Loading...
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 * The probe helpers share the function table structures with other display
58 * helper libraries. See struct &drm_connector_helper_funcs for the details.
59 */
60
61static bool drm_kms_helper_poll = true;
62module_param_named(poll, drm_kms_helper_poll, bool, 0600);
63
64static enum drm_mode_status
65drm_mode_validate_flag(const struct drm_display_mode *mode,
66 int flags)
67{
68 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
69 !(flags & DRM_MODE_FLAG_INTERLACE))
70 return MODE_NO_INTERLACE;
71
72 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
73 !(flags & DRM_MODE_FLAG_DBLSCAN))
74 return MODE_NO_DBLESCAN;
75
76 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
77 !(flags & DRM_MODE_FLAG_3D_MASK))
78 return MODE_NO_STEREO;
79
80 return MODE_OK;
81}
82
83static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
84{
85 struct drm_display_mode *mode;
86
87 if (!connector->cmdline_mode.specified)
88 return 0;
89
90 mode = drm_mode_create_from_cmdline_mode(connector->dev,
91 &connector->cmdline_mode);
92 if (mode == NULL)
93 return 0;
94
95 drm_mode_probed_add(connector, mode);
96 return 1;
97}
98
99#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
100/**
101 * drm_kms_helper_poll_enable_locked - re-enable output polling.
102 * @dev: drm_device
103 *
104 * This function re-enables the output polling work without
105 * locking the mode_config mutex.
106 *
107 * This is like drm_kms_helper_poll_enable() however it is to be
108 * called from a context where the mode_config mutex is locked
109 * already.
110 */
111void drm_kms_helper_poll_enable_locked(struct drm_device *dev)
112{
113 bool poll = false;
114 struct drm_connector *connector;
115
116 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
117
118 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
119 return;
120
121 drm_for_each_connector(connector, dev) {
122 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
123 DRM_CONNECTOR_POLL_DISCONNECT))
124 poll = true;
125 }
126
127 if (poll)
128 schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
129}
130EXPORT_SYMBOL(drm_kms_helper_poll_enable_locked);
131
132/**
133 * drm_helper_probe_single_connector_modes - get complete set of display modes
134 * @connector: connector to probe
135 * @maxX: max width for modes
136 * @maxY: max height for modes
137 *
138 * Based on the helper callbacks implemented by @connector in struct
139 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
140 * be added to the connector's probed_modes list, then culled (based on validity
141 * and the @maxX, @maxY parameters) and put into the normal modes list.
142 *
143 * Intended to be used as a generic implementation of the ->fill_modes()
144 * @connector vfunc for drivers that use the CRTC helpers for output mode
145 * filtering and detection.
146 *
147 * The basic procedure is as follows
148 *
149 * 1. All modes currently on the connector's modes list are marked as stale
150 *
151 * 2. New modes are added to the connector's probed_modes list with
152 * drm_mode_probed_add(). New modes start their life with status as OK.
153 * Modes are added from a single source using the following priority order.
154 *
155 * - debugfs 'override_edid' (used for testing only)
156 * - firmware EDID (drm_load_edid_firmware())
157 * - connector helper ->get_modes() vfunc
158 * - if the connector status is connector_status_connected, standard
159 * VESA DMT modes up to 1024x768 are automatically added
160 * (drm_add_modes_noedid())
161 *
162 * Finally modes specified via the kernel command line (video=...) are
163 * added in addition to what the earlier probes produced
164 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
165 * using the VESA GTF/CVT formulas.
166 *
167 * 3. Modes are moved from the probed_modes list to the modes list. Potential
168 * duplicates are merged together (see drm_mode_connector_list_update()).
169 * After this step the probed_modes list will be empty again.
170 *
171 * 4. Any non-stale mode on the modes list then undergoes validation
172 *
173 * - drm_mode_validate_basic() performs basic sanity checks
174 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
175 * (if specified)
176 * - drm_mode_validate_flag() checks the modes againt basic connector
177 * capabilites (interlace_allowed,doublescan_allowed,stereo_allowed)
178 * - the optional connector ->mode_valid() helper can perform driver and/or
179 * hardware specific checks
180 *
181 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
182 * accompanied by a debug message indicating the reason for the mode's
183 * rejection (see drm_mode_prune_invalid()).
184 *
185 * Returns:
186 * The number of modes found on @connector.
187 */
188int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
189 uint32_t maxX, uint32_t maxY)
190{
191 struct drm_device *dev = connector->dev;
192 struct drm_display_mode *mode;
193 const struct drm_connector_helper_funcs *connector_funcs =
194 connector->helper_private;
195 int count = 0;
196 int mode_flags = 0;
197 bool verbose_prune = true;
198 enum drm_connector_status old_status;
199
200 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
201
202 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
203 connector->name);
204 /* set all old modes to the stale state */
205 list_for_each_entry(mode, &connector->modes, head)
206 mode->status = MODE_STALE;
207
208 old_status = connector->status;
209
210 if (connector->force) {
211 if (connector->force == DRM_FORCE_ON ||
212 connector->force == DRM_FORCE_ON_DIGITAL)
213 connector->status = connector_status_connected;
214 else
215 connector->status = connector_status_disconnected;
216 if (connector->funcs->force)
217 connector->funcs->force(connector);
218 } else {
219 connector->status = connector->funcs->detect(connector, true);
220 }
221
222 /*
223 * Normally either the driver's hpd code or the poll loop should
224 * pick up any changes and fire the hotplug event. But if
225 * userspace sneaks in a probe, we might miss a change. Hence
226 * check here, and if anything changed start the hotplug code.
227 */
228 if (old_status != connector->status) {
229 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
230 connector->base.id,
231 connector->name,
232 drm_get_connector_status_name(old_status),
233 drm_get_connector_status_name(connector->status));
234
235 /*
236 * The hotplug event code might call into the fb
237 * helpers, and so expects that we do not hold any
238 * locks. Fire up the poll struct instead, it will
239 * disable itself again.
240 */
241 dev->mode_config.delayed_event = true;
242 if (dev->mode_config.poll_enabled)
243 schedule_delayed_work(&dev->mode_config.output_poll_work,
244 0);
245 }
246
247 /* Re-enable polling in case the global poll config changed. */
248 if (drm_kms_helper_poll != dev->mode_config.poll_running)
249 drm_kms_helper_poll_enable_locked(dev);
250
251 dev->mode_config.poll_running = drm_kms_helper_poll;
252
253 if (connector->status == connector_status_disconnected) {
254 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
255 connector->base.id, connector->name);
256 drm_mode_connector_update_edid_property(connector, NULL);
257 verbose_prune = false;
258 goto prune;
259 }
260
261 if (connector->override_edid) {
262 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
263
264 count = drm_add_edid_modes(connector, edid);
265 drm_edid_to_eld(connector, edid);
266 } else {
267#ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
268 count = drm_load_edid_firmware(connector);
269 if (count == 0)
270#endif
271 count = (*connector_funcs->get_modes)(connector);
272 }
273
274 if (count == 0 && connector->status == connector_status_connected)
275 count = drm_add_modes_noedid(connector, 1024, 768);
276 count += drm_helper_probe_add_cmdline_mode(connector);
277 if (count == 0)
278 goto prune;
279
280 drm_mode_connector_list_update(connector);
281
282 if (connector->interlace_allowed)
283 mode_flags |= DRM_MODE_FLAG_INTERLACE;
284 if (connector->doublescan_allowed)
285 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
286 if (connector->stereo_allowed)
287 mode_flags |= DRM_MODE_FLAG_3D_MASK;
288
289 list_for_each_entry(mode, &connector->modes, head) {
290 if (mode->status == MODE_OK)
291 mode->status = drm_mode_validate_basic(mode);
292
293 if (mode->status == MODE_OK)
294 mode->status = drm_mode_validate_size(mode, maxX, maxY);
295
296 if (mode->status == MODE_OK)
297 mode->status = drm_mode_validate_flag(mode, mode_flags);
298
299 if (mode->status == MODE_OK && connector_funcs->mode_valid)
300 mode->status = connector_funcs->mode_valid(connector,
301 mode);
302 }
303
304prune:
305 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
306
307 if (list_empty(&connector->modes))
308 return 0;
309
310 list_for_each_entry(mode, &connector->modes, head)
311 mode->vrefresh = drm_mode_vrefresh(mode);
312
313 drm_mode_sort(&connector->modes);
314
315 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
316 connector->name);
317 list_for_each_entry(mode, &connector->modes, head) {
318 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
319 drm_mode_debug_printmodeline(mode);
320 }
321
322 return count;
323}
324EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
325
326/**
327 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
328 * @dev: drm_device whose connector state changed
329 *
330 * This function fires off the uevent for userspace and also calls the
331 * output_poll_changed function, which is most commonly used to inform the fbdev
332 * emulation code and allow it to update the fbcon output configuration.
333 *
334 * Drivers should call this from their hotplug handling code when a change is
335 * detected. Note that this function does not do any output detection of its
336 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
337 * driver already.
338 *
339 * This function must be called from process context with no mode
340 * setting locks held.
341 */
342void drm_kms_helper_hotplug_event(struct drm_device *dev)
343{
344 /* send a uevent + call fbdev */
345 drm_sysfs_hotplug_event(dev);
346 if (dev->mode_config.funcs->output_poll_changed)
347 dev->mode_config.funcs->output_poll_changed(dev);
348}
349EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
350
351static void output_poll_execute(struct work_struct *work)
352{
353 struct delayed_work *delayed_work = to_delayed_work(work);
354 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
355 struct drm_connector *connector;
356 enum drm_connector_status old_status;
357 bool repoll = false, changed;
358
359 /* Pick up any changes detected by the probe functions. */
360 changed = dev->mode_config.delayed_event;
361 dev->mode_config.delayed_event = false;
362
363 if (!drm_kms_helper_poll)
364 goto out;
365
366 mutex_lock(&dev->mode_config.mutex);
367 drm_for_each_connector(connector, dev) {
368
369 /* Ignore forced connectors. */
370 if (connector->force)
371 continue;
372
373 /* Ignore HPD capable connectors and connectors where we don't
374 * want any hotplug detection at all for polling. */
375 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
376 continue;
377
378 old_status = connector->status;
379 /* if we are connected and don't want to poll for disconnect
380 skip it */
381 if (old_status == connector_status_connected &&
382 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
383 continue;
384
385 repoll = true;
386
387 connector->status = connector->funcs->detect(connector, false);
388 if (old_status != connector->status) {
389 const char *old, *new;
390
391 /*
392 * The poll work sets force=false when calling detect so
393 * that drivers can avoid to do disruptive tests (e.g.
394 * when load detect cycles could cause flickering on
395 * other, running displays). This bears the risk that we
396 * flip-flop between unknown here in the poll work and
397 * the real state when userspace forces a full detect
398 * call after receiving a hotplug event due to this
399 * change.
400 *
401 * Hence clamp an unknown detect status to the old
402 * value.
403 */
404 if (connector->status == connector_status_unknown) {
405 connector->status = old_status;
406 continue;
407 }
408
409 old = drm_get_connector_status_name(old_status);
410 new = drm_get_connector_status_name(connector->status);
411
412 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
413 "status updated from %s to %s\n",
414 connector->base.id,
415 connector->name,
416 old, new);
417
418 changed = true;
419 }
420 }
421
422 mutex_unlock(&dev->mode_config.mutex);
423
424out:
425 if (changed)
426 drm_kms_helper_hotplug_event(dev);
427
428 if (repoll)
429 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
430}
431
432/**
433 * drm_kms_helper_poll_disable - disable output polling
434 * @dev: drm_device
435 *
436 * This function disables the output polling work.
437 *
438 * Drivers can call this helper from their device suspend implementation. It is
439 * not an error to call this even when output polling isn't enabled or arlready
440 * disabled.
441 */
442void drm_kms_helper_poll_disable(struct drm_device *dev)
443{
444 if (!dev->mode_config.poll_enabled)
445 return;
446 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
447}
448EXPORT_SYMBOL(drm_kms_helper_poll_disable);
449
450/**
451 * drm_kms_helper_poll_enable - re-enable output polling.
452 * @dev: drm_device
453 *
454 * This function re-enables the output polling work.
455 *
456 * Drivers can call this helper from their device resume implementation. It is
457 * an error to call this when the output polling support has not yet been set
458 * up.
459 */
460void drm_kms_helper_poll_enable(struct drm_device *dev)
461{
462 mutex_lock(&dev->mode_config.mutex);
463 drm_kms_helper_poll_enable_locked(dev);
464 mutex_unlock(&dev->mode_config.mutex);
465}
466EXPORT_SYMBOL(drm_kms_helper_poll_enable);
467
468/**
469 * drm_kms_helper_poll_init - initialize and enable output polling
470 * @dev: drm_device
471 *
472 * This function intializes and then also enables output polling support for
473 * @dev. Drivers which do not have reliable hotplug support in hardware can use
474 * this helper infrastructure to regularly poll such connectors for changes in
475 * their connection state.
476 *
477 * Drivers can control which connectors are polled by setting the
478 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
479 * connectors where probing live outputs can result in visual distortion drivers
480 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
481 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
482 * completely ignored by the polling logic.
483 *
484 * Note that a connector can be both polled and probed from the hotplug handler,
485 * in case the hotplug interrupt is known to be unreliable.
486 */
487void drm_kms_helper_poll_init(struct drm_device *dev)
488{
489 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
490 dev->mode_config.poll_enabled = true;
491
492 drm_kms_helper_poll_enable(dev);
493}
494EXPORT_SYMBOL(drm_kms_helper_poll_init);
495
496/**
497 * drm_kms_helper_poll_fini - disable output polling and clean it up
498 * @dev: drm_device
499 */
500void drm_kms_helper_poll_fini(struct drm_device *dev)
501{
502 drm_kms_helper_poll_disable(dev);
503}
504EXPORT_SYMBOL(drm_kms_helper_poll_fini);
505
506/**
507 * drm_helper_hpd_irq_event - hotplug processing
508 * @dev: drm_device
509 *
510 * Drivers can use this helper function to run a detect cycle on all connectors
511 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
512 * other connectors are ignored, which is useful to avoid reprobing fixed
513 * panels.
514 *
515 * This helper function is useful for drivers which can't or don't track hotplug
516 * interrupts for each connector.
517 *
518 * Drivers which support hotplug interrupts for each connector individually and
519 * which have a more fine-grained detect logic should bypass this code and
520 * directly call drm_kms_helper_hotplug_event() in case the connector state
521 * changed.
522 *
523 * This function must be called from process context with no mode
524 * setting locks held.
525 *
526 * Note that a connector can be both polled and probed from the hotplug handler,
527 * in case the hotplug interrupt is known to be unreliable.
528 */
529bool drm_helper_hpd_irq_event(struct drm_device *dev)
530{
531 struct drm_connector *connector;
532 enum drm_connector_status old_status;
533 bool changed = false;
534
535 if (!dev->mode_config.poll_enabled)
536 return false;
537
538 mutex_lock(&dev->mode_config.mutex);
539 drm_for_each_connector(connector, dev) {
540
541 /* Only handle HPD capable connectors. */
542 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
543 continue;
544
545 old_status = connector->status;
546
547 connector->status = connector->funcs->detect(connector, false);
548 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
549 connector->base.id,
550 connector->name,
551 drm_get_connector_status_name(old_status),
552 drm_get_connector_status_name(connector->status));
553 if (old_status != connector->status)
554 changed = true;
555 }
556
557 mutex_unlock(&dev->mode_config.mutex);
558
559 if (changed)
560 drm_kms_helper_hotplug_event(dev);
561
562 return changed;
563}
564EXPORT_SYMBOL(drm_helper_hpd_irq_event);
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/drm_bridge.h>
36#include <drm/drm_client.h>
37#include <drm/drm_crtc.h>
38#include <drm/drm_edid.h>
39#include <drm/drm_fb_helper.h>
40#include <drm/drm_fourcc.h>
41#include <drm/drm_modeset_helper_vtables.h>
42#include <drm/drm_print.h>
43#include <drm/drm_probe_helper.h>
44#include <drm/drm_sysfs.h>
45
46#include "drm_crtc_helper_internal.h"
47
48/**
49 * DOC: output probing helper overview
50 *
51 * This library provides some helper code for output probing. It provides an
52 * implementation of the core &drm_connector_funcs.fill_modes interface with
53 * drm_helper_probe_single_connector_modes().
54 *
55 * It also provides support for polling connectors with a work item and for
56 * generic hotplug interrupt handling where the driver doesn't or cannot keep
57 * track of a per-connector hpd interrupt.
58 *
59 * This helper library can be used independently of the modeset helper library.
60 * Drivers can also overwrite different parts e.g. use their own hotplug
61 * handling code to avoid probing unrelated outputs.
62 *
63 * The probe helpers share the function table structures with other display
64 * helper libraries. See &struct drm_connector_helper_funcs for the details.
65 */
66
67static bool drm_kms_helper_poll = true;
68module_param_named(poll, drm_kms_helper_poll, bool, 0600);
69
70static enum drm_mode_status
71drm_mode_validate_flag(const struct drm_display_mode *mode,
72 int flags)
73{
74 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
75 !(flags & DRM_MODE_FLAG_INTERLACE))
76 return MODE_NO_INTERLACE;
77
78 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
79 !(flags & DRM_MODE_FLAG_DBLSCAN))
80 return MODE_NO_DBLESCAN;
81
82 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
83 !(flags & DRM_MODE_FLAG_3D_MASK))
84 return MODE_NO_STEREO;
85
86 return MODE_OK;
87}
88
89static int
90drm_mode_validate_pipeline(struct drm_display_mode *mode,
91 struct drm_connector *connector,
92 struct drm_modeset_acquire_ctx *ctx,
93 enum drm_mode_status *status)
94{
95 struct drm_device *dev = connector->dev;
96 struct drm_encoder *encoder;
97 int ret;
98
99 /* Step 1: Validate against connector */
100 ret = drm_connector_mode_valid(connector, mode, ctx, status);
101 if (ret || *status != MODE_OK)
102 return ret;
103
104 /* Step 2: Validate against encoders and crtcs */
105 drm_connector_for_each_possible_encoder(connector, encoder) {
106 struct drm_bridge *bridge;
107 struct drm_crtc *crtc;
108
109 *status = drm_encoder_mode_valid(encoder, mode);
110 if (*status != MODE_OK) {
111 /* No point in continuing for crtc check as this encoder
112 * will not accept the mode anyway. If all encoders
113 * reject the mode then, at exit, ret will not be
114 * MODE_OK. */
115 continue;
116 }
117
118 bridge = drm_bridge_chain_get_first_bridge(encoder);
119 *status = drm_bridge_chain_mode_valid(bridge,
120 &connector->display_info,
121 mode);
122 if (*status != MODE_OK) {
123 /* There is also no point in continuing for crtc check
124 * here. */
125 continue;
126 }
127
128 drm_for_each_crtc(crtc, dev) {
129 if (!drm_encoder_crtc_ok(encoder, crtc))
130 continue;
131
132 *status = drm_crtc_mode_valid(crtc, mode);
133 if (*status == MODE_OK) {
134 /* If we get to this point there is at least
135 * one combination of encoder+crtc that works
136 * for this mode. Lets return now. */
137 return 0;
138 }
139 }
140 }
141
142 return 0;
143}
144
145static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
146{
147 struct drm_cmdline_mode *cmdline_mode;
148 struct drm_display_mode *mode;
149
150 cmdline_mode = &connector->cmdline_mode;
151 if (!cmdline_mode->specified)
152 return 0;
153
154 /* Only add a GTF mode if we find no matching probed modes */
155 list_for_each_entry(mode, &connector->probed_modes, head) {
156 if (mode->hdisplay != cmdline_mode->xres ||
157 mode->vdisplay != cmdline_mode->yres)
158 continue;
159
160 if (cmdline_mode->refresh_specified) {
161 /* The probed mode's vrefresh is set until later */
162 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
163 continue;
164 }
165
166 /* Mark the matching mode as being preferred by the user */
167 mode->type |= DRM_MODE_TYPE_USERDEF;
168 return 0;
169 }
170
171 mode = drm_mode_create_from_cmdline_mode(connector->dev,
172 cmdline_mode);
173 if (mode == NULL)
174 return 0;
175
176 drm_mode_probed_add(connector, mode);
177 return 1;
178}
179
180enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
181 const struct drm_display_mode *mode)
182{
183 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
184
185 if (!crtc_funcs || !crtc_funcs->mode_valid)
186 return MODE_OK;
187
188 return crtc_funcs->mode_valid(crtc, mode);
189}
190
191enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
192 const struct drm_display_mode *mode)
193{
194 const struct drm_encoder_helper_funcs *encoder_funcs =
195 encoder->helper_private;
196
197 if (!encoder_funcs || !encoder_funcs->mode_valid)
198 return MODE_OK;
199
200 return encoder_funcs->mode_valid(encoder, mode);
201}
202
203int
204drm_connector_mode_valid(struct drm_connector *connector,
205 struct drm_display_mode *mode,
206 struct drm_modeset_acquire_ctx *ctx,
207 enum drm_mode_status *status)
208{
209 const struct drm_connector_helper_funcs *connector_funcs =
210 connector->helper_private;
211 int ret = 0;
212
213 if (!connector_funcs)
214 *status = MODE_OK;
215 else if (connector_funcs->mode_valid_ctx)
216 ret = connector_funcs->mode_valid_ctx(connector, mode, ctx,
217 status);
218 else if (connector_funcs->mode_valid)
219 *status = connector_funcs->mode_valid(connector, mode);
220 else
221 *status = MODE_OK;
222
223 return ret;
224}
225
226#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
227/**
228 * drm_kms_helper_poll_enable - re-enable output polling.
229 * @dev: drm_device
230 *
231 * This function re-enables the output polling work, after it has been
232 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
233 * suspend/resume.
234 *
235 * Drivers can call this helper from their device resume implementation. It is
236 * not an error to call this even when output polling isn't enabled.
237 *
238 * Note that calls to enable and disable polling must be strictly ordered, which
239 * is automatically the case when they're only call from suspend/resume
240 * callbacks.
241 */
242void drm_kms_helper_poll_enable(struct drm_device *dev)
243{
244 bool poll = false;
245 struct drm_connector *connector;
246 struct drm_connector_list_iter conn_iter;
247 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
248
249 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
250 return;
251
252 drm_connector_list_iter_begin(dev, &conn_iter);
253 drm_for_each_connector_iter(connector, &conn_iter) {
254 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
255 DRM_CONNECTOR_POLL_DISCONNECT))
256 poll = true;
257 }
258 drm_connector_list_iter_end(&conn_iter);
259
260 if (dev->mode_config.delayed_event) {
261 /*
262 * FIXME:
263 *
264 * Use short (1s) delay to handle the initial delayed event.
265 * This delay should not be needed, but Optimus/nouveau will
266 * fail in a mysterious way if the delayed event is handled as
267 * soon as possible like it is done in
268 * drm_helper_probe_single_connector_modes() in case the poll
269 * was enabled before.
270 */
271 poll = true;
272 delay = HZ;
273 }
274
275 if (poll)
276 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
277}
278EXPORT_SYMBOL(drm_kms_helper_poll_enable);
279
280static enum drm_connector_status
281drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
282{
283 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
284 struct drm_modeset_acquire_ctx ctx;
285 int ret;
286
287 drm_modeset_acquire_init(&ctx, 0);
288
289retry:
290 ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
291 if (!ret) {
292 if (funcs->detect_ctx)
293 ret = funcs->detect_ctx(connector, &ctx, force);
294 else if (connector->funcs->detect)
295 ret = connector->funcs->detect(connector, force);
296 else
297 ret = connector_status_connected;
298 }
299
300 if (ret == -EDEADLK) {
301 drm_modeset_backoff(&ctx);
302 goto retry;
303 }
304
305 if (WARN_ON(ret < 0))
306 ret = connector_status_unknown;
307
308 if (ret != connector->status)
309 connector->epoch_counter += 1;
310
311 drm_modeset_drop_locks(&ctx);
312 drm_modeset_acquire_fini(&ctx);
313
314 return ret;
315}
316
317/**
318 * drm_helper_probe_detect - probe connector status
319 * @connector: connector to probe
320 * @ctx: acquire_ctx, or NULL to let this function handle locking.
321 * @force: Whether destructive probe operations should be performed.
322 *
323 * This function calls the detect callbacks of the connector.
324 * This function returns &drm_connector_status, or
325 * if @ctx is set, it might also return -EDEADLK.
326 */
327int
328drm_helper_probe_detect(struct drm_connector *connector,
329 struct drm_modeset_acquire_ctx *ctx,
330 bool force)
331{
332 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
333 struct drm_device *dev = connector->dev;
334 int ret;
335
336 if (!ctx)
337 return drm_helper_probe_detect_ctx(connector, force);
338
339 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
340 if (ret)
341 return ret;
342
343 if (funcs->detect_ctx)
344 ret = funcs->detect_ctx(connector, ctx, force);
345 else if (connector->funcs->detect)
346 ret = connector->funcs->detect(connector, force);
347 else
348 ret = connector_status_connected;
349
350 if (ret != connector->status)
351 connector->epoch_counter += 1;
352
353 return ret;
354}
355EXPORT_SYMBOL(drm_helper_probe_detect);
356
357/**
358 * drm_helper_probe_single_connector_modes - get complete set of display modes
359 * @connector: connector to probe
360 * @maxX: max width for modes
361 * @maxY: max height for modes
362 *
363 * Based on the helper callbacks implemented by @connector in struct
364 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
365 * be added to the connector's probed_modes list, then culled (based on validity
366 * and the @maxX, @maxY parameters) and put into the normal modes list.
367 *
368 * Intended to be used as a generic implementation of the
369 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
370 * for output mode filtering and detection.
371 *
372 * The basic procedure is as follows
373 *
374 * 1. All modes currently on the connector's modes list are marked as stale
375 *
376 * 2. New modes are added to the connector's probed_modes list with
377 * drm_mode_probed_add(). New modes start their life with status as OK.
378 * Modes are added from a single source using the following priority order.
379 *
380 * - &drm_connector_helper_funcs.get_modes vfunc
381 * - if the connector status is connector_status_connected, standard
382 * VESA DMT modes up to 1024x768 are automatically added
383 * (drm_add_modes_noedid())
384 *
385 * Finally modes specified via the kernel command line (video=...) are
386 * added in addition to what the earlier probes produced
387 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
388 * using the VESA GTF/CVT formulas.
389 *
390 * 3. Modes are moved from the probed_modes list to the modes list. Potential
391 * duplicates are merged together (see drm_connector_list_update()).
392 * After this step the probed_modes list will be empty again.
393 *
394 * 4. Any non-stale mode on the modes list then undergoes validation
395 *
396 * - drm_mode_validate_basic() performs basic sanity checks
397 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
398 * (if specified)
399 * - drm_mode_validate_flag() checks the modes against basic connector
400 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
401 * - the optional &drm_connector_helper_funcs.mode_valid or
402 * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
403 * and/or sink specific checks
404 * - the optional &drm_crtc_helper_funcs.mode_valid,
405 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
406 * helpers can perform driver and/or source specific checks which are also
407 * enforced by the modeset/atomic helpers
408 *
409 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
410 * accompanied by a debug message indicating the reason for the mode's
411 * rejection (see drm_mode_prune_invalid()).
412 *
413 * Returns:
414 * The number of modes found on @connector.
415 */
416int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
417 uint32_t maxX, uint32_t maxY)
418{
419 struct drm_device *dev = connector->dev;
420 struct drm_display_mode *mode;
421 const struct drm_connector_helper_funcs *connector_funcs =
422 connector->helper_private;
423 int count = 0, ret;
424 int mode_flags = 0;
425 bool verbose_prune = true;
426 enum drm_connector_status old_status;
427 struct drm_modeset_acquire_ctx ctx;
428
429 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
430
431 drm_modeset_acquire_init(&ctx, 0);
432
433 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
434 connector->name);
435
436retry:
437 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
438 if (ret == -EDEADLK) {
439 drm_modeset_backoff(&ctx);
440 goto retry;
441 } else
442 WARN_ON(ret < 0);
443
444 /* set all old modes to the stale state */
445 list_for_each_entry(mode, &connector->modes, head)
446 mode->status = MODE_STALE;
447
448 old_status = connector->status;
449
450 if (connector->force) {
451 if (connector->force == DRM_FORCE_ON ||
452 connector->force == DRM_FORCE_ON_DIGITAL)
453 connector->status = connector_status_connected;
454 else
455 connector->status = connector_status_disconnected;
456 if (connector->funcs->force)
457 connector->funcs->force(connector);
458 } else {
459 ret = drm_helper_probe_detect(connector, &ctx, true);
460
461 if (ret == -EDEADLK) {
462 drm_modeset_backoff(&ctx);
463 goto retry;
464 } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
465 ret = connector_status_unknown;
466
467 connector->status = ret;
468 }
469
470 /*
471 * Normally either the driver's hpd code or the poll loop should
472 * pick up any changes and fire the hotplug event. But if
473 * userspace sneaks in a probe, we might miss a change. Hence
474 * check here, and if anything changed start the hotplug code.
475 */
476 if (old_status != connector->status) {
477 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
478 connector->base.id,
479 connector->name,
480 drm_get_connector_status_name(old_status),
481 drm_get_connector_status_name(connector->status));
482
483 /*
484 * The hotplug event code might call into the fb
485 * helpers, and so expects that we do not hold any
486 * locks. Fire up the poll struct instead, it will
487 * disable itself again.
488 */
489 dev->mode_config.delayed_event = true;
490 if (dev->mode_config.poll_enabled)
491 schedule_delayed_work(&dev->mode_config.output_poll_work,
492 0);
493 }
494
495 /* Re-enable polling in case the global poll config changed. */
496 if (drm_kms_helper_poll != dev->mode_config.poll_running)
497 drm_kms_helper_poll_enable(dev);
498
499 dev->mode_config.poll_running = drm_kms_helper_poll;
500
501 if (connector->status == connector_status_disconnected) {
502 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
503 connector->base.id, connector->name);
504 drm_connector_update_edid_property(connector, NULL);
505 verbose_prune = false;
506 goto prune;
507 }
508
509 count = (*connector_funcs->get_modes)(connector);
510
511 /*
512 * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
513 * override/firmware EDID.
514 */
515 if (count == 0 && connector->status == connector_status_connected)
516 count = drm_add_override_edid_modes(connector);
517
518 if (count == 0 && (connector->status == connector_status_connected ||
519 connector->status == connector_status_unknown))
520 count = drm_add_modes_noedid(connector, 1024, 768);
521 count += drm_helper_probe_add_cmdline_mode(connector);
522 if (count == 0)
523 goto prune;
524
525 drm_connector_list_update(connector);
526
527 if (connector->interlace_allowed)
528 mode_flags |= DRM_MODE_FLAG_INTERLACE;
529 if (connector->doublescan_allowed)
530 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
531 if (connector->stereo_allowed)
532 mode_flags |= DRM_MODE_FLAG_3D_MASK;
533
534 list_for_each_entry(mode, &connector->modes, head) {
535 if (mode->status != MODE_OK)
536 continue;
537
538 mode->status = drm_mode_validate_driver(dev, mode);
539 if (mode->status != MODE_OK)
540 continue;
541
542 mode->status = drm_mode_validate_size(mode, maxX, maxY);
543 if (mode->status != MODE_OK)
544 continue;
545
546 mode->status = drm_mode_validate_flag(mode, mode_flags);
547 if (mode->status != MODE_OK)
548 continue;
549
550 ret = drm_mode_validate_pipeline(mode, connector, &ctx,
551 &mode->status);
552 if (ret) {
553 drm_dbg_kms(dev,
554 "drm_mode_validate_pipeline failed: %d\n",
555 ret);
556
557 if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK)) {
558 mode->status = MODE_ERROR;
559 } else {
560 drm_modeset_backoff(&ctx);
561 goto retry;
562 }
563 }
564
565 if (mode->status != MODE_OK)
566 continue;
567 mode->status = drm_mode_validate_ycbcr420(mode, connector);
568 }
569
570prune:
571 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
572
573 drm_modeset_drop_locks(&ctx);
574 drm_modeset_acquire_fini(&ctx);
575
576 if (list_empty(&connector->modes))
577 return 0;
578
579 drm_mode_sort(&connector->modes);
580
581 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
582 connector->name);
583 list_for_each_entry(mode, &connector->modes, head) {
584 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
585 drm_mode_debug_printmodeline(mode);
586 }
587
588 return count;
589}
590EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
591
592/**
593 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
594 * @dev: drm_device whose connector state changed
595 *
596 * This function fires off the uevent for userspace and also calls the
597 * output_poll_changed function, which is most commonly used to inform the fbdev
598 * emulation code and allow it to update the fbcon output configuration.
599 *
600 * Drivers should call this from their hotplug handling code when a change is
601 * detected. Note that this function does not do any output detection of its
602 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
603 * driver already.
604 *
605 * This function must be called from process context with no mode
606 * setting locks held.
607 */
608void drm_kms_helper_hotplug_event(struct drm_device *dev)
609{
610 /* send a uevent + call fbdev */
611 drm_sysfs_hotplug_event(dev);
612 if (dev->mode_config.funcs->output_poll_changed)
613 dev->mode_config.funcs->output_poll_changed(dev);
614
615 drm_client_dev_hotplug(dev);
616}
617EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
618
619static void output_poll_execute(struct work_struct *work)
620{
621 struct delayed_work *delayed_work = to_delayed_work(work);
622 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
623 struct drm_connector *connector;
624 struct drm_connector_list_iter conn_iter;
625 enum drm_connector_status old_status;
626 bool repoll = false, changed;
627 u64 old_epoch_counter;
628
629 if (!dev->mode_config.poll_enabled)
630 return;
631
632 /* Pick up any changes detected by the probe functions. */
633 changed = dev->mode_config.delayed_event;
634 dev->mode_config.delayed_event = false;
635
636 if (!drm_kms_helper_poll)
637 goto out;
638
639 if (!mutex_trylock(&dev->mode_config.mutex)) {
640 repoll = true;
641 goto out;
642 }
643
644 drm_connector_list_iter_begin(dev, &conn_iter);
645 drm_for_each_connector_iter(connector, &conn_iter) {
646 /* Ignore forced connectors. */
647 if (connector->force)
648 continue;
649
650 /* Ignore HPD capable connectors and connectors where we don't
651 * want any hotplug detection at all for polling. */
652 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
653 continue;
654
655 old_status = connector->status;
656 /* if we are connected and don't want to poll for disconnect
657 skip it */
658 if (old_status == connector_status_connected &&
659 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
660 continue;
661
662 repoll = true;
663
664 old_epoch_counter = connector->epoch_counter;
665 connector->status = drm_helper_probe_detect(connector, NULL, false);
666 if (old_epoch_counter != connector->epoch_counter) {
667 const char *old, *new;
668
669 /*
670 * The poll work sets force=false when calling detect so
671 * that drivers can avoid to do disruptive tests (e.g.
672 * when load detect cycles could cause flickering on
673 * other, running displays). This bears the risk that we
674 * flip-flop between unknown here in the poll work and
675 * the real state when userspace forces a full detect
676 * call after receiving a hotplug event due to this
677 * change.
678 *
679 * Hence clamp an unknown detect status to the old
680 * value.
681 */
682 if (connector->status == connector_status_unknown) {
683 connector->status = old_status;
684 continue;
685 }
686
687 old = drm_get_connector_status_name(old_status);
688 new = drm_get_connector_status_name(connector->status);
689
690 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
691 "status updated from %s to %s\n",
692 connector->base.id,
693 connector->name,
694 old, new);
695 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
696 connector->base.id, connector->name,
697 old_epoch_counter, connector->epoch_counter);
698
699 changed = true;
700 }
701 }
702 drm_connector_list_iter_end(&conn_iter);
703
704 mutex_unlock(&dev->mode_config.mutex);
705
706out:
707 if (changed)
708 drm_kms_helper_hotplug_event(dev);
709
710 if (repoll)
711 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
712}
713
714/**
715 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
716 *
717 * Determine if %current task is an output poll worker. This can be used
718 * to select distinct code paths for output polling versus other contexts.
719 *
720 * One use case is to avoid a deadlock between the output poll worker and
721 * the autosuspend worker wherein the latter waits for polling to finish
722 * upon calling drm_kms_helper_poll_disable(), while the former waits for
723 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
724 * connector ->detect hook.
725 */
726bool drm_kms_helper_is_poll_worker(void)
727{
728 struct work_struct *work = current_work();
729
730 return work && work->func == output_poll_execute;
731}
732EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
733
734/**
735 * drm_kms_helper_poll_disable - disable output polling
736 * @dev: drm_device
737 *
738 * This function disables the output polling work.
739 *
740 * Drivers can call this helper from their device suspend implementation. It is
741 * not an error to call this even when output polling isn't enabled or already
742 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
743 *
744 * Note that calls to enable and disable polling must be strictly ordered, which
745 * is automatically the case when they're only call from suspend/resume
746 * callbacks.
747 */
748void drm_kms_helper_poll_disable(struct drm_device *dev)
749{
750 if (!dev->mode_config.poll_enabled)
751 return;
752 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
753}
754EXPORT_SYMBOL(drm_kms_helper_poll_disable);
755
756/**
757 * drm_kms_helper_poll_init - initialize and enable output polling
758 * @dev: drm_device
759 *
760 * This function intializes and then also enables output polling support for
761 * @dev. Drivers which do not have reliable hotplug support in hardware can use
762 * this helper infrastructure to regularly poll such connectors for changes in
763 * their connection state.
764 *
765 * Drivers can control which connectors are polled by setting the
766 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
767 * connectors where probing live outputs can result in visual distortion drivers
768 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
769 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
770 * completely ignored by the polling logic.
771 *
772 * Note that a connector can be both polled and probed from the hotplug handler,
773 * in case the hotplug interrupt is known to be unreliable.
774 */
775void drm_kms_helper_poll_init(struct drm_device *dev)
776{
777 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
778 dev->mode_config.poll_enabled = true;
779
780 drm_kms_helper_poll_enable(dev);
781}
782EXPORT_SYMBOL(drm_kms_helper_poll_init);
783
784/**
785 * drm_kms_helper_poll_fini - disable output polling and clean it up
786 * @dev: drm_device
787 */
788void drm_kms_helper_poll_fini(struct drm_device *dev)
789{
790 if (!dev->mode_config.poll_enabled)
791 return;
792
793 dev->mode_config.poll_enabled = false;
794 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
795}
796EXPORT_SYMBOL(drm_kms_helper_poll_fini);
797
798/**
799 * drm_helper_hpd_irq_event - hotplug processing
800 * @dev: drm_device
801 *
802 * Drivers can use this helper function to run a detect cycle on all connectors
803 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
804 * other connectors are ignored, which is useful to avoid reprobing fixed
805 * panels.
806 *
807 * This helper function is useful for drivers which can't or don't track hotplug
808 * interrupts for each connector.
809 *
810 * Drivers which support hotplug interrupts for each connector individually and
811 * which have a more fine-grained detect logic should bypass this code and
812 * directly call drm_kms_helper_hotplug_event() in case the connector state
813 * changed.
814 *
815 * This function must be called from process context with no mode
816 * setting locks held.
817 *
818 * Note that a connector can be both polled and probed from the hotplug handler,
819 * in case the hotplug interrupt is known to be unreliable.
820 */
821bool drm_helper_hpd_irq_event(struct drm_device *dev)
822{
823 struct drm_connector *connector;
824 struct drm_connector_list_iter conn_iter;
825 enum drm_connector_status old_status;
826 bool changed = false;
827 u64 old_epoch_counter;
828
829 if (!dev->mode_config.poll_enabled)
830 return false;
831
832 mutex_lock(&dev->mode_config.mutex);
833 drm_connector_list_iter_begin(dev, &conn_iter);
834 drm_for_each_connector_iter(connector, &conn_iter) {
835 /* Only handle HPD capable connectors. */
836 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
837 continue;
838
839 old_status = connector->status;
840
841 old_epoch_counter = connector->epoch_counter;
842
843 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Old epoch counter %llu\n", connector->base.id,
844 connector->name,
845 old_epoch_counter);
846
847 connector->status = drm_helper_probe_detect(connector, NULL, false);
848 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
849 connector->base.id,
850 connector->name,
851 drm_get_connector_status_name(old_status),
852 drm_get_connector_status_name(connector->status));
853
854 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] New epoch counter %llu\n",
855 connector->base.id,
856 connector->name,
857 connector->epoch_counter);
858
859 /*
860 * Check if epoch counter had changed, meaning that we need
861 * to send a uevent.
862 */
863 if (old_epoch_counter != connector->epoch_counter)
864 changed = true;
865
866 }
867 drm_connector_list_iter_end(&conn_iter);
868 mutex_unlock(&dev->mode_config.mutex);
869
870 if (changed) {
871 drm_kms_helper_hotplug_event(dev);
872 DRM_DEBUG_KMS("Sent hotplug event\n");
873 }
874
875 return changed;
876}
877EXPORT_SYMBOL(drm_helper_hpd_irq_event);