// 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"
#include "exynos_drm_gem.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;

        drm_fb_helper_fini(fb_helper);

        drm_client_buffer_delete(fb_helper->buffer);
        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 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 drm_client_dev *client = &helper->client;
        struct drm_device *dev = client->dev;
        struct drm_file *file = client->file;
        struct fb_info *info = helper->info;
        u32 fourcc, pitch;
        u64 size;
        const struct drm_format_info *format;
        struct exynos_drm_gem *exynos_gem;
        struct drm_gem_object *obj;
        struct drm_client_buffer *buffer;
        u32 handle;
        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);

        fourcc = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
        if (fourcc == DRM_FORMAT_INVALID)
                return -EINVAL;
        format = drm_get_format_info(dev, fourcc, DRM_FORMAT_MOD_LINEAR);
        if (!format)
                return -EINVAL;
        pitch = drm_format_info_min_pitch(format, 0, sizes->surface_width);
        if (!pitch)
                return -EINVAL;
        if (check_mul_overflow(pitch, sizes->surface_height, &size))
                return -EINVAL;
        size = ALIGN(size, PAGE_SIZE);
        if (size < PAGE_SIZE)
                return -EINVAL;

        exynos_gem = exynos_drm_gem_create(dev, EXYNOS_BO_WC, size, true);
        if (IS_ERR(exynos_gem))
                return PTR_ERR(exynos_gem);
        obj = &exynos_gem->base;

        ret = drm_gem_handle_create(file, obj, &handle);
        if (ret)
                goto err_drm_gem_object_put;

        buffer = drm_client_buffer_create(client, sizes->surface_width, sizes->surface_height,
                                          fourcc, handle, pitch);
        if (IS_ERR(buffer)) {
                ret = PTR_ERR(buffer);
                goto err_drm_gem_handle_delete;
        }

        helper->funcs = &exynos_drm_fbdev_helper_funcs;
        helper->buffer = buffer;
        helper->fb = buffer->fb;

        info->fbops = &exynos_drm_fb_ops;

        drm_fb_helper_fill_info(info, helper, sizes);

        info->flags |= FBINFO_VIRTFB;
        info->screen_buffer = exynos_gem->kvaddr;
        info->screen_size = obj->size;
        info->fix.smem_len = obj->size;

        /* The handle is only needed for creating the framebuffer. */
        drm_gem_handle_delete(file, handle);

        /* The framebuffer still holds a reference on the GEM object. */
        drm_gem_object_put(obj);

        return 0;

err_drm_gem_handle_delete:
        drm_gem_handle_delete(file, handle);
err_drm_gem_object_put:
        drm_gem_object_put(obj);
        return ret;
}