drivers/gpu/drm/i915/intel_overlay.c

/*
 * Copyright © 2009
 *
 * 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:
 *    Daniel Vetter <daniel@ffwll.ch>
 *
 * Derived from Xorg ddx, xf86-video-intel, src/i830_video.c
 */
#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"
#include "i915_reg.h"
#include "intel_drv.h"

/* Limits for overlay size. According to intel doc, the real limits are:
 * Y width: 4095, UV width (planar): 2047, Y height: 2047,
 * UV width (planar): * 1023. But the xorg thinks 2048 for height and width. Use
 * the mininum of both.  */
#define IMAGE_MAX_WIDTH		2048
#define IMAGE_MAX_HEIGHT	2046 /* 2 * 1023 */
/* on 830 and 845 these large limits result in the card hanging */
#define IMAGE_MAX_WIDTH_LEGACY	1024
#define IMAGE_MAX_HEIGHT_LEGACY	1088

/* overlay register definitions */
/* OCMD register */
#define OCMD_TILED_SURFACE	(0x1<<19)
#define OCMD_MIRROR_MASK	(0x3<<17)
#define OCMD_MIRROR_MODE	(0x3<<17)
#define OCMD_MIRROR_HORIZONTAL	(0x1<<17)
#define OCMD_MIRROR_VERTICAL	(0x2<<17)
#define OCMD_MIRROR_BOTH	(0x3<<17)
#define OCMD_BYTEORDER_MASK	(0x3<<14) /* zero for YUYV or FOURCC YUY2 */
#define OCMD_UV_SWAP		(0x1<<14) /* YVYU */
#define OCMD_Y_SWAP		(0x2<<14) /* UYVY or FOURCC UYVY */
#define OCMD_Y_AND_UV_SWAP	(0x3<<14) /* VYUY */
#define OCMD_SOURCE_FORMAT_MASK (0xf<<10)
#define OCMD_RGB_888		(0x1<<10) /* not in i965 Intel docs */
#define OCMD_RGB_555		(0x2<<10) /* not in i965 Intel docs */
#define OCMD_RGB_565		(0x3<<10) /* not in i965 Intel docs */
#define OCMD_YUV_422_PACKED	(0x8<<10)
#define OCMD_YUV_411_PACKED	(0x9<<10) /* not in i965 Intel docs */
#define OCMD_YUV_420_PLANAR	(0xc<<10)
#define OCMD_YUV_422_PLANAR	(0xd<<10)
#define OCMD_YUV_410_PLANAR	(0xe<<10) /* also 411 */
#define OCMD_TVSYNCFLIP_PARITY	(0x1<<9)
#define OCMD_TVSYNCFLIP_ENABLE	(0x1<<7)
#define OCMD_BUF_TYPE_MASK	(Ox1<<5)
#define OCMD_BUF_TYPE_FRAME	(0x0<<5)
#define OCMD_BUF_TYPE_FIELD	(0x1<<5)
#define OCMD_TEST_MODE		(0x1<<4)
#define OCMD_BUFFER_SELECT	(0x3<<2)
#define OCMD_BUFFER0		(0x0<<2)
#define OCMD_BUFFER1		(0x1<<2)
#define OCMD_FIELD_SELECT	(0x1<<2)
#define OCMD_FIELD0		(0x0<<1)
#define OCMD_FIELD1		(0x1<<1)
#define OCMD_ENABLE		(0x1<<0)

/* OCONFIG register */
#define OCONF_PIPE_MASK		(0x1<<18)
#define OCONF_PIPE_A		(0x0<<18)
#define OCONF_PIPE_B		(0x1<<18)
#define OCONF_GAMMA2_ENABLE	(0x1<<16)
#define OCONF_CSC_MODE_BT601	(0x0<<5)
#define OCONF_CSC_MODE_BT709	(0x1<<5)
#define OCONF_CSC_BYPASS	(0x1<<4)
#define OCONF_CC_OUT_8BIT	(0x1<<3)
#define OCONF_TEST_MODE		(0x1<<2)
#define OCONF_THREE_LINE_BUFFER	(0x1<<0)
#define OCONF_TWO_LINE_BUFFER	(0x0<<0)

/* DCLRKM (dst-key) register */
#define DST_KEY_ENABLE		(0x1<<31)
#define CLK_RGB24_MASK		0x0
#define CLK_RGB16_MASK		0x070307
#define CLK_RGB15_MASK		0x070707
#define CLK_RGB8I_MASK		0xffffff

#define RGB16_TO_COLORKEY(c) \
	(((c & 0xF800) << 8) | ((c & 0x07E0) << 5) | ((c & 0x001F) << 3))
#define RGB15_TO_COLORKEY(c) \
	(((c & 0x7c00) << 9) | ((c & 0x03E0) << 6) | ((c & 0x001F) << 3))

/* overlay flip addr flag */
#define OFC_UPDATE		0x1

/* polyphase filter coefficients */
#define N_HORIZ_Y_TAPS          5
#define N_VERT_Y_TAPS           3
#define N_HORIZ_UV_TAPS         3
#define N_VERT_UV_TAPS          3
#define N_PHASES                17
#define MAX_TAPS                5

/* memory bufferd overlay registers */
struct overlay_registers {
    u32 OBUF_0Y;
    u32 OBUF_1Y;
    u32 OBUF_0U;
    u32 OBUF_0V;
    u32 OBUF_1U;
    u32 OBUF_1V;
    u32 OSTRIDE;
    u32 YRGB_VPH;
    u32 UV_VPH;
    u32 HORZ_PH;
    u32 INIT_PHS;
    u32 DWINPOS;
    u32 DWINSZ;
    u32 SWIDTH;
    u32 SWIDTHSW;
    u32 SHEIGHT;
    u32 YRGBSCALE;
    u32 UVSCALE;
    u32 OCLRC0;
    u32 OCLRC1;
    u32 DCLRKV;
    u32 DCLRKM;
    u32 SCLRKVH;
    u32 SCLRKVL;
    u32 SCLRKEN;
    u32 OCONFIG;
    u32 OCMD;
    u32 RESERVED1; /* 0x6C */
    u32 OSTART_0Y;
    u32 OSTART_1Y;
    u32 OSTART_0U;
    u32 OSTART_0V;
    u32 OSTART_1U;
    u32 OSTART_1V;
    u32 OTILEOFF_0Y;
    u32 OTILEOFF_1Y;
    u32 OTILEOFF_0U;
    u32 OTILEOFF_0V;
    u32 OTILEOFF_1U;
    u32 OTILEOFF_1V;
    u32 FASTHSCALE; /* 0xA0 */
    u32 UVSCALEV; /* 0xA4 */
    u32 RESERVEDC[(0x200 - 0xA8) / 4]; /* 0xA8 - 0x1FC */
    u16 Y_VCOEFS[N_VERT_Y_TAPS * N_PHASES]; /* 0x200 */
    u16 RESERVEDD[0x100 / 2 - N_VERT_Y_TAPS * N_PHASES];
    u16 Y_HCOEFS[N_HORIZ_Y_TAPS * N_PHASES]; /* 0x300 */
    u16 RESERVEDE[0x200 / 2 - N_HORIZ_Y_TAPS * N_PHASES];
    u16 UV_VCOEFS[N_VERT_UV_TAPS * N_PHASES]; /* 0x500 */
    u16 RESERVEDF[0x100 / 2 - N_VERT_UV_TAPS * N_PHASES];
    u16 UV_HCOEFS[N_HORIZ_UV_TAPS * N_PHASES]; /* 0x600 */
    u16 RESERVEDG[0x100 / 2 - N_HORIZ_UV_TAPS * N_PHASES];
};

/* overlay flip addr flag */
#define OFC_UPDATE		0x1

#define OVERLAY_NONPHYSICAL(dev) (IS_G33(dev) || IS_I965G(dev))
#define OVERLAY_EXISTS(dev) (!IS_G4X(dev) && !IS_IGDNG(dev))


static struct overlay_registers *intel_overlay_map_regs_atomic(struct intel_overlay *overlay)
{
        drm_i915_private_t *dev_priv = overlay->dev->dev_private;
	struct overlay_registers *regs;

	/* no recursive mappings */
	BUG_ON(overlay->virt_addr);

	if (OVERLAY_NONPHYSICAL(overlay->dev)) {
		regs = io_mapping_map_atomic_wc(dev_priv->mm.gtt_mapping,
				overlay->reg_bo->gtt_offset);

		if (!regs) {
			DRM_ERROR("failed to map overlay regs in GTT\n");
			return NULL;
		}
	} else
		regs = overlay->reg_bo->phys_obj->handle->vaddr;

	return overlay->virt_addr = regs;
}

static void intel_overlay_unmap_regs_atomic(struct intel_overlay *overlay)
{
	struct drm_device *dev = overlay->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;

	if (OVERLAY_NONPHYSICAL(overlay->dev))
		io_mapping_unmap_atomic(overlay->virt_addr);

	overlay->virt_addr = NULL;

	I915_READ(OVADD); /* flush wc cashes */

	return;
}

/* overlay needs to be disable in OCMD reg */
static int intel_overlay_on(struct intel_overlay *overlay)
{
	struct drm_device *dev = overlay->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
	int ret;
	RING_LOCALS;

	BUG_ON(overlay->active);

	overlay->active = 1;
	overlay->hw_wedged = NEEDS_WAIT_FOR_FLIP;

	BEGIN_LP_RING(6);
	OUT_RING(MI_FLUSH);
	OUT_RING(MI_NOOP);
	OUT_RING(MI_OVERLAY_FLIP | MI_OVERLAY_ON);
	OUT_RING(overlay->flip_addr | OFC_UPDATE);
	OUT_RING(MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP);
	OUT_RING(MI_NOOP);
	ADVANCE_LP_RING();

	overlay->last_flip_req = i915_add_request(dev, NULL, 0);
	if (overlay->last_flip_req == 0)
		return -ENOMEM;

	ret = i915_do_wait_request(dev, overlay->last_flip_req, 1);
	if (ret != 0)
		return ret;

	overlay->hw_wedged = 0;
	overlay->last_flip_req = 0;
	return 0;
}

/* overlay needs to be enabled in OCMD reg */
static void intel_overlay_continue(struct intel_overlay *overlay,
			    bool load_polyphase_filter)
{
	struct drm_device *dev = overlay->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
	u32 flip_addr = overlay->flip_addr;
	u32 tmp;
	RING_LOCALS;

	BUG_ON(!overlay->active);

	if (load_polyphase_filter)
		flip_addr |= OFC_UPDATE;

	/* check for underruns */
	tmp = I915_READ(DOVSTA);
	if (tmp & (1 << 17))
		DRM_DEBUG("overlay underrun, DOVSTA: %x\n", tmp);

	BEGIN_LP_RING(4);
	OUT_RING(MI_FLUSH);
	OUT_RING(MI_NOOP);
	OUT_RING(MI_OVERLAY_FLIP | MI_OVERLAY_CONTINUE);
	OUT_RING(flip_addr);
        ADVANCE_LP_RING();

	overlay->last_flip_req = i915_add_request(dev, NULL, 0);
}

static int intel_overlay_wait_flip(struct intel_overlay *overlay)
{
	struct drm_device *dev = overlay->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
	int ret;
	u32 tmp;
	RING_LOCALS;

	if (overlay->last_flip_req != 0) {
		ret = i915_do_wait_request(dev, overlay->last_flip_req, 0);
		if (ret != 0)
			return ret;

		overlay->last_flip_req = 0;

		tmp = I915_READ(ISR);

		if (!(tmp & I915_OVERLAY_PLANE_FLIP_PENDING_INTERRUPT))
			return 0;
	}

	/* synchronous slowpath */
	overlay->hw_wedged = RELEASE_OLD_VID;

	BEGIN_LP_RING(2);
        OUT_RING(MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP);
        OUT_RING(MI_NOOP);
        ADVANCE_LP_RING();

	overlay->last_flip_req = i915_add_request(dev, NULL, 0);
	if (overlay->last_flip_req == 0)
		return -ENOMEM;

	ret = i915_do_wait_request(dev, overlay->last_flip_req, 1);
	if (ret != 0)
		return ret;

	overlay->hw_wedged = 0;
	overlay->last_flip_req = 0;
	return 0;
}

/* overlay needs to be disabled in OCMD reg */
static int intel_overlay_off(struct intel_overlay *overlay)
{
	u32 flip_addr = overlay->flip_addr;
	struct drm_device *dev = overlay->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
	int ret;
	RING_LOCALS;

	BUG_ON(!overlay->active);

	/* According to intel docs the overlay hw may hang (when switching
	 * off) without loading the filter coeffs. It is however unclear whether
	 * this applies to the disabling of the overlay or to the switching off
	 * of the hw. Do it in both cases */
	flip_addr |= OFC_UPDATE;

	/* wait for overlay to go idle */
	overlay->hw_wedged = SWITCH_OFF_STAGE_1;

	BEGIN_LP_RING(6);
	OUT_RING(MI_FLUSH);
	OUT_RING(MI_NOOP);
	OUT_RING(MI_OVERLAY_FLIP | MI_OVERLAY_CONTINUE);
	OUT_RING(flip_addr);
        OUT_RING(MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP);
        OUT_RING(MI_NOOP);
        ADVANCE_LP_RING();

	overlay->last_flip_req = i915_add_request(dev, NULL, 0);
	if (overlay->last_flip_req == 0)
		return -ENOMEM;

	ret = i915_do_wait_request(dev, overlay->last_flip_req, 1);
	if (ret != 0)
		return ret;

	/* turn overlay off */
	overlay->hw_wedged = SWITCH_OFF_STAGE_2;

	BEGIN_LP_RING(6);
        OUT_RING(MI_FLUSH);
        OUT_RING(MI_NOOP);
        OUT_RING(MI_OVERLAY_FLIP | MI_OVERLAY_OFF);
	OUT_RING(flip_addr);
        OUT_RING(MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP);
        OUT_RING(MI_NOOP);
	ADVANCE_LP_RING();

	overlay->last_flip_req = i915_add_request(dev, NULL, 0);
	if (overlay->last_flip_req == 0)
		return -ENOMEM;

	ret = i915_do_wait_request(dev, overlay->last_flip_req, 1);
	if (ret != 0)
		return ret;

	overlay->active = 0;
	overlay->hw_wedged = 0;
	overlay->last_flip_req = 0;
	return ret;
}

/* recover from an interruption due to a signal
 * We have to be careful not to repeat work forever an make forward progess. */
int intel_overlay_recover_from_interrupt(struct intel_overlay *overlay,
					 int interruptible)
{
	struct drm_device *dev = overlay->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
	struct drm_gem_object *obj;
	u32 flip_addr;
	int ret;
	RING_LOCALS;

	if (overlay->hw_wedged == HW_WEDGED)
		return -EIO;

	if (overlay->last_flip_req == 0) {
		overlay->last_flip_req = i915_add_request(dev, NULL, 0);
		if (overlay->last_flip_req == 0)
			return -ENOMEM;
	}

	ret = i915_do_wait_request(dev, overlay->last_flip_req, interruptible);
	if (ret != 0)
		return ret;

	switch (overlay->hw_wedged) {
		case RELEASE_OLD_VID:
			obj = overlay->old_vid_bo->obj;
			i915_gem_object_unpin(obj);
			drm_gem_object_unreference(obj);
			overlay->old_vid_bo = NULL;
			break;
		case SWITCH_OFF_STAGE_1:
			flip_addr = overlay->flip_addr;
			flip_addr |= OFC_UPDATE;

			overlay->hw_wedged = SWITCH_OFF_STAGE_2;

			BEGIN_LP_RING(6);
			OUT_RING(MI_FLUSH);
			OUT_RING(MI_NOOP);
			OUT_RING(MI_OVERLAY_FLIP | MI_OVERLAY_OFF);
			OUT_RING(flip_addr);
			OUT_RING(MI_WAIT_FOR_EVENT | MI_WAIT_FOR_OVERLAY_FLIP);
			OUT_RING(MI_NOOP);
			ADVANCE_LP_RING();

			overlay->last_flip_req = i915_add_request(dev, NULL, 0);
			if (overlay->last_flip_req == 0)
				return -ENOMEM;

			ret = i915_do_wait_request(dev, overlay->last_flip_req,
					interruptible);
			if (ret != 0)
				return ret;

		case SWITCH_OFF_STAGE_2:
			printk("switch off 2\n");

			BUG_ON(!overlay->vid_bo);
			obj = overlay->vid_bo->obj;

			i915_gem_object_unpin(obj);
			drm_gem_object_unreference(obj);
			overlay->vid_bo = NULL;

			overlay->crtc->overlay = NULL;
			overlay->crtc = NULL;

			overlay->active = 0;
			break;
		default:
			BUG_ON(overlay->hw_wedged != NEEDS_WAIT_FOR_FLIP);
	}

	overlay->hw_wedged = 0;
	overlay->last_flip_req = 0;
	return 0;
}

/* Wait for pending overlay flip and release old frame.
 * Needs to be called before the overlay register are changed
 * via intel_overlay_(un)map_regs_atomic */
static int intel_overlay_release_old_vid(struct intel_overlay *overlay)
{
	int ret;
	struct drm_gem_object *obj;

	/* only wait if there is actually an old frame to release to
	 * guarantee forward progress */
	if (!overlay->old_vid_bo)
		return 0;

	ret = intel_overlay_wait_flip(overlay);
	if (ret != 0)
		return ret;

	obj = overlay->old_vid_bo->obj;
	i915_gem_object_unpin(obj);
	drm_gem_object_unreference(obj);
	overlay->old_vid_bo = NULL;

	return 0;
}

struct put_image_params {
	int format;
	short dst_x;
	short dst_y;
	short dst_w;
	short dst_h;
	short src_w;
	short src_scan_h;
	short src_scan_w;
	short src_h;
	short stride_Y;
	short stride_UV;
	int offset_Y;
	int offset_U;
	int offset_V;
};

static int packed_depth_bytes(u32 format)
{
	switch (format & I915_OVERLAY_DEPTH_MASK) {
		case I915_OVERLAY_YUV422:
			return 4;
		case I915_OVERLAY_YUV411:
			/* return 6; not implemented */
		default:
			return -EINVAL;
	}
}

static int packed_width_bytes(u32 format, short width)
{
	switch (format & I915_OVERLAY_DEPTH_MASK) {
		case I915_OVERLAY_YUV422:
			return width << 1;
		default:
			return -EINVAL;
	}
}

static int uv_hsubsampling(u32 format)
{
	switch (format & I915_OVERLAY_DEPTH_MASK) {
		case I915_OVERLAY_YUV422:
		case I915_OVERLAY_YUV420:
			return 2;
		case I915_OVERLAY_YUV411:
		case I915_OVERLAY_YUV410:
			return 4;
		default:
			return -EINVAL;
	}
}

static int uv_vsubsampling(u32 format)
{
	switch (format & I915_OVERLAY_DEPTH_MASK) {
		case I915_OVERLAY_YUV420:
		case I915_OVERLAY_YUV410:
			return 2;
		case I915_OVERLAY_YUV422:
		case I915_OVERLAY_YUV411:
			return 1;
		default:
			return -EINVAL;
	}
}

static u32 calc_swidthsw(struct drm_device *dev, u32 offset, u32 width)
{
	u32 mask, shift, ret;
	if (IS_I9XX(dev)) {
		mask = 0x3f;
		shift = 6;
	} else {
		mask = 0x1f;
		shift = 5;
	}
	ret = ((offset + width + mask) >> shift) - (offset >> shift);
	if (IS_I9XX(dev))
		ret <<= 1;
	ret -=1;
	return ret << 2;
}

static const u16 y_static_hcoeffs[N_HORIZ_Y_TAPS * N_PHASES] = {
	0x3000, 0xb4a0, 0x1930, 0x1920, 0xb4a0,
	0x3000, 0xb500, 0x19d0, 0x1880, 0xb440,
	0x3000, 0xb540, 0x1a88, 0x2f80, 0xb3e0,
	0x3000, 0xb580, 0x1b30, 0x2e20, 0xb380,
	0x3000, 0xb5c0, 0x1bd8, 0x2cc0, 0xb320,
	0x3020, 0xb5e0, 0x1c60, 0x2b80, 0xb2c0,
	0x3020, 0xb5e0, 0x1cf8, 0x2a20, 0xb260,
	0x3020, 0xb5e0, 0x1d80, 0x28e0, 0xb200,
	0x3020, 0xb5c0, 0x1e08, 0x3f40, 0xb1c0,
	0x3020, 0xb580, 0x1e78, 0x3ce0, 0xb160,
	0x3040, 0xb520, 0x1ed8, 0x3aa0, 0xb120,
	0x3040, 0xb4a0, 0x1f30, 0x3880, 0xb0e0,
	0x3040, 0xb400, 0x1f78, 0x3680, 0xb0a0,
	0x3020, 0xb340, 0x1fb8, 0x34a0, 0xb060,
	0x3020, 0xb240, 0x1fe0, 0x32e0, 0xb040,
	0x3020, 0xb140, 0x1ff8, 0x3160, 0xb020,
	0xb000, 0x3000, 0x0800, 0x3000, 0xb000};
static const u16 uv_static_hcoeffs[N_HORIZ_UV_TAPS * N_PHASES] = {
	0x3000, 0x1800, 0x1800, 0xb000, 0x18d0, 0x2e60,
	0xb000, 0x1990, 0x2ce0, 0xb020, 0x1a68, 0x2b40,
	0xb040, 0x1b20, 0x29e0, 0xb060, 0x1bd8, 0x2880,
	0xb080, 0x1c88, 0x3e60, 0xb0a0, 0x1d28, 0x3c00,
	0xb0c0, 0x1db8, 0x39e0, 0xb0e0, 0x1e40, 0x37e0,
	0xb100, 0x1eb8, 0x3620, 0xb100, 0x1f18, 0x34a0,
	0xb100, 0x1f68, 0x3360, 0xb0e0, 0x1fa8, 0x3240,
	0xb0c0, 0x1fe0, 0x3140, 0xb060, 0x1ff0, 0x30a0,
	0x3000, 0x0800, 0x3000};

static void update_polyphase_filter(struct overlay_registers *regs)
{
	memcpy(regs->Y_HCOEFS, y_static_hcoeffs, sizeof(y_static_hcoeffs));
	memcpy(regs->UV_HCOEFS, uv_static_hcoeffs, sizeof(uv_static_hcoeffs));
}

static bool update_scaling_factors(struct intel_overlay *overlay,
				   struct overlay_registers *regs,
				   struct put_image_params *params)
{
	/* fixed point with a 12 bit shift */
	u32 xscale, yscale, xscale_UV, yscale_UV;
#define FP_SHIFT 12
#define FRACT_MASK 0xfff
	bool scale_changed = false;
	int uv_hscale = uv_hsubsampling(params->format);
	int uv_vscale = uv_vsubsampling(params->format);

	if (params->dst_w > 1)
		xscale = ((params->src_scan_w - 1) << FP_SHIFT)
			/(params->dst_w);
	else
		xscale = 1 << FP_SHIFT;

	if (params->dst_h > 1)
		yscale = ((params->src_scan_h - 1) << FP_SHIFT)
			/(params->dst_h);
	else
		yscale = 1 << FP_SHIFT;

	/*if (params->format & I915_OVERLAY_YUV_PLANAR) {*/
		xscale_UV = xscale/uv_hscale;
		yscale_UV = yscale/uv_vscale;
		/* make the Y scale to UV scale ratio an exact multiply */
		xscale = xscale_UV * uv_hscale;
		yscale = yscale_UV * uv_vscale;
	/*} else {
		xscale_UV = 0;
		yscale_UV = 0;
	}*/

	if (xscale != overlay->old_xscale || yscale != overlay->old_yscale)
		scale_changed = true;
	overlay->old_xscale = xscale;
	overlay->old_yscale = yscale;

	regs->YRGBSCALE = ((yscale & FRACT_MASK) << 20)
		| ((xscale >> FP_SHIFT) << 16)
		| ((xscale & FRACT_MASK) << 3);
	regs->UVSCALE = ((yscale_UV & FRACT_MASK) << 20)
		| ((xscale_UV >> FP_SHIFT) << 16)
		| ((xscale_UV & FRACT_MASK) << 3);
	regs->UVSCALEV = ((yscale >> FP_SHIFT) << 16)
		| ((yscale_UV >> FP_SHIFT) << 0);

	if (scale_changed)
		update_polyphase_filter(regs);

	return scale_changed;
}

static void update_colorkey(struct intel_overlay *overlay,
			    struct overlay_registers *regs)
{
	u32 key = overlay->color_key;
	switch (overlay->crtc->base.fb->bits_per_pixel) {
		case 8:
			regs->DCLRKV = 0;
			regs->DCLRKM = CLK_RGB8I_MASK | DST_KEY_ENABLE;
		case 16:
			if (overlay->crtc->base.fb->depth == 15) {
				regs->DCLRKV = RGB15_TO_COLORKEY(key);
				regs->DCLRKM = CLK_RGB15_MASK | DST_KEY_ENABLE;
			} else {
				regs->DCLRKV = RGB16_TO_COLORKEY(key);
				regs->DCLRKM = CLK_RGB16_MASK | DST_KEY_ENABLE;
			}
		case 24:
		case 32:
			regs->DCLRKV = key;
			regs->DCLRKM = CLK_RGB24_MASK | DST_KEY_ENABLE;
	}
}

static u32 overlay_cmd_reg(struct put_image_params *params)
{
	u32 cmd = OCMD_ENABLE | OCMD_BUF_TYPE_FRAME | OCMD_BUFFER0;

	if (params->format & I915_OVERLAY_YUV_PLANAR) {
		switch (params->format & I915_OVERLAY_DEPTH_MASK) {
			case I915_OVERLAY_YUV422:
				cmd |= OCMD_YUV_422_PLANAR;
				break;
			case I915_OVERLAY_YUV420:
				cmd |= OCMD_YUV_420_PLANAR;
				break;
			case I915_OVERLAY_YUV411:
			case I915_OVERLAY_YUV410:
				cmd |= OCMD_YUV_410_PLANAR;
				break;
		}
	} else { /* YUV packed */
		switch (params->format & I915_OVERLAY_DEPTH_MASK) {
			case I915_OVERLAY_YUV422:
				cmd |= OCMD_YUV_422_PACKED;
				break;
			case I915_OVERLAY_YUV411:
				cmd |= OCMD_YUV_411_PACKED;
				break;
		}

		switch (params->format & I915_OVERLAY_SWAP_MASK) {
			case I915_OVERLAY_NO_SWAP:
				break;
			case I915_OVERLAY_UV_SWAP:
				cmd |= OCMD_UV_SWAP;
				break;
			case I915_OVERLAY_Y_SWAP:
				cmd |= OCMD_Y_SWAP;
				break;
			case I915_OVERLAY_Y_AND_UV_SWAP:
				cmd |= OCMD_Y_AND_UV_SWAP;
				break;
		}
	}

	return cmd;
}

int intel_overlay_do_put_image(struct intel_overlay *overlay,
			       struct drm_gem_object *new_bo,
			       struct put_image_params *params)
{
	int ret, tmp_width;
	struct overlay_registers *regs;
	bool scale_changed = false;
	struct drm_i915_gem_object *bo_priv = new_bo->driver_private;
	struct drm_device *dev = overlay->dev;

	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
	BUG_ON(!mutex_is_locked(&dev->mode_config.mutex));
	BUG_ON(!overlay);

	ret = intel_overlay_release_old_vid(overlay);
	if (ret != 0)
		return ret;

	ret = i915_gem_object_pin(new_bo, PAGE_SIZE);
	if (ret != 0)
		return ret;

	ret = i915_gem_object_set_to_gtt_domain(new_bo, 0);
	if (ret != 0)
		goto out_unpin;

	if (!overlay->active) {
		regs = intel_overlay_map_regs_atomic(overlay);
		if (!regs) {
			ret = -ENOMEM;
			goto out_unpin;
		}
		regs->OCONFIG = OCONF_CC_OUT_8BIT;
		if (IS_I965GM(overlay->dev))
			regs->OCONFIG |= OCONF_CSC_MODE_BT709;
		regs->OCONFIG |= overlay->crtc->pipe == 0 ?
			OCONF_PIPE_A : OCONF_PIPE_B;
		intel_overlay_unmap_regs_atomic(overlay);

		ret = intel_overlay_on(overlay);
		if (ret != 0)
			goto out_unpin;
	}

	regs = intel_overlay_map_regs_atomic(overlay);
	if (!regs) {
		ret = -ENOMEM;
		goto out_unpin;
	}

	regs->DWINPOS = (params->dst_y << 16) | params->dst_x;
	regs->DWINSZ = (params->dst_h << 16) | params->dst_w;

	if (params->format & I915_OVERLAY_YUV_PACKED)
		tmp_width = packed_width_bytes(params->format, params->src_w);
	else
		tmp_width = params->src_w;

	regs->SWIDTH = params->src_w;
	regs->SWIDTHSW = calc_swidthsw(overlay->dev,
			params->offset_Y, tmp_width);
	regs->SHEIGHT = params->src_h;
	regs->OBUF_0Y = bo_priv->gtt_offset + params-> offset_Y;
	regs->OSTRIDE = params->stride_Y;

	if (params->format & I915_OVERLAY_YUV_PLANAR) {
		int uv_hscale = uv_hsubsampling(params->format);
		int uv_vscale = uv_vsubsampling(params->format);
		u32 tmp_U, tmp_V;
		regs->SWIDTH |= (params->src_w/uv_hscale) << 16;
		tmp_U = calc_swidthsw(overlay->dev, params->offset_U,
				params->src_w/uv_hscale);
		tmp_V = calc_swidthsw(overlay->dev, params->offset_V,
				params->src_w/uv_hscale);
		regs->SWIDTHSW |= max_t(u32, tmp_U, tmp_V) << 16;
		regs->SHEIGHT |= (params->src_h/uv_vscale) << 16;
		regs->OBUF_0U = bo_priv->gtt_offset + params->offset_U;
		regs->OBUF_0V = bo_priv->gtt_offset + params->offset_V;
		regs->OSTRIDE |= params->stride_UV << 16;
	}

	scale_changed = update_scaling_factors(overlay, regs, params);

	update_colorkey(overlay, regs);

	regs->OCMD = overlay_cmd_reg(params);

	intel_overlay_unmap_regs_atomic(overlay);

	intel_overlay_continue(overlay, scale_changed);

	overlay->old_vid_bo = overlay->vid_bo;
	overlay->vid_bo = new_bo->driver_private;

	return 0;

out_unpin:
	i915_gem_object_unpin(new_bo);
	return ret;
}

int intel_overlay_switch_off(struct intel_overlay *overlay)
{
	int ret;
	struct overlay_registers *regs;
	struct drm_gem_object *obj;
	struct drm_device *dev = overlay->dev;

	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
	BUG_ON(!mutex_is_locked(&dev->mode_config.mutex));

	if (!overlay->active)
		return 0;

	if (overlay->hw_wedged)
		return -EBUSY;

	ret = intel_overlay_release_old_vid(overlay);
	if (ret != 0)
		return ret;

	regs = intel_overlay_map_regs_atomic(overlay);
	regs->OCMD = 0;
	intel_overlay_unmap_regs_atomic(overlay);

	ret = intel_overlay_off(overlay);
	if (ret != 0)
		return ret;

	/* never have the overlay hw on without showing a frame */
	BUG_ON(!overlay->vid_bo);
	obj = overlay->vid_bo->obj;

	i915_gem_object_unpin(obj);
	drm_gem_object_unreference(obj);
	overlay->vid_bo = NULL;

	overlay->crtc->overlay = NULL;
	overlay->crtc = NULL;

	return 0;
}

static int check_overlay_possible_on_crtc(struct intel_overlay *overlay,
					  struct intel_crtc *crtc)
{
        drm_i915_private_t *dev_priv = overlay->dev->dev_private;
	u32 pipeconf;
	int pipeconf_reg = (crtc->pipe == 0) ? PIPEACONF : PIPEBCONF;

	if (!crtc->base.enabled || crtc->dpms_mode != DRM_MODE_DPMS_ON)
		return -EINVAL;

	pipeconf = I915_READ(pipeconf_reg);

	/* can't use the overlay with double wide pipe */
	if (!IS_I965G(overlay->dev) && pipeconf & PIPEACONF_DOUBLE_WIDE)
		return -EINVAL;

	return 0;
}

static void update_pfit_vscale_ratio(struct intel_overlay *overlay)
{
	struct drm_device *dev = overlay->dev;
        drm_i915_private_t *dev_priv = dev->dev_private;
	u32 ratio;
	u32 pfit_control = I915_READ(PFIT_CONTROL);

	/* XXX: This is not the same logic as in the xorg driver, but more in
	 * line with the intel documentation for the i965 */
	if (!IS_I965G(dev) && (pfit_control & VERT_AUTO_SCALE)) {
		ratio = I915_READ(PFIT_AUTO_RATIOS) >> PFIT_VERT_SCALE_SHIFT;
	} else { /* on i965 use the PGM reg to read out the autoscaler values */
		ratio = I915_READ(PFIT_PGM_RATIOS);
		if (IS_I965G(dev))
			ratio >>= PFIT_VERT_SCALE_SHIFT_965;
		else
			ratio >>= PFIT_VERT_SCALE_SHIFT;
	}

	overlay->pfit_vscale_ratio = ratio;
}

static int check_overlay_dst(struct intel_overlay *overlay,
			     struct drm_intel_overlay_put_image *rec)
{
	struct drm_display_mode *mode = &overlay->crtc->base.mode;

	if ((rec->dst_x < mode->crtc_hdisplay)
	    && (rec->dst_x + rec->dst_width
		    <= mode->crtc_hdisplay)
	    && (rec->dst_y < mode->crtc_vdisplay)
	    && (rec->dst_y + rec->dst_height
		    <= mode->crtc_vdisplay))
		return 0;
	else
		return -EINVAL;
}

static int check_overlay_scaling(struct put_image_params *rec)
{
	u32 tmp;

	/* downscaling limit is 8.0 */
	tmp = ((rec->src_scan_h << 16) / rec->dst_h) >> 16;
	if (tmp > 7)
		return -EINVAL;
	tmp = ((rec->src_scan_w << 16) / rec->dst_w) >> 16;
	if (tmp > 7)
		return -EINVAL;

	return 0;
}

static int check_overlay_src(struct drm_device *dev,
			     struct drm_intel_overlay_put_image *rec,
			     struct drm_gem_object *new_bo)
{
	u32 stride_mask;
	int depth;
	int uv_hscale = uv_hsubsampling(rec->flags);
	int uv_vscale = uv_vsubsampling(rec->flags);
	size_t tmp;

	/* check src dimensions */
	if (IS_845G(dev) || IS_I830(dev)) {
		if (rec->src_height > IMAGE_MAX_HEIGHT_LEGACY
		    || rec->src_width > IMAGE_MAX_WIDTH_LEGACY)
			return -EINVAL;
	} else {
		if (rec->src_height > IMAGE_MAX_HEIGHT
		    || rec->src_width > IMAGE_MAX_WIDTH)
			return -EINVAL;
	}
	/* better safe than sorry, use 4 as the maximal subsampling ratio */
	if (rec->src_height < N_VERT_Y_TAPS*4
	    || rec->src_width < N_HORIZ_Y_TAPS*4)
		return -EINVAL;

	/* check alingment constrains */
	switch (rec->flags & I915_OVERLAY_TYPE_MASK) {
		case I915_OVERLAY_RGB:
			/* not implemented */
			return -EINVAL;
		case I915_OVERLAY_YUV_PACKED:
			depth = packed_depth_bytes(rec->flags);
			if (uv_vscale != 1)
				return -EINVAL;
			if (depth < 0)
				return depth;
			/* ignore UV planes */
			rec->stride_UV = 0;
			rec->offset_U = 0;
			rec->offset_V = 0;
			/* check pixel alignment */
			if (rec->offset_Y % depth)
				return -EINVAL;
			break;
		case I915_OVERLAY_YUV_PLANAR:
			if (uv_vscale < 0 || uv_hscale < 0)
				return -EINVAL;
			/* no offset restrictions for planar formats */
			break;
		default:
			return -EINVAL;
	}

	if (rec->src_width % uv_hscale)
		return -EINVAL;

	/* stride checking */
	stride_mask = 63;

	if (rec->stride_Y & stride_mask || rec->stride_UV & stride_mask)
		return -EINVAL;
	if (IS_I965G(dev) && rec->stride_Y < 512)
		return -EINVAL;

	tmp = (rec->flags & I915_OVERLAY_TYPE_MASK) == I915_OVERLAY_YUV_PLANAR ?
		4 : 8;
	if (rec->stride_Y > tmp*1024 || rec->stride_UV > 2*1024)
		return -EINVAL;

	/* check buffer dimensions */
	switch (rec->flags & I915_OVERLAY_TYPE_MASK) {
		case I915_OVERLAY_RGB:
		case I915_OVERLAY_YUV_PACKED:
			/* always 4 Y values per depth pixels */
			if (packed_width_bytes(rec->flags, rec->src_width)
					> rec->stride_Y)
				return -EINVAL;

			tmp = rec->stride_Y*rec->src_height;
			if (rec->offset_Y + tmp > new_bo->size)
				return -EINVAL;
			break;
		case I915_OVERLAY_YUV_PLANAR:
			if (rec->src_width > rec->stride_Y)
				return -EINVAL;
			if (rec->src_width/uv_hscale > rec->stride_UV)
				return -EINVAL;

			tmp = rec->stride_Y*rec->src_height;
			if (rec->offset_Y + tmp > new_bo->size)
				return -EINVAL;
			tmp = rec->stride_UV*rec->src_height;
			tmp /= uv_vscale;
			if (rec->offset_U + tmp > new_bo->size
			    || rec->offset_V + tmp > new_bo->size)
				return -EINVAL;
			break;
	}

	return 0;
}

int intel_overlay_put_image(struct drm_device *dev, void *data,
                            struct drm_file *file_priv)
{
	struct drm_intel_overlay_put_image *put_image_rec = data;
	drm_i915_private_t *dev_priv = dev->dev_private;
	struct intel_overlay *overlay;
	struct drm_mode_object *drmmode_obj;
	struct intel_crtc *crtc;
	struct drm_gem_object *new_bo;
	struct put_image_params *params;
	int ret;

	if (!dev_priv) {
		DRM_ERROR("called with no initialization\n");
		return -EINVAL;
	}

	overlay = dev_priv->overlay;
	if (!overlay) {
		DRM_DEBUG("userspace bug: no overlay\n");
		return -ENODEV;
	}

	if (!(put_image_rec->flags & I915_OVERLAY_ENABLE)) {
		mutex_lock(&dev->mode_config.mutex);
		mutex_lock(&dev->struct_mutex);

		ret = intel_overlay_switch_off(overlay);

		mutex_unlock(&dev->struct_mutex);
		mutex_unlock(&dev->mode_config.mutex);

		return ret;
	}

	params = kmalloc(sizeof(struct put_image_params), GFP_KERNEL);
	if (!params)
		return -ENOMEM;

	drmmode_obj = drm_mode_object_find(dev, put_image_rec->crtc_id,
                        DRM_MODE_OBJECT_CRTC);
	if (!drmmode_obj)
		return -ENOENT;
	crtc = to_intel_crtc(obj_to_crtc(drmmode_obj));

	new_bo = drm_gem_object_lookup(dev, file_priv,
			put_image_rec->bo_handle);
	if (!new_bo)
		return -ENOENT;

	mutex_lock(&dev->mode_config.mutex);
	mutex_lock(&dev->struct_mutex);

	if (overlay->hw_wedged) {
		ret = intel_overlay_recover_from_interrupt(overlay, 1);
		if (ret != 0)
			goto out_unlock;
	}

	if (overlay->crtc != crtc) {
		struct drm_display_mode *mode = &crtc->base.mode;
		ret = intel_overlay_switch_off(overlay);
		if (ret != 0)
			goto out_unlock;

		ret = check_overlay_possible_on_crtc(overlay, crtc);
		if (ret != 0)
			goto out_unlock;

		overlay->crtc = crtc;
		crtc->overlay = overlay;

		if (intel_panel_fitter_pipe(dev) == crtc->pipe
		    /* and line to wide, i.e. one-line-mode */
		    && mode->hdisplay > 1024) {
			overlay->pfit_active = 1;
			update_pfit_vscale_ratio(overlay);
		} else
			overlay->pfit_active = 0;
	}

	ret = check_overlay_dst(overlay, put_image_rec);
	if (ret != 0)
		goto out_unlock;

	if (overlay->pfit_active) {
		params->dst_y = ((((u32)put_image_rec->dst_y) << 12) /
			overlay->pfit_vscale_ratio);
		/* shifting right rounds downwards, so add 1 */
		params->dst_h = ((((u32)put_image_rec->dst_height) << 12) /
			overlay->pfit_vscale_ratio) + 1;
	} else {
		params->dst_y = put_image_rec->dst_y;
		params->dst_h = put_image_rec->dst_height;
	}
	params->dst_x = put_image_rec->dst_x;
	params->dst_w = put_image_rec->dst_width;

	params->src_w = put_image_rec->src_width;
	params->src_h = put_image_rec->src_height;
	params->src_scan_w = put_image_rec->src_scan_width;
	params->src_scan_h = put_image_rec->src_scan_height;
	if (params->src_scan_h > params->src_h
	    || params->src_scan_w > params->src_w) {
		ret = -EINVAL;
		goto out_unlock;
	}

	ret = check_overlay_src(dev, put_image_rec, new_bo);
	if (ret != 0)
		goto out_unlock;
	params->format = put_image_rec->flags & ~I915_OVERLAY_FLAGS_MASK;
	params->stride_Y = put_image_rec->stride_Y;
	params->stride_UV = put_image_rec->stride_UV;
	params->offset_Y = put_image_rec->offset_Y;
	params->offset_U = put_image_rec->offset_U;
	params->offset_V = put_image_rec->offset_V;

	/* Check scaling after src size to prevent a divide-by-zero. */
	ret = check_overlay_scaling(params);
	if (ret != 0)
		goto out_unlock;

	ret = intel_overlay_do_put_image(overlay, new_bo, params);
	if (ret != 0)
		goto out_unlock;

	mutex_unlock(&dev->struct_mutex);
	mutex_unlock(&dev->mode_config.mutex);

	kfree(params);

	return 0;

out_unlock:
	mutex_unlock(&dev->struct_mutex);
	mutex_unlock(&dev->mode_config.mutex);
	drm_gem_object_unreference(new_bo);
	kfree(params);

	return ret;
}

static void update_reg_attrs(struct intel_overlay *overlay,
			     struct overlay_registers *regs)
{
	regs->OCLRC0 = (overlay->contrast << 18) | (overlay->brightness & 0xff);
	regs->OCLRC1 = overlay->saturation;
}

static bool check_gamma_bounds(u32 gamma1, u32 gamma2)
{
	int i;

	if (gamma1 & 0xff000000 || gamma2 & 0xff000000)
		return false;

	for (i = 0; i < 3; i++) {
		if (((gamma1 >> i * 8) & 0xff) >= ((gamma2 >> i*8) & 0xff))
			return false;
	}

	return true;
}

static bool check_gamma5_errata(u32 gamma5)
{
	int i;

	for (i = 0; i < 3; i++) {
		if (((gamma5 >> i*8) & 0xff) == 0x80)
			return false;
	}

	return true;
}

static int check_gamma(struct drm_intel_overlay_attrs *attrs)
{
	if (!check_gamma_bounds(0, attrs->gamma0)
	    || !check_gamma_bounds(attrs->gamma0, attrs->gamma1)
	    || !check_gamma_bounds(attrs->gamma1, attrs->gamma2)
	    || !check_gamma_bounds(attrs->gamma2, attrs->gamma3)
	    || !check_gamma_bounds(attrs->gamma3, attrs->gamma4)
	    || !check_gamma_bounds(attrs->gamma4, attrs->gamma5)
	    || !check_gamma_bounds(attrs->gamma5, 0x00ffffff))
		return -EINVAL;
	if (!check_gamma5_errata(attrs->gamma5))
		return -EINVAL;
	return 0;
}

int intel_overlay_attrs(struct drm_device *dev, void *data,
                        struct drm_file *file_priv)
{
	struct drm_intel_overlay_attrs *attrs = data;
        drm_i915_private_t *dev_priv = dev->dev_private;
	struct intel_overlay *overlay;
	struct overlay_registers *regs;
	int ret;

	if (!dev_priv) {
		DRM_ERROR("called with no initialization\n");
		return -EINVAL;
	}

	overlay = dev_priv->overlay;
	if (!overlay) {
		DRM_DEBUG("userspace bug: no overlay\n");
		return -ENODEV;
	}

	mutex_lock(&dev->mode_config.mutex);
	mutex_lock(&dev->struct_mutex);

	if (!(attrs->flags & I915_OVERLAY_UPDATE_ATTRS)) {
		attrs->color_key = overlay->color_key;
		attrs->brightness = overlay->brightness;
		attrs->contrast = overlay->contrast;
		attrs->saturation = overlay->saturation;

		if (IS_I9XX(dev)) {
			attrs->gamma0 = I915_READ(OGAMC0);
			attrs->gamma1 = I915_READ(OGAMC1);
			attrs->gamma2 = I915_READ(OGAMC2);
			attrs->gamma3 = I915_READ(OGAMC3);
			attrs->gamma4 = I915_READ(OGAMC4);
			attrs->gamma5 = I915_READ(OGAMC5);
		}
		ret = 0;
	} else {
		overlay->color_key = attrs->color_key;
		if (attrs->brightness >= -128 && attrs->brightness <= 127) {
			overlay->brightness = attrs->brightness;
		} else {
			ret = -EINVAL;
			goto out_unlock;
		}
		if (attrs->contrast <= 255) {
			overlay->contrast = attrs->contrast;
		} else {
			ret = -EINVAL;
			goto out_unlock;
		}
		if (attrs->saturation <= 1023) {
			overlay->saturation = attrs->saturation;
		} else {
			ret = -EINVAL;
			goto out_unlock;
		}

		regs = intel_overlay_map_regs_atomic(overlay);
		if (!regs) {
			ret = -ENOMEM;
			goto out_unlock;
		}

		update_reg_attrs(overlay, regs);

		intel_overlay_unmap_regs_atomic(overlay);

		if (attrs->flags & I915_OVERLAY_UPDATE_GAMMA) {
			if (!IS_I9XX(dev)) {
				ret = -EINVAL;
				goto out_unlock;
			}

			if (overlay->active) {
				ret = -EBUSY;
				goto out_unlock;
			}

			ret = check_gamma(attrs);
			if (ret != 0)
				goto out_unlock;

			I915_WRITE(OGAMC0, attrs->gamma0);
			I915_WRITE(OGAMC1, attrs->gamma1);
			I915_WRITE(OGAMC2, attrs->gamma2);
			I915_WRITE(OGAMC3, attrs->gamma3);
			I915_WRITE(OGAMC4, attrs->gamma4);
			I915_WRITE(OGAMC5, attrs->gamma5);
		}
		ret = 0;
	}

out_unlock:
	mutex_unlock(&dev->struct_mutex);
	mutex_unlock(&dev->mode_config.mutex);

	return ret;
}

void intel_setup_overlay(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
	struct intel_overlay *overlay;
	struct drm_gem_object *reg_bo;
	struct overlay_registers *regs;
	int ret;

	if (!OVERLAY_EXISTS(dev))
		return;

	overlay = kzalloc(sizeof(struct intel_overlay), GFP_KERNEL);
	if (!overlay)
		return;
	overlay->dev = dev;

	reg_bo = drm_gem_object_alloc(dev, PAGE_SIZE);
	if (!reg_bo)
		goto out_free;
	overlay->reg_bo = reg_bo->driver_private;

	if (OVERLAY_NONPHYSICAL(dev)) {
		ret = i915_gem_object_pin(reg_bo, PAGE_SIZE);
		if (ret) {
                        DRM_ERROR("failed to pin overlay register bo\n");
                        goto out_free_bo;
                }
		overlay->flip_addr = overlay->reg_bo->gtt_offset;
	} else {
		ret = i915_gem_attach_phys_object(dev, reg_bo,
				I915_GEM_PHYS_OVERLAY_REGS);
                if (ret) {
                        DRM_ERROR("failed to attach phys overlay regs\n");
                        goto out_free_bo;
                }
		overlay->flip_addr = overlay->reg_bo->phys_obj->handle->busaddr;
	}

	/* init all values */
	overlay->color_key = 0x0101fe;
	overlay->brightness = -19;
	overlay->contrast = 75;
	overlay->saturation = 146;

	regs = intel_overlay_map_regs_atomic(overlay);
	if (!regs)
		goto out_free_bo;

	memset(regs, 0, sizeof(struct overlay_registers));
	update_polyphase_filter(regs);

	update_reg_attrs(overlay, regs);

	intel_overlay_unmap_regs_atomic(overlay);

	dev_priv->overlay = overlay;
	DRM_INFO("initialized overlay support\n");
	return;

out_free_bo:
	drm_gem_object_unreference(reg_bo);
out_free:
	kfree(overlay);
	return;
}

void intel_cleanup_overlay(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;

	if (dev_priv->overlay) {
		/* The bo's should be free'd by the generic code already.
		 * Furthermore modesetting teardown happens beforehand so the
		 * hardware should be off already */
		BUG_ON(dev_priv->overlay->active);

		kfree(dev_priv->overlay);
	}
}