/* exynos_drm_fb.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>
 *
 * 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 <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_fb_helper.h>
#include <uapi/drm/exynos_drm.h>

#include "exynos_drm_drv.h"
#include "exynos_drm_fb.h"
#include "exynos_drm_gem.h"
#include "exynos_drm_iommu.h"
#include "exynos_drm_encoder.h"

#define to_exynos_fb(x) container_of(x, struct exynos_drm_fb, fb)

/*
 * exynos specific framebuffer structure.
 *
 * @fb: drm framebuffer obejct.
 * @buf_cnt: a buffer count to drm framebuffer.
 * @exynos_gem_obj: array of exynos specific gem object containing a gem object.
 */
struct exynos_drm_fb {
        struct drm_framebuffer          fb;
        unsigned int                    buf_cnt;
        struct exynos_drm_gem_obj       *exynos_gem_obj[MAX_FB_BUFFER];
};

static int check_fb_gem_memory_type(struct drm_device *drm_dev,
                                struct exynos_drm_gem_obj *exynos_gem_obj)
{
        unsigned int flags;

        /*
         * if exynos drm driver supports iommu then framebuffer can use
         * all the buffer types.
         */
        if (is_drm_iommu_supported(drm_dev))
                return 0;

        flags = exynos_gem_obj->flags;

        /*
         * without iommu support, not support physically non-continuous memory
         * for framebuffer.
         */
        if (IS_NONCONTIG_BUFFER(flags)) {
                DRM_ERROR("cannot use this gem memory type for fb.\n");
                return -EINVAL;
        }

        return 0;
}

static void exynos_drm_fb_destroy(struct drm_framebuffer *fb)
{
        struct exynos_drm_fb *exynos_fb = to_exynos_fb(fb);
        unsigned int i;

        /* make sure that overlay data are updated before relesing fb. */
        exynos_drm_encoder_complete_scanout(fb);

        drm_framebuffer_cleanup(fb);

        for (i = 0; i < ARRAY_SIZE(exynos_fb->exynos_gem_obj); i++) {
                struct drm_gem_object *obj;

                if (exynos_fb->exynos_gem_obj[i] == NULL)
                        continue;

                obj = &exynos_fb->exynos_gem_obj[i]->base;
                drm_gem_object_unreference_unlocked(obj);
        }

        kfree(exynos_fb);
        exynos_fb = NULL;
}

static int exynos_drm_fb_create_handle(struct drm_framebuffer *fb,
                                        struct drm_file *file_priv,
                                        unsigned int *handle)
{
        struct exynos_drm_fb *exynos_fb = to_exynos_fb(fb);

        /* This fb should have only one gem object. */
        if (WARN_ON(exynos_fb->buf_cnt != 1))
                return -EINVAL;

        return drm_gem_handle_create(file_priv,
                        &exynos_fb->exynos_gem_obj[0]->base, handle);
}

static int exynos_drm_fb_dirty(struct drm_framebuffer *fb,
                                struct drm_file *file_priv, unsigned flags,
                                unsigned color, struct drm_clip_rect *clips,
                                unsigned num_clips)
{
        /* TODO */

        return 0;
}

static struct drm_framebuffer_funcs exynos_drm_fb_funcs = {
        .destroy        = exynos_drm_fb_destroy,
        .create_handle  = exynos_drm_fb_create_handle,
        .dirty          = exynos_drm_fb_dirty,
};

void exynos_drm_fb_set_buf_cnt(struct drm_framebuffer *fb,
                                                unsigned int cnt)
{
        struct exynos_drm_fb *exynos_fb;

        exynos_fb = to_exynos_fb(fb);

        exynos_fb->buf_cnt = cnt;
}

unsigned int exynos_drm_fb_get_buf_cnt(struct drm_framebuffer *fb)
{
        struct exynos_drm_fb *exynos_fb;

        exynos_fb = to_exynos_fb(fb);

        return exynos_fb->buf_cnt;
}

struct drm_framebuffer *
exynos_drm_framebuffer_init(struct drm_device *dev,
                            struct drm_mode_fb_cmd2 *mode_cmd,
                            struct drm_gem_object *obj)
{
        struct exynos_drm_fb *exynos_fb;
        struct exynos_drm_gem_obj *exynos_gem_obj;
        int ret;

        exynos_gem_obj = to_exynos_gem_obj(obj);

        ret = check_fb_gem_memory_type(dev, exynos_gem_obj);
        if (ret < 0) {
                DRM_ERROR("cannot use this gem memory type for fb.\n");
                return ERR_PTR(-EINVAL);
        }

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

        drm_helper_mode_fill_fb_struct(&exynos_fb->fb, mode_cmd);
        exynos_fb->exynos_gem_obj[0] = exynos_gem_obj;

        ret = drm_framebuffer_init(dev, &exynos_fb->fb, &exynos_drm_fb_funcs);
        if (ret) {
                DRM_ERROR("failed to initialize framebuffer\n");
                return ERR_PTR(ret);
        }

        return &exynos_fb->fb;
}

static u32 exynos_drm_format_num_buffers(struct drm_mode_fb_cmd2 *mode_cmd)
{
        unsigned int cnt = 0;

        if (mode_cmd->pixel_format != DRM_FORMAT_NV12)
                return drm_format_num_planes(mode_cmd->pixel_format);

        while (cnt != MAX_FB_BUFFER) {
                if (!mode_cmd->handles[cnt])
                        break;
                cnt++;
        }

        /*
         * check if NV12 or NV12M.
         *
         * NV12
         * handles[0] = base1, offsets[0] = 0
         * handles[1] = base1, offsets[1] = Y_size
         *
         * NV12M
         * handles[0] = base1, offsets[0] = 0
         * handles[1] = base2, offsets[1] = 0
         */
        if (cnt == 2) {
                /*
                 * in case of NV12 format, offsets[1] is not 0 and
                 * handles[0] is same as handles[1].
                 */
                if (mode_cmd->offsets[1] &&
                        mode_cmd->handles[0] == mode_cmd->handles[1])
                        cnt = 1;
        }

        return cnt;
}

static struct drm_framebuffer *
exynos_user_fb_create(struct drm_device *dev, struct drm_file *file_priv,
                      struct drm_mode_fb_cmd2 *mode_cmd)
{
        struct drm_gem_object *obj;
        struct exynos_drm_gem_obj *exynos_gem_obj;
        struct exynos_drm_fb *exynos_fb;
        int i, ret;

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

        obj = drm_gem_object_lookup(dev, file_priv, mode_cmd->handles[0]);
        if (!obj) {
                DRM_ERROR("failed to lookup gem object\n");
                ret = -ENOENT;
                goto err_free;
        }

        drm_helper_mode_fill_fb_struct(&exynos_fb->fb, mode_cmd);
        exynos_fb->exynos_gem_obj[0] = to_exynos_gem_obj(obj);
        exynos_fb->buf_cnt = exynos_drm_format_num_buffers(mode_cmd);

        DRM_DEBUG_KMS("buf_cnt = %d\n", exynos_fb->buf_cnt);

        for (i = 1; i < exynos_fb->buf_cnt; i++) {
                obj = drm_gem_object_lookup(dev, file_priv,
                                mode_cmd->handles[i]);
                if (!obj) {
                        DRM_ERROR("failed to lookup gem object\n");
                        ret = -ENOENT;
                        exynos_fb->buf_cnt = i;
                        goto err_unreference;
                }

                exynos_gem_obj = to_exynos_gem_obj(obj);
                exynos_fb->exynos_gem_obj[i] = exynos_gem_obj;

                ret = check_fb_gem_memory_type(dev, exynos_gem_obj);
                if (ret < 0) {
                        DRM_ERROR("cannot use this gem memory type for fb.\n");
                        goto err_unreference;
                }
        }

        ret = drm_framebuffer_init(dev, &exynos_fb->fb, &exynos_drm_fb_funcs);
        if (ret) {
                DRM_ERROR("failed to init framebuffer.\n");
                goto err_unreference;
        }

        return &exynos_fb->fb;

err_unreference:
        for (i = 0; i < exynos_fb->buf_cnt; i++) {
                struct drm_gem_object *obj;

                obj = &exynos_fb->exynos_gem_obj[i]->base;
                if (obj)
                        drm_gem_object_unreference_unlocked(obj);
        }
err_free:
        kfree(exynos_fb);
        return ERR_PTR(ret);
}

struct exynos_drm_gem_buf *exynos_drm_fb_buffer(struct drm_framebuffer *fb,
                                                int index)
{
        struct exynos_drm_fb *exynos_fb = to_exynos_fb(fb);
        struct exynos_drm_gem_buf *buffer;

        if (index >= MAX_FB_BUFFER)
                return NULL;

        buffer = exynos_fb->exynos_gem_obj[index]->buffer;
        if (!buffer)
                return NULL;

        DRM_DEBUG_KMS("dma_addr = 0x%lx\n", (unsigned long)buffer->dma_addr);

        return buffer;
}

static void exynos_drm_output_poll_changed(struct drm_device *dev)
{
        struct exynos_drm_private *private = dev->dev_private;
        struct drm_fb_helper *fb_helper = private->fb_helper;

        if (fb_helper)
                drm_fb_helper_hotplug_event(fb_helper);
}

static const struct drm_mode_config_funcs exynos_drm_mode_config_funcs = {
        .fb_create = exynos_user_fb_create,
        .output_poll_changed = exynos_drm_output_poll_changed,
};

void exynos_drm_mode_config_init(struct drm_device *dev)
{
        dev->mode_config.min_width = 0;
        dev->mode_config.min_height = 0;

        /*
         * set max width and height as default value(4096x4096).
         * this value would be used to check framebuffer size limitation
         * at drm_mode_addfb().
         */
        dev->mode_config.max_width = 4096;
        dev->mode_config.max_height = 4096;

        dev->mode_config.funcs = &exynos_drm_mode_config_funcs;
}