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#include <linux/export.h>
24
25#include <drm/drm_bridge.h>
26#include <drm/drm_device.h>
27#include <drm/drm_drv.h>
28#include <drm/drm_encoder.h>
29#include <drm/drm_managed.h>
30#include <drm/drm_print.h>
31
32#include "drm_crtc_internal.h"
33#include "drm_internal.h"
34
35/**
36 * DOC: overview
37 *
38 * Encoders represent the connecting element between the CRTC (as the overall
39 * pixel pipeline, represented by &struct drm_crtc) and the connectors (as the
40 * generic sink entity, represented by &struct drm_connector). An encoder takes
41 * pixel data from a CRTC and converts it to a format suitable for any attached
42 * connector. Encoders are objects exposed to userspace, originally to allow
43 * userspace to infer cloning and connector/CRTC restrictions. Unfortunately
44 * almost all drivers get this wrong, making the uabi pretty much useless. On
45 * top of that the exposed restrictions are too simple for today's hardware, and
46 * the recommended way to infer restrictions is by using the
47 * DRM_MODE_ATOMIC_TEST_ONLY flag for the atomic IOCTL.
48 *
49 * Otherwise encoders aren't used in the uapi at all (any modeset request from
50 * userspace directly connects a connector with a CRTC), drivers are therefore
51 * free to use them however they wish. Modeset helper libraries make strong use
52 * of encoders to facilitate code sharing. But for more complex settings it is
53 * usually better to move shared code into a separate &drm_bridge. Compared to
54 * encoders, bridges also have the benefit of being purely an internal
55 * abstraction since they are not exposed to userspace at all.
56 *
57 * Encoders are initialized with drm_encoder_init() and cleaned up using
58 * drm_encoder_cleanup().
59 */
60static const struct drm_prop_enum_list drm_encoder_enum_list[] = {
61 { DRM_MODE_ENCODER_NONE, "None" },
62 { DRM_MODE_ENCODER_DAC, "DAC" },
63 { DRM_MODE_ENCODER_TMDS, "TMDS" },
64 { DRM_MODE_ENCODER_LVDS, "LVDS" },
65 { DRM_MODE_ENCODER_TVDAC, "TV" },
66 { DRM_MODE_ENCODER_VIRTUAL, "Virtual" },
67 { DRM_MODE_ENCODER_DSI, "DSI" },
68 { DRM_MODE_ENCODER_DPMST, "DP MST" },
69 { DRM_MODE_ENCODER_DPI, "DPI" },
70};
71
72int drm_encoder_register_all(struct drm_device *dev)
73{
74 struct drm_encoder *encoder;
75 int ret = 0;
76
77 drm_for_each_encoder(encoder, dev) {
78 drm_debugfs_encoder_add(encoder);
79
80 if (encoder->funcs && encoder->funcs->late_register)
81 ret = encoder->funcs->late_register(encoder);
82 if (ret)
83 return ret;
84 }
85
86 return 0;
87}
88
89void drm_encoder_unregister_all(struct drm_device *dev)
90{
91 struct drm_encoder *encoder;
92
93 drm_for_each_encoder(encoder, dev) {
94 if (encoder->funcs && encoder->funcs->early_unregister)
95 encoder->funcs->early_unregister(encoder);
96 drm_debugfs_encoder_remove(encoder);
97 }
98}
99
100__printf(5, 0)
101static int __drm_encoder_init(struct drm_device *dev,
102 struct drm_encoder *encoder,
103 const struct drm_encoder_funcs *funcs,
104 int encoder_type, const char *name, va_list ap)
105{
106 int ret;
107
108 /* encoder index is used with 32bit bitmasks */
109 if (WARN_ON(dev->mode_config.num_encoder >= 32))
110 return -EINVAL;
111
112 ret = drm_mode_object_add(dev, obj: &encoder->base, DRM_MODE_OBJECT_ENCODER);
113 if (ret)
114 return ret;
115
116 encoder->dev = dev;
117 encoder->encoder_type = encoder_type;
118 encoder->funcs = funcs;
119 if (name) {
120 encoder->name = kvasprintf(GFP_KERNEL, fmt: name, args: ap);
121 } else {
122 encoder->name = kasprintf(GFP_KERNEL, fmt: "%s-%d",
123 drm_encoder_enum_list[encoder_type].name,
124 encoder->base.id);
125 }
126 if (!encoder->name) {
127 ret = -ENOMEM;
128 goto out_put;
129 }
130
131 INIT_LIST_HEAD(list: &encoder->bridge_chain);
132 list_add_tail(new: &encoder->head, head: &dev->mode_config.encoder_list);
133 encoder->index = dev->mode_config.num_encoder++;
134
135out_put:
136 if (ret)
137 drm_mode_object_unregister(dev, object: &encoder->base);
138
139 return ret;
140}
141
142/**
143 * drm_encoder_init - Init a preallocated encoder
144 * @dev: drm device
145 * @encoder: the encoder to init
146 * @funcs: callbacks for this encoder
147 * @encoder_type: user visible type of the encoder
148 * @name: printf style format string for the encoder name, or NULL for default name
149 *
150 * Initializes a preallocated encoder. Encoder should be subclassed as part of
151 * driver encoder objects. At driver unload time the driver's
152 * &drm_encoder_funcs.destroy hook should call drm_encoder_cleanup() and kfree()
153 * the encoder structure. The encoder structure should not be allocated with
154 * devm_kzalloc().
155 *
156 * Note: consider using drmm_encoder_alloc() or drmm_encoder_init()
157 * instead of drm_encoder_init() to let the DRM managed resource
158 * infrastructure take care of cleanup and deallocation.
159 *
160 * Returns:
161 * Zero on success, error code on failure.
162 */
163int drm_encoder_init(struct drm_device *dev,
164 struct drm_encoder *encoder,
165 const struct drm_encoder_funcs *funcs,
166 int encoder_type, const char *name, ...)
167{
168 va_list ap;
169 int ret;
170
171 WARN_ON(!funcs->destroy);
172
173 va_start(ap, name);
174 ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
175 va_end(ap);
176
177 return ret;
178}
179EXPORT_SYMBOL(drm_encoder_init);
180
181/**
182 * drm_encoder_cleanup - cleans up an initialised encoder
183 * @encoder: encoder to cleanup
184 *
185 * Cleans up the encoder but doesn't free the object.
186 */
187void drm_encoder_cleanup(struct drm_encoder *encoder)
188{
189 struct drm_device *dev = encoder->dev;
190 struct drm_bridge *bridge, *next;
191
192 /* Note that the encoder_list is considered to be static; should we
193 * remove the drm_encoder at runtime we would have to decrement all
194 * the indices on the drm_encoder after us in the encoder_list.
195 */
196
197 list_for_each_entry_safe(bridge, next, &encoder->bridge_chain,
198 chain_node)
199 drm_bridge_detach(bridge);
200
201 drm_mode_object_unregister(dev, object: &encoder->base);
202 kfree(objp: encoder->name);
203 list_del(entry: &encoder->head);
204 dev->mode_config.num_encoder--;
205
206 memset(encoder, 0, sizeof(*encoder));
207}
208EXPORT_SYMBOL(drm_encoder_cleanup);
209
210static void drmm_encoder_alloc_release(struct drm_device *dev, void *ptr)
211{
212 struct drm_encoder *encoder = ptr;
213
214 if (WARN_ON(!encoder->dev))
215 return;
216
217 drm_encoder_cleanup(encoder);
218}
219
220__printf(5, 0)
221static int __drmm_encoder_init(struct drm_device *dev,
222 struct drm_encoder *encoder,
223 const struct drm_encoder_funcs *funcs,
224 int encoder_type,
225 const char *name,
226 va_list args)
227{
228 int ret;
229
230 if (drm_WARN_ON(dev, funcs && funcs->destroy))
231 return -EINVAL;
232
233 ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap: args);
234 if (ret)
235 return ret;
236
237 ret = drmm_add_action_or_reset(dev, drmm_encoder_alloc_release, encoder);
238 if (ret)
239 return ret;
240
241 return 0;
242}
243
244void *__drmm_encoder_alloc(struct drm_device *dev, size_t size, size_t offset,
245 const struct drm_encoder_funcs *funcs,
246 int encoder_type, const char *name, ...)
247{
248 void *container;
249 struct drm_encoder *encoder;
250 va_list ap;
251 int ret;
252
253 container = drmm_kzalloc(dev, size, GFP_KERNEL);
254 if (!container)
255 return ERR_PTR(error: -ENOMEM);
256
257 encoder = container + offset;
258
259 va_start(ap, name);
260 ret = __drmm_encoder_init(dev, encoder, funcs, encoder_type, name, args: ap);
261 va_end(ap);
262 if (ret)
263 return ERR_PTR(error: ret);
264
265 return container;
266}
267EXPORT_SYMBOL(__drmm_encoder_alloc);
268
269/**
270 * drmm_encoder_init - Initialize a preallocated encoder
271 * @dev: drm device
272 * @encoder: the encoder to init
273 * @funcs: callbacks for this encoder (optional)
274 * @encoder_type: user visible type of the encoder
275 * @name: printf style format string for the encoder name, or NULL for default name
276 *
277 * Initializes a preallocated encoder. Encoder should be subclassed as
278 * part of driver encoder objects. Cleanup is automatically handled
279 * through registering drm_encoder_cleanup() with drmm_add_action(). The
280 * encoder structure should be allocated with drmm_kzalloc().
281 *
282 * The @drm_encoder_funcs.destroy hook must be NULL.
283 *
284 * Returns:
285 * Zero on success, error code on failure.
286 */
287int drmm_encoder_init(struct drm_device *dev, struct drm_encoder *encoder,
288 const struct drm_encoder_funcs *funcs,
289 int encoder_type, const char *name, ...)
290{
291 va_list ap;
292 int ret;
293
294 va_start(ap, name);
295 ret = __drmm_encoder_init(dev, encoder, funcs, encoder_type, name, args: ap);
296 va_end(ap);
297 if (ret)
298 return ret;
299
300 return 0;
301}
302EXPORT_SYMBOL(drmm_encoder_init);
303
304static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder)
305{
306 struct drm_connector *connector;
307 struct drm_device *dev = encoder->dev;
308 bool uses_atomic = false;
309 struct drm_connector_list_iter conn_iter;
310
311 /* For atomic drivers only state objects are synchronously updated and
312 * protected by modeset locks, so check those first. */
313 drm_connector_list_iter_begin(dev, iter: &conn_iter);
314 drm_for_each_connector_iter(connector, &conn_iter) {
315 if (!connector->state)
316 continue;
317
318 uses_atomic = true;
319
320 if (connector->state->best_encoder != encoder)
321 continue;
322
323 drm_connector_list_iter_end(iter: &conn_iter);
324 return connector->state->crtc;
325 }
326 drm_connector_list_iter_end(iter: &conn_iter);
327
328 /* Don't return stale data (e.g. pending async disable). */
329 if (uses_atomic)
330 return NULL;
331
332 return encoder->crtc;
333}
334
335int drm_mode_getencoder(struct drm_device *dev, void *data,
336 struct drm_file *file_priv)
337{
338 struct drm_mode_get_encoder *enc_resp = data;
339 struct drm_encoder *encoder;
340 struct drm_crtc *crtc;
341
342 if (!drm_core_check_feature(dev, feature: DRIVER_MODESET))
343 return -EOPNOTSUPP;
344
345 encoder = drm_encoder_find(dev, file_priv, id: enc_resp->encoder_id);
346 if (!encoder)
347 return -ENOENT;
348
349 drm_modeset_lock(lock: &dev->mode_config.connection_mutex, NULL);
350 crtc = drm_encoder_get_crtc(encoder);
351 if (crtc && drm_lease_held(file_priv, id: crtc->base.id))
352 enc_resp->crtc_id = crtc->base.id;
353 else
354 enc_resp->crtc_id = 0;
355 drm_modeset_unlock(lock: &dev->mode_config.connection_mutex);
356
357 enc_resp->encoder_type = encoder->encoder_type;
358 enc_resp->encoder_id = encoder->base.id;
359 enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
360 crtcs: encoder->possible_crtcs);
361 enc_resp->possible_clones = encoder->possible_clones;
362
363 return 0;
364}
365

source code of linux/drivers/gpu/drm/drm_encoder.c