/* exynos_drm_fb.c
 *
 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
 * Authors:
 *      Inki Dae <inki.dae@samsung.com>
 *      Joonyoung Shim <jy0922.shim@samsung.com>
 *      Seung-Woo Kim <sw0312.kim@samsung.com>
 *
 * This program is free software; you can redistribute  it and/or modify it
 * under  the terms of  the GNU General  Public License as published by the
 * Free Software Foundation;  either version 2 of the  License, or (at your
 * option) any later version.
 */

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_atomic.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <uapi/drm/exynos_drm.h>

#include "exynos_drm_drv.h"
#include "exynos_drm_fb.h"
#include "exynos_drm_fbdev.h"
#include "exynos_drm_iommu.h"
#include "exynos_drm_crtc.h"

static int check_fb_gem_memory_type(struct drm_device *drm_dev,
                                    struct exynos_drm_gem *exynos_gem)
{
        unsigned int flags;

        /*
         * if exynos drm driver supports iommu then framebuffer can use
         * all the buffer types.
         */
        if (is_drm_iommu_supported(drm_dev))
                return 0;

        flags = exynos_gem->flags;

        /*
         * Physically non-contiguous memory type for framebuffer is not
         * supported without IOMMU.
         */
        if (IS_NONCONTIG_BUFFER(flags)) {
                DRM_ERROR("Non-contiguous GEM memory is not supported.\n");
                return -EINVAL;
        }

        return 0;
}

static const struct drm_framebuffer_funcs exynos_drm_fb_funcs = {
        .destroy        = drm_gem_fb_destroy,
        .create_handle  = drm_gem_fb_create_handle,
};

struct drm_framebuffer *
exynos_drm_framebuffer_init(struct drm_device *dev,
                            const struct drm_mode_fb_cmd2 *mode_cmd,
                            struct exynos_drm_gem **exynos_gem,
                            int count)
{
        struct drm_framebuffer *fb;
        int i;
        int ret;

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

        for (i = 0; i < count; i++) {
                ret = check_fb_gem_memory_type(dev, exynos_gem[i]);
                if (ret < 0)
                        goto err;

                fb->obj[i] = &exynos_gem[i]->base;
        }

        drm_helper_mode_fill_fb_struct(dev, fb, mode_cmd);

        ret = drm_framebuffer_init(dev, fb, &exynos_drm_fb_funcs);
        if (ret < 0) {
                DRM_ERROR("failed to initialize framebuffer\n");
                goto err;
        }

        return fb;

err:
        kfree(fb);
        return ERR_PTR(ret);
}

static struct drm_framebuffer *
exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
                      const struct drm_mode_fb_cmd2 *mode_cmd)
{
        const struct drm_format_info *info = drm_get_format_info(dev, mode_cmd);
        struct exynos_drm_gem *exynos_gem[MAX_FB_BUFFER];
        struct drm_gem_object *obj;
        struct drm_framebuffer *fb;
        int i;
        int ret;

        for (i = 0; i < info->num_planes; i++) {
                unsigned int height = (i == 0) ? mode_cmd->height :
                                     DIV_ROUND_UP(mode_cmd->height, info->vsub);
                unsigned long size = height * mode_cmd->pitches[i] +
                                     mode_cmd->offsets[i];

                obj = drm_gem_object_lookup(file_priv, mode_cmd->handles[i]);
                if (!obj) {
                        DRM_ERROR("failed to lookup gem object\n");
                        ret = -ENOENT;
                        goto err;
                }

                exynos_gem[i] = to_exynos_gem(obj);

                if (size > exynos_gem[i]->size) {
                        i++;
                        ret = -EINVAL;
                        goto err;
                }
        }

        fb = exynos_drm_framebuffer_init(dev, mode_cmd, exynos_gem, i);
        if (IS_ERR(fb)) {
                ret = PTR_ERR(fb);
                goto err;
        }

        return fb;

err:
        while (i--)
                drm_gem_object_put_unlocked(&exynos_gem[i]->base);

        return ERR_PTR(ret);
}

dma_addr_t exynos_drm_fb_dma_addr(struct drm_framebuffer *fb, int index)
{
        struct exynos_drm_gem *exynos_gem;

        if (WARN_ON_ONCE(index >= MAX_FB_BUFFER))
                return 0;

        exynos_gem = to_exynos_gem(fb->obj[index]);
        return exynos_gem->dma_addr + fb->offsets[index];
}

static struct drm_mode_config_helper_funcs exynos_drm_mode_config_helpers = {
        .atomic_commit_tail = drm_atomic_helper_commit_tail_rpm,
};

static const struct drm_mode_config_funcs exynos_drm_mode_config_funcs = {
        .fb_create = exynos_user_fb_create,
        .output_poll_changed = drm_fb_helper_output_poll_changed,
        .atomic_check = drm_atomic_helper_check,
        .atomic_commit = drm_atomic_helper_commit,
};

void exynos_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 = &exynos_drm_mode_config_funcs;
        dev->mode_config.helper_private = &exynos_drm_mode_config_helpers;

        dev->mode_config.allow_fb_modifiers = true;

        dev->mode_config.normalize_zpos = true;
}