1 /* $NetBSD: drm_encoder.h,v 1.2 2021/12/18 23:45:45 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 2016 Intel Corporation
5 *
6 * Permission to use, copy, modify, distribute, and sell this software and its
7 * documentation for any purpose is hereby granted without fee, provided that
8 * the above copyright notice appear in all copies and that both that copyright
9 * notice and this permission notice appear in supporting documentation, and
10 * that the name of the copyright holders not be used in advertising or
11 * publicity pertaining to distribution of the software without specific,
12 * written prior permission. The copyright holders make no representations
13 * about the suitability of this software for any purpose. It is provided "as
14 * is" without express or implied warranty.
15 *
16 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
17 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
18 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
19 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
20 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
21 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
22 * OF THIS SOFTWARE.
23 */
24
25 #ifndef __DRM_ENCODER_H__
26 #define __DRM_ENCODER_H__
27
28 #include <linux/list.h>
29 #include <linux/ctype.h>
30 #include <drm/drm_crtc.h>
31 #include <drm/drm_mode.h>
32 #include <drm/drm_mode_object.h>
33 #include <drm/drm_util.h>
34
35 struct drm_encoder;
36
37 /**
38 * struct drm_encoder_funcs - encoder controls
39 *
40 * Encoders sit between CRTCs and connectors.
41 */
42 struct drm_encoder_funcs {
43 /**
44 * @reset:
45 *
46 * Reset encoder hardware and software state to off. This function isn't
47 * called by the core directly, only through drm_mode_config_reset().
48 * It's not a helper hook only for historical reasons.
49 */
50 void (*reset)(struct drm_encoder *encoder);
51
52 /**
53 * @destroy:
54 *
55 * Clean up encoder resources. This is only called at driver unload time
56 * through drm_mode_config_cleanup() since an encoder cannot be
57 * hotplugged in DRM.
58 */
59 void (*destroy)(struct drm_encoder *encoder);
60
61 /**
62 * @late_register:
63 *
64 * This optional hook can be used to register additional userspace
65 * interfaces attached to the encoder like debugfs interfaces.
66 * It is called late in the driver load sequence from drm_dev_register().
67 * Everything added from this callback should be unregistered in
68 * the early_unregister callback.
69 *
70 * Returns:
71 *
72 * 0 on success, or a negative error code on failure.
73 */
74 int (*late_register)(struct drm_encoder *encoder);
75
76 /**
77 * @early_unregister:
78 *
79 * This optional hook should be used to unregister the additional
80 * userspace interfaces attached to the encoder from
81 * @late_register. It is called from drm_dev_unregister(),
82 * early in the driver unload sequence to disable userspace access
83 * before data structures are torndown.
84 */
85 void (*early_unregister)(struct drm_encoder *encoder);
86 };
87
88 /**
89 * struct drm_encoder - central DRM encoder structure
90 * @dev: parent DRM device
91 * @head: list management
92 * @base: base KMS object
93 * @name: human readable name, can be overwritten by the driver
94 * @bridge: bridge associated to the encoder
95 * @funcs: control functions
96 * @helper_private: mid-layer private data
97 *
98 * CRTCs drive pixels to encoders, which convert them into signals
99 * appropriate for a given connector or set of connectors.
100 */
101 struct drm_encoder {
102 struct drm_device *dev;
103 struct list_head head;
104
105 struct drm_mode_object base;
106 char *name;
107 /**
108 * @encoder_type:
109 *
110 * One of the DRM_MODE_ENCODER_<foo> types in drm_mode.h. The following
111 * encoder types are defined thus far:
112 *
113 * - DRM_MODE_ENCODER_DAC for VGA and analog on DVI-I/DVI-A.
114 *
115 * - DRM_MODE_ENCODER_TMDS for DVI, HDMI and (embedded) DisplayPort.
116 *
117 * - DRM_MODE_ENCODER_LVDS for display panels, or in general any panel
118 * with a proprietary parallel connector.
119 *
120 * - DRM_MODE_ENCODER_TVDAC for TV output (Composite, S-Video,
121 * Component, SCART).
122 *
123 * - DRM_MODE_ENCODER_VIRTUAL for virtual machine displays
124 *
125 * - DRM_MODE_ENCODER_DSI for panels connected using the DSI serial bus.
126 *
127 * - DRM_MODE_ENCODER_DPI for panels connected using the DPI parallel
128 * bus.
129 *
130 * - DRM_MODE_ENCODER_DPMST for special fake encoders used to allow
131 * mutliple DP MST streams to share one physical encoder.
132 */
133 int encoder_type;
134
135 /**
136 * @index: Position inside the mode_config.list, can be used as an array
137 * index. It is invariant over the lifetime of the encoder.
138 */
139 unsigned index;
140
141 /**
142 * @possible_crtcs: Bitmask of potential CRTC bindings, using
143 * drm_crtc_index() as the index into the bitfield. The driver must set
144 * the bits for all &drm_crtc objects this encoder can be connected to
145 * before calling drm_dev_register().
146 *
147 * In reality almost every driver gets this wrong.
148 *
149 * Note that since CRTC objects can't be hotplugged the assigned indices
150 * are stable and hence known before registering all objects.
151 */
152 uint32_t possible_crtcs;
153
154 /**
155 * @possible_clones: Bitmask of potential sibling encoders for cloning,
156 * using drm_encoder_index() as the index into the bitfield. The driver
157 * must set the bits for all &drm_encoder objects which can clone a
158 * &drm_crtc together with this encoder before calling
159 * drm_dev_register(). Drivers should set the bit representing the
160 * encoder itself, too. Cloning bits should be set such that when two
161 * encoders can be used in a cloned configuration, they both should have
162 * each another bits set.
163 *
164 * In reality almost every driver gets this wrong.
165 *
166 * Note that since encoder objects can't be hotplugged the assigned indices
167 * are stable and hence known before registering all objects.
168 */
169 uint32_t possible_clones;
170
171 /**
172 * @crtc: Currently bound CRTC, only really meaningful for non-atomic
173 * drivers. Atomic drivers should instead check
174 * &drm_connector_state.crtc.
175 */
176 struct drm_crtc *crtc;
177
178 /**
179 * @bridge_chain: Bridges attached to this encoder.
180 */
181 struct list_head bridge_chain;
182
183 const struct drm_encoder_funcs *funcs;
184 const struct drm_encoder_helper_funcs *helper_private;
185 };
186
187 #define obj_to_encoder(x) container_of(x, struct drm_encoder, base)
188
189 __printf(5, 6)
190 int drm_encoder_init(struct drm_device *dev,
191 struct drm_encoder *encoder,
192 const struct drm_encoder_funcs *funcs,
193 int encoder_type, const char *name, ...);
194
195 /**
196 * drm_encoder_index - find the index of a registered encoder
197 * @encoder: encoder to find index for
198 *
199 * Given a registered encoder, return the index of that encoder within a DRM
200 * device's list of encoders.
201 */
drm_encoder_index(const struct drm_encoder * encoder)202 static inline unsigned int drm_encoder_index(const struct drm_encoder *encoder)
203 {
204 return encoder->index;
205 }
206
207 /**
208 * drm_encoder_mask - find the mask of a registered encoder
209 * @encoder: encoder to find mask for
210 *
211 * Given a registered encoder, return the mask bit of that encoder for an
212 * encoder's possible_clones field.
213 */
drm_encoder_mask(const struct drm_encoder * encoder)214 static inline u32 drm_encoder_mask(const struct drm_encoder *encoder)
215 {
216 return 1 << drm_encoder_index(encoder);
217 }
218
219 /**
220 * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
221 * @encoder: encoder to test
222 * @crtc: crtc to test
223 *
224 * Returns false if @encoder can't be driven by @crtc, true otherwise.
225 */
drm_encoder_crtc_ok(struct drm_encoder * encoder,struct drm_crtc * crtc)226 static inline bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
227 struct drm_crtc *crtc)
228 {
229 return !!(encoder->possible_crtcs & drm_crtc_mask(crtc));
230 }
231
232 /**
233 * drm_encoder_find - find a &drm_encoder
234 * @dev: DRM device
235 * @file_priv: drm file to check for lease against.
236 * @id: encoder id
237 *
238 * Returns the encoder with @id, NULL if it doesn't exist. Simple wrapper around
239 * drm_mode_object_find().
240 */
drm_encoder_find(struct drm_device * dev,struct drm_file * file_priv,uint32_t id)241 static inline struct drm_encoder *drm_encoder_find(struct drm_device *dev,
242 struct drm_file *file_priv,
243 uint32_t id)
244 {
245 struct drm_mode_object *mo;
246
247 mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_ENCODER);
248
249 return mo ? obj_to_encoder(mo) : NULL;
250 }
251
252 void drm_encoder_cleanup(struct drm_encoder *encoder);
253
254 /**
255 * drm_for_each_encoder_mask - iterate over encoders specified by bitmask
256 * @encoder: the loop cursor
257 * @dev: the DRM device
258 * @encoder_mask: bitmask of encoder indices
259 *
260 * Iterate over all encoders specified by bitmask.
261 */
262 #define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
263 list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
264 for_each_if ((encoder_mask) & drm_encoder_mask(encoder))
265
266 /**
267 * drm_for_each_encoder - iterate over all encoders
268 * @encoder: the loop cursor
269 * @dev: the DRM device
270 *
271 * Iterate over all encoders of @dev.
272 */
273 #define drm_for_each_encoder(encoder, dev) \
274 list_for_each_entry(encoder, &(dev)->mode_config.encoder_list, head)
275
276 #endif
277