// 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 tegra_bo *bo = tegra_fb_get_plane(helper->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_client_buffer_delete(helper->buffer);
        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 drm_client_dev *client = &helper->client;
        struct drm_device *drm = client->dev;
        struct drm_file *file = client->file;
        struct tegra_drm *tegra = drm->dev_private;
        struct fb_info *info = helper->info;
        u32 fourcc, pitch;
        u64 size;
        const struct drm_format_info *format;
        struct tegra_bo *bo;
        struct drm_gem_object *gem;
        u32 handle;
        struct drm_client_buffer *buffer;
        int err;

        fourcc = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth);
        format = drm_get_format_info(drm, fourcc, DRM_FORMAT_MOD_LINEAR);
        pitch = round_up(drm_format_info_min_pitch(format, 0, sizes->surface_width),
                         tegra->pitch_align);
        size = ALIGN(pitch * sizes->surface_height, PAGE_SIZE);

        bo = tegra_bo_create(drm, size, 0);
        if (IS_ERR(bo))
                return PTR_ERR(bo);
        gem = &bo->gem;

        err = drm_gem_handle_create(file, gem, &handle);
        if (err)
                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)) {
                err = PTR_ERR(buffer);
                goto err_drm_gem_handle_delete;
        }

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

        info->fbops = &tegra_fb_ops;

        drm_fb_helper_fill_info(info, helper, sizes);

        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 err_drm_client_buffer_delete;
                }
        }

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

        return 0;

err_drm_client_buffer_delete:
        drm_client_buffer_delete(buffer);
err_drm_gem_handle_delete:
        drm_gem_handle_delete(file, handle);
err_drm_gem_object_put:
        drm_gem_object_put(gem);
        return err;
}