/*
 * Copyright 2010 Matt Turner.
 * Copyright 2012 Red Hat
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License version 2. See the file COPYING in the main
 * directory of this archive for more details.
 *
 * Authors: Matthew Garrett
 *          Matt Turner
 *          Dave Airlie
 */
#include <drm/drmP.h>
#include <drm/drm_crtc_helper.h>
#include "mgag200_drv.h"

static void mga_user_framebuffer_destroy(struct drm_framebuffer *fb)
{
	struct mga_framebuffer *mga_fb = to_mga_framebuffer(fb);
	if (mga_fb->obj)
		drm_gem_object_unreference_unlocked(mga_fb->obj);
	drm_framebuffer_cleanup(fb);
	kfree(fb);
}

static const struct drm_framebuffer_funcs mga_fb_funcs = {
	.destroy = mga_user_framebuffer_destroy,
};

int mgag200_framebuffer_init(struct drm_device *dev,
			     struct mga_framebuffer *gfb,
			     struct drm_mode_fb_cmd2 *mode_cmd,
			     struct drm_gem_object *obj)
{
	int ret;
	
	drm_helper_mode_fill_fb_struct(&gfb->base, mode_cmd);
	gfb->obj = obj;
	ret = drm_framebuffer_init(dev, &gfb->base, &mga_fb_funcs);
	if (ret) {
		DRM_ERROR("drm_framebuffer_init failed: %d\n", ret);
		return ret;
	}
	return 0;
}

static struct drm_framebuffer *
mgag200_user_framebuffer_create(struct drm_device *dev,
				struct drm_file *filp,
				struct drm_mode_fb_cmd2 *mode_cmd)
{
	struct drm_gem_object *obj;
	struct mga_framebuffer *mga_fb;
	int ret;

	obj = drm_gem_object_lookup(dev, filp, mode_cmd->handles[0]);
	if (obj == NULL)
		return ERR_PTR(-ENOENT);

	mga_fb = kzalloc(sizeof(*mga_fb), GFP_KERNEL);
	if (!mga_fb) {
		drm_gem_object_unreference_unlocked(obj);
		return ERR_PTR(-ENOMEM);
	}

	ret = mgag200_framebuffer_init(dev, mga_fb, mode_cmd, obj);
	if (ret) {
		drm_gem_object_unreference_unlocked(obj);
		kfree(mga_fb);
		return ERR_PTR(ret);
	}
	return &mga_fb->base;
}

static const struct drm_mode_config_funcs mga_mode_funcs = {
	.fb_create = mgag200_user_framebuffer_create,
};

static int mga_probe_vram(struct mga_device *mdev, void __iomem *mem)
{
	int offset;
	int orig;
	int test1, test2;
	int orig1, orig2;

	/* Probe */
	orig = ioread16(mem);
	iowrite16(0, mem);

	for (offset = 0x100000; offset < mdev->mc.vram_window; offset += 0x4000) {
		orig1 = ioread8(mem + offset);
		orig2 = ioread8(mem + offset + 0x100);

		iowrite16(0xaa55, mem + offset);
		iowrite16(0xaa55, mem + offset + 0x100);

		test1 = ioread16(mem + offset);
		test2 = ioread16(mem);

		iowrite16(orig1, mem + offset);
		iowrite16(orig2, mem + offset + 0x100);

		if (test1 != 0xaa55) {
			break;
		}

		if (test2) {
			break;
		}
	}

	iowrite16(orig, mem);
	return offset - 65536;
}

/* Map the framebuffer from the card and configure the core */
static int mga_vram_init(struct mga_device *mdev)
{
	void __iomem *mem;
	struct apertures_struct *aper = alloc_apertures(1);
	if (!aper)
		return -ENOMEM;

	/* BAR 0 is VRAM */
	mdev->mc.vram_base = pci_resource_start(mdev->dev->pdev, 0);
	mdev->mc.vram_window = pci_resource_len(mdev->dev->pdev, 0);

	aper->ranges[0].base = mdev->mc.vram_base;
	aper->ranges[0].size = mdev->mc.vram_window;

	remove_conflicting_framebuffers(aper, "mgafb", true);
	kfree(aper);

	if (!devm_request_mem_region(mdev->dev->dev, mdev->mc.vram_base, mdev->mc.vram_window,
				"mgadrmfb_vram")) {
		DRM_ERROR("can't reserve VRAM\n");
		return -ENXIO;
	}

	mem = pci_iomap(mdev->dev->pdev, 0, 0);

	mdev->mc.vram_size = mga_probe_vram(mdev, mem);

	pci_iounmap(mdev->dev->pdev, mem);

	return 0;
}

static int mgag200_device_init(struct drm_device *dev,
			       uint32_t flags)
{
	struct mga_device *mdev = dev->dev_private;
	int ret, option;

	mdev->type = flags;

	/* Hardcode the number of CRTCs to 1 */
	mdev->num_crtc = 1;

	pci_read_config_dword(dev->pdev, PCI_MGA_OPTION, &option);
	mdev->has_sdram = !(option & (1 << 14));

	/* BAR 0 is the framebuffer, BAR 1 contains registers */
	mdev->rmmio_base = pci_resource_start(mdev->dev->pdev, 1);
	mdev->rmmio_size = pci_resource_len(mdev->dev->pdev, 1);

	if (!devm_request_mem_region(mdev->dev->dev, mdev->rmmio_base, mdev->rmmio_size,
				"mgadrmfb_mmio")) {
		DRM_ERROR("can't reserve mmio registers\n");
		return -ENOMEM;
	}

	mdev->rmmio = pcim_iomap(dev->pdev, 1, 0);
	if (mdev->rmmio == NULL)
		return -ENOMEM;

	/* stash G200 SE model number for later use */
	if (IS_G200_SE(mdev))
		mdev->unique_rev_id = RREG32(0x1e24);

	ret = mga_vram_init(mdev);
	if (ret)
		return ret;

	mdev->bpp_shifts[0] = 0;
	mdev->bpp_shifts[1] = 1;
	mdev->bpp_shifts[2] = 0;
	mdev->bpp_shifts[3] = 2;
	return 0;
}

/*
 * Functions here will be called by the core once it's bound the driver to
 * a PCI device
 */


int mgag200_driver_load(struct drm_device *dev, unsigned long flags)
{
	struct mga_device *mdev;
	int r;

	mdev = devm_kzalloc(dev->dev, sizeof(struct mga_device), GFP_KERNEL);
	if (mdev == NULL)
		return -ENOMEM;
	dev->dev_private = (void *)mdev;
	mdev->dev = dev;

	r = mgag200_device_init(dev, flags);
	if (r) {
		dev_err(&dev->pdev->dev, "Fatal error during GPU init: %d\n", r);
		return r;
	}
	r = mgag200_mm_init(mdev);
	if (r)
		goto out;

	drm_mode_config_init(dev);
	dev->mode_config.funcs = (void *)&mga_mode_funcs;
	dev->mode_config.preferred_depth = 24;
	dev->mode_config.prefer_shadow = 1;

	r = mgag200_modeset_init(mdev);
	if (r) {
		dev_err(&dev->pdev->dev, "Fatal error during modeset init: %d\n", r);
		goto out;
	}

	/* Make small buffers to store a hardware cursor (double buffered icon updates) */
	mgag200_bo_create(dev, roundup(48*64, PAGE_SIZE), 0, 0,
					  &mdev->cursor.pixels_1);
	mgag200_bo_create(dev, roundup(48*64, PAGE_SIZE), 0, 0,
					  &mdev->cursor.pixels_2);
	if (!mdev->cursor.pixels_2 || !mdev->cursor.pixels_1)
		goto cursor_nospace;
	mdev->cursor.pixels_current = mdev->cursor.pixels_1;
	mdev->cursor.pixels_prev = mdev->cursor.pixels_2;
	goto cursor_done;
 cursor_nospace:
	mdev->cursor.pixels_1 = NULL;
	mdev->cursor.pixels_2 = NULL;
	dev_warn(&dev->pdev->dev, "Could not allocate space for cursors. Not doing hardware cursors.\n");
 cursor_done:

out:
	if (r)
		mgag200_driver_unload(dev);
	return r;
}

int mgag200_driver_unload(struct drm_device *dev)
{
	struct mga_device *mdev = dev->dev_private;

	if (mdev == NULL)
		return 0;
	mgag200_modeset_fini(mdev);
	mgag200_fbdev_fini(mdev);
	drm_mode_config_cleanup(dev);
	mgag200_mm_fini(mdev);
	dev->dev_private = NULL;
	return 0;
}

int mgag200_gem_create(struct drm_device *dev,
		   u32 size, bool iskernel,
		   struct drm_gem_object **obj)
{
	struct mgag200_bo *astbo;
	int ret;

	*obj = NULL;

	size = roundup(size, PAGE_SIZE);
	if (size == 0)
		return -EINVAL;

	ret = mgag200_bo_create(dev, size, 0, 0, &astbo);
	if (ret) {
		if (ret != -ERESTARTSYS)
			DRM_ERROR("failed to allocate GEM object\n");
		return ret;
	}
	*obj = &astbo->gem;
	return 0;
}

int mgag200_dumb_create(struct drm_file *file,
		    struct drm_device *dev,
		    struct drm_mode_create_dumb *args)
{
	int ret;
	struct drm_gem_object *gobj;
	u32 handle;

	args->pitch = args->width * ((args->bpp + 7) / 8);
	args->size = args->pitch * args->height;

	ret = mgag200_gem_create(dev, args->size, false,
			     &gobj);
	if (ret)
		return ret;

	ret = drm_gem_handle_create(file, gobj, &handle);
	drm_gem_object_unreference_unlocked(gobj);
	if (ret)
		return ret;

	args->handle = handle;
	return 0;
}

void mgag200_bo_unref(struct mgag200_bo **bo)
{
	struct ttm_buffer_object *tbo;

	if ((*bo) == NULL)
		return;

	tbo = &((*bo)->bo);
	ttm_bo_unref(&tbo);
	if (tbo == NULL)
		*bo = NULL;

}

void mgag200_gem_free_object(struct drm_gem_object *obj)
{
	struct mgag200_bo *mgag200_bo = gem_to_mga_bo(obj);

	if (!mgag200_bo)
		return;
	mgag200_bo_unref(&mgag200_bo);
}


static inline u64 mgag200_bo_mmap_offset(struct mgag200_bo *bo)
{
	return drm_vma_node_offset_addr(&bo->bo.vma_node);
}

int
mgag200_dumb_mmap_offset(struct drm_file *file,
		     struct drm_device *dev,
		     uint32_t handle,
		     uint64_t *offset)
{
	struct drm_gem_object *obj;
	int ret;
	struct mgag200_bo *bo;

	mutex_lock(&dev->struct_mutex);
	obj = drm_gem_object_lookup(dev, file, handle);
	if (obj == NULL) {
		ret = -ENOENT;
		goto out_unlock;
	}

	bo = gem_to_mga_bo(obj);
	*offset = mgag200_bo_mmap_offset(bo);

	drm_gem_object_unreference(obj);
	ret = 0;
out_unlock:
	mutex_unlock(&dev->struct_mutex);
	return ret;

}
