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

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