/*
 * 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"

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_alloc(struct drm_fb_helper *helper,
			 struct drm_fb_helper_surface_size *sizes)
{
	struct intel_fbdev *ifbdev =
		container_of(helper, struct intel_fbdev, helper);
	struct drm_device *dev = helper->dev;
	struct drm_mode_fb_cmd2 mode_cmd = {};
	struct drm_i915_gem_object *obj;
	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 *
				    DIV_ROUND_UP(sizes->surface_bpp, 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_object_create_stolen(dev, size);
	if (obj == NULL)
		obj = i915_gem_alloc_object(dev, size);
	if (!obj) {
		DRM_ERROR("failed to allocate framebuffer\n");
		ret = -ENOMEM;
		goto out;
	}

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

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

	return 0;

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

static int intelfb_create(struct drm_fb_helper *helper,
			  struct drm_fb_helper_surface_size *sizes)
{
	struct intel_fbdev *ifbdev =
		container_of(helper, struct intel_fbdev, helper);
	struct intel_framebuffer *intel_fb = &ifbdev->ifb;
	struct drm_device *dev = helper->dev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct fb_info *info;
	struct drm_framebuffer *fb;
	struct drm_i915_gem_object *obj;
	int size, ret;

	mutex_lock(&dev->struct_mutex);

	if (!intel_fb->obj) {
		DRM_DEBUG_KMS("no BIOS fb, allocating a new one\n");
		ret = intelfb_alloc(helper, sizes);
		if (ret)
			goto out_unlock;
	} else {
		DRM_DEBUG_KMS("re-using BIOS fb\n");
		sizes->fb_width = intel_fb->base.width;
		sizes->fb_height = intel_fb->base.height;
	}

	obj = intel_fb->obj;
	size = obj->base.size;

	info = framebuffer_alloc(0, &dev->pdev->dev);
	if (!info) {
		ret = -ENOMEM;
		goto out_unpin;
	}

	info->par = helper;

	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;

	ret = fb_alloc_cmap(&info->cmap, 256, 0);
	if (ret) {
		ret = -ENOMEM;
		goto out_unpin;
	}
	/* 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->gtt.mappable_end;

	info->fix.smem_start = dev->mode_config.fb_base + i915_gem_obj_ggtt_offset(obj);
	info->fix.smem_len = size;

	info->screen_base =
		ioremap_wc(dev_priv->gtt.mappable_base + i915_gem_obj_ggtt_offset(obj),
			   size);
	if (!info->screen_base) {
		ret = -ENOSPC;
		goto out_unpin;
	}
	info->screen_size = size;

	/* This driver doesn't need a VT switch to restore the mode on resume */
	info->skip_vt_switch = true;

	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);

	/* If the object is shmemfs backed, it will have given us zeroed pages.
	 * If the object is stolen however, it will be full of whatever
	 * garbage was left in there.
	 */
	if (ifbdev->ifb.obj->stolen)
		memset_io(info->screen_base, 0, info->screen_size);

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

	DRM_DEBUG_KMS("allocated %dx%d fb: 0x%08lx, bo %p\n",
		      fb->width, fb->height,
		      i915_gem_obj_ggtt_offset(obj), obj);

	mutex_unlock(&dev->struct_mutex);
	vga_switcheroo_client_fb_set(dev->pdev, info);
	return 0;

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

/** Sets the color ramps on behalf of RandR */
static void intel_crtc_fb_gamma_set(struct drm_crtc *crtc, u16 red, u16 green,
				    u16 blue, int regno)
{
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);

	intel_crtc->lut_r[regno] = red >> 8;
	intel_crtc->lut_g[regno] = green >> 8;
	intel_crtc->lut_b[regno] = blue >> 8;
}

static void intel_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
				    u16 *blue, int regno)
{
	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);

	*red = intel_crtc->lut_r[regno] << 8;
	*green = intel_crtc->lut_g[regno] << 8;
	*blue = intel_crtc->lut_b[regno] << 8;
}

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 = intelfb_create,
};

static void intel_fbdev_destroy(struct drm_device *dev,
				struct intel_fbdev *ifbdev)
{
	if (ifbdev->helper.fbdev) {
		struct fb_info *info = ifbdev->helper.fbdev;

		unregister_framebuffer(info);
		iounmap(info->screen_base);
		if (info->cmap.len)
			fb_dealloc_cmap(&info->cmap);

		framebuffer_release(info);
	}

	drm_fb_helper_fini(&ifbdev->helper);

	drm_framebuffer_unregister_private(&ifbdev->ifb.base);
	intel_framebuffer_fini(&ifbdev->ifb);
}

int intel_fbdev_init(struct drm_device *dev)
{
	struct intel_fbdev *ifbdev;
	struct drm_i915_private *dev_priv = dev->dev_private;
	int ret;

	ifbdev = kzalloc(sizeof(*ifbdev), 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,
				 INTEL_INFO(dev)->num_pipes,
				 4);
	if (ret) {
		kfree(ifbdev);
		return ret;
	}

	drm_fb_helper_single_add_all_connectors(&ifbdev->helper);

	return 0;
}

void intel_fbdev_initial_config(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;

	/* Due to peculiar init order wrt to hpd handling this is separate. */
	drm_fb_helper_initial_config(&dev_priv->fbdev->helper, 32);
}

void intel_fbdev_fini(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	if (!dev_priv->fbdev)
		return;

	intel_fbdev_destroy(dev, dev_priv->fbdev);
	kfree(dev_priv->fbdev);
	dev_priv->fbdev = NULL;
}

void intel_fbdev_set_suspend(struct drm_device *dev, int state)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	struct intel_fbdev *ifbdev = dev_priv->fbdev;
	struct fb_info *info;

	if (!ifbdev)
		return;

	info = ifbdev->helper.fbdev;

	/* On resume from hibernation: If the object is shmemfs backed, it has
	 * been restored from swap. If the object is stolen however, it will be
	 * full of whatever garbage was left in there.
	 */
	if (state == FBINFO_STATE_RUNNING && ifbdev->ifb.obj->stolen)
		memset_io(info->screen_base, 0, info->screen_size);

	fb_set_suspend(info, state);
}

MODULE_LICENSE("GPL and additional rights");

void intel_fbdev_output_poll_changed(struct drm_device *dev)
{
	struct drm_i915_private *dev_priv = dev->dev_private;
	drm_fb_helper_hotplug_event(&dev_priv->fbdev->helper);
}

void intel_fbdev_restore_mode(struct drm_device *dev)
{
	int ret;
	struct drm_i915_private *dev_priv = dev->dev_private;

	if (INTEL_INFO(dev)->num_pipes == 0)
		return;

	drm_modeset_lock_all(dev);

	ret = drm_fb_helper_restore_fbdev_mode(&dev_priv->fbdev->helper);
	if (ret)
		DRM_DEBUG("failed to restore crtc mode\n");

	drm_modeset_unlock_all(dev);
}