/*
 * Copyright © 2007 David Airlie
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *     David Airlie
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
//#include <linux/mm.h>
//#include <linux/tty.h>
#include <linux/sysrq.h>
//#include <linux/delay.h>
#include <linux/fb.h>
//#include <linux/init.h>
//#include <linux/vga_switcheroo.h>

#include <drm/drmP.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include "intel_drv.h"
#include <drm/i915_drm.h>
#include "i915_drv.h"


struct fb_info *framebuffer_alloc(size_t size, struct device *dev)
{
#define BYTES_PER_LONG (BITS_PER_LONG/8)
#define PADDING (BYTES_PER_LONG - (sizeof(struct fb_info) % BYTES_PER_LONG))
    int fb_info_size = sizeof(struct fb_info);
    struct fb_info *info;
    char *p;

    if (size)
        fb_info_size += PADDING;

    p = kzalloc(fb_info_size + size, GFP_KERNEL);

    if (!p)
        return NULL;

    info = (struct fb_info *) p;

    if (size)
        info->par = p + fb_info_size;

    return info;
#undef PADDING
#undef BYTES_PER_LONG
}


static struct fb_ops intelfb_ops = {
	.owner = THIS_MODULE,
	.fb_check_var = drm_fb_helper_check_var,
	.fb_set_par = drm_fb_helper_set_par,
//   .fb_fillrect = cfb_fillrect,
//   .fb_copyarea = cfb_copyarea,
//   .fb_imageblit = cfb_imageblit,
//   .fb_pan_display = drm_fb_helper_pan_display,
	.fb_blank = drm_fb_helper_blank,
//   .fb_setcmap = drm_fb_helper_setcmap,
//   .fb_debug_enter = drm_fb_helper_debug_enter,
//   .fb_debug_leave = drm_fb_helper_debug_leave,
};

static int intelfb_create(struct intel_fbdev *ifbdev,
			  struct drm_fb_helper_surface_size *sizes)
{
	struct drm_device *dev = ifbdev->helper.dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct fb_info *info;
	struct drm_framebuffer *fb;
	struct drm_mode_fb_cmd2 mode_cmd = {};
	struct drm_i915_gem_object *obj;
	struct device *device = &dev->pdev->dev;
	int size, ret;

	/* we don't do packed 24bpp */
	if (sizes->surface_bpp == 24)
		sizes->surface_bpp = 32;

	mode_cmd.width = sizes->surface_width;
	mode_cmd.height = sizes->surface_height;

	mode_cmd.pitches[0] = ALIGN(mode_cmd.width * ((sizes->surface_bpp + 7) /
						      8), 64);
	mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
							  sizes->surface_depth);

	size = mode_cmd.pitches[0] * mode_cmd.height;
	size = ALIGN(size, PAGE_SIZE);
	obj = i915_gem_alloc_object(dev, size);
	if (!obj) {
		DRM_ERROR("failed to allocate framebuffer\n");
		ret = -ENOMEM;
		goto out;
	}

	mutex_lock(&dev->struct_mutex);

#if 0
// skip this part and use existing framebiffer

	/* Flush everything out, we'll be doing GTT only from now on */
	ret = intel_pin_and_fence_fb_obj(dev, obj, false);
	if (ret) {
		DRM_ERROR("failed to pin fb: %d\n", ret);
		goto out_unref;
	}
#endif

/***********************************************************************/
    {
#define LFB_SIZE 0xC00000

        static struct drm_mm_node lfb_vm_node;

        lfb_vm_node.size = LFB_SIZE;
        lfb_vm_node.start = 0;
        lfb_vm_node.mm = NULL;

        obj->gtt_space = &lfb_vm_node;
        obj->gtt_offset = 0;
        obj->pin_count = 2;
    }
/***********************************************************************/

	info = framebuffer_alloc(0, device);
	if (!info) {
		ret = -ENOMEM;
		goto out_unpin;
	}

	info->par = ifbdev;

	ret = intel_framebuffer_init(dev, &ifbdev->ifb, &mode_cmd, obj);
	if (ret)
		goto out_unpin;

	fb = &ifbdev->ifb.base;

	ifbdev->helper.fb = fb;
	ifbdev->helper.fbdev = info;

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

    info->flags = FBINFO_DEFAULT | FBINFO_CAN_FORCE_OUTPUT;
    info->fbops = &intelfb_ops;

    /* setup aperture base/size for vesafb takeover */
	info->apertures = alloc_apertures(1);
	if (!info->apertures) {
		ret = -ENOMEM;
		goto out_unpin;
	}
	info->apertures->ranges[0].base = dev->mode_config.fb_base;
	info->apertures->ranges[0].size =
		dev_priv->mm.gtt->gtt_mappable_entries << PAGE_SHIFT;

	info->fix.smem_start = dev->mode_config.fb_base + obj->gtt_offset;
	info->fix.smem_len = size;

	info->screen_base = 0xFE000000;
	info->screen_size = size;

//	memset(info->screen_base, 0, size);

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

	/* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */

	DRM_DEBUG_KMS("allocated %dx%d fb: 0x%08x, bo %p\n",
		      fb->width, fb->height,
		      obj->gtt_offset, obj);


	mutex_unlock(&dev->struct_mutex);
//   vga_switcheroo_client_fb_set(dev->pdev, info);

	return 0;

out_unpin:
	i915_gem_object_unpin(obj);
out_unref:
	drm_gem_object_unreference(&obj->base);
	mutex_unlock(&dev->struct_mutex);
out:
	return ret;
}

static int intel_fb_find_or_create_single(struct drm_fb_helper *helper,
					  struct drm_fb_helper_surface_size *sizes)
{
	struct intel_fbdev *ifbdev = (struct intel_fbdev *)helper;
	int new_fb = 0;
	int ret;

	if (!helper->fb) {
		ret = intelfb_create(ifbdev, sizes);
		if (ret)
			return ret;
		new_fb = 1;
	}
	return new_fb;
}

static struct drm_fb_helper_funcs intel_fb_helper_funcs = {
	.gamma_set = intel_crtc_fb_gamma_set,
	.gamma_get = intel_crtc_fb_gamma_get,
    .fb_probe = intel_fb_find_or_create_single,
};


int intel_fbdev_init(struct drm_device *dev)
{
	struct intel_fbdev *ifbdev;
	drm_i915_private_t *dev_priv = dev->dev_private;
	int ret;

    ENTER();

	ifbdev = kzalloc(sizeof(struct intel_fbdev), GFP_KERNEL);
	if (!ifbdev)
		return -ENOMEM;

	dev_priv->fbdev = ifbdev;
	ifbdev->helper.funcs = &intel_fb_helper_funcs;

	ret = drm_fb_helper_init(dev, &ifbdev->helper,
				 dev_priv->num_pipe,
				 INTELFB_CONN_LIMIT);
	if (ret) {
		kfree(ifbdev);
		return ret;
	}

	drm_fb_helper_single_add_all_connectors(&ifbdev->helper);
	drm_fb_helper_initial_config(&ifbdev->helper, 32);

    LEAVE();
	return 0;
}