// 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/console.h>
#include <linux/dma-mapping.h>
#include <linux/vmalloc.h>

#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_probe_helper.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
#define PREFERRED_BPP           32

#define to_exynos_fbdev(x)      container_of(x, struct exynos_drm_fbdev,\
                                drm_fb_helper)

struct exynos_drm_fbdev {
        struct drm_fb_helper    drm_fb_helper;
        struct exynos_drm_gem   *exynos_gem;
};

static int exynos_drm_fb_mmap(struct fb_info *info,
                        struct vm_area_struct *vma)
{
        struct drm_fb_helper *helper = info->par;
        struct exynos_drm_fbdev *exynos_fbd = to_exynos_fbdev(helper);
        struct exynos_drm_gem *exynos_gem = exynos_fbd->exynos_gem;
        unsigned long vm_size;
        int ret;

        vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;

        vm_size = vma->vm_end - vma->vm_start;

        if (vm_size > exynos_gem->size)
                return -EINVAL;

        ret = dma_mmap_attrs(to_dma_dev(helper->dev), vma, exynos_gem->cookie,
                             exynos_gem->dma_addr, exynos_gem->size,
                             exynos_gem->dma_attrs);
        if (ret < 0) {
                DRM_DEV_ERROR(to_dma_dev(helper->dev), "failed to mmap.\n");
                return ret;
        }

        return 0;
}

static const struct fb_ops exynos_drm_fb_ops = {
        .owner          = THIS_MODULE,
        DRM_FB_HELPER_DEFAULT_OPS,
        .fb_mmap        = exynos_drm_fb_mmap,
        .fb_fillrect    = drm_fb_helper_cfb_fillrect,
        .fb_copyarea    = drm_fb_helper_cfb_copyarea,
        .fb_imageblit   = drm_fb_helper_cfb_imageblit,
};

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;
        struct drm_framebuffer *fb = helper->fb;
        unsigned int size = fb->width * fb->height * fb->format->cpp[0];
        unsigned long offset;

        fbi = drm_fb_helper_alloc_fbi(helper);
        if (IS_ERR(fbi)) {
                DRM_DEV_ERROR(to_dma_dev(helper->dev),
                              "failed to allocate fb info.\n");
                return PTR_ERR(fbi);
        }

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

        return 0;
}

static int exynos_drm_fbdev_create(struct drm_fb_helper *helper,
                                    struct drm_fb_helper_surface_size *sizes)
{
        struct exynos_drm_fbdev *exynos_fbdev = to_exynos_fbdev(helper);
        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);

        exynos_fbdev->exynos_gem = exynos_gem;

        helper->fb =
                exynos_drm_framebuffer_init(dev, &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;
        }

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

        return ret;

err_destroy_framebuffer:
        drm_framebuffer_cleanup(helper->fb);
err_destroy_gem:
        exynos_drm_gem_destroy(exynos_gem);

        /*
         * if failed, all resources allocated above would be released by
         * drm_mode_config_cleanup() when drm_load() had been called prior
         * to any specific driver such as fimd or hdmi driver.
         */

        return ret;
}

static const struct drm_fb_helper_funcs exynos_drm_fb_helper_funcs = {
        .fb_probe =     exynos_drm_fbdev_create,
};

int exynos_drm_fbdev_init(struct drm_device *dev)
{
        struct exynos_drm_fbdev *fbdev;
        struct exynos_drm_private *private = dev->dev_private;
        struct drm_fb_helper *helper;
        int ret;

        if (!dev->mode_config.num_crtc)
                return 0;

        fbdev = kzalloc(sizeof(*fbdev), GFP_KERNEL);
        if (!fbdev)
                return -ENOMEM;

        private->fb_helper = helper = &fbdev->drm_fb_helper;

        drm_fb_helper_prepare(dev, helper, &exynos_drm_fb_helper_funcs);

        ret = drm_fb_helper_init(dev, helper);
        if (ret < 0) {
                DRM_DEV_ERROR(dev->dev,
                              "failed to initialize drm fb helper.\n");
                goto err_init;
        }

        ret = drm_fb_helper_initial_config(helper, PREFERRED_BPP);
        if (ret < 0) {
                DRM_DEV_ERROR(dev->dev,
                              "failed to set up hw configuration.\n");
                goto err_setup;
        }

        return 0;

err_setup:
        drm_fb_helper_fini(helper);

err_init:
        private->fb_helper = NULL;
        kfree(fbdev);

        return ret;
}

static void exynos_drm_fbdev_destroy(struct drm_device *dev,
                                      struct drm_fb_helper *fb_helper)
{
        struct drm_framebuffer *fb;

        /* release drm framebuffer and real buffer */
        if (fb_helper->fb && fb_helper->fb->funcs) {
                fb = fb_helper->fb;
                if (fb)
                        drm_framebuffer_remove(fb);
        }

        drm_fb_helper_unregister_fbi(fb_helper);

        drm_fb_helper_fini(fb_helper);
}

void exynos_drm_fbdev_fini(struct drm_device *dev)
{
        struct exynos_drm_private *private = dev->dev_private;
        struct exynos_drm_fbdev *fbdev;

        if (!private || !private->fb_helper)
                return;

        fbdev = to_exynos_fbdev(private->fb_helper);

        exynos_drm_fbdev_destroy(dev, private->fb_helper);
        kfree(fbdev);
        private->fb_helper = NULL;
}