1 /*
2 * Copyright (c) 2006-2008 Intel Corporation
3 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
4 *
5 * DRM core CRTC related functions
6 *
7 * Permission to use, copy, modify, distribute, and sell this software and its
8 * documentation for any purpose is hereby granted without fee, provided that
9 * the above copyright notice appear in all copies and that both that copyright
10 * notice and this permission notice appear in supporting documentation, and
11 * that the name of the copyright holders not be used in advertising or
12 * publicity pertaining to distribution of the software without specific,
13 * written prior permission. The copyright holders make no representations
14 * about the suitability of this software for any purpose. It is provided "as
15 * is" without express or implied warranty.
16 *
17 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
19 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
20 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
21 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
22 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
23 * OF THIS SOFTWARE.
24 *
25 * Authors:
26 * Keith Packard
27 * Eric Anholt <eric@anholt.net>
28 * Dave Airlie <airlied@linux.ie>
29 * Jesse Barnes <jesse.barnes@intel.com>
30 */
31
32 #include <linux/export.h>
33 #include <linux/moduleparam.h>
34
35 #include <drm/drmP.h>
36 #include <drm/drm_crtc.h>
37 #include <drm/drm_fourcc.h>
38 #include <drm/drm_crtc_helper.h>
39 #include <drm/drm_fb_helper.h>
40 #include <drm/drm_edid.h>
41
42 /**
43 * DOC: output probing helper overview
44 *
45 * This library provides some helper code for output probing. It provides an
46 * implementation of the core connector->fill_modes interface with
47 * drm_helper_probe_single_connector_modes.
48 *
49 * It also provides support for polling connectors with a work item and for
50 * generic hotplug interrupt handling where the driver doesn't or cannot keep
51 * track of a per-connector hpd interrupt.
52 *
53 * This helper library can be used independently of the modeset helper library.
54 * Drivers can also overwrite different parts e.g. use their own hotplug
55 * handling code to avoid probing unrelated outputs.
56 */
57
58 static bool drm_kms_helper_poll = true;
59 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
60
61 static enum drm_mode_status
drm_mode_validate_flag(const struct drm_display_mode * mode,int flags)62 drm_mode_validate_flag(const struct drm_display_mode *mode,
63 int flags)
64 {
65 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
66 !(flags & DRM_MODE_FLAG_INTERLACE))
67 return MODE_NO_INTERLACE;
68
69 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
70 !(flags & DRM_MODE_FLAG_DBLSCAN))
71 return MODE_NO_DBLESCAN;
72
73 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
74 !(flags & DRM_MODE_FLAG_3D_MASK))
75 return MODE_NO_STEREO;
76
77 return MODE_OK;
78 }
79
drm_helper_probe_add_cmdline_mode(struct drm_connector * connector)80 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
81 {
82 struct drm_display_mode *mode;
83
84 if (!connector->cmdline_mode.specified)
85 return 0;
86
87 mode = drm_mode_create_from_cmdline_mode(connector->dev,
88 &connector->cmdline_mode);
89 if (mode == NULL)
90 return 0;
91
92 drm_mode_probed_add(connector, mode);
93 return 1;
94 }
95
drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector * connector,uint32_t maxX,uint32_t maxY,bool merge_type_bits)96 static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector *connector,
97 uint32_t maxX, uint32_t maxY, bool merge_type_bits)
98 {
99 struct drm_device *dev = connector->dev;
100 struct drm_display_mode *mode;
101 const struct drm_connector_helper_funcs *connector_funcs =
102 connector->helper_private;
103 int count = 0;
104 int mode_flags = 0;
105 bool verbose_prune = true;
106 enum drm_connector_status old_status;
107
108 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
109
110 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
111 connector->name);
112 /* set all modes to the unverified state */
113 list_for_each_entry(mode, &connector->modes, head)
114 mode->status = MODE_UNVERIFIED;
115
116 if (connector->force) {
117 if (connector->force == DRM_FORCE_ON ||
118 connector->force == DRM_FORCE_ON_DIGITAL)
119 connector->status = connector_status_connected;
120 else
121 connector->status = connector_status_disconnected;
122 if (connector->funcs->force)
123 connector->funcs->force(connector);
124 } else {
125 old_status = connector->status;
126
127 connector->status = connector->funcs->detect(connector, true);
128
129 /*
130 * Normally either the driver's hpd code or the poll loop should
131 * pick up any changes and fire the hotplug event. But if
132 * userspace sneaks in a probe, we might miss a change. Hence
133 * check here, and if anything changed start the hotplug code.
134 */
135 if (old_status != connector->status) {
136 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
137 connector->base.id,
138 connector->name,
139 old_status, connector->status);
140
141 /*
142 * The hotplug event code might call into the fb
143 * helpers, and so expects that we do not hold any
144 * locks. Fire up the poll struct instead, it will
145 * disable itself again.
146 */
147 dev->mode_config.delayed_event = true;
148 if (dev->mode_config.poll_enabled)
149 schedule_delayed_work(&dev->mode_config.output_poll_work,
150 0);
151 }
152 }
153
154 /* Re-enable polling in case the global poll config changed. */
155 if (drm_kms_helper_poll != dev->mode_config.poll_running)
156 drm_kms_helper_poll_enable(dev);
157
158 dev->mode_config.poll_running = drm_kms_helper_poll;
159
160 if (connector->status == connector_status_disconnected) {
161 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
162 connector->base.id, connector->name);
163 drm_mode_connector_update_edid_property(connector, NULL);
164 verbose_prune = false;
165 goto prune;
166 }
167
168 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
169 count = drm_load_edid_firmware(connector);
170 if (count == 0)
171 #endif
172 {
173 if (connector->override_edid) {
174 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
175
176 count = drm_add_edid_modes(connector, edid);
177 drm_edid_to_eld(connector, edid);
178 } else
179 count = (*connector_funcs->get_modes)(connector);
180 }
181
182 if (count == 0 && connector->status == connector_status_connected)
183 count = drm_add_modes_noedid(connector, 1024, 768);
184 count += drm_helper_probe_add_cmdline_mode(connector);
185 if (count == 0)
186 goto prune;
187
188 drm_mode_connector_list_update(connector, merge_type_bits);
189
190 if (connector->interlace_allowed)
191 mode_flags |= DRM_MODE_FLAG_INTERLACE;
192 if (connector->doublescan_allowed)
193 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
194 if (connector->stereo_allowed)
195 mode_flags |= DRM_MODE_FLAG_3D_MASK;
196
197 list_for_each_entry(mode, &connector->modes, head) {
198 if (mode->status == MODE_OK)
199 mode->status = drm_mode_validate_basic(mode);
200
201 if (mode->status == MODE_OK)
202 mode->status = drm_mode_validate_size(mode, maxX, maxY);
203
204 if (mode->status == MODE_OK)
205 mode->status = drm_mode_validate_flag(mode, mode_flags);
206
207 if (mode->status == MODE_OK && connector_funcs->mode_valid)
208 mode->status = connector_funcs->mode_valid(connector,
209 mode);
210 }
211
212 prune:
213 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
214
215 if (list_empty(&connector->modes))
216 return 0;
217
218 list_for_each_entry(mode, &connector->modes, head)
219 mode->vrefresh = drm_mode_vrefresh(mode);
220
221 drm_mode_sort(&connector->modes);
222
223 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
224 connector->name);
225 list_for_each_entry(mode, &connector->modes, head) {
226 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
227 drm_mode_debug_printmodeline(mode);
228 }
229
230 return count;
231 }
232
233 /**
234 * drm_helper_probe_single_connector_modes - get complete set of display modes
235 * @connector: connector to probe
236 * @maxX: max width for modes
237 * @maxY: max height for modes
238 *
239 * Based on the helper callbacks implemented by @connector try to detect all
240 * valid modes. Modes will first be added to the connector's probed_modes list,
241 * then culled (based on validity and the @maxX, @maxY parameters) and put into
242 * the normal modes list.
243 *
244 * Intended to be use as a generic implementation of the ->fill_modes()
245 * @connector vfunc for drivers that use the crtc helpers for output mode
246 * filtering and detection.
247 *
248 * Returns:
249 * The number of modes found on @connector.
250 */
drm_helper_probe_single_connector_modes(struct drm_connector * connector,uint32_t maxX,uint32_t maxY)251 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
252 uint32_t maxX, uint32_t maxY)
253 {
254 return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, true);
255 }
256 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
257
258 /**
259 * drm_helper_probe_single_connector_modes_nomerge - get complete set of display modes
260 * @connector: connector to probe
261 * @maxX: max width for modes
262 * @maxY: max height for modes
263 *
264 * This operates like drm_hehlper_probe_single_connector_modes except it
265 * replaces the mode bits instead of merging them for preferred modes.
266 */
drm_helper_probe_single_connector_modes_nomerge(struct drm_connector * connector,uint32_t maxX,uint32_t maxY)267 int drm_helper_probe_single_connector_modes_nomerge(struct drm_connector *connector,
268 uint32_t maxX, uint32_t maxY)
269 {
270 return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, false);
271 }
272 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes_nomerge);
273
274 /**
275 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
276 * @dev: drm_device whose connector state changed
277 *
278 * This function fires off the uevent for userspace and also calls the
279 * output_poll_changed function, which is most commonly used to inform the fbdev
280 * emulation code and allow it to update the fbcon output configuration.
281 *
282 * Drivers should call this from their hotplug handling code when a change is
283 * detected. Note that this function does not do any output detection of its
284 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
285 * driver already.
286 *
287 * This function must be called from process context with no mode
288 * setting locks held.
289 */
drm_kms_helper_hotplug_event(struct drm_device * dev)290 void drm_kms_helper_hotplug_event(struct drm_device *dev)
291 {
292 /* send a uevent + call fbdev */
293 drm_sysfs_hotplug_event(dev);
294 if (dev->mode_config.funcs->output_poll_changed)
295 dev->mode_config.funcs->output_poll_changed(dev);
296 }
297 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
298
299 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
output_poll_execute(struct work_struct * work)300 static void output_poll_execute(struct work_struct *work)
301 {
302 struct delayed_work *delayed_work = to_delayed_work(work);
303 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
304 struct drm_connector *connector;
305 enum drm_connector_status old_status;
306 bool repoll = false, changed;
307
308 /* Pick up any changes detected by the probe functions. */
309 changed = dev->mode_config.delayed_event;
310 dev->mode_config.delayed_event = false;
311
312 if (!drm_kms_helper_poll)
313 goto out;
314
315 mutex_lock(&dev->mode_config.mutex);
316 list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
317
318 /* Ignore forced connectors. */
319 if (connector->force)
320 continue;
321
322 /* Ignore HPD capable connectors and connectors where we don't
323 * want any hotplug detection at all for polling. */
324 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
325 continue;
326
327 repoll = true;
328
329 old_status = connector->status;
330 /* if we are connected and don't want to poll for disconnect
331 skip it */
332 if (old_status == connector_status_connected &&
333 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
334 continue;
335
336 connector->status = connector->funcs->detect(connector, false);
337 if (old_status != connector->status) {
338 const char *old, *new;
339
340 /*
341 * The poll work sets force=false when calling detect so
342 * that drivers can avoid to do disruptive tests (e.g.
343 * when load detect cycles could cause flickering on
344 * other, running displays). This bears the risk that we
345 * flip-flop between unknown here in the poll work and
346 * the real state when userspace forces a full detect
347 * call after receiving a hotplug event due to this
348 * change.
349 *
350 * Hence clamp an unknown detect status to the old
351 * value.
352 */
353 if (connector->status == connector_status_unknown) {
354 connector->status = old_status;
355 continue;
356 }
357
358 old = drm_get_connector_status_name(old_status);
359 new = drm_get_connector_status_name(connector->status);
360
361 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
362 "status updated from %s to %s\n",
363 connector->base.id,
364 connector->name,
365 old, new);
366
367 changed = true;
368 }
369 }
370
371 mutex_unlock(&dev->mode_config.mutex);
372
373 out:
374 if (changed)
375 drm_kms_helper_hotplug_event(dev);
376
377 if (repoll)
378 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
379 }
380
381 /**
382 * drm_kms_helper_poll_disable - disable output polling
383 * @dev: drm_device
384 *
385 * This function disables the output polling work.
386 *
387 * Drivers can call this helper from their device suspend implementation. It is
388 * not an error to call this even when output polling isn't enabled or arlready
389 * disabled.
390 */
drm_kms_helper_poll_disable(struct drm_device * dev)391 void drm_kms_helper_poll_disable(struct drm_device *dev)
392 {
393 if (!dev->mode_config.poll_enabled)
394 return;
395 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
396 }
397 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
398
399 /**
400 * drm_kms_helper_poll_enable - re-enable output polling.
401 * @dev: drm_device
402 *
403 * This function re-enables the output polling work.
404 *
405 * Drivers can call this helper from their device resume implementation. It is
406 * an error to call this when the output polling support has not yet been set
407 * up.
408 */
drm_kms_helper_poll_enable(struct drm_device * dev)409 void drm_kms_helper_poll_enable(struct drm_device *dev)
410 {
411 bool poll = false;
412 struct drm_connector *connector;
413
414 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
415 return;
416
417 list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
418 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
419 DRM_CONNECTOR_POLL_DISCONNECT))
420 poll = true;
421 }
422
423 if (poll)
424 schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
425 }
426 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
427
428 /**
429 * drm_kms_helper_poll_init - initialize and enable output polling
430 * @dev: drm_device
431 *
432 * This function intializes and then also enables output polling support for
433 * @dev. Drivers which do not have reliable hotplug support in hardware can use
434 * this helper infrastructure to regularly poll such connectors for changes in
435 * their connection state.
436 *
437 * Drivers can control which connectors are polled by setting the
438 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
439 * connectors where probing live outputs can result in visual distortion drivers
440 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
441 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
442 * completely ignored by the polling logic.
443 *
444 * Note that a connector can be both polled and probed from the hotplug handler,
445 * in case the hotplug interrupt is known to be unreliable.
446 */
drm_kms_helper_poll_init(struct drm_device * dev)447 void drm_kms_helper_poll_init(struct drm_device *dev)
448 {
449 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
450 dev->mode_config.poll_enabled = true;
451
452 drm_kms_helper_poll_enable(dev);
453 }
454 EXPORT_SYMBOL(drm_kms_helper_poll_init);
455
456 /**
457 * drm_kms_helper_poll_fini - disable output polling and clean it up
458 * @dev: drm_device
459 */
drm_kms_helper_poll_fini(struct drm_device * dev)460 void drm_kms_helper_poll_fini(struct drm_device *dev)
461 {
462 drm_kms_helper_poll_disable(dev);
463 }
464 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
465
466 /**
467 * drm_helper_hpd_irq_event - hotplug processing
468 * @dev: drm_device
469 *
470 * Drivers can use this helper function to run a detect cycle on all connectors
471 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
472 * other connectors are ignored, which is useful to avoid reprobing fixed
473 * panels.
474 *
475 * This helper function is useful for drivers which can't or don't track hotplug
476 * interrupts for each connector.
477 *
478 * Drivers which support hotplug interrupts for each connector individually and
479 * which have a more fine-grained detect logic should bypass this code and
480 * directly call drm_kms_helper_hotplug_event() in case the connector state
481 * changed.
482 *
483 * This function must be called from process context with no mode
484 * setting locks held.
485 *
486 * Note that a connector can be both polled and probed from the hotplug handler,
487 * in case the hotplug interrupt is known to be unreliable.
488 */
drm_helper_hpd_irq_event(struct drm_device * dev)489 bool drm_helper_hpd_irq_event(struct drm_device *dev)
490 {
491 struct drm_connector *connector;
492 enum drm_connector_status old_status;
493 bool changed = false;
494
495 if (!dev->mode_config.poll_enabled)
496 return false;
497
498 mutex_lock(&dev->mode_config.mutex);
499 list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
500
501 /* Only handle HPD capable connectors. */
502 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
503 continue;
504
505 old_status = connector->status;
506
507 connector->status = connector->funcs->detect(connector, false);
508 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
509 connector->base.id,
510 connector->name,
511 drm_get_connector_status_name(old_status),
512 drm_get_connector_status_name(connector->status));
513 if (old_status != connector->status)
514 changed = true;
515 }
516
517 mutex_unlock(&dev->mode_config.mutex);
518
519 if (changed)
520 drm_kms_helper_hotplug_event(dev);
521
522 return changed;
523 }
524 EXPORT_SYMBOL(drm_helper_hpd_irq_event);
525