/*
 * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
 * Author:Mark Yao <mark.yao@rock-chips.com>
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <drm/drm.h>
#include <drm/drmP.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>

#include "rockchip_drm_drv.h"
#include "rockchip_drm_gem.h"

#define to_rockchip_fb(x) container_of(x, struct rockchip_drm_fb, fb)

struct rockchip_drm_fb {
	struct drm_framebuffer fb;
	struct drm_gem_object *obj[ROCKCHIP_MAX_FB_BUFFER];
};

struct drm_gem_object *rockchip_fb_get_gem_obj(struct drm_framebuffer *fb,
					       unsigned int plane)
{
	struct rockchip_drm_fb *rk_fb = to_rockchip_fb(fb);

	if (plane >= ROCKCHIP_MAX_FB_BUFFER)
		return NULL;

	return rk_fb->obj[plane];
}
EXPORT_SYMBOL_GPL(rockchip_fb_get_gem_obj);

static void rockchip_drm_fb_destroy(struct drm_framebuffer *fb)
{
	struct rockchip_drm_fb *rockchip_fb = to_rockchip_fb(fb);
	struct drm_gem_object *obj;
	int i;

	for (i = 0; i < ROCKCHIP_MAX_FB_BUFFER; i++) {
		obj = rockchip_fb->obj[i];
		if (obj)
			drm_gem_object_unreference_unlocked(obj);
	}

	drm_framebuffer_cleanup(fb);
	kfree(rockchip_fb);
}

static int rockchip_drm_fb_create_handle(struct drm_framebuffer *fb,
					 struct drm_file *file_priv,
					 unsigned int *handle)
{
	struct rockchip_drm_fb *rockchip_fb = to_rockchip_fb(fb);

	return drm_gem_handle_create(file_priv,
				     rockchip_fb->obj[0], handle);
}

static struct drm_framebuffer_funcs rockchip_drm_fb_funcs = {
	.destroy	= rockchip_drm_fb_destroy,
	.create_handle	= rockchip_drm_fb_create_handle,
};

static struct rockchip_drm_fb *
rockchip_fb_alloc(struct drm_device *dev, struct drm_mode_fb_cmd2 *mode_cmd,
		  struct drm_gem_object **obj, unsigned int num_planes)
{
	struct rockchip_drm_fb *rockchip_fb;
	int ret;
	int i;

	rockchip_fb = kzalloc(sizeof(*rockchip_fb), GFP_KERNEL);
	if (!rockchip_fb)
		return ERR_PTR(-ENOMEM);

	drm_helper_mode_fill_fb_struct(&rockchip_fb->fb, mode_cmd);

	for (i = 0; i < num_planes; i++)
		rockchip_fb->obj[i] = obj[i];

	ret = drm_framebuffer_init(dev, &rockchip_fb->fb,
				   &rockchip_drm_fb_funcs);
	if (ret) {
		dev_err(dev->dev, "Failed to initialize framebuffer: %d\n",
			ret);
		kfree(rockchip_fb);
		return ERR_PTR(ret);
	}

	return rockchip_fb;
}

static struct drm_framebuffer *
rockchip_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
			struct drm_mode_fb_cmd2 *mode_cmd)
{
	struct rockchip_drm_fb *rockchip_fb;
	struct drm_gem_object *objs[ROCKCHIP_MAX_FB_BUFFER];
	struct drm_gem_object *obj;
	unsigned int hsub;
	unsigned int vsub;
	int num_planes;
	int ret;
	int i;

	hsub = drm_format_horz_chroma_subsampling(mode_cmd->pixel_format);
	vsub = drm_format_vert_chroma_subsampling(mode_cmd->pixel_format);
	num_planes = min(drm_format_num_planes(mode_cmd->pixel_format),
			 ROCKCHIP_MAX_FB_BUFFER);

	for (i = 0; i < num_planes; i++) {
		unsigned int width = mode_cmd->width / (i ? hsub : 1);
		unsigned int height = mode_cmd->height / (i ? vsub : 1);
		unsigned int min_size;

		obj = drm_gem_object_lookup(dev, file_priv,
					    mode_cmd->handles[i]);
		if (!obj) {
			dev_err(dev->dev, "Failed to lookup GEM object\n");
			ret = -ENXIO;
			goto err_gem_object_unreference;
		}

		min_size = (height - 1) * mode_cmd->pitches[i] +
			mode_cmd->offsets[i] +
			width * drm_format_plane_cpp(mode_cmd->pixel_format, i);

		if (obj->size < min_size) {
			drm_gem_object_unreference_unlocked(obj);
			ret = -EINVAL;
			goto err_gem_object_unreference;
		}
		objs[i] = obj;
	}

	rockchip_fb = rockchip_fb_alloc(dev, mode_cmd, objs, i);
	if (IS_ERR(rockchip_fb)) {
		ret = PTR_ERR(rockchip_fb);
		goto err_gem_object_unreference;
	}

	return &rockchip_fb->fb;

err_gem_object_unreference:
	for (i--; i >= 0; i--)
		drm_gem_object_unreference_unlocked(objs[i]);
	return ERR_PTR(ret);
}

static void rockchip_drm_output_poll_changed(struct drm_device *dev)
{
	struct rockchip_drm_private *private = dev->dev_private;
	struct drm_fb_helper *fb_helper = &private->fbdev_helper;

	if (fb_helper)
		drm_fb_helper_hotplug_event(fb_helper);
}

static const struct drm_mode_config_funcs rockchip_drm_mode_config_funcs = {
	.fb_create = rockchip_user_fb_create,
	.output_poll_changed = rockchip_drm_output_poll_changed,
};

struct drm_framebuffer *
rockchip_drm_framebuffer_init(struct drm_device *dev,
			      struct drm_mode_fb_cmd2 *mode_cmd,
			      struct drm_gem_object *obj)
{
	struct rockchip_drm_fb *rockchip_fb;

	rockchip_fb = rockchip_fb_alloc(dev, mode_cmd, &obj, 1);
	if (IS_ERR(rockchip_fb))
		return NULL;

	return &rockchip_fb->fb;
}

void rockchip_drm_mode_config_init(struct drm_device *dev)
{
	dev->mode_config.min_width = 0;
	dev->mode_config.min_height = 0;

	/*
	 * set max width and height as default value(4096x4096).
	 * this value would be used to check framebuffer size limitation
	 * at drm_mode_addfb().
	 */
	dev->mode_config.max_width = 4096;
	dev->mode_config.max_height = 4096;

	dev->mode_config.funcs = &rockchip_drm_mode_config_funcs;
}