// SPDX-License-Identifier: GPL-2.0-or-later
/* exynos_drm_fbdev.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>
 */

#include <linux/fb.h>

#include <drm/drm_crtc_helper.h>
#include <drm/drm_drv.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_prime.h>
#include <drm/drm_print.h>
#include <drm/exynos_drm.h>

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

#define MAX_CONNECTOR           4

static int exynos_drm_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
        struct drm_fb_helper *helper = info->par;
        struct drm_gem_object *obj = drm_gem_fb_get_obj(helper->fb, 0);

        return drm_gem_prime_mmap(obj, vma);
}

static void exynos_drm_fb_destroy(struct fb_info *info)
{
        struct drm_fb_helper *fb_helper = info->par;
        struct drm_framebuffer *fb = fb_helper->fb;

        drm_fb_helper_fini(fb_helper);

        drm_framebuffer_remove(fb);

        drm_client_release(&fb_helper->client);
}

static const struct fb_ops exynos_drm_fb_ops = {
        .owner          = THIS_MODULE,
        __FB_DEFAULT_DMAMEM_OPS_RDWR,
        DRM_FB_HELPER_DEFAULT_OPS,
        __FB_DEFAULT_DMAMEM_OPS_DRAW,
        .fb_mmap        = exynos_drm_fb_mmap,
        .fb_destroy     = exynos_drm_fb_destroy,
};

static int exynos_drm_fbdev_update(struct drm_fb_helper *helper,
                                   struct drm_fb_helper_surface_size *sizes,
                                   struct exynos_drm_gem *exynos_gem)
{
        struct fb_info *fbi = helper->info;
        struct drm_framebuffer *fb = helper->fb;
        unsigned int size = fb->width * fb->height * fb->format->cpp[0];
        unsigned long offset;

        fbi->fbops = &exynos_drm_fb_ops;

        drm_fb_helper_fill_info(fbi, helper, sizes);

        offset = fbi->var.xoffset * fb->format->cpp[0];
        offset += fbi->var.yoffset * fb->pitches[0];

        fbi->flags |= FBINFO_VIRTFB;
        fbi->screen_buffer = exynos_gem->kvaddr + offset;
        fbi->screen_size = size;
        fbi->fix.smem_len = size;

        return 0;
}

static const struct drm_fb_helper_funcs exynos_drm_fbdev_helper_funcs = {
};

int exynos_drm_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
                                        struct drm_fb_helper_surface_size *sizes)
{
        struct exynos_drm_gem *exynos_gem;
        struct drm_device *dev = helper->dev;
        struct drm_mode_fb_cmd2 mode_cmd = { 0 };
        unsigned long size;
        int ret;

        DRM_DEV_DEBUG_KMS(dev->dev,
                          "surface width(%d), height(%d) and bpp(%d\n",
                          sizes->surface_width, sizes->surface_height,
                          sizes->surface_bpp);

        mode_cmd.width = sizes->surface_width;
        mode_cmd.height = sizes->surface_height;
        mode_cmd.pitches[0] = sizes->surface_width * (sizes->surface_bpp >> 3);
        mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
                                                          sizes->surface_depth);

        size = mode_cmd.pitches[0] * mode_cmd.height;

        exynos_gem = exynos_drm_gem_create(dev, EXYNOS_BO_WC, size, true);
        if (IS_ERR(exynos_gem))
                return PTR_ERR(exynos_gem);

        helper->fb =
                exynos_drm_framebuffer_init(dev,
                                            drm_get_format_info(dev, mode_cmd.pixel_format,
                                                                mode_cmd.modifier[0]),
                                            &mode_cmd, &exynos_gem, 1);
        if (IS_ERR(helper->fb)) {
                DRM_DEV_ERROR(dev->dev, "failed to create drm framebuffer.\n");
                ret = PTR_ERR(helper->fb);
                goto err_destroy_gem;
        }
        helper->funcs = &exynos_drm_fbdev_helper_funcs;

        ret = exynos_drm_fbdev_update(helper, sizes, exynos_gem);
        if (ret < 0)
                goto err_destroy_framebuffer;

        return 0;

err_destroy_framebuffer:
        drm_framebuffer_cleanup(helper->fb);
        helper->fb = NULL;
err_destroy_gem:
        exynos_drm_gem_destroy(exynos_gem);
        return ret;
}