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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, &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, name, ap);
121 } else {
122 encoder->name = kasprintf(GFP_KERNEL, "%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(&encoder->bridge_chain);
132 mutex_init(&encoder->bridge_chain_mutex);
133 list_add_tail(&encoder->head, &dev->mode_config.encoder_list);
134 encoder->index = dev->mode_config.num_encoder++;
135
136out_put:
137 if (ret)
138 drm_mode_object_unregister(dev, &encoder->base);
139
140 return ret;
141}
142
143/**
144 * drm_encoder_init - Init a preallocated encoder
145 * @dev: drm device
146 * @encoder: the encoder to init
147 * @funcs: callbacks for this encoder
148 * @encoder_type: user visible type of the encoder
149 * @name: printf style format string for the encoder name, or NULL for default name
150 *
151 * Initializes a preallocated encoder. Encoder should be subclassed as part of
152 * driver encoder objects. At driver unload time the driver's
153 * &drm_encoder_funcs.destroy hook should call drm_encoder_cleanup() and kfree()
154 * the encoder structure. The encoder structure should not be allocated with
155 * devm_kzalloc().
156 *
157 * Note: consider using drmm_encoder_alloc() or drmm_encoder_init()
158 * instead of drm_encoder_init() to let the DRM managed resource
159 * infrastructure take care of cleanup and deallocation.
160 *
161 * Returns:
162 * Zero on success, error code on failure.
163 */
164int drm_encoder_init(struct drm_device *dev,
165 struct drm_encoder *encoder,
166 const struct drm_encoder_funcs *funcs,
167 int encoder_type, const char *name, ...)
168{
169 va_list ap;
170 int ret;
171
172 WARN_ON(!funcs->destroy);
173
174 va_start(ap, name);
175 ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
176 va_end(ap);
177
178 return ret;
179}
180EXPORT_SYMBOL(drm_encoder_init);
181
182/**
183 * drm_encoder_cleanup - cleans up an initialised encoder
184 * @encoder: encoder to cleanup
185 *
186 * Cleans up the encoder but doesn't free the object.
187 */
188void drm_encoder_cleanup(struct drm_encoder *encoder)
189{
190 struct drm_device *dev = encoder->dev;
191 struct drm_bridge *bridge, *next;
192 LIST_HEAD(tmplist);
193
194 /* Note that the encoder_list is considered to be static; should we
195 * remove the drm_encoder at runtime we would have to decrement all
196 * the indices on the drm_encoder after us in the encoder_list.
197 */
198
199 /*
200 * We need the bridge_chain_mutex to modify the chain, but
201 * drm_bridge_detach() will call DRM_MODESET_LOCK_ALL_BEGIN() (in
202 * drm_modeset_lock_fini()), resulting in a possible ABBA circular
203 * deadlock. Avoid it by first moving all the bridges to a
204 * temporary list holding the lock, and then calling
205 * drm_bridge_detach() without the lock.
206 */
207 mutex_lock(&encoder->bridge_chain_mutex);
208 list_cut_before(&tmplist, &encoder->bridge_chain, &encoder->bridge_chain);
209 mutex_unlock(&encoder->bridge_chain_mutex);
210
211 list_for_each_entry_safe(bridge, next, &tmplist, chain_node)
212 drm_bridge_detach(bridge);
213
214 drm_mode_object_unregister(dev, &encoder->base);
215 kfree(encoder->name);
216 list_del(&encoder->head);
217 dev->mode_config.num_encoder--;
218 mutex_destroy(&encoder->bridge_chain_mutex);
219
220 memset(encoder, 0, sizeof(*encoder));
221}
222EXPORT_SYMBOL(drm_encoder_cleanup);
223
224static void drmm_encoder_alloc_release(struct drm_device *dev, void *ptr)
225{
226 struct drm_encoder *encoder = ptr;
227
228 if (WARN_ON(!encoder->dev))
229 return;
230
231 drm_encoder_cleanup(encoder);
232}
233
234__printf(5, 0)
235static int __drmm_encoder_init(struct drm_device *dev,
236 struct drm_encoder *encoder,
237 const struct drm_encoder_funcs *funcs,
238 int encoder_type,
239 const char *name,
240 va_list args)
241{
242 int ret;
243
244 if (drm_WARN_ON(dev, funcs && funcs->destroy))
245 return -EINVAL;
246
247 ret = __drm_encoder_init(dev, encoder, funcs, encoder_type, name, args);
248 if (ret)
249 return ret;
250
251 ret = drmm_add_action_or_reset(dev, drmm_encoder_alloc_release, encoder);
252 if (ret)
253 return ret;
254
255 return 0;
256}
257
258void *__drmm_encoder_alloc(struct drm_device *dev, size_t size, size_t offset,
259 const struct drm_encoder_funcs *funcs,
260 int encoder_type, const char *name, ...)
261{
262 void *container;
263 struct drm_encoder *encoder;
264 va_list ap;
265 int ret;
266
267 container = drmm_kzalloc(dev, size, GFP_KERNEL);
268 if (!container)
269 return ERR_PTR(-ENOMEM);
270
271 encoder = container + offset;
272
273 va_start(ap, name);
274 ret = __drmm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
275 va_end(ap);
276 if (ret)
277 return ERR_PTR(ret);
278
279 return container;
280}
281EXPORT_SYMBOL(__drmm_encoder_alloc);
282
283/**
284 * drmm_encoder_init - Initialize a preallocated encoder
285 * @dev: drm device
286 * @encoder: the encoder to init
287 * @funcs: callbacks for this encoder (optional)
288 * @encoder_type: user visible type of the encoder
289 * @name: printf style format string for the encoder name, or NULL for default name
290 *
291 * Initializes a preallocated encoder. Encoder should be subclassed as
292 * part of driver encoder objects. Cleanup is automatically handled
293 * through registering drm_encoder_cleanup() with drmm_add_action(). The
294 * encoder structure should be allocated with drmm_kzalloc().
295 *
296 * The @drm_encoder_funcs.destroy hook must be NULL.
297 *
298 * Returns:
299 * Zero on success, error code on failure.
300 */
301int drmm_encoder_init(struct drm_device *dev, struct drm_encoder *encoder,
302 const struct drm_encoder_funcs *funcs,
303 int encoder_type, const char *name, ...)
304{
305 va_list ap;
306 int ret;
307
308 va_start(ap, name);
309 ret = __drmm_encoder_init(dev, encoder, funcs, encoder_type, name, ap);
310 va_end(ap);
311 if (ret)
312 return ret;
313
314 return 0;
315}
316EXPORT_SYMBOL(drmm_encoder_init);
317
318static struct drm_crtc *drm_encoder_get_crtc(struct drm_encoder *encoder)
319{
320 struct drm_connector *connector;
321 struct drm_device *dev = encoder->dev;
322 bool uses_atomic = false;
323 struct drm_connector_list_iter conn_iter;
324
325 /* For atomic drivers only state objects are synchronously updated and
326 * protected by modeset locks, so check those first. */
327 drm_connector_list_iter_begin(dev, &conn_iter);
328 drm_for_each_connector_iter(connector, &conn_iter) {
329 if (!connector->state)
330 continue;
331
332 uses_atomic = true;
333
334 if (connector->state->best_encoder != encoder)
335 continue;
336
337 drm_connector_list_iter_end(&conn_iter);
338 return connector->state->crtc;
339 }
340 drm_connector_list_iter_end(&conn_iter);
341
342 /* Don't return stale data (e.g. pending async disable). */
343 if (uses_atomic)
344 return NULL;
345
346 return encoder->crtc;
347}
348
349int drm_mode_getencoder(struct drm_device *dev, void *data,
350 struct drm_file *file_priv)
351{
352 struct drm_mode_get_encoder *enc_resp = data;
353 struct drm_encoder *encoder;
354 struct drm_crtc *crtc;
355
356 if (!drm_core_check_feature(dev, DRIVER_MODESET))
357 return -EOPNOTSUPP;
358
359 encoder = drm_encoder_find(dev, file_priv, enc_resp->encoder_id);
360 if (!encoder)
361 return -ENOENT;
362
363 drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
364 crtc = drm_encoder_get_crtc(encoder);
365 if (crtc && drm_lease_held(file_priv, crtc->base.id))
366 enc_resp->crtc_id = crtc->base.id;
367 else
368 enc_resp->crtc_id = 0;
369 drm_modeset_unlock(&dev->mode_config.connection_mutex);
370
371 enc_resp->encoder_type = encoder->encoder_type;
372 enc_resp->encoder_id = encoder->base.id;
373 enc_resp->possible_crtcs = drm_lease_filter_crtcs(file_priv,
374 encoder->possible_crtcs);
375 enc_resp->possible_clones = encoder->possible_clones;
376
377 return 0;
378}