xref: /openbmc/linux/drivers/gpu/drm/drm_color_mgmt.c (revision 37c7c23a)
1 /*
2  * Copyright (c) 2016 Intel Corporation
3  *
4  * Permission to use, copy, modify, distribute, and sell this software and its
5  * documentation for any purpose is hereby granted without fee, provided that
6  * the above copyright notice appear in all copies and that both that copyright
7  * notice and this permission notice appear in supporting documentation, and
8  * that the name of the copyright holders not be used in advertising or
9  * publicity pertaining to distribution of the software without specific,
10  * written prior permission.  The copyright holders make no representations
11  * about the suitability of this software for any purpose.  It is provided "as
12  * is" without express or implied warranty.
13  *
14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20  * OF THIS SOFTWARE.
21  */
22 
23 #include <linux/uaccess.h>
24 
25 #include <drm/drm_atomic.h>
26 #include <drm/drm_color_mgmt.h>
27 #include <drm/drm_crtc.h>
28 #include <drm/drm_device.h>
29 #include <drm/drm_drv.h>
30 #include <drm/drm_print.h>
31 
32 #include "drm_crtc_internal.h"
33 
34 /**
35  * DOC: overview
36  *
37  * Color management or color space adjustments is supported through a set of 5
38  * properties on the &drm_crtc object. They are set up by calling
39  * drm_crtc_enable_color_mgmt().
40  *
41  * "DEGAMMA_LUT”:
42  *	Blob property to set the degamma lookup table (LUT) mapping pixel data
43  *	from the framebuffer before it is given to the transformation matrix.
44  *	The data is interpreted as an array of &struct drm_color_lut elements.
45  *	Hardware might choose not to use the full precision of the LUT elements
46  *	nor use all the elements of the LUT (for example the hardware might
47  *	choose to interpolate between LUT[0] and LUT[4]).
48  *
49  *	Setting this to NULL (blob property value set to 0) means a
50  *	linear/pass-thru gamma table should be used. This is generally the
51  *	driver boot-up state too. Drivers can access this blob through
52  *	&drm_crtc_state.degamma_lut.
53  *
54  * “DEGAMMA_LUT_SIZE”:
55  *	Unsinged range property to give the size of the lookup table to be set
56  *	on the DEGAMMA_LUT property (the size depends on the underlying
57  *	hardware). If drivers support multiple LUT sizes then they should
58  *	publish the largest size, and sub-sample smaller sized LUTs (e.g. for
59  *	split-gamma modes) appropriately.
60  *
61  * “CTM”:
62  *	Blob property to set the current transformation matrix (CTM) apply to
63  *	pixel data after the lookup through the degamma LUT and before the
64  *	lookup through the gamma LUT. The data is interpreted as a struct
65  *	&drm_color_ctm.
66  *
67  *	Setting this to NULL (blob property value set to 0) means a
68  *	unit/pass-thru matrix should be used. This is generally the driver
69  *	boot-up state too. Drivers can access the blob for the color conversion
70  *	matrix through &drm_crtc_state.ctm.
71  *
72  * “GAMMA_LUT”:
73  *	Blob property to set the gamma lookup table (LUT) mapping pixel data
74  *	after the transformation matrix to data sent to the connector. The
75  *	data is interpreted as an array of &struct drm_color_lut elements.
76  *	Hardware might choose not to use the full precision of the LUT elements
77  *	nor use all the elements of the LUT (for example the hardware might
78  *	choose to interpolate between LUT[0] and LUT[4]).
79  *
80  *	Setting this to NULL (blob property value set to 0) means a
81  *	linear/pass-thru gamma table should be used. This is generally the
82  *	driver boot-up state too. Drivers can access this blob through
83  *	&drm_crtc_state.gamma_lut.
84  *
85  *	Note that for mostly historical reasons stemming from Xorg heritage,
86  *	this is also used to store the color map (also sometimes color lut, CLUT
87  *	or color palette) for indexed formats like DRM_FORMAT_C8.
88  *
89  * “GAMMA_LUT_SIZE”:
90  *	Unsigned range property to give the size of the lookup table to be set
91  *	on the GAMMA_LUT property (the size depends on the underlying hardware).
92  *	If drivers support multiple LUT sizes then they should publish the
93  *	largest size, and sub-sample smaller sized LUTs (e.g. for split-gamma
94  *	modes) appropriately.
95  *
96  * There is also support for a legacy gamma table, which is set up by calling
97  * drm_mode_crtc_set_gamma_size(). The DRM core will then alias the legacy gamma
98  * ramp with "GAMMA_LUT" or, if that is unavailable, "DEGAMMA_LUT".
99  *
100  * Support for different non RGB color encodings is controlled through
101  * &drm_plane specific COLOR_ENCODING and COLOR_RANGE properties. They
102  * are set up by calling drm_plane_create_color_properties().
103  *
104  * "COLOR_ENCODING":
105  * 	Optional plane enum property to support different non RGB
106  * 	color encodings. The driver can provide a subset of standard
107  * 	enum values supported by the DRM plane.
108  *
109  * "COLOR_RANGE":
110  * 	Optional plane enum property to support different non RGB
111  * 	color parameter ranges. The driver can provide a subset of
112  * 	standard enum values supported by the DRM plane.
113  */
114 
115 /**
116  * drm_color_ctm_s31_32_to_qm_n
117  *
118  * @user_input: input value
119  * @m: number of integer bits, only support m <= 32, include the sign-bit
120  * @n: number of fractional bits, only support n <= 32
121  *
122  * Convert and clamp S31.32 sign-magnitude to Qm.n (signed 2's complement).
123  * The sign-bit BIT(m+n-1) and above are 0 for positive value and 1 for negative
124  * the range of value is [-2^(m-1), 2^(m-1) - 2^-n]
125  *
126  * For example
127  * A Q3.12 format number:
128  * - required bit: 3 + 12 = 15bits
129  * - range: [-2^2, 2^2 - 2^−15]
130  *
131  * NOTE: the m can be zero if all bit_precision are used to present fractional
132  *       bits like Q0.32
133  */
drm_color_ctm_s31_32_to_qm_n(u64 user_input,u32 m,u32 n)134 u64 drm_color_ctm_s31_32_to_qm_n(u64 user_input, u32 m, u32 n)
135 {
136 	u64 mag = (user_input & ~BIT_ULL(63)) >> (32 - n);
137 	bool negative = !!(user_input & BIT_ULL(63));
138 	s64 val;
139 
140 	WARN_ON(m > 32 || n > 32);
141 
142 	val = clamp_val(mag, 0, negative ?
143 				BIT_ULL(n + m - 1) : BIT_ULL(n + m - 1) - 1);
144 
145 	return negative ? -val : val;
146 }
147 EXPORT_SYMBOL(drm_color_ctm_s31_32_to_qm_n);
148 
149 /**
150  * drm_crtc_enable_color_mgmt - enable color management properties
151  * @crtc: DRM CRTC
152  * @degamma_lut_size: the size of the degamma lut (before CSC)
153  * @has_ctm: whether to attach ctm_property for CSC matrix
154  * @gamma_lut_size: the size of the gamma lut (after CSC)
155  *
156  * This function lets the driver enable the color correction
157  * properties on a CRTC. This includes 3 degamma, csc and gamma
158  * properties that userspace can set and 2 size properties to inform
159  * the userspace of the lut sizes. Each of the properties are
160  * optional. The gamma and degamma properties are only attached if
161  * their size is not 0 and ctm_property is only attached if has_ctm is
162  * true.
163  */
drm_crtc_enable_color_mgmt(struct drm_crtc * crtc,uint degamma_lut_size,bool has_ctm,uint gamma_lut_size)164 void drm_crtc_enable_color_mgmt(struct drm_crtc *crtc,
165 				uint degamma_lut_size,
166 				bool has_ctm,
167 				uint gamma_lut_size)
168 {
169 	struct drm_device *dev = crtc->dev;
170 	struct drm_mode_config *config = &dev->mode_config;
171 
172 	if (degamma_lut_size) {
173 		drm_object_attach_property(&crtc->base,
174 					   config->degamma_lut_property, 0);
175 		drm_object_attach_property(&crtc->base,
176 					   config->degamma_lut_size_property,
177 					   degamma_lut_size);
178 	}
179 
180 	if (has_ctm)
181 		drm_object_attach_property(&crtc->base,
182 					   config->ctm_property, 0);
183 
184 	if (gamma_lut_size) {
185 		drm_object_attach_property(&crtc->base,
186 					   config->gamma_lut_property, 0);
187 		drm_object_attach_property(&crtc->base,
188 					   config->gamma_lut_size_property,
189 					   gamma_lut_size);
190 	}
191 }
192 EXPORT_SYMBOL(drm_crtc_enable_color_mgmt);
193 
194 /**
195  * drm_mode_crtc_set_gamma_size - set the gamma table size
196  * @crtc: CRTC to set the gamma table size for
197  * @gamma_size: size of the gamma table
198  *
199  * Drivers which support gamma tables should set this to the supported gamma
200  * table size when initializing the CRTC. Currently the drm core only supports a
201  * fixed gamma table size.
202  *
203  * Returns:
204  * Zero on success, negative errno on failure.
205  */
drm_mode_crtc_set_gamma_size(struct drm_crtc * crtc,int gamma_size)206 int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
207 				 int gamma_size)
208 {
209 	uint16_t *r_base, *g_base, *b_base;
210 	int i;
211 
212 	crtc->gamma_size = gamma_size;
213 
214 	crtc->gamma_store = kcalloc(gamma_size, sizeof(uint16_t) * 3,
215 				    GFP_KERNEL);
216 	if (!crtc->gamma_store) {
217 		crtc->gamma_size = 0;
218 		return -ENOMEM;
219 	}
220 
221 	r_base = crtc->gamma_store;
222 	g_base = r_base + gamma_size;
223 	b_base = g_base + gamma_size;
224 	for (i = 0; i < gamma_size; i++) {
225 		r_base[i] = i << 8;
226 		g_base[i] = i << 8;
227 		b_base[i] = i << 8;
228 	}
229 
230 
231 	return 0;
232 }
233 EXPORT_SYMBOL(drm_mode_crtc_set_gamma_size);
234 
235 /**
236  * drm_crtc_supports_legacy_gamma - does the crtc support legacy gamma correction table
237  * @crtc: CRTC object
238  *
239  * Returns true/false if the given crtc supports setting the legacy gamma
240  * correction table.
241  */
drm_crtc_supports_legacy_gamma(struct drm_crtc * crtc)242 static bool drm_crtc_supports_legacy_gamma(struct drm_crtc *crtc)
243 {
244 	u32 gamma_id = crtc->dev->mode_config.gamma_lut_property->base.id;
245 	u32 degamma_id = crtc->dev->mode_config.degamma_lut_property->base.id;
246 
247 	if (!crtc->gamma_size)
248 		return false;
249 
250 	if (crtc->funcs->gamma_set)
251 		return true;
252 
253 	return !!(drm_mode_obj_find_prop_id(&crtc->base, gamma_id) ||
254 		  drm_mode_obj_find_prop_id(&crtc->base, degamma_id));
255 }
256 
257 /**
258  * drm_crtc_legacy_gamma_set - set the legacy gamma correction table
259  * @crtc: CRTC object
260  * @red: red correction table
261  * @green: green correction table
262  * @blue: blue correction table
263  * @size: size of the tables
264  * @ctx: lock acquire context
265  *
266  * Implements support for legacy gamma correction table for drivers
267  * that have set drm_crtc_funcs.gamma_set or that support color management
268  * through the DEGAMMA_LUT/GAMMA_LUT properties. See
269  * drm_crtc_enable_color_mgmt() and the containing chapter for
270  * how the atomic color management and gamma tables work.
271  *
272  * This function sets the gamma using drm_crtc_funcs.gamma_set if set, or
273  * alternatively using crtc color management properties.
274  */
drm_crtc_legacy_gamma_set(struct drm_crtc * crtc,u16 * red,u16 * green,u16 * blue,u32 size,struct drm_modeset_acquire_ctx * ctx)275 static int drm_crtc_legacy_gamma_set(struct drm_crtc *crtc,
276 				     u16 *red, u16 *green, u16 *blue,
277 				     u32 size,
278 				     struct drm_modeset_acquire_ctx *ctx)
279 {
280 	struct drm_device *dev = crtc->dev;
281 	struct drm_atomic_state *state;
282 	struct drm_crtc_state *crtc_state;
283 	struct drm_property_blob *blob;
284 	struct drm_color_lut *blob_data;
285 	u32 gamma_id = dev->mode_config.gamma_lut_property->base.id;
286 	u32 degamma_id = dev->mode_config.degamma_lut_property->base.id;
287 	bool use_gamma_lut;
288 	int i, ret = 0;
289 	bool replaced;
290 
291 	if (crtc->funcs->gamma_set)
292 		return crtc->funcs->gamma_set(crtc, red, green, blue, size, ctx);
293 
294 	if (drm_mode_obj_find_prop_id(&crtc->base, gamma_id))
295 		use_gamma_lut = true;
296 	else if (drm_mode_obj_find_prop_id(&crtc->base, degamma_id))
297 		use_gamma_lut = false;
298 	else
299 		return -ENODEV;
300 
301 	state = drm_atomic_state_alloc(crtc->dev);
302 	if (!state)
303 		return -ENOMEM;
304 
305 	blob = drm_property_create_blob(dev,
306 					sizeof(struct drm_color_lut) * size,
307 					NULL);
308 	if (IS_ERR(blob)) {
309 		ret = PTR_ERR(blob);
310 		blob = NULL;
311 		goto fail;
312 	}
313 
314 	/* Prepare GAMMA_LUT with the legacy values. */
315 	blob_data = blob->data;
316 	for (i = 0; i < size; i++) {
317 		blob_data[i].red = red[i];
318 		blob_data[i].green = green[i];
319 		blob_data[i].blue = blue[i];
320 	}
321 
322 	state->acquire_ctx = ctx;
323 	crtc_state = drm_atomic_get_crtc_state(state, crtc);
324 	if (IS_ERR(crtc_state)) {
325 		ret = PTR_ERR(crtc_state);
326 		goto fail;
327 	}
328 
329 	/* Set GAMMA_LUT and reset DEGAMMA_LUT and CTM */
330 	replaced = drm_property_replace_blob(&crtc_state->degamma_lut,
331 					     use_gamma_lut ? NULL : blob);
332 	replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
333 	replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
334 					      use_gamma_lut ? blob : NULL);
335 	crtc_state->color_mgmt_changed |= replaced;
336 
337 	ret = drm_atomic_commit(state);
338 
339 fail:
340 	drm_atomic_state_put(state);
341 	drm_property_blob_put(blob);
342 	return ret;
343 }
344 
345 /**
346  * drm_mode_gamma_set_ioctl - set the gamma table
347  * @dev: DRM device
348  * @data: ioctl data
349  * @file_priv: DRM file info
350  *
351  * Set the gamma table of a CRTC to the one passed in by the user. Userspace can
352  * inquire the required gamma table size through drm_mode_gamma_get_ioctl.
353  *
354  * Called by the user via ioctl.
355  *
356  * Returns:
357  * Zero on success, negative errno on failure.
358  */
drm_mode_gamma_set_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)359 int drm_mode_gamma_set_ioctl(struct drm_device *dev,
360 			     void *data, struct drm_file *file_priv)
361 {
362 	struct drm_mode_crtc_lut *crtc_lut = data;
363 	struct drm_crtc *crtc;
364 	void *r_base, *g_base, *b_base;
365 	int size;
366 	struct drm_modeset_acquire_ctx ctx;
367 	int ret = 0;
368 
369 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
370 		return -EOPNOTSUPP;
371 
372 	crtc = drm_crtc_find(dev, file_priv, crtc_lut->crtc_id);
373 	if (!crtc)
374 		return -ENOENT;
375 
376 	if (!drm_crtc_supports_legacy_gamma(crtc))
377 		return -ENOSYS;
378 
379 	/* memcpy into gamma store */
380 	if (crtc_lut->gamma_size != crtc->gamma_size)
381 		return -EINVAL;
382 
383 	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, ret);
384 
385 	size = crtc_lut->gamma_size * (sizeof(uint16_t));
386 	r_base = crtc->gamma_store;
387 	if (copy_from_user(r_base, (void __user *)(unsigned long)crtc_lut->red, size)) {
388 		ret = -EFAULT;
389 		goto out;
390 	}
391 
392 	g_base = r_base + size;
393 	if (copy_from_user(g_base, (void __user *)(unsigned long)crtc_lut->green, size)) {
394 		ret = -EFAULT;
395 		goto out;
396 	}
397 
398 	b_base = g_base + size;
399 	if (copy_from_user(b_base, (void __user *)(unsigned long)crtc_lut->blue, size)) {
400 		ret = -EFAULT;
401 		goto out;
402 	}
403 
404 	ret = drm_crtc_legacy_gamma_set(crtc, r_base, g_base, b_base,
405 					crtc->gamma_size, &ctx);
406 
407 out:
408 	DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);
409 	return ret;
410 
411 }
412 
413 /**
414  * drm_mode_gamma_get_ioctl - get the gamma table
415  * @dev: DRM device
416  * @data: ioctl data
417  * @file_priv: DRM file info
418  *
419  * Copy the current gamma table into the storage provided. This also provides
420  * the gamma table size the driver expects, which can be used to size the
421  * allocated storage.
422  *
423  * Called by the user via ioctl.
424  *
425  * Returns:
426  * Zero on success, negative errno on failure.
427  */
drm_mode_gamma_get_ioctl(struct drm_device * dev,void * data,struct drm_file * file_priv)428 int drm_mode_gamma_get_ioctl(struct drm_device *dev,
429 			     void *data, struct drm_file *file_priv)
430 {
431 	struct drm_mode_crtc_lut *crtc_lut = data;
432 	struct drm_crtc *crtc;
433 	void *r_base, *g_base, *b_base;
434 	int size;
435 	int ret = 0;
436 
437 	if (!drm_core_check_feature(dev, DRIVER_MODESET))
438 		return -EOPNOTSUPP;
439 
440 	crtc = drm_crtc_find(dev, file_priv, crtc_lut->crtc_id);
441 	if (!crtc)
442 		return -ENOENT;
443 
444 	/* memcpy into gamma store */
445 	if (crtc_lut->gamma_size != crtc->gamma_size)
446 		return -EINVAL;
447 
448 	drm_modeset_lock(&crtc->mutex, NULL);
449 	size = crtc_lut->gamma_size * (sizeof(uint16_t));
450 	r_base = crtc->gamma_store;
451 	if (copy_to_user((void __user *)(unsigned long)crtc_lut->red, r_base, size)) {
452 		ret = -EFAULT;
453 		goto out;
454 	}
455 
456 	g_base = r_base + size;
457 	if (copy_to_user((void __user *)(unsigned long)crtc_lut->green, g_base, size)) {
458 		ret = -EFAULT;
459 		goto out;
460 	}
461 
462 	b_base = g_base + size;
463 	if (copy_to_user((void __user *)(unsigned long)crtc_lut->blue, b_base, size)) {
464 		ret = -EFAULT;
465 		goto out;
466 	}
467 out:
468 	drm_modeset_unlock(&crtc->mutex);
469 	return ret;
470 }
471 
472 static const char * const color_encoding_name[] = {
473 	[DRM_COLOR_YCBCR_BT601] = "ITU-R BT.601 YCbCr",
474 	[DRM_COLOR_YCBCR_BT709] = "ITU-R BT.709 YCbCr",
475 	[DRM_COLOR_YCBCR_BT2020] = "ITU-R BT.2020 YCbCr",
476 };
477 
478 static const char * const color_range_name[] = {
479 	[DRM_COLOR_YCBCR_FULL_RANGE] = "YCbCr full range",
480 	[DRM_COLOR_YCBCR_LIMITED_RANGE] = "YCbCr limited range",
481 };
482 
483 /**
484  * drm_get_color_encoding_name - return a string for color encoding
485  * @encoding: color encoding to compute name of
486  *
487  * In contrast to the other drm_get_*_name functions this one here returns a
488  * const pointer and hence is threadsafe.
489  */
drm_get_color_encoding_name(enum drm_color_encoding encoding)490 const char *drm_get_color_encoding_name(enum drm_color_encoding encoding)
491 {
492 	if (WARN_ON(encoding >= ARRAY_SIZE(color_encoding_name)))
493 		return "unknown";
494 
495 	return color_encoding_name[encoding];
496 }
497 
498 /**
499  * drm_get_color_range_name - return a string for color range
500  * @range: color range to compute name of
501  *
502  * In contrast to the other drm_get_*_name functions this one here returns a
503  * const pointer and hence is threadsafe.
504  */
drm_get_color_range_name(enum drm_color_range range)505 const char *drm_get_color_range_name(enum drm_color_range range)
506 {
507 	if (WARN_ON(range >= ARRAY_SIZE(color_range_name)))
508 		return "unknown";
509 
510 	return color_range_name[range];
511 }
512 
513 /**
514  * drm_plane_create_color_properties - color encoding related plane properties
515  * @plane: plane object
516  * @supported_encodings: bitfield indicating supported color encodings
517  * @supported_ranges: bitfileld indicating supported color ranges
518  * @default_encoding: default color encoding
519  * @default_range: default color range
520  *
521  * Create and attach plane specific COLOR_ENCODING and COLOR_RANGE
522  * properties to @plane. The supported encodings and ranges should
523  * be provided in supported_encodings and supported_ranges bitmasks.
524  * Each bit set in the bitmask indicates that its number as enum
525  * value is supported.
526  */
drm_plane_create_color_properties(struct drm_plane * plane,u32 supported_encodings,u32 supported_ranges,enum drm_color_encoding default_encoding,enum drm_color_range default_range)527 int drm_plane_create_color_properties(struct drm_plane *plane,
528 				      u32 supported_encodings,
529 				      u32 supported_ranges,
530 				      enum drm_color_encoding default_encoding,
531 				      enum drm_color_range default_range)
532 {
533 	struct drm_device *dev = plane->dev;
534 	struct drm_property *prop;
535 	struct drm_prop_enum_list enum_list[max_t(int, DRM_COLOR_ENCODING_MAX,
536 						       DRM_COLOR_RANGE_MAX)];
537 	int i, len;
538 
539 	if (WARN_ON(supported_encodings == 0 ||
540 		    (supported_encodings & -BIT(DRM_COLOR_ENCODING_MAX)) != 0 ||
541 		    (supported_encodings & BIT(default_encoding)) == 0))
542 		return -EINVAL;
543 
544 	if (WARN_ON(supported_ranges == 0 ||
545 		    (supported_ranges & -BIT(DRM_COLOR_RANGE_MAX)) != 0 ||
546 		    (supported_ranges & BIT(default_range)) == 0))
547 		return -EINVAL;
548 
549 	len = 0;
550 	for (i = 0; i < DRM_COLOR_ENCODING_MAX; i++) {
551 		if ((supported_encodings & BIT(i)) == 0)
552 			continue;
553 
554 		enum_list[len].type = i;
555 		enum_list[len].name = color_encoding_name[i];
556 		len++;
557 	}
558 
559 	prop = drm_property_create_enum(dev, 0, "COLOR_ENCODING",
560 					enum_list, len);
561 	if (!prop)
562 		return -ENOMEM;
563 	plane->color_encoding_property = prop;
564 	drm_object_attach_property(&plane->base, prop, default_encoding);
565 	if (plane->state)
566 		plane->state->color_encoding = default_encoding;
567 
568 	len = 0;
569 	for (i = 0; i < DRM_COLOR_RANGE_MAX; i++) {
570 		if ((supported_ranges & BIT(i)) == 0)
571 			continue;
572 
573 		enum_list[len].type = i;
574 		enum_list[len].name = color_range_name[i];
575 		len++;
576 	}
577 
578 	prop = drm_property_create_enum(dev, 0, "COLOR_RANGE",
579 					enum_list, len);
580 	if (!prop)
581 		return -ENOMEM;
582 	plane->color_range_property = prop;
583 	drm_object_attach_property(&plane->base, prop, default_range);
584 	if (plane->state)
585 		plane->state->color_range = default_range;
586 
587 	return 0;
588 }
589 EXPORT_SYMBOL(drm_plane_create_color_properties);
590 
591 /**
592  * drm_color_lut_check - check validity of lookup table
593  * @lut: property blob containing LUT to check
594  * @tests: bitmask of tests to run
595  *
596  * Helper to check whether a userspace-provided lookup table is valid and
597  * satisfies hardware requirements.  Drivers pass a bitmask indicating which of
598  * the tests in &drm_color_lut_tests should be performed.
599  *
600  * Returns 0 on success, -EINVAL on failure.
601  */
drm_color_lut_check(const struct drm_property_blob * lut,u32 tests)602 int drm_color_lut_check(const struct drm_property_blob *lut, u32 tests)
603 {
604 	const struct drm_color_lut *entry;
605 	int i;
606 
607 	if (!lut || !tests)
608 		return 0;
609 
610 	entry = lut->data;
611 	for (i = 0; i < drm_color_lut_size(lut); i++) {
612 		if (tests & DRM_COLOR_LUT_EQUAL_CHANNELS) {
613 			if (entry[i].red != entry[i].blue ||
614 			    entry[i].red != entry[i].green) {
615 				DRM_DEBUG_KMS("All LUT entries must have equal r/g/b\n");
616 				return -EINVAL;
617 			}
618 		}
619 
620 		if (i > 0 && tests & DRM_COLOR_LUT_NON_DECREASING) {
621 			if (entry[i].red < entry[i - 1].red ||
622 			    entry[i].green < entry[i - 1].green ||
623 			    entry[i].blue < entry[i - 1].blue) {
624 				DRM_DEBUG_KMS("LUT entries must never decrease.\n");
625 				return -EINVAL;
626 			}
627 		}
628 	}
629 
630 	return 0;
631 }
632 EXPORT_SYMBOL(drm_color_lut_check);
633