xref: /openbmc/linux/drivers/gpu/drm/i915/gvt/fb_decoder.c (revision ce2fce25)
1 /*
2  * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  *
23  * Authors:
24  *    Kevin Tian <kevin.tian@intel.com>
25  *
26  * Contributors:
27  *    Bing Niu <bing.niu@intel.com>
28  *    Xu Han <xu.han@intel.com>
29  *    Ping Gao <ping.a.gao@intel.com>
30  *    Xiaoguang Chen <xiaoguang.chen@intel.com>
31  *    Yang Liu <yang2.liu@intel.com>
32  *    Tina Zhang <tina.zhang@intel.com>
33  *
34  */
35 
36 #include <uapi/drm/drm_fourcc.h>
37 #include "i915_drv.h"
38 #include "gvt.h"
39 #include "i915_pvinfo.h"
40 #include "i915_reg.h"
41 
42 #define PRIMARY_FORMAT_NUM	16
43 struct pixel_format {
44 	int drm_format;	/* Pixel format in DRM definition */
45 	int bpp; /* Bits per pixel, 0 indicates invalid */
46 	const char *desc; /* The description */
47 };
48 
49 static const struct pixel_format bdw_pixel_formats[] = {
50 	{DRM_FORMAT_C8, 8, "8-bit Indexed"},
51 	{DRM_FORMAT_RGB565, 16, "16-bit BGRX (5:6:5 MSB-R:G:B)"},
52 	{DRM_FORMAT_XRGB8888, 32, "32-bit BGRX (8:8:8:8 MSB-X:R:G:B)"},
53 	{DRM_FORMAT_XBGR2101010, 32, "32-bit RGBX (2:10:10:10 MSB-X:B:G:R)"},
54 
55 	{DRM_FORMAT_XRGB2101010, 32, "32-bit BGRX (2:10:10:10 MSB-X:R:G:B)"},
56 	{DRM_FORMAT_XBGR8888, 32, "32-bit RGBX (8:8:8:8 MSB-X:B:G:R)"},
57 
58 	/* non-supported format has bpp default to 0 */
59 	{0, 0, NULL},
60 };
61 
62 static const struct pixel_format skl_pixel_formats[] = {
63 	{DRM_FORMAT_YUYV, 16, "16-bit packed YUYV (8:8:8:8 MSB-V:Y2:U:Y1)"},
64 	{DRM_FORMAT_UYVY, 16, "16-bit packed UYVY (8:8:8:8 MSB-Y2:V:Y1:U)"},
65 	{DRM_FORMAT_YVYU, 16, "16-bit packed YVYU (8:8:8:8 MSB-U:Y2:V:Y1)"},
66 	{DRM_FORMAT_VYUY, 16, "16-bit packed VYUY (8:8:8:8 MSB-Y2:U:Y1:V)"},
67 
68 	{DRM_FORMAT_C8, 8, "8-bit Indexed"},
69 	{DRM_FORMAT_RGB565, 16, "16-bit BGRX (5:6:5 MSB-R:G:B)"},
70 	{DRM_FORMAT_ABGR8888, 32, "32-bit RGBA (8:8:8:8 MSB-A:B:G:R)"},
71 	{DRM_FORMAT_XBGR8888, 32, "32-bit RGBX (8:8:8:8 MSB-X:B:G:R)"},
72 
73 	{DRM_FORMAT_ARGB8888, 32, "32-bit BGRA (8:8:8:8 MSB-A:R:G:B)"},
74 	{DRM_FORMAT_XRGB8888, 32, "32-bit BGRX (8:8:8:8 MSB-X:R:G:B)"},
75 	{DRM_FORMAT_XBGR2101010, 32, "32-bit RGBX (2:10:10:10 MSB-X:B:G:R)"},
76 	{DRM_FORMAT_XRGB2101010, 32, "32-bit BGRX (2:10:10:10 MSB-X:R:G:B)"},
77 
78 	/* non-supported format has bpp default to 0 */
79 	{0, 0, NULL},
80 };
81 
bdw_format_to_drm(int format)82 static int bdw_format_to_drm(int format)
83 {
84 	int bdw_pixel_formats_index = 6;
85 
86 	switch (format) {
87 	case DISP_FORMAT_8BPP:
88 		bdw_pixel_formats_index = 0;
89 		break;
90 	case DISP_FORMAT_BGRX565:
91 		bdw_pixel_formats_index = 1;
92 		break;
93 	case DISP_FORMAT_BGRX888:
94 		bdw_pixel_formats_index = 2;
95 		break;
96 	case DISP_FORMAT_RGBX101010:
97 		bdw_pixel_formats_index = 3;
98 		break;
99 	case DISP_FORMAT_BGRX101010:
100 		bdw_pixel_formats_index = 4;
101 		break;
102 	case DISP_FORMAT_RGBX888:
103 		bdw_pixel_formats_index = 5;
104 		break;
105 
106 	default:
107 		break;
108 	}
109 
110 	return bdw_pixel_formats_index;
111 }
112 
skl_format_to_drm(int format,bool rgb_order,bool alpha,int yuv_order)113 static int skl_format_to_drm(int format, bool rgb_order, bool alpha,
114 	int yuv_order)
115 {
116 	int skl_pixel_formats_index = 12;
117 
118 	switch (format) {
119 	case PLANE_CTL_FORMAT_INDEXED:
120 		skl_pixel_formats_index = 4;
121 		break;
122 	case PLANE_CTL_FORMAT_RGB_565:
123 		skl_pixel_formats_index = 5;
124 		break;
125 	case PLANE_CTL_FORMAT_XRGB_8888:
126 		if (rgb_order)
127 			skl_pixel_formats_index = alpha ? 6 : 7;
128 		else
129 			skl_pixel_formats_index = alpha ? 8 : 9;
130 		break;
131 	case PLANE_CTL_FORMAT_XRGB_2101010:
132 		skl_pixel_formats_index = rgb_order ? 10 : 11;
133 		break;
134 	case PLANE_CTL_FORMAT_YUV422:
135 		skl_pixel_formats_index = yuv_order >> 16;
136 		if (skl_pixel_formats_index > 3)
137 			return -EINVAL;
138 		break;
139 
140 	default:
141 		break;
142 	}
143 
144 	return skl_pixel_formats_index;
145 }
146 
intel_vgpu_get_stride(struct intel_vgpu * vgpu,int pipe,u32 tiled,int stride_mask,int bpp)147 static u32 intel_vgpu_get_stride(struct intel_vgpu *vgpu, int pipe,
148 	u32 tiled, int stride_mask, int bpp)
149 {
150 	struct drm_i915_private *dev_priv = vgpu->gvt->gt->i915;
151 
152 	u32 stride_reg = vgpu_vreg_t(vgpu, DSPSTRIDE(pipe)) & stride_mask;
153 	u32 stride = stride_reg;
154 
155 	if (GRAPHICS_VER(dev_priv) >= 9) {
156 		switch (tiled) {
157 		case PLANE_CTL_TILED_LINEAR:
158 			stride = stride_reg * 64;
159 			break;
160 		case PLANE_CTL_TILED_X:
161 			stride = stride_reg * 512;
162 			break;
163 		case PLANE_CTL_TILED_Y:
164 			stride = stride_reg * 128;
165 			break;
166 		case PLANE_CTL_TILED_YF:
167 			if (bpp == 8)
168 				stride = stride_reg * 64;
169 			else if (bpp == 16 || bpp == 32 || bpp == 64)
170 				stride = stride_reg * 128;
171 			else
172 				gvt_dbg_core("skl: unsupported bpp:%d\n", bpp);
173 			break;
174 		default:
175 			gvt_dbg_core("skl: unsupported tile format:%x\n",
176 				tiled);
177 		}
178 	}
179 
180 	return stride;
181 }
182 
get_active_pipe(struct intel_vgpu * vgpu)183 static int get_active_pipe(struct intel_vgpu *vgpu)
184 {
185 	int i;
186 
187 	for (i = 0; i < I915_MAX_PIPES; i++)
188 		if (pipe_is_enabled(vgpu, i))
189 			break;
190 
191 	return i;
192 }
193 
194 /**
195  * intel_vgpu_decode_primary_plane - Decode primary plane
196  * @vgpu: input vgpu
197  * @plane: primary plane to save decoded info
198  * This function is called for decoding plane
199  *
200  * Returns:
201  * 0 on success, non-zero if failed.
202  */
intel_vgpu_decode_primary_plane(struct intel_vgpu * vgpu,struct intel_vgpu_primary_plane_format * plane)203 int intel_vgpu_decode_primary_plane(struct intel_vgpu *vgpu,
204 	struct intel_vgpu_primary_plane_format *plane)
205 {
206 	struct drm_i915_private *dev_priv = vgpu->gvt->gt->i915;
207 	u32 val, fmt;
208 	int pipe;
209 
210 	pipe = get_active_pipe(vgpu);
211 	if (pipe >= I915_MAX_PIPES)
212 		return -ENODEV;
213 
214 	val = vgpu_vreg_t(vgpu, DSPCNTR(pipe));
215 	plane->enabled = !!(val & DISP_ENABLE);
216 	if (!plane->enabled)
217 		return -ENODEV;
218 
219 	if (GRAPHICS_VER(dev_priv) >= 9) {
220 		plane->tiled = val & PLANE_CTL_TILED_MASK;
221 		fmt = skl_format_to_drm(
222 			val & PLANE_CTL_FORMAT_MASK_SKL,
223 			val & PLANE_CTL_ORDER_RGBX,
224 			val & PLANE_CTL_ALPHA_MASK,
225 			val & PLANE_CTL_YUV422_ORDER_MASK);
226 
227 		if (fmt >= ARRAY_SIZE(skl_pixel_formats)) {
228 			gvt_vgpu_err("Out-of-bounds pixel format index\n");
229 			return -EINVAL;
230 		}
231 
232 		plane->bpp = skl_pixel_formats[fmt].bpp;
233 		plane->drm_format = skl_pixel_formats[fmt].drm_format;
234 	} else {
235 		plane->tiled = val & DISP_TILED;
236 		fmt = bdw_format_to_drm(val & DISP_FORMAT_MASK);
237 		plane->bpp = bdw_pixel_formats[fmt].bpp;
238 		plane->drm_format = bdw_pixel_formats[fmt].drm_format;
239 	}
240 
241 	if (!plane->bpp) {
242 		gvt_vgpu_err("Non-supported pixel format (0x%x)\n", fmt);
243 		return -EINVAL;
244 	}
245 
246 	plane->hw_format = fmt;
247 
248 	plane->base = vgpu_vreg_t(vgpu, DSPSURF(pipe)) & I915_GTT_PAGE_MASK;
249 	if (!vgpu_gmadr_is_valid(vgpu, plane->base))
250 		return  -EINVAL;
251 
252 	plane->base_gpa = intel_vgpu_gma_to_gpa(vgpu->gtt.ggtt_mm, plane->base);
253 	if (plane->base_gpa == INTEL_GVT_INVALID_ADDR) {
254 		gvt_vgpu_err("Translate primary plane gma 0x%x to gpa fail\n",
255 				plane->base);
256 		return  -EINVAL;
257 	}
258 
259 	plane->stride = intel_vgpu_get_stride(vgpu, pipe, plane->tiled,
260 		(GRAPHICS_VER(dev_priv) >= 9) ?
261 		(_PRI_PLANE_STRIDE_MASK >> 6) :
262 		_PRI_PLANE_STRIDE_MASK, plane->bpp);
263 
264 	plane->width = (vgpu_vreg_t(vgpu, PIPESRC(pipe)) & _PIPE_H_SRCSZ_MASK) >>
265 		_PIPE_H_SRCSZ_SHIFT;
266 	plane->width += 1;
267 	plane->height = (vgpu_vreg_t(vgpu, PIPESRC(pipe)) &
268 			_PIPE_V_SRCSZ_MASK) >> _PIPE_V_SRCSZ_SHIFT;
269 	plane->height += 1;	/* raw height is one minus the real value */
270 
271 	val = vgpu_vreg_t(vgpu, DSPTILEOFF(pipe));
272 	plane->x_offset = (val & _PRI_PLANE_X_OFF_MASK) >>
273 		_PRI_PLANE_X_OFF_SHIFT;
274 	plane->y_offset = (val & _PRI_PLANE_Y_OFF_MASK) >>
275 		_PRI_PLANE_Y_OFF_SHIFT;
276 
277 	return 0;
278 }
279 
280 #define CURSOR_FORMAT_NUM	(1 << 6)
281 struct cursor_mode_format {
282 	int drm_format;	/* Pixel format in DRM definition */
283 	u8 bpp; /* Bits per pixel; 0 indicates invalid */
284 	u32 width; /* In pixel */
285 	u32 height; /* In lines */
286 	const char *desc; /* The description */
287 };
288 
289 static const struct cursor_mode_format cursor_pixel_formats[] = {
290 	{DRM_FORMAT_ARGB8888, 32, 128, 128, "128x128 32bpp ARGB"},
291 	{DRM_FORMAT_ARGB8888, 32, 256, 256, "256x256 32bpp ARGB"},
292 	{DRM_FORMAT_ARGB8888, 32, 64, 64, "64x64 32bpp ARGB"},
293 	{DRM_FORMAT_ARGB8888, 32, 64, 64, "64x64 32bpp ARGB"},
294 
295 	/* non-supported format has bpp default to 0 */
296 	{0, 0, 0, 0, NULL},
297 };
298 
cursor_mode_to_drm(int mode)299 static int cursor_mode_to_drm(int mode)
300 {
301 	int cursor_pixel_formats_index = 4;
302 
303 	switch (mode) {
304 	case MCURSOR_MODE_128_ARGB_AX:
305 		cursor_pixel_formats_index = 0;
306 		break;
307 	case MCURSOR_MODE_256_ARGB_AX:
308 		cursor_pixel_formats_index = 1;
309 		break;
310 	case MCURSOR_MODE_64_ARGB_AX:
311 		cursor_pixel_formats_index = 2;
312 		break;
313 	case MCURSOR_MODE_64_32B_AX:
314 		cursor_pixel_formats_index = 3;
315 		break;
316 
317 	default:
318 		break;
319 	}
320 
321 	return cursor_pixel_formats_index;
322 }
323 
324 /**
325  * intel_vgpu_decode_cursor_plane - Decode sprite plane
326  * @vgpu: input vgpu
327  * @plane: cursor plane to save decoded info
328  * This function is called for decoding plane
329  *
330  * Returns:
331  * 0 on success, non-zero if failed.
332  */
intel_vgpu_decode_cursor_plane(struct intel_vgpu * vgpu,struct intel_vgpu_cursor_plane_format * plane)333 int intel_vgpu_decode_cursor_plane(struct intel_vgpu *vgpu,
334 	struct intel_vgpu_cursor_plane_format *plane)
335 {
336 	struct drm_i915_private *dev_priv = vgpu->gvt->gt->i915;
337 	u32 val, mode, index;
338 	u32 alpha_plane, alpha_force;
339 	int pipe;
340 
341 	pipe = get_active_pipe(vgpu);
342 	if (pipe >= I915_MAX_PIPES)
343 		return -ENODEV;
344 
345 	val = vgpu_vreg_t(vgpu, CURCNTR(pipe));
346 	mode = val & MCURSOR_MODE_MASK;
347 	plane->enabled = (mode != MCURSOR_MODE_DISABLE);
348 	if (!plane->enabled)
349 		return -ENODEV;
350 
351 	index = cursor_mode_to_drm(mode);
352 
353 	if (!cursor_pixel_formats[index].bpp) {
354 		gvt_vgpu_err("Non-supported cursor mode (0x%x)\n", mode);
355 		return -EINVAL;
356 	}
357 	plane->mode = mode;
358 	plane->bpp = cursor_pixel_formats[index].bpp;
359 	plane->drm_format = cursor_pixel_formats[index].drm_format;
360 	plane->width = cursor_pixel_formats[index].width;
361 	plane->height = cursor_pixel_formats[index].height;
362 
363 	alpha_plane = (val & _CURSOR_ALPHA_PLANE_MASK) >>
364 				_CURSOR_ALPHA_PLANE_SHIFT;
365 	alpha_force = (val & _CURSOR_ALPHA_FORCE_MASK) >>
366 				_CURSOR_ALPHA_FORCE_SHIFT;
367 	if (alpha_plane || alpha_force)
368 		gvt_dbg_core("alpha_plane=0x%x, alpha_force=0x%x\n",
369 			alpha_plane, alpha_force);
370 
371 	plane->base = vgpu_vreg_t(vgpu, CURBASE(pipe)) & I915_GTT_PAGE_MASK;
372 	if (!vgpu_gmadr_is_valid(vgpu, plane->base))
373 		return  -EINVAL;
374 
375 	plane->base_gpa = intel_vgpu_gma_to_gpa(vgpu->gtt.ggtt_mm, plane->base);
376 	if (plane->base_gpa == INTEL_GVT_INVALID_ADDR) {
377 		gvt_vgpu_err("Translate cursor plane gma 0x%x to gpa fail\n",
378 				plane->base);
379 		return  -EINVAL;
380 	}
381 
382 	val = vgpu_vreg_t(vgpu, CURPOS(pipe));
383 	plane->x_pos = (val & _CURSOR_POS_X_MASK) >> _CURSOR_POS_X_SHIFT;
384 	plane->x_sign = (val & _CURSOR_SIGN_X_MASK) >> _CURSOR_SIGN_X_SHIFT;
385 	plane->y_pos = (val & _CURSOR_POS_Y_MASK) >> _CURSOR_POS_Y_SHIFT;
386 	plane->y_sign = (val & _CURSOR_SIGN_Y_MASK) >> _CURSOR_SIGN_Y_SHIFT;
387 
388 	plane->x_hot = vgpu_vreg_t(vgpu, vgtif_reg(cursor_x_hot));
389 	plane->y_hot = vgpu_vreg_t(vgpu, vgtif_reg(cursor_y_hot));
390 	return 0;
391 }
392 
393 #define SPRITE_FORMAT_NUM	(1 << 3)
394 
395 static const struct pixel_format sprite_pixel_formats[SPRITE_FORMAT_NUM] = {
396 	[0x0] = {DRM_FORMAT_YUV422, 16, "YUV 16-bit 4:2:2 packed"},
397 	[0x1] = {DRM_FORMAT_XRGB2101010, 32, "RGB 32-bit 2:10:10:10"},
398 	[0x2] = {DRM_FORMAT_XRGB8888, 32, "RGB 32-bit 8:8:8:8"},
399 	[0x4] = {DRM_FORMAT_AYUV, 32,
400 		"YUV 32-bit 4:4:4 packed (8:8:8:8 MSB-X:Y:U:V)"},
401 };
402 
403 /**
404  * intel_vgpu_decode_sprite_plane - Decode sprite plane
405  * @vgpu: input vgpu
406  * @plane: sprite plane to save decoded info
407  * This function is called for decoding plane
408  *
409  * Returns:
410  * 0 on success, non-zero if failed.
411  */
intel_vgpu_decode_sprite_plane(struct intel_vgpu * vgpu,struct intel_vgpu_sprite_plane_format * plane)412 int intel_vgpu_decode_sprite_plane(struct intel_vgpu *vgpu,
413 	struct intel_vgpu_sprite_plane_format *plane)
414 {
415 	u32 val, fmt;
416 	u32 color_order, yuv_order;
417 	int drm_format;
418 	int pipe;
419 
420 	pipe = get_active_pipe(vgpu);
421 	if (pipe >= I915_MAX_PIPES)
422 		return -ENODEV;
423 
424 	val = vgpu_vreg_t(vgpu, SPRCTL(pipe));
425 	plane->enabled = !!(val & SPRITE_ENABLE);
426 	if (!plane->enabled)
427 		return -ENODEV;
428 
429 	plane->tiled = !!(val & SPRITE_TILED);
430 	color_order = !!(val & SPRITE_RGB_ORDER_RGBX);
431 	yuv_order = (val & SPRITE_YUV_ORDER_MASK) >>
432 				_SPRITE_YUV_ORDER_SHIFT;
433 
434 	fmt = (val & SPRITE_FORMAT_MASK) >> _SPRITE_FMT_SHIFT;
435 	if (!sprite_pixel_formats[fmt].bpp) {
436 		gvt_vgpu_err("Non-supported pixel format (0x%x)\n", fmt);
437 		return -EINVAL;
438 	}
439 	plane->hw_format = fmt;
440 	plane->bpp = sprite_pixel_formats[fmt].bpp;
441 	drm_format = sprite_pixel_formats[fmt].drm_format;
442 
443 	/* Order of RGB values in an RGBxxx buffer may be ordered RGB or
444 	 * BGR depending on the state of the color_order field
445 	 */
446 	if (!color_order) {
447 		if (drm_format == DRM_FORMAT_XRGB2101010)
448 			drm_format = DRM_FORMAT_XBGR2101010;
449 		else if (drm_format == DRM_FORMAT_XRGB8888)
450 			drm_format = DRM_FORMAT_XBGR8888;
451 	}
452 
453 	if (drm_format == DRM_FORMAT_YUV422) {
454 		switch (yuv_order) {
455 		case 0:
456 			drm_format = DRM_FORMAT_YUYV;
457 			break;
458 		case 1:
459 			drm_format = DRM_FORMAT_UYVY;
460 			break;
461 		case 2:
462 			drm_format = DRM_FORMAT_YVYU;
463 			break;
464 		case 3:
465 			drm_format = DRM_FORMAT_VYUY;
466 			break;
467 		default:
468 			/* yuv_order has only 2 bits */
469 			break;
470 		}
471 	}
472 
473 	plane->drm_format = drm_format;
474 
475 	plane->base = vgpu_vreg_t(vgpu, SPRSURF(pipe)) & I915_GTT_PAGE_MASK;
476 	if (!vgpu_gmadr_is_valid(vgpu, plane->base))
477 		return  -EINVAL;
478 
479 	plane->base_gpa = intel_vgpu_gma_to_gpa(vgpu->gtt.ggtt_mm, plane->base);
480 	if (plane->base_gpa == INTEL_GVT_INVALID_ADDR) {
481 		gvt_vgpu_err("Translate sprite plane gma 0x%x to gpa fail\n",
482 				plane->base);
483 		return  -EINVAL;
484 	}
485 
486 	plane->stride = vgpu_vreg_t(vgpu, SPRSTRIDE(pipe)) &
487 				_SPRITE_STRIDE_MASK;
488 
489 	val = vgpu_vreg_t(vgpu, SPRSIZE(pipe));
490 	plane->height = (val & _SPRITE_SIZE_HEIGHT_MASK) >>
491 		_SPRITE_SIZE_HEIGHT_SHIFT;
492 	plane->width = (val & _SPRITE_SIZE_WIDTH_MASK) >>
493 		_SPRITE_SIZE_WIDTH_SHIFT;
494 	plane->height += 1;	/* raw height is one minus the real value */
495 	plane->width += 1;	/* raw width is one minus the real value */
496 
497 	val = vgpu_vreg_t(vgpu, SPRPOS(pipe));
498 	plane->x_pos = (val & _SPRITE_POS_X_MASK) >> _SPRITE_POS_X_SHIFT;
499 	plane->y_pos = (val & _SPRITE_POS_Y_MASK) >> _SPRITE_POS_Y_SHIFT;
500 
501 	val = vgpu_vreg_t(vgpu, SPROFFSET(pipe));
502 	plane->x_offset = (val & _SPRITE_OFFSET_START_X_MASK) >>
503 			   _SPRITE_OFFSET_START_X_SHIFT;
504 	plane->y_offset = (val & _SPRITE_OFFSET_START_Y_MASK) >>
505 			   _SPRITE_OFFSET_START_Y_SHIFT;
506 
507 	return 0;
508 }
509