xref: /openbmc/linux/include/drm/drm_property.h (revision 5086ea4b)
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_PROPERTY_H__
24 #define __DRM_PROPERTY_H__
25 
26 #include <linux/list.h>
27 #include <linux/ctype.h>
28 #include <drm/drm_mode_object.h>
29 
30 #include <uapi/drm/drm_mode.h>
31 
32 /**
33  * struct drm_property_enum - symbolic values for enumerations
34  * @value: numeric property value for this enum entry
35  * @head: list of enum values, linked to &drm_property.enum_list
36  * @name: symbolic name for the enum
37  *
38  * For enumeration and bitmask properties this structure stores the symbolic
39  * decoding for each value. This is used for example for the rotation property.
40  */
41 struct drm_property_enum {
42 	uint64_t value;
43 	struct list_head head;
44 	char name[DRM_PROP_NAME_LEN];
45 };
46 
47 /**
48  * struct drm_property - modeset object property
49  *
50  * This structure represent a modeset object property. It combines both the name
51  * of the property with the set of permissible values. This means that when a
52  * driver wants to use a property with the same name on different objects, but
53  * with different value ranges, then it must create property for each one. An
54  * example would be rotation of &drm_plane, when e.g. the primary plane cannot
55  * be rotated. But if both the name and the value range match, then the same
56  * property structure can be instantiated multiple times for the same object.
57  * Userspace must be able to cope with this and cannot assume that the same
58  * symbolic property will have the same modeset object ID on all modeset
59  * objects.
60  *
61  * Properties are created by one of the special functions, as explained in
62  * detail in the @flags structure member.
63  *
64  * To actually expose a property it must be attached to each object using
65  * drm_object_attach_property(). Currently properties can only be attached to
66  * &drm_connector, &drm_crtc and &drm_plane.
67  *
68  * Properties are also used as the generic metadatatransport for the atomic
69  * IOCTL. Everything that was set directly in structures in the legacy modeset
70  * IOCTLs (like the plane source or destination windows, or e.g. the links to
71  * the CRTC) is exposed as a property with the DRM_MODE_PROP_ATOMIC flag set.
72  */
73 struct drm_property {
74 	/**
75 	 * @head: per-device list of properties, for cleanup.
76 	 */
77 	struct list_head head;
78 
79 	/**
80 	 * @base: base KMS object
81 	 */
82 	struct drm_mode_object base;
83 
84 	/**
85 	 * @flags:
86 	 *
87 	 * Property flags and type. A property needs to be one of the following
88 	 * types:
89 	 *
90 	 * DRM_MODE_PROP_RANGE
91 	 *     Range properties report their minimum and maximum admissible unsigned values.
92 	 *     The KMS core verifies that values set by application fit in that
93 	 *     range. The range is unsigned. Range properties are created using
94 	 *     drm_property_create_range().
95 	 *
96 	 * DRM_MODE_PROP_SIGNED_RANGE
97 	 *     Range properties report their minimum and maximum admissible unsigned values.
98 	 *     The KMS core verifies that values set by application fit in that
99 	 *     range. The range is signed. Range properties are created using
100 	 *     drm_property_create_signed_range().
101 	 *
102 	 * DRM_MODE_PROP_ENUM
103 	 *     Enumerated properties take a numerical value that ranges from 0 to
104 	 *     the number of enumerated values defined by the property minus one,
105 	 *     and associate a free-formed string name to each value. Applications
106 	 *     can retrieve the list of defined value-name pairs and use the
107 	 *     numerical value to get and set property instance values. Enum
108 	 *     properties are created using drm_property_create_enum().
109 	 *
110 	 * DRM_MODE_PROP_BITMASK
111 	 *     Bitmask properties are enumeration properties that additionally
112 	 *     restrict all enumerated values to the 0..63 range. Bitmask property
113 	 *     instance values combine one or more of the enumerated bits defined
114 	 *     by the property. Bitmask properties are created using
115 	 *     drm_property_create_bitmask().
116 	 *
117 	 * DRM_MODE_PROP_OBJECT
118 	 *     Object properties are used to link modeset objects. This is used
119 	 *     extensively in the atomic support to create the display pipeline,
120 	 *     by linking &drm_framebuffer to &drm_plane, &drm_plane to
121 	 *     &drm_crtc and &drm_connector to &drm_crtc. An object property can
122 	 *     only link to a specific type of &drm_mode_object, this limit is
123 	 *     enforced by the core. Object properties are created using
124 	 *     drm_property_create_object().
125 	 *
126 	 *     Object properties work like blob properties, but in a more
127 	 *     general fashion. They are limited to atomic drivers and must have
128 	 *     the DRM_MODE_PROP_ATOMIC flag set.
129 	 *
130 	 * DRM_MODE_PROP_BLOB
131 	 *     Blob properties store a binary blob without any format restriction.
132 	 *     The binary blobs are created as KMS standalone objects, and blob
133 	 *     property instance values store the ID of their associated blob
134 	 *     object. Blob properties are created by calling
135 	 *     drm_property_create() with DRM_MODE_PROP_BLOB as the type.
136 	 *
137 	 *     Actual blob objects to contain blob data are created using
138 	 *     drm_property_create_blob(), or through the corresponding IOCTL.
139 	 *
140 	 *     Besides the built-in limit to only accept blob objects blob
141 	 *     properties work exactly like object properties. The only reasons
142 	 *     blob properties exist is backwards compatibility with existing
143 	 *     userspace.
144 	 *
145 	 * In addition a property can have any combination of the below flags:
146 	 *
147 	 * DRM_MODE_PROP_ATOMIC
148 	 *     Set for properties which encode atomic modeset state. Such
149 	 *     properties are not exposed to legacy userspace.
150 	 *
151 	 * DRM_MODE_PROP_IMMUTABLE
152 	 *     Set for properties whose values cannot be changed by
153 	 *     userspace. The kernel is allowed to update the value of these
154 	 *     properties. This is generally used to expose probe state to
155 	 *     userspace, e.g. the EDID, or the connector path property on DP
156 	 *     MST sinks. Kernel can update the value of an immutable property
157 	 *     by calling drm_object_property_set_value().
158 	 */
159 	uint32_t flags;
160 
161 	/**
162 	 * @name: symbolic name of the properties
163 	 */
164 	char name[DRM_PROP_NAME_LEN];
165 
166 	/**
167 	 * @num_values: size of the @values array.
168 	 */
169 	uint32_t num_values;
170 
171 	/**
172 	 * @values:
173 	 *
174 	 * Array with limits and values for the property. The
175 	 * interpretation of these limits is dependent upon the type per @flags.
176 	 */
177 	uint64_t *values;
178 
179 	/**
180 	 * @dev: DRM device
181 	 */
182 	struct drm_device *dev;
183 
184 	/**
185 	 * @enum_list:
186 	 *
187 	 * List of &drm_prop_enum_list structures with the symbolic names for
188 	 * enum and bitmask values.
189 	 */
190 	struct list_head enum_list;
191 };
192 
193 /**
194  * struct drm_property_blob - Blob data for &drm_property
195  * @base: base KMS object
196  * @dev: DRM device
197  * @head_global: entry on the global blob list in
198  * 	&drm_mode_config.property_blob_list.
199  * @head_file: entry on the per-file blob list in &drm_file.blobs list.
200  * @length: size of the blob in bytes, invariant over the lifetime of the object
201  * @data: actual data, embedded at the end of this structure
202  *
203  * Blobs are used to store bigger values than what fits directly into the 64
204  * bits available for a &drm_property.
205  *
206  * Blobs are reference counted using drm_property_blob_get() and
207  * drm_property_blob_put(). They are created using drm_property_create_blob().
208  */
209 struct drm_property_blob {
210 	struct drm_mode_object base;
211 	struct drm_device *dev;
212 	struct list_head head_global;
213 	struct list_head head_file;
214 	size_t length;
215 	void *data;
216 };
217 
218 struct drm_prop_enum_list {
219 	int type;
220 	const char *name;
221 };
222 
223 #define obj_to_property(x) container_of(x, struct drm_property, base)
224 #define obj_to_blob(x) container_of(x, struct drm_property_blob, base)
225 
226 /**
227  * drm_property_type_is - check the type of a property
228  * @property: property to check
229  * @type: property type to compare with
230  *
231  * This is a helper function becauase the uapi encoding of property types is
232  * a bit special for historical reasons.
233  */
234 static inline bool drm_property_type_is(struct drm_property *property,
235 					uint32_t type)
236 {
237 	/* instanceof for props.. handles extended type vs original types: */
238 	if (property->flags & DRM_MODE_PROP_EXTENDED_TYPE)
239 		return (property->flags & DRM_MODE_PROP_EXTENDED_TYPE) == type;
240 	return property->flags & type;
241 }
242 
243 struct drm_property *drm_property_create(struct drm_device *dev,
244 					 u32 flags, const char *name,
245 					 int num_values);
246 struct drm_property *drm_property_create_enum(struct drm_device *dev,
247 					      u32 flags, const char *name,
248 					      const struct drm_prop_enum_list *props,
249 					      int num_values);
250 struct drm_property *drm_property_create_bitmask(struct drm_device *dev,
251 						 u32 flags, const char *name,
252 						 const struct drm_prop_enum_list *props,
253 						 int num_props,
254 						 uint64_t supported_bits);
255 struct drm_property *drm_property_create_range(struct drm_device *dev,
256 					       u32 flags, const char *name,
257 					       uint64_t min, uint64_t max);
258 struct drm_property *drm_property_create_signed_range(struct drm_device *dev,
259 						      u32 flags, const char *name,
260 						      int64_t min, int64_t max);
261 struct drm_property *drm_property_create_object(struct drm_device *dev,
262 						u32 flags, const char *name,
263 						uint32_t type);
264 struct drm_property *drm_property_create_bool(struct drm_device *dev,
265 					      u32 flags, const char *name);
266 int drm_property_add_enum(struct drm_property *property,
267 			  uint64_t value, const char *name);
268 void drm_property_destroy(struct drm_device *dev, struct drm_property *property);
269 
270 struct drm_property_blob *drm_property_create_blob(struct drm_device *dev,
271 						   size_t length,
272 						   const void *data);
273 struct drm_property_blob *drm_property_lookup_blob(struct drm_device *dev,
274 						   uint32_t id);
275 int drm_property_replace_global_blob(struct drm_device *dev,
276 				     struct drm_property_blob **replace,
277 				     size_t length,
278 				     const void *data,
279 				     struct drm_mode_object *obj_holds_id,
280 				     struct drm_property *prop_holds_id);
281 bool drm_property_replace_blob(struct drm_property_blob **blob,
282 			       struct drm_property_blob *new_blob);
283 struct drm_property_blob *drm_property_blob_get(struct drm_property_blob *blob);
284 void drm_property_blob_put(struct drm_property_blob *blob);
285 
286 /**
287  * drm_property_find - find property object
288  * @dev: DRM device
289  * @file_priv: drm file to check for lease against.
290  * @id: property object id
291  *
292  * This function looks up the property object specified by id and returns it.
293  */
294 static inline struct drm_property *drm_property_find(struct drm_device *dev,
295 						     struct drm_file *file_priv,
296 						     uint32_t id)
297 {
298 	struct drm_mode_object *mo;
299 	mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_PROPERTY);
300 	return mo ? obj_to_property(mo) : NULL;
301 }
302 
303 #endif
304