xref: /linux/include/drm/drm_encoder.h (revision 63ba5b0fb4f54db256ec43b3062b2606b383055d)
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.
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 	 * @debugfs_init:
87 	 *
88 	 * Allows encoders to create encoder-specific debugfs files.
89 	 */
90 	void (*debugfs_init)(struct drm_encoder *encoder, struct dentry *root);
91 };
92 
93 /**
94  * struct drm_encoder - central DRM encoder structure
95  * @dev: parent DRM device
96  * @head: list management
97  * @base: base KMS object
98  * @name: human readable name, can be overwritten by the driver
99  * @funcs: control functions, can be NULL for simple managed encoders
100  * @helper_private: mid-layer private data
101  *
102  * CRTCs drive pixels to encoders, which convert them into signals
103  * appropriate for a given connector or set of connectors.
104  */
105 struct drm_encoder {
106 	struct drm_device *dev;
107 	struct list_head head;
108 
109 	struct drm_mode_object base;
110 	char *name;
111 	/**
112 	 * @encoder_type:
113 	 *
114 	 * One of the DRM_MODE_ENCODER_<foo> types in drm_mode.h. The following
115 	 * encoder types are defined thus far:
116 	 *
117 	 * - DRM_MODE_ENCODER_DAC for VGA and analog on DVI-I/DVI-A.
118 	 *
119 	 * - DRM_MODE_ENCODER_TMDS for DVI, HDMI and (embedded) DisplayPort.
120 	 *
121 	 * - DRM_MODE_ENCODER_LVDS for display panels, or in general any panel
122 	 *   with a proprietary parallel connector.
123 	 *
124 	 * - DRM_MODE_ENCODER_TVDAC for TV output (Composite, S-Video,
125 	 *   Component, SCART).
126 	 *
127 	 * - DRM_MODE_ENCODER_VIRTUAL for virtual machine displays
128 	 *
129 	 * - DRM_MODE_ENCODER_DSI for panels connected using the DSI serial bus.
130 	 *
131 	 * - DRM_MODE_ENCODER_DPI for panels connected using the DPI parallel
132 	 *   bus.
133 	 *
134 	 * - DRM_MODE_ENCODER_DPMST for special fake encoders used to allow
135 	 *   mutliple DP MST streams to share one physical encoder.
136 	 */
137 	int encoder_type;
138 
139 	/**
140 	 * @index: Position inside the mode_config.list, can be used as an array
141 	 * index. It is invariant over the lifetime of the encoder.
142 	 */
143 	unsigned index;
144 
145 	/**
146 	 * @possible_crtcs: Bitmask of potential CRTC bindings, using
147 	 * drm_crtc_index() as the index into the bitfield. The driver must set
148 	 * the bits for all &drm_crtc objects this encoder can be connected to
149 	 * before calling drm_dev_register().
150 	 *
151 	 * You will get a WARN if you get this wrong in the driver.
152 	 *
153 	 * Note that since CRTC objects can't be hotplugged the assigned indices
154 	 * are stable and hence known before registering all objects.
155 	 */
156 	uint32_t possible_crtcs;
157 
158 	/**
159 	 * @possible_clones: Bitmask of potential sibling encoders for cloning,
160 	 * using drm_encoder_index() as the index into the bitfield. The driver
161 	 * must set the bits for all &drm_encoder objects which can clone a
162 	 * &drm_crtc together with this encoder before calling
163 	 * drm_dev_register(). Drivers should set the bit representing the
164 	 * encoder itself, too. Cloning bits should be set such that when two
165 	 * encoders can be used in a cloned configuration, they both should have
166 	 * each another bits set.
167 	 *
168 	 * As an exception to the above rule if the driver doesn't implement
169 	 * any cloning it can leave @possible_clones set to 0. The core will
170 	 * automagically fix this up by setting the bit for the encoder itself.
171 	 *
172 	 * You will get a WARN if you get this wrong in the driver.
173 	 *
174 	 * Note that since encoder objects can't be hotplugged the assigned indices
175 	 * are stable and hence known before registering all objects.
176 	 */
177 	uint32_t possible_clones;
178 
179 	/**
180 	 * @crtc: Currently bound CRTC, only really meaningful for non-atomic
181 	 * drivers.  Atomic drivers should instead check
182 	 * &drm_connector_state.crtc.
183 	 */
184 	struct drm_crtc *crtc;
185 
186 	/**
187 	 * @bridge_chain: Bridges attached to this encoder. Drivers shall not
188 	 * access this field directly.
189 	 */
190 	struct list_head bridge_chain;
191 
192 	const struct drm_encoder_funcs *funcs;
193 	const struct drm_encoder_helper_funcs *helper_private;
194 
195 	/**
196 	 * @debugfs_entry:
197 	 *
198 	 * Debugfs directory for this CRTC.
199 	 */
200 	struct dentry *debugfs_entry;
201 };
202 
203 #define obj_to_encoder(x) container_of(x, struct drm_encoder, base)
204 
205 __printf(5, 6)
206 int drm_encoder_init(struct drm_device *dev,
207 		     struct drm_encoder *encoder,
208 		     const struct drm_encoder_funcs *funcs,
209 		     int encoder_type, const char *name, ...);
210 
211 __printf(5, 6)
212 int drmm_encoder_init(struct drm_device *dev,
213 		      struct drm_encoder *encoder,
214 		      const struct drm_encoder_funcs *funcs,
215 		      int encoder_type, const char *name, ...);
216 
217 __printf(6, 7)
218 void *__drmm_encoder_alloc(struct drm_device *dev,
219 			   size_t size, size_t offset,
220 			   const struct drm_encoder_funcs *funcs,
221 			   int encoder_type,
222 			   const char *name, ...);
223 
224 /**
225  * drmm_encoder_alloc - Allocate and initialize an encoder
226  * @dev: drm device
227  * @type: the type of the struct which contains struct &drm_encoder
228  * @member: the name of the &drm_encoder within @type
229  * @funcs: callbacks for this encoder (optional)
230  * @encoder_type: user visible type of the encoder
231  * @name: printf style format string for the encoder name, or NULL for default name
232  *
233  * Allocates and initializes an encoder. Encoder should be subclassed as part of
234  * driver encoder objects. Cleanup is automatically handled through registering
235  * drm_encoder_cleanup() with drmm_add_action().
236  *
237  * The @drm_encoder_funcs.destroy hook must be NULL.
238  *
239  * Returns:
240  * Pointer to new encoder, or ERR_PTR on failure.
241  */
242 #define drmm_encoder_alloc(dev, type, member, funcs, encoder_type, name, ...) \
243 	((type *)__drmm_encoder_alloc(dev, sizeof(type), \
244 				      offsetof(type, member), funcs, \
245 				      encoder_type, name, ##__VA_ARGS__))
246 
247 /**
248  * drmm_plain_encoder_alloc - Allocate and initialize an encoder
249  * @dev: drm device
250  * @funcs: callbacks for this encoder (optional)
251  * @encoder_type: user visible type of the encoder
252  * @name: printf style format string for the encoder name, or NULL for default name
253  *
254  * This is a simplified version of drmm_encoder_alloc(), which only allocates
255  * and returns a struct drm_encoder instance, with no subclassing.
256  *
257  * Returns:
258  * Pointer to the new drm_encoder struct, or ERR_PTR on failure.
259  */
260 #define drmm_plain_encoder_alloc(dev, funcs, encoder_type, name, ...) \
261 	((struct drm_encoder *) \
262 	 __drmm_encoder_alloc(dev, sizeof(struct drm_encoder), \
263 			      0, funcs, encoder_type, name, ##__VA_ARGS__))
264 
265 /**
266  * drm_encoder_index - find the index of a registered encoder
267  * @encoder: encoder to find index for
268  *
269  * Given a registered encoder, return the index of that encoder within a DRM
270  * device's list of encoders.
271  */
272 static inline unsigned int drm_encoder_index(const struct drm_encoder *encoder)
273 {
274 	return encoder->index;
275 }
276 
277 /**
278  * drm_encoder_mask - find the mask of a registered encoder
279  * @encoder: encoder to find mask for
280  *
281  * Given a registered encoder, return the mask bit of that encoder for an
282  * encoder's possible_clones field.
283  */
284 static inline u32 drm_encoder_mask(const struct drm_encoder *encoder)
285 {
286 	return 1 << drm_encoder_index(encoder);
287 }
288 
289 /**
290  * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
291  * @encoder: encoder to test
292  * @crtc: crtc to test
293  *
294  * Returns false if @encoder can't be driven by @crtc, true otherwise.
295  */
296 static inline bool drm_encoder_crtc_ok(struct drm_encoder *encoder,
297 				       struct drm_crtc *crtc)
298 {
299 	return !!(encoder->possible_crtcs & drm_crtc_mask(crtc));
300 }
301 
302 /**
303  * drm_encoder_find - find a &drm_encoder
304  * @dev: DRM device
305  * @file_priv: drm file to check for lease against.
306  * @id: encoder id
307  *
308  * Returns the encoder with @id, NULL if it doesn't exist. Simple wrapper around
309  * drm_mode_object_find().
310  */
311 static inline struct drm_encoder *drm_encoder_find(struct drm_device *dev,
312 						   struct drm_file *file_priv,
313 						   uint32_t id)
314 {
315 	struct drm_mode_object *mo;
316 
317 	mo = drm_mode_object_find(dev, file_priv, id, DRM_MODE_OBJECT_ENCODER);
318 
319 	return mo ? obj_to_encoder(mo) : NULL;
320 }
321 
322 void drm_encoder_cleanup(struct drm_encoder *encoder);
323 
324 /**
325  * drm_for_each_encoder_mask - iterate over encoders specified by bitmask
326  * @encoder: the loop cursor
327  * @dev: the DRM device
328  * @encoder_mask: bitmask of encoder indices
329  *
330  * Iterate over all encoders specified by bitmask.
331  */
332 #define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
333 	list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
334 		for_each_if ((encoder_mask) & drm_encoder_mask(encoder))
335 
336 /**
337  * drm_for_each_encoder - iterate over all encoders
338  * @encoder: the loop cursor
339  * @dev: the DRM device
340  *
341  * Iterate over all encoders of @dev.
342  */
343 #define drm_for_each_encoder(encoder, dev) \
344 	list_for_each_entry(encoder, &(dev)->mode_config.encoder_list, head)
345 
346 #endif
347