc && vkms_state->frame_info->fb) {
		/* dropping the reference we acquired in
		 * vkms_primary_plane_update()
		 */
		if (drm_framebuffer_read_refcount(vkms_state->frame_info->fb))
			drm_framebuffer_put(vkms_state->frame_info->fb);
	}

	kfree(vkms_state->frame_info);
	vkms_state->frame_info = NULL;

	__drm_gem_destroy_shadow_plane_state(&vkms_state->base);
	kfree(vkms_state);
}

static void vkms_plane_reset(struct drm_plane *plane)
{
	struct vkms_plane_state *vkms_state;

	if (plane->state) {
		vkms_plane_destroy_state(plane, plane->state);
		plane->state = NULL; /* must be set to NULL here */
	}

	vkms_state = kzalloc(sizeof(*vkms_state), GFP_KERNEL);
	if (!vkms_state) {
		DRM_ERROR("Cannot allocate vkms_plane_state\n");
		return;
	}

	__drm_gem_reset_shadow_plane(plane, &vkms_state->base);
}

static const struct drm_plane_funcs vkms_plane_funcs = {
	.update_plane		= drm_atomic_helper_update_plane,
	.disable_plane		= drm_atomic_helper_disable_plane,
	.reset			= vkms_plane_reset,
	.atomic_duplicate_state = vkms_plane_duplicate_state,
	.atomic_destroy_state	= vkms_plane_destroy_state,
};

static void vkms_plane_atomic_update(struct drm_plane *plane,
				     struct drm_atomic_state *state)
{
	struct drm_plane_state *new_state = drm_atomic_get_new_plane_state(state,
									   plane);
	struct vkms_plane_state *vkms_plane_state;
	struct drm_shadow_plane_state *shadow_plane_state;
	struct drm_framebuffer *fb = new_state->fb;
	struct vkms_frame_info *frame_info;
	u32 fmt;

	if (!new_state->crtc || !fb)
		return;

	fmt = fb->format->format;
	vkms_plane_state = to_vkms_plane_state(new_state);
	shadow_plane_state = &vkms_plane_state->base;

	frame_info = vkms_plane_state->frame_info;
	memcpy(&frame_info->src, &new_state->src, sizeof(struct drm_rect));
	memcpy(&frame_info->dst, &new_state->dst, sizeof(struct drm_rect));
	memcpy(&frame_info->rotated, &new_state->dst, sizeof(struct drm_rect));
	frame_info->fb = fb;
	memcpy(&frame_info->map, &shadow_plane_state->data, sizeof(frame_info->map));
	drm_framebuffer_get(frame_info->fb);
	frame_info->rotation = drm_rotation_simplify(new_state->rotation, DRM_MODE_ROTATE_0 |
						     DRM_MODE_ROTATE_90 |
						     DRM_MODE_ROTATE_270 |
						     DRM_MODE_REFLECT_X |
						     DRM_MODE_REFLECT_Y);

	drm_rect_rotate(&frame_info->rotated, drm_rect_width(&frame_info->rotated),
			drm_rect_height(&frame_info->rotated), frame_info->rotation);

	frame_info->offset = fb->offsets[0];
	frame_info->pitch = fb->pitches[0];
	frame_info->cpp = fb->format->cpp[0];
	vkms_plane_state->pixel_read = get_pixel_conversion_function(fmt);
}

static int vkms_plane_atomic_check(struct drm_plane *plane,
				   struct drm_atomic_state *state)
{
	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
										 plane);
	struct drm_crtc_state *crtc_state;
	int ret;

	if (!new_plane_state->fb || WARN_ON(!new_plane_state->crtc))
		return 0;

	crtc_state = drm_atomic_get_crtc_state(state,
					       new_plane_state->crtc);
	if (IS_ERR(crtc_state))
		return PTR_ERR(crtc_state);

	ret = drm_atomic_helper_check_plane_state(new_plane_state, crtc_state,
						  DRM_PLANE_NO_SCALING,
						  DRM_PLANE_NO_SCALING,
						  true, true);
	if (ret != 0)
		return ret;

	return 0;
}

static int vkms_prepare_fb(struct drm_plane *plane,
			   struct drm_plane_state *state)
{
	struct drm_shadow_plane_state *shadow_plane_state;
	struct drm_framebuffer *fb = state->fb;
	int ret;

	if (!fb)
		return 0;

	shadow_plane_state = to_drm_shadow_plane_state(state);

	ret = drm_gem_plane_helper_prepare_fb(plane, state);
	if (ret)
		return ret;

	return drm_gem_fb_vmap(fb, shadow_plane_state->map, shadow_plane_state->data);
}

static void vkms_cleanup_fb(struct drm_plane *plane,
			    struct drm_plane_state *state)
{
	struct drm_shadow_plane_state *shadow_plane_state;
	struct drm_framebuffer *fb = state->fb;

	if (!fb)
		return;

	shadow_plane_state = to_drm_shadow_plane_state(state);

	drm_gem_fb_vunmap(fb, shadow_plane_state->map);
}

static const struct drm_plane_helper_funcs vkms_plane_helper_funcs = {
	.atomic_update		= vkms_plane_atomic_update,
	.atomic_check		= vkms_plane_atomic_check,
	.prepare_fb		= vkms_prepare_fb,
	.cleanup_fb		= vkms_cleanup_fb,
};

struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
				   enum drm_plane_type type, int index)
{
	struct drm_device *dev = &vkmsdev->drm;
	struct vkms_plane *plane;

	plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 1 << index,
					   &vkms_plane_funcs,
					   vkms_formats, ARRAY_SIZE(vkms_formats),
					   NULL, type, NULL);
	if (IS_ERR(plane))
		return plane;

	drm_plane_helper_add(&plane->base, &vkms_plane_helper_funcs);

	drm_plane_create_rotation_property(&plane->base, DRM_MODE_ROTATE_0,
					   DRM_MODE_ROTATE_MASK | DRM_MODE_REFLECT_MASK);

	return plane;
}