xref: /openbmc/linux/include/drm/drm_encoder.h (revision dea54fba)
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 
32 struct drm_encoder;
33 
34 /**
35  * struct drm_encoder_funcs - encoder controls
36  *
37  * Encoders sit between CRTCs and connectors.
38  */
39 struct drm_encoder_funcs {
40 	/**
41 	 * @reset:
42 	 *
43 	 * Reset encoder hardware and software state to off. This function isn't
44 	 * called by the core directly, only through drm_mode_config_reset().
45 	 * It's not a helper hook only for historical reasons.
46 	 */
47 	void (*reset)(struct drm_encoder *encoder);
48 
49 	/**
50 	 * @destroy:
51 	 *
52 	 * Clean up encoder resources. This is only called at driver unload time
53 	 * through drm_mode_config_cleanup() since an encoder cannot be
54 	 * hotplugged in DRM.
55 	 */
56 	void (*destroy)(struct drm_encoder *encoder);
57 
58 	/**
59 	 * @late_register:
60 	 *
61 	 * This optional hook can be used to register additional userspace
62 	 * interfaces attached to the encoder like debugfs interfaces.
63 	 * It is called late in the driver load sequence from drm_dev_register().
64 	 * Everything added from this callback should be unregistered in
65 	 * the early_unregister callback.
66 	 *
67 	 * Returns:
68 	 *
69 	 * 0 on success, or a negative error code on failure.
70 	 */
71 	int (*late_register)(struct drm_encoder *encoder);
72 
73 	/**
74 	 * @early_unregister:
75 	 *
76 	 * This optional hook should be used to unregister the additional
77 	 * userspace interfaces attached to the encoder from
78 	 * @late_register. It is called from drm_dev_unregister(),
79 	 * early in the driver unload sequence to disable userspace access
80 	 * before data structures are torndown.
81 	 */
82 	void (*early_unregister)(struct drm_encoder *encoder);
83 };
84 
85 /**
86  * struct drm_encoder - central DRM encoder structure
87  * @dev: parent DRM device
88  * @head: list management
89  * @base: base KMS object
90  * @name: human readable name, can be overwritten by the driver
91  * @crtc: currently bound CRTC
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_encoder_init().
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_encoder_init(). 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 	struct drm_crtc *crtc;
170 	struct drm_bridge *bridge;
171 	const struct drm_encoder_funcs *funcs;
172 	const struct drm_encoder_helper_funcs *helper_private;
173 };
174 
175 #define obj_to_encoder(x) container_of(x, struct drm_encoder, base)
176 
177 __printf(5, 6)
178 int drm_encoder_init(struct drm_device *dev,
179 		     struct drm_encoder *encoder,
180 		     const struct drm_encoder_funcs *funcs,
181 		     int encoder_type, const char *name, ...);
182 
183 /**
184  * drm_encoder_index - find the index of a registered encoder
185  * @encoder: encoder to find index for
186  *
187  * Given a registered encoder, return the index of that encoder within a DRM
188  * device's list of encoders.
189  */
190 static inline unsigned int drm_encoder_index(struct drm_encoder *encoder)
191 {
192 	return encoder->index;
193 }
194 
195 /**
196  * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
197  * @encoder: encoder to test
198  * @crtc: crtc to test
199  *
200  * Returns false if @encoder can't be driven by @crtc, true otherwise.
201  */
202 static inline bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
203 				       struct drm_crtc *crtc)
204 {
205 	return !!(encoder->possible_crtcs & drm_crtc_mask(crtc));
206 }
207 
208 /**
209  * drm_encoder_find - find a &drm_encoder
210  * @dev: DRM device
211  * @id: encoder id
212  *
213  * Returns the encoder with @id, NULL if it doesn't exist. Simple wrapper around
214  * drm_mode_object_find().
215  */
216 static inline struct drm_encoder *drm_encoder_find(struct drm_device *dev,
217 						   uint32_t id)
218 {
219 	struct drm_mode_object *mo;
220 
221 	mo = drm_mode_object_find(dev, id, DRM_MODE_OBJECT_ENCODER);
222 
223 	return mo ? obj_to_encoder(mo) : NULL;
224 }
225 
226 void drm_encoder_cleanup(struct drm_encoder *encoder);
227 
228 /**
229  * drm_for_each_encoder_mask - iterate over encoders specified by bitmask
230  * @encoder: the loop cursor
231  * @dev: the DRM device
232  * @encoder_mask: bitmask of encoder indices
233  *
234  * Iterate over all encoders specified by bitmask.
235  */
236 #define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
237 	list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
238 		for_each_if ((encoder_mask) & (1 << drm_encoder_index(encoder)))
239 
240 /**
241  * drm_for_each_encoder - iterate over all encoders
242  * @encoder: the loop cursor
243  * @dev: the DRM device
244  *
245  * Iterate over all encoders of @dev.
246  */
247 #define drm_for_each_encoder(encoder, dev) \
248 	list_for_each_entry(encoder, &(dev)->mode_config.encoder_list, head)
249 
250 #endif
251