2 * Copyright (c) 2016 Intel Corporation
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.
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
24 #include <drm/drm_crtc.h>
25 #include <drm/drm_color_mgmt.h>
27 #include "drm_crtc_internal.h"
32 * Color management or color space adjustments is supported through a set of 5
33 * properties on the &drm_crtc object. They are set up by calling
34 * drm_crtc_enable_color_mgmt().
37 * Blob property to set the degamma lookup table (LUT) mapping pixel data
38 * from the framebuffer before it is given to the transformation matrix.
39 * The data is interpreted as an array of &struct drm_color_lut elements.
40 * Hardware might choose not to use the full precision of the LUT elements
41 * nor use all the elements of the LUT (for example the hardware might
42 * choose to interpolate between LUT[0] and LUT[4]).
44 * Setting this to NULL (blob property value set to 0) means a
45 * linear/pass-thru gamma table should be used. This is generally the
46 * driver boot-up state too.
49 * Unsinged range property to give the size of the lookup table to be set
50 * on the DEGAMMA_LUT property (the size depends on the underlying
51 * hardware). If drivers support multiple LUT sizes then they should
52 * publish the largest size, and sub-sample smaller sized LUTs (e.g. for
53 * split-gamma modes) appropriately.
56 * Blob property to set the current transformation matrix (CTM) apply to
57 * pixel data after the lookup through the degamma LUT and before the
58 * lookup through the gamma LUT. The data is interpreted as a struct
61 * Setting this to NULL (blob property value set to 0) means a
62 * unit/pass-thru matrix should be used. This is generally the driver
66 * Blob property to set the gamma lookup table (LUT) mapping pixel data
67 * after the transformation matrix to data sent to the connector. The
68 * data is interpreted as an array of &struct drm_color_lut elements.
69 * Hardware might choose not to use the full precision of the LUT elements
70 * nor use all the elements of the LUT (for example the hardware might
71 * choose to interpolate between LUT[0] and LUT[4]).
73 * Setting this to NULL (blob property value set to 0) means a
74 * linear/pass-thru gamma table should be used. This is generally the
75 * driver boot-up state too.
78 * Unsigned range property to give the size of the lookup table to be set
79 * on the GAMMA_LUT property (the size depends on the underlying hardware).
80 * If drivers support multiple LUT sizes then they should publish the
81 * largest size, and sub-sample smaller sized LUTs (e.g. for split-gamma
82 * modes) appropriately.
84 * There is also support for a legacy gamma table, which is set up by calling
85 * drm_mode_crtc_set_gamma_size(). Drivers which support both should use
86 * drm_atomic_helper_legacy_gamma_set() to alias the legacy gamma ramp with the
87 * "GAMMA_LUT" property above.
91 * drm_color_lut_extract - clamp&round LUT entries
92 * @user_input: input value
93 * @bit_precision: number of bits the hw LUT supports
95 * Extract a degamma/gamma LUT value provided by user (in the form of
96 * &drm_color_lut entries) and round it to the precision supported by the
99 uint32_t drm_color_lut_extract(uint32_t user_input
, uint32_t bit_precision
)
101 uint32_t val
= user_input
;
102 uint32_t max
= 0xffff >> (16 - bit_precision
);
104 /* Round only if we're not using full precision. */
105 if (bit_precision
< 16) {
106 val
+= 1UL << (16 - bit_precision
- 1);
107 val
>>= 16 - bit_precision
;
110 return clamp_val(val
, 0, max
);
112 EXPORT_SYMBOL(drm_color_lut_extract
);
115 * drm_crtc_enable_color_mgmt - enable color management properties
117 * @degamma_lut_size: the size of the degamma lut (before CSC)
118 * @has_ctm: whether to attach ctm_property for CSC matrix
119 * @gamma_lut_size: the size of the gamma lut (after CSC)
121 * This function lets the driver enable the color correction
122 * properties on a CRTC. This includes 3 degamma, csc and gamma
123 * properties that userspace can set and 2 size properties to inform
124 * the userspace of the lut sizes. Each of the properties are
125 * optional. The gamma and degamma properties are only attached if
126 * their size is not 0 and ctm_property is only attached if has_ctm is
129 void drm_crtc_enable_color_mgmt(struct drm_crtc
*crtc
,
130 uint degamma_lut_size
,
134 struct drm_device
*dev
= crtc
->dev
;
135 struct drm_mode_config
*config
= &dev
->mode_config
;
137 if (degamma_lut_size
) {
138 drm_object_attach_property(&crtc
->base
,
139 config
->degamma_lut_property
, 0);
140 drm_object_attach_property(&crtc
->base
,
141 config
->degamma_lut_size_property
,
146 drm_object_attach_property(&crtc
->base
,
147 config
->ctm_property
, 0);
149 if (gamma_lut_size
) {
150 drm_object_attach_property(&crtc
->base
,
151 config
->gamma_lut_property
, 0);
152 drm_object_attach_property(&crtc
->base
,
153 config
->gamma_lut_size_property
,
157 EXPORT_SYMBOL(drm_crtc_enable_color_mgmt
);
160 * drm_mode_crtc_set_gamma_size - set the gamma table size
161 * @crtc: CRTC to set the gamma table size for
162 * @gamma_size: size of the gamma table
164 * Drivers which support gamma tables should set this to the supported gamma
165 * table size when initializing the CRTC. Currently the drm core only supports a
166 * fixed gamma table size.
169 * Zero on success, negative errno on failure.
171 int drm_mode_crtc_set_gamma_size(struct drm_crtc
*crtc
,
174 uint16_t *r_base
, *g_base
, *b_base
;
177 crtc
->gamma_size
= gamma_size
;
179 crtc
->gamma_store
= kcalloc(gamma_size
, sizeof(uint16_t) * 3,
181 if (!crtc
->gamma_store
) {
182 crtc
->gamma_size
= 0;
186 r_base
= crtc
->gamma_store
;
187 g_base
= r_base
+ gamma_size
;
188 b_base
= g_base
+ gamma_size
;
189 for (i
= 0; i
< gamma_size
; i
++) {
198 EXPORT_SYMBOL(drm_mode_crtc_set_gamma_size
);
201 * drm_mode_gamma_set_ioctl - set the gamma table
204 * @file_priv: DRM file info
206 * Set the gamma table of a CRTC to the one passed in by the user. Userspace can
207 * inquire the required gamma table size through drm_mode_gamma_get_ioctl.
209 * Called by the user via ioctl.
212 * Zero on success, negative errno on failure.
214 int drm_mode_gamma_set_ioctl(struct drm_device
*dev
,
215 void *data
, struct drm_file
*file_priv
)
217 struct drm_mode_crtc_lut
*crtc_lut
= data
;
218 struct drm_crtc
*crtc
;
219 void *r_base
, *g_base
, *b_base
;
223 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
226 drm_modeset_lock_all(dev
);
227 crtc
= drm_crtc_find(dev
, crtc_lut
->crtc_id
);
233 if (crtc
->funcs
->gamma_set
== NULL
) {
238 /* memcpy into gamma store */
239 if (crtc_lut
->gamma_size
!= crtc
->gamma_size
) {
244 size
= crtc_lut
->gamma_size
* (sizeof(uint16_t));
245 r_base
= crtc
->gamma_store
;
246 if (copy_from_user(r_base
, (void __user
*)(unsigned long)crtc_lut
->red
, size
)) {
251 g_base
= r_base
+ size
;
252 if (copy_from_user(g_base
, (void __user
*)(unsigned long)crtc_lut
->green
, size
)) {
257 b_base
= g_base
+ size
;
258 if (copy_from_user(b_base
, (void __user
*)(unsigned long)crtc_lut
->blue
, size
)) {
263 ret
= crtc
->funcs
->gamma_set(crtc
, r_base
, g_base
, b_base
, crtc
->gamma_size
);
266 drm_modeset_unlock_all(dev
);
272 * drm_mode_gamma_get_ioctl - get the gamma table
275 * @file_priv: DRM file info
277 * Copy the current gamma table into the storage provided. This also provides
278 * the gamma table size the driver expects, which can be used to size the
281 * Called by the user via ioctl.
284 * Zero on success, negative errno on failure.
286 int drm_mode_gamma_get_ioctl(struct drm_device
*dev
,
287 void *data
, struct drm_file
*file_priv
)
289 struct drm_mode_crtc_lut
*crtc_lut
= data
;
290 struct drm_crtc
*crtc
;
291 void *r_base
, *g_base
, *b_base
;
295 if (!drm_core_check_feature(dev
, DRIVER_MODESET
))
298 drm_modeset_lock_all(dev
);
299 crtc
= drm_crtc_find(dev
, crtc_lut
->crtc_id
);
305 /* memcpy into gamma store */
306 if (crtc_lut
->gamma_size
!= crtc
->gamma_size
) {
311 size
= crtc_lut
->gamma_size
* (sizeof(uint16_t));
312 r_base
= crtc
->gamma_store
;
313 if (copy_to_user((void __user
*)(unsigned long)crtc_lut
->red
, r_base
, size
)) {
318 g_base
= r_base
+ size
;
319 if (copy_to_user((void __user
*)(unsigned long)crtc_lut
->green
, g_base
, size
)) {
324 b_base
= g_base
+ size
;
325 if (copy_to_user((void __user
*)(unsigned long)crtc_lut
->blue
, b_base
, size
)) {
330 drm_modeset_unlock_all(dev
);