xref: /openbmc/linux/include/drm/drm_encoder.h (revision adb57164)
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_ENCODER_H__
24 #define __DRM_ENCODER_H__
25 
26 #include <linux/list.h>
27 #include <linux/ctype.h>
28 #include <drm/drm_crtc.h>
29 #include <drm/drm_mode.h>
30 #include <drm/drm_mode_object.h>
31 #include <drm/drm_util.h>
32 
33 struct drm_encoder;
34 
35 /**
36  * struct drm_encoder_funcs - encoder controls
37  *
38  * Encoders sit between CRTCs and connectors.
39  */
40 struct drm_encoder_funcs {
41 	/**
42 	 * @reset:
43 	 *
44 	 * Reset encoder hardware and software state to off. This function isn't
45 	 * called by the core directly, only through drm_mode_config_reset().
46 	 * It's not a helper hook only for historical reasons.
47 	 */
48 	void (*reset)(struct drm_encoder *encoder);
49 
50 	/**
51 	 * @destroy:
52 	 *
53 	 * Clean up encoder resources. This is only called at driver unload time
54 	 * through drm_mode_config_cleanup() since an encoder cannot be
55 	 * hotplugged in DRM.
56 	 */
57 	void (*destroy)(struct drm_encoder *encoder);
58 
59 	/**
60 	 * @late_register:
61 	 *
62 	 * This optional hook can be used to register additional userspace
63 	 * interfaces attached to the encoder like debugfs interfaces.
64 	 * It is called late in the driver load sequence from drm_dev_register().
65 	 * Everything added from this callback should be unregistered in
66 	 * the early_unregister callback.
67 	 *
68 	 * Returns:
69 	 *
70 	 * 0 on success, or a negative error code on failure.
71 	 */
72 	int (*late_register)(struct drm_encoder *encoder);
73 
74 	/**
75 	 * @early_unregister:
76 	 *
77 	 * This optional hook should be used to unregister the additional
78 	 * userspace interfaces attached to the encoder from
79 	 * @late_register. It is called from drm_dev_unregister(),
80 	 * early in the driver unload sequence to disable userspace access
81 	 * before data structures are torndown.
82 	 */
83 	void (*early_unregister)(struct drm_encoder *encoder);
84 };
85 
86 /**
87  * struct drm_encoder - central DRM encoder structure
88  * @dev: parent DRM device
89  * @head: list management
90  * @base: base KMS object
91  * @name: human readable name, can be overwritten by the driver
92  * @bridge: bridge associated to the encoder
93  * @funcs: control functions
94  * @helper_private: mid-layer private data
95  *
96  * CRTCs drive pixels to encoders, which convert them into signals
97  * appropriate for a given connector or set of connectors.
98  */
99 struct drm_encoder {
100 	struct drm_device *dev;
101 	struct list_head head;
102 
103 	struct drm_mode_object base;
104 	char *name;
105 	/**
106 	 * @encoder_type:
107 	 *
108 	 * One of the DRM_MODE_ENCODER_<foo> types in drm_mode.h. The following
109 	 * encoder types are defined thus far:
110 	 *
111 	 * - DRM_MODE_ENCODER_DAC for VGA and analog on DVI-I/DVI-A.
112 	 *
113 	 * - DRM_MODE_ENCODER_TMDS for DVI, HDMI and (embedded) DisplayPort.
114 	 *
115 	 * - DRM_MODE_ENCODER_LVDS for display panels, or in general any panel
116 	 *   with a proprietary parallel connector.
117 	 *
118 	 * - DRM_MODE_ENCODER_TVDAC for TV output (Composite, S-Video,
119 	 *   Component, SCART).
120 	 *
121 	 * - DRM_MODE_ENCODER_VIRTUAL for virtual machine displays
122 	 *
123 	 * - DRM_MODE_ENCODER_DSI for panels connected using the DSI serial bus.
124 	 *
125 	 * - DRM_MODE_ENCODER_DPI for panels connected using the DPI parallel
126 	 *   bus.
127 	 *
128 	 * - DRM_MODE_ENCODER_DPMST for special fake encoders used to allow
129 	 *   mutliple DP MST streams to share one physical encoder.
130 	 */
131 	int encoder_type;
132 
133 	/**
134 	 * @index: Position inside the mode_config.list, can be used as an array
135 	 * index. It is invariant over the lifetime of the encoder.
136 	 */
137 	unsigned index;
138 
139 	/**
140 	 * @possible_crtcs: Bitmask of potential CRTC bindings, using
141 	 * drm_crtc_index() as the index into the bitfield. The driver must set
142 	 * the bits for all &drm_crtc objects this encoder can be connected to
143 	 * before calling drm_dev_register().
144 	 *
145 	 * In reality almost every driver gets this wrong.
146 	 *
147 	 * Note that since CRTC objects can't be hotplugged the assigned indices
148 	 * are stable and hence known before registering all objects.
149 	 */
150 	uint32_t possible_crtcs;
151 
152 	/**
153 	 * @possible_clones: Bitmask of potential sibling encoders for cloning,
154 	 * using drm_encoder_index() as the index into the bitfield. The driver
155 	 * must set the bits for all &drm_encoder objects which can clone a
156 	 * &drm_crtc together with this encoder before calling
157 	 * drm_dev_register(). Drivers should set the bit representing the
158 	 * encoder itself, too. Cloning bits should be set such that when two
159 	 * encoders can be used in a cloned configuration, they both should have
160 	 * each another bits set.
161 	 *
162 	 * In reality almost every driver gets this wrong.
163 	 *
164 	 * Note that since encoder objects can't be hotplugged the assigned indices
165 	 * are stable and hence known before registering all objects.
166 	 */
167 	uint32_t possible_clones;
168 
169 	/**
170 	 * @crtc: Currently bound CRTC, only really meaningful for non-atomic
171 	 * drivers.  Atomic drivers should instead check
172 	 * &drm_connector_state.crtc.
173 	 */
174 	struct drm_crtc *crtc;
175 
176 	/**
177 	 * @bridge_chain: Bridges attached to this encoder. Drivers shall not
178 	 * access this field directly.
179 	 */
180 	struct list_head bridge_chain;
181 
182 	const struct drm_encoder_funcs *funcs;
183 	const struct drm_encoder_helper_funcs *helper_private;
184 };
185 
186 #define obj_to_encoder(x) container_of(x, struct drm_encoder, base)
187 
188 __printf(5, 6)
189 int drm_encoder_init(struct drm_device *dev,
190 		     struct drm_encoder *encoder,
191 		     const struct drm_encoder_funcs *funcs,
192 		     int encoder_type, const char *name, ...);
193 
194 /**
195  * drm_encoder_index - find the index of a registered encoder
196  * @encoder: encoder to find index for
197  *
198  * Given a registered encoder, return the index of that encoder within a DRM
199  * device's list of encoders.
200  */
201 static inline unsigned int drm_encoder_index(const struct drm_encoder *encoder)
202 {
203 	return encoder->index;
204 }
205 
206 /**
207  * drm_encoder_mask - find the mask of a registered encoder
208  * @encoder: encoder to find mask for
209  *
210  * Given a registered encoder, return the mask bit of that encoder for an
211  * encoder's possible_clones field.
212  */
213 static inline u32 drm_encoder_mask(const struct drm_encoder *encoder)
214 {
215 	return 1 << drm_encoder_index(encoder);
216 }
217 
218 /**
219  * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
220  * @encoder: encoder to test
221  * @crtc: crtc to test
222  *
223  * Returns false if @encoder can't be driven by @crtc, true otherwise.
224  */
225 static inline bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
226 				       struct drm_crtc *crtc)
227 {
228 	return !!(encoder->possible_crtcs & drm_crtc_mask(crtc));
229 }
230 
231 /**
232  * drm_encoder_find - find a &drm_encoder
233  * @dev: DRM device
234  * @file_priv: drm file to check for lease against.
235  * @id: encoder id
236  *
237  * Returns the encoder with @id, NULL if it doesn't exist. Simple wrapper around
238  * drm_mode_object_find().
239  */
240 static inline struct drm_encoder *drm_encoder_find(struct drm_device *dev,
241 						   struct drm_file *file_priv,
242 						   uint32_t id)
243 {
244 	struct drm_mode_object *mo;
245 
246 	mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_ENCODER);
247 
248 	return mo ? obj_to_encoder(mo) : NULL;
249 }
250 
251 void drm_encoder_cleanup(struct drm_encoder *encoder);
252 
253 /**
254  * drm_for_each_encoder_mask - iterate over encoders specified by bitmask
255  * @encoder: the loop cursor
256  * @dev: the DRM device
257  * @encoder_mask: bitmask of encoder indices
258  *
259  * Iterate over all encoders specified by bitmask.
260  */
261 #define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
262 	list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
263 		for_each_if ((encoder_mask) & drm_encoder_mask(encoder))
264 
265 /**
266  * drm_for_each_encoder - iterate over all encoders
267  * @encoder: the loop cursor
268  * @dev: the DRM device
269  *
270  * Iterate over all encoders of @dev.
271  */
272 #define drm_for_each_encoder(encoder, dev) \
273 	list_for_each_entry(encoder, &(dev)->mode_config.encoder_list, head)
274 
275 #endif
276