// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2012-2013 Avionic Design GmbH
 * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
 *
 * Based on the KMS/FB DMA helpers
 *   Copyright (C) 2012 Analog Devices Inc.
 */

#include <linux/console.h>
#include <linux/fb.h>
#include <linux/vmalloc.h>

#include <drm/drm_drv.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_modeset_helper.h>

#include "drm.h"
#include "gem.h"

static int tegra_fb_mmap(struct fb_info *info, struct vm_area_struct *vma)
{
        struct drm_fb_helper *helper = info->par;
        struct tegra_bo *bo;
        int err;

        bo = tegra_fb_get_plane(helper->fb, 0);

        err = drm_gem_mmap_obj(&bo->gem, bo->gem.size, vma);
        if (err < 0)
                return err;

        return __tegra_gem_mmap(&bo->gem, vma);
}

static void tegra_fbdev_fb_destroy(struct fb_info *info)
{
        struct drm_fb_helper *helper = info->par;
        struct drm_framebuffer *fb = helper->fb;
        struct tegra_bo *bo = tegra_fb_get_plane(fb, 0);

        drm_fb_helper_fini(helper);

        /* Undo the special mapping we made in fbdev probe. */
        if (bo->pages) {
                vunmap(bo->vaddr);
                bo->vaddr = NULL;
        }
        drm_framebuffer_remove(fb);

        drm_client_release(&helper->client);
}

static const struct fb_ops tegra_fb_ops = {
        .owner = THIS_MODULE,
        __FB_DEFAULT_DMAMEM_OPS_RDWR,
        DRM_FB_HELPER_DEFAULT_OPS,
        __FB_DEFAULT_DMAMEM_OPS_DRAW,
        .fb_mmap = tegra_fb_mmap,
        .fb_destroy = tegra_fbdev_fb_destroy,
};

static const struct drm_fb_helper_funcs tegra_fbdev_helper_funcs = {
};

int tegra_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
                                   struct drm_fb_helper_surface_size *sizes)
{
        struct tegra_drm *tegra = helper->dev->dev_private;
        struct drm_device *drm = helper->dev;
        struct drm_mode_fb_cmd2 cmd = { 0 };
        struct fb_info *info = helper->info;
        unsigned int bytes_per_pixel;
        struct drm_framebuffer *fb;
        unsigned long offset;
        struct tegra_bo *bo;
        size_t size;
        int err;

        bytes_per_pixel = DIV_ROUND_UP(sizes->surface_bpp, 8);

        cmd.width = sizes->surface_width;
        cmd.height = sizes->surface_height;
        cmd.pitches[0] = round_up(sizes->surface_width * bytes_per_pixel,
                                  tegra->pitch_align);

        cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
                                                     sizes->surface_depth);

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

        bo = tegra_bo_create(drm, size, 0);
        if (IS_ERR(bo))
                return PTR_ERR(bo);

        fb = tegra_fb_alloc(drm,
                            drm_get_format_info(drm, cmd.pixel_format, cmd.modifier[0]),
                            &cmd, &bo, 1);
        if (IS_ERR(fb)) {
                err = PTR_ERR(fb);
                dev_err(drm->dev, "failed to allocate DRM framebuffer: %d\n",
                        err);
                drm_gem_object_put(&bo->gem);
                return PTR_ERR(fb);
        }

        helper->funcs = &tegra_fbdev_helper_funcs;
        helper->fb = fb;
        helper->info = info;

        info->fbops = &tegra_fb_ops;

        drm_fb_helper_fill_info(info, helper, sizes);

        offset = info->var.xoffset * bytes_per_pixel +
                 info->var.yoffset * fb->pitches[0];

        if (bo->pages) {
                bo->vaddr = vmap(bo->pages, bo->num_pages, VM_MAP,
                                 pgprot_writecombine(PAGE_KERNEL));
                if (!bo->vaddr) {
                        dev_err(drm->dev, "failed to vmap() framebuffer\n");
                        err = -ENOMEM;
                        goto destroy;
                }
        }

        info->flags |= FBINFO_VIRTFB;
        info->screen_buffer = bo->vaddr + offset;
        info->screen_size = size;
        info->fix.smem_start = (unsigned long)(bo->iova + offset);
        info->fix.smem_len = size;

        return 0;

destroy:
        drm_framebuffer_remove(fb);
        return err;
}