xref: /linux/include/drm/drm_color_mgmt.h (revision 41c177cf354126a22443b5c80cec9fdd313e67e1)
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 #ifndef __DRM_COLOR_MGMT_H__
24 #define __DRM_COLOR_MGMT_H__
25 
26 #include <linux/ctype.h>
27 #include <linux/math64.h>
28 #include <drm/drm_property.h>
29 
30 struct drm_crtc;
31 struct drm_plane;
32 
33 /**
34  * drm_color_lut_extract - clamp and round LUT entries
35  * @user_input: input value
36  * @bit_precision: number of bits the hw LUT supports
37  *
38  * Extract a degamma/gamma LUT value provided by user (in the form of
39  * &drm_color_lut entries) and round it to the precision supported by the
40  * hardware, following OpenGL int<->float conversion rules
41  * (see eg. OpenGL 4.6 specification - 2.3.5 Fixed-Point Data Conversions).
42  */
drm_color_lut_extract(u32 user_input,int bit_precision)43 static inline u32 drm_color_lut_extract(u32 user_input, int bit_precision)
44 {
45 	if (bit_precision > 16)
46 		return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(user_input, (1 << bit_precision) - 1),
47 					     (1 << 16) - 1);
48 	else
49 		return DIV_ROUND_CLOSEST(user_input * ((1 << bit_precision) - 1),
50 					 (1 << 16) - 1);
51 }
52 
53 u64 drm_color_ctm_s31_32_to_qm_n(u64 user_input, u32 m, u32 n);
54 
55 void drm_crtc_enable_color_mgmt(struct drm_crtc *crtc,
56 				uint degamma_lut_size,
57 				bool has_ctm,
58 				uint gamma_lut_size);
59 
60 int drm_mode_crtc_set_gamma_size(struct drm_crtc *crtc,
61 				 int gamma_size);
62 
63 /**
64  * drm_color_lut_size - calculate the number of entries in the LUT
65  * @blob: blob containing the LUT
66  *
67  * Returns:
68  * The number of entries in the color LUT stored in @blob.
69  */
drm_color_lut_size(const struct drm_property_blob * blob)70 static inline int drm_color_lut_size(const struct drm_property_blob *blob)
71 {
72 	return blob->length / sizeof(struct drm_color_lut);
73 }
74 
75 enum drm_color_encoding {
76 	DRM_COLOR_YCBCR_BT601,
77 	DRM_COLOR_YCBCR_BT709,
78 	DRM_COLOR_YCBCR_BT2020,
79 	DRM_COLOR_ENCODING_MAX,
80 };
81 
82 enum drm_color_range {
83 	DRM_COLOR_YCBCR_LIMITED_RANGE,
84 	DRM_COLOR_YCBCR_FULL_RANGE,
85 	DRM_COLOR_RANGE_MAX,
86 };
87 
88 int drm_plane_create_color_properties(struct drm_plane *plane,
89 				      u32 supported_encodings,
90 				      u32 supported_ranges,
91 				      enum drm_color_encoding default_encoding,
92 				      enum drm_color_range default_range);
93 
94 /**
95  * enum drm_color_lut_tests - hw-specific LUT tests to perform
96  *
97  * The drm_color_lut_check() function takes a bitmask of the values here to
98  * determine which tests to apply to a userspace-provided LUT.
99  */
100 enum drm_color_lut_tests {
101 	/**
102 	 * @DRM_COLOR_LUT_EQUAL_CHANNELS:
103 	 *
104 	 * Checks whether the entries of a LUT all have equal values for the
105 	 * red, green, and blue channels.  Intended for hardware that only
106 	 * accepts a single value per LUT entry and assumes that value applies
107 	 * to all three color components.
108 	 */
109 	DRM_COLOR_LUT_EQUAL_CHANNELS = BIT(0),
110 
111 	/**
112 	 * @DRM_COLOR_LUT_NON_DECREASING:
113 	 *
114 	 * Checks whether the entries of a LUT are always flat or increasing
115 	 * (never decreasing).
116 	 */
117 	DRM_COLOR_LUT_NON_DECREASING = BIT(1),
118 };
119 
120 int drm_color_lut_check(const struct drm_property_blob *lut, u32 tests);
121 #endif
122