/*
 * 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_atomic.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_crtc_helper.h>

#include "rockchip_drm_drv.h"
#include "rockchip_drm_fb.h"
#include "rockchip_drm_gem.h"
#include "rockchip_drm_psr.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];
}

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

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

        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 int rockchip_drm_fb_dirty(struct drm_framebuffer *fb,
                                 struct drm_file *file,
                                 unsigned int flags, unsigned int color,
                                 struct drm_clip_rect *clips,
                                 unsigned int num_clips)
{
        rockchip_drm_psr_flush_all(fb->dev);
        return 0;
}

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

static struct rockchip_drm_fb *
rockchip_fb_alloc(struct drm_device *dev, const 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(dev, &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,
                        const 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(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_put_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_put_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;

        drm_fb_helper_hotplug_event(&private->fbdev_helper);
}

static const struct drm_mode_config_helper_funcs rockchip_mode_config_helpers = {
        .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
};

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,
        .atomic_check = drm_atomic_helper_check,
        .atomic_commit = drm_atomic_helper_commit,
};

struct drm_framebuffer *
rockchip_drm_framebuffer_init(struct drm_device *dev,
                              const 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 ERR_CAST(rockchip_fb);

        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;
        dev->mode_config.helper_private = &rockchip_mode_config_helpers;
}