/*
 * 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 "bochs.h"

/* ---------------------------------------------------------------------- */

static int bochsfb_mmap(struct fb_info *info,
                        struct vm_area_struct *vma)
{
        struct drm_fb_helper *fb_helper = info->par;
        struct bochs_device *bochs =
                container_of(fb_helper, struct bochs_device, fb.helper);
        struct bochs_bo *bo = gem_to_bochs_bo(bochs->fb.gfb.obj);

        return ttm_fbdev_mmap(vma, &bo->bo);
}

static struct fb_ops bochsfb_ops = {
        .owner = THIS_MODULE,
        DRM_FB_HELPER_DEFAULT_OPS,
        .fb_fillrect = drm_fb_helper_sys_fillrect,
        .fb_copyarea = drm_fb_helper_sys_copyarea,
        .fb_imageblit = drm_fb_helper_sys_imageblit,
        .fb_mmap = bochsfb_mmap,
};

static int bochsfb_create_object(struct bochs_device *bochs,
                                 const struct drm_mode_fb_cmd2 *mode_cmd,
                                 struct drm_gem_object **gobj_p)
{
        struct drm_device *dev = bochs->dev;
        struct drm_gem_object *gobj;
        u32 size;
        int ret = 0;

        size = mode_cmd->pitches[0] * mode_cmd->height;
        ret = bochs_gem_create(dev, size, true, &gobj);
        if (ret)
                return ret;

        *gobj_p = gobj;
        return ret;
}

static int bochsfb_create(struct drm_fb_helper *helper,
                          struct drm_fb_helper_surface_size *sizes)
{
        struct bochs_device *bochs =
                container_of(helper, struct bochs_device, fb.helper);
        struct fb_info *info;
        struct drm_framebuffer *fb;
        struct drm_mode_fb_cmd2 mode_cmd;
        struct drm_gem_object *gobj = NULL;
        struct bochs_bo *bo = NULL;
        int size, ret;

        if (sizes->surface_bpp != 32)
                return -EINVAL;

        mode_cmd.width = sizes->surface_width;
        mode_cmd.height = sizes->surface_height;
        mode_cmd.pitches[0] = mode_cmd.width * ((sizes->surface_bpp + 7) / 8);
        mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
                                                          sizes->surface_depth);
        size = mode_cmd.pitches[0] * mode_cmd.height;

        /* alloc, pin & map bo */
        ret = bochsfb_create_object(bochs, &mode_cmd, &gobj);
        if (ret) {
                DRM_ERROR("failed to create fbcon backing object %d\n", ret);
                return ret;
        }

        bo = gem_to_bochs_bo(gobj);

        ret = ttm_bo_reserve(&bo->bo, true, false, NULL);
        if (ret)
                return ret;

        ret = bochs_bo_pin(bo, TTM_PL_FLAG_VRAM, NULL);
        if (ret) {
                DRM_ERROR("failed to pin fbcon\n");
                ttm_bo_unreserve(&bo->bo);
                return ret;
        }

        ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages,
                          &bo->kmap);
        if (ret) {
                DRM_ERROR("failed to kmap fbcon\n");
                ttm_bo_unreserve(&bo->bo);
                return ret;
        }

        ttm_bo_unreserve(&bo->bo);

        /* init fb device */
        info = drm_fb_helper_alloc_fbi(helper);
        if (IS_ERR(info))
                return PTR_ERR(info);

        info->par = &bochs->fb.helper;

        ret = bochs_framebuffer_init(bochs->dev, &bochs->fb.gfb, &mode_cmd, gobj);
        if (ret)
                return ret;

        bochs->fb.size = size;

        /* setup helper */
        fb = &bochs->fb.gfb.base;
        bochs->fb.helper.fb = fb;

        strcpy(info->fix.id, "bochsdrmfb");

        info->flags = FBINFO_DEFAULT;
        info->fbops = &bochsfb_ops;

        drm_fb_helper_fill_fix(info, fb->pitches[0], fb->format->depth);
        drm_fb_helper_fill_var(info, &bochs->fb.helper, sizes->fb_width,
                               sizes->fb_height);

        info->screen_base = bo->kmap.virtual;
        info->screen_size = size;

        drm_vma_offset_remove(&bo->bo.bdev->vma_manager, &bo->bo.vma_node);
        info->fix.smem_start = 0;
        info->fix.smem_len = size;

        bochs->fb.initialized = true;
        return 0;
}

static int bochs_fbdev_destroy(struct bochs_device *bochs)
{
        struct bochs_framebuffer *gfb = &bochs->fb.gfb;

        DRM_DEBUG_DRIVER("\n");

        drm_fb_helper_unregister_fbi(&bochs->fb.helper);

        if (gfb->obj) {
                drm_gem_object_unreference_unlocked(gfb->obj);
                gfb->obj = NULL;
        }

        drm_framebuffer_unregister_private(&gfb->base);
        drm_framebuffer_cleanup(&gfb->base);

        return 0;
}

static const struct drm_fb_helper_funcs bochs_fb_helper_funcs = {
        .fb_probe = bochsfb_create,
};

int bochs_fbdev_init(struct bochs_device *bochs)
{
        int ret;

        drm_fb_helper_prepare(bochs->dev, &bochs->fb.helper,
                              &bochs_fb_helper_funcs);

        ret = drm_fb_helper_init(bochs->dev, &bochs->fb.helper, 1);
        if (ret)
                return ret;

        ret = drm_fb_helper_single_add_all_connectors(&bochs->fb.helper);
        if (ret)
                goto fini;

        drm_helper_disable_unused_functions(bochs->dev);

        ret = drm_fb_helper_initial_config(&bochs->fb.helper, 32);
        if (ret)
                goto fini;

        return 0;

fini:
        drm_fb_helper_fini(&bochs->fb.helper);
        return ret;
}

void bochs_fbdev_fini(struct bochs_device *bochs)
{
        if (bochs->fb.initialized)
                bochs_fbdev_destroy(bochs);

        if (bochs->fb.helper.fbdev)
                drm_fb_helper_fini(&bochs->fb.helper);

        bochs->fb.initialized = false;
}