2 * Copyright (c) 2006-2008 Intel Corporation
3 * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
5 * DRM core CRTC related functions
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.
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
27 * Eric Anholt <eric@anholt.net>
28 * Dave Airlie <airlied@linux.ie>
29 * Jesse Barnes <jesse.barnes@intel.com>
32 #include <linux/export.h>
33 #include <linux/moduleparam.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>
43 * DOC: output probing helper overview
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.
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.
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.
57 * The probe helpers share the function table structures with other display
58 * helper libraries. See struct &drm_connector_helper_funcs for the details.
61 static bool drm_kms_helper_poll = true;
62 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
64 static enum drm_mode_status
65 drm_mode_validate_flag(const struct drm_display_mode *mode,
68 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
69 !(flags & DRM_MODE_FLAG_INTERLACE))
70 return MODE_NO_INTERLACE;
72 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
73 !(flags & DRM_MODE_FLAG_DBLSCAN))
74 return MODE_NO_DBLESCAN;
76 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
77 !(flags & DRM_MODE_FLAG_3D_MASK))
78 return MODE_NO_STEREO;
83 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
85 struct drm_cmdline_mode *cmdline_mode;
86 struct drm_display_mode *mode;
88 cmdline_mode = &connector->cmdline_mode;
89 if (!cmdline_mode->specified)
92 /* Only add a GTF mode if we find no matching probed modes */
93 list_for_each_entry(mode, &connector->probed_modes, head) {
94 if (mode->hdisplay != cmdline_mode->xres ||
95 mode->vdisplay != cmdline_mode->yres)
98 if (cmdline_mode->refresh_specified) {
99 /* The probed mode's vrefresh is set until later */
100 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
107 mode = drm_mode_create_from_cmdline_mode(connector->dev,
112 drm_mode_probed_add(connector, mode);
116 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
118 * drm_kms_helper_poll_enable_locked - re-enable output polling.
121 * This function re-enables the output polling work without
122 * locking the mode_config mutex.
124 * This is like drm_kms_helper_poll_enable() however it is to be
125 * called from a context where the mode_config mutex is locked
128 void drm_kms_helper_poll_enable_locked(struct drm_device *dev)
131 struct drm_connector *connector;
132 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
134 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
136 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
139 drm_for_each_connector(connector, dev) {
140 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
141 DRM_CONNECTOR_POLL_DISCONNECT))
145 if (dev->mode_config.delayed_event) {
149 * Use short (1s) delay to handle the initial delayed event.
150 * This delay should not be needed, but Optimus/nouveau will
151 * fail in a mysterious way if the delayed event is handled as
152 * soon as possible like it is done in
153 * drm_helper_probe_single_connector_modes() in case the poll
154 * was enabled before.
161 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
163 EXPORT_SYMBOL(drm_kms_helper_poll_enable_locked);
166 * drm_helper_probe_single_connector_modes - get complete set of display modes
167 * @connector: connector to probe
168 * @maxX: max width for modes
169 * @maxY: max height for modes
171 * Based on the helper callbacks implemented by @connector in struct
172 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
173 * be added to the connector's probed_modes list, then culled (based on validity
174 * and the @maxX, @maxY parameters) and put into the normal modes list.
176 * Intended to be used as a generic implementation of the ->fill_modes()
177 * @connector vfunc for drivers that use the CRTC helpers for output mode
178 * filtering and detection.
180 * The basic procedure is as follows
182 * 1. All modes currently on the connector's modes list are marked as stale
184 * 2. New modes are added to the connector's probed_modes list with
185 * drm_mode_probed_add(). New modes start their life with status as OK.
186 * Modes are added from a single source using the following priority order.
188 * - debugfs 'override_edid' (used for testing only)
189 * - firmware EDID (drm_load_edid_firmware())
190 * - connector helper ->get_modes() vfunc
191 * - if the connector status is connector_status_connected, standard
192 * VESA DMT modes up to 1024x768 are automatically added
193 * (drm_add_modes_noedid())
195 * Finally modes specified via the kernel command line (video=...) are
196 * added in addition to what the earlier probes produced
197 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
198 * using the VESA GTF/CVT formulas.
200 * 3. Modes are moved from the probed_modes list to the modes list. Potential
201 * duplicates are merged together (see drm_mode_connector_list_update()).
202 * After this step the probed_modes list will be empty again.
204 * 4. Any non-stale mode on the modes list then undergoes validation
206 * - drm_mode_validate_basic() performs basic sanity checks
207 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
209 * - drm_mode_validate_flag() checks the modes againt basic connector
210 * capabilites (interlace_allowed,doublescan_allowed,stereo_allowed)
211 * - the optional connector ->mode_valid() helper can perform driver and/or
212 * hardware specific checks
214 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
215 * accompanied by a debug message indicating the reason for the mode's
216 * rejection (see drm_mode_prune_invalid()).
219 * The number of modes found on @connector.
221 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
222 uint32_t maxX, uint32_t maxY)
224 struct drm_device *dev = connector->dev;
225 struct drm_display_mode *mode;
226 const struct drm_connector_helper_funcs *connector_funcs =
227 connector->helper_private;
230 bool verbose_prune = true;
231 enum drm_connector_status old_status;
233 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
235 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
237 /* set all old modes to the stale state */
238 list_for_each_entry(mode, &connector->modes, head)
239 mode->status = MODE_STALE;
241 old_status = connector->status;
243 if (connector->force) {
244 if (connector->force == DRM_FORCE_ON ||
245 connector->force == DRM_FORCE_ON_DIGITAL)
246 connector->status = connector_status_connected;
248 connector->status = connector_status_disconnected;
249 if (connector->funcs->force)
250 connector->funcs->force(connector);
252 connector->status = connector->funcs->detect(connector, true);
256 * Normally either the driver's hpd code or the poll loop should
257 * pick up any changes and fire the hotplug event. But if
258 * userspace sneaks in a probe, we might miss a change. Hence
259 * check here, and if anything changed start the hotplug code.
261 if (old_status != connector->status) {
262 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
265 drm_get_connector_status_name(old_status),
266 drm_get_connector_status_name(connector->status));
269 * The hotplug event code might call into the fb
270 * helpers, and so expects that we do not hold any
271 * locks. Fire up the poll struct instead, it will
272 * disable itself again.
274 dev->mode_config.delayed_event = true;
275 if (dev->mode_config.poll_enabled)
276 schedule_delayed_work(&dev->mode_config.output_poll_work,
280 /* Re-enable polling in case the global poll config changed. */
281 if (drm_kms_helper_poll != dev->mode_config.poll_running)
282 drm_kms_helper_poll_enable_locked(dev);
284 dev->mode_config.poll_running = drm_kms_helper_poll;
286 if (connector->status == connector_status_disconnected) {
287 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
288 connector->base.id, connector->name);
289 drm_mode_connector_update_edid_property(connector, NULL);
290 verbose_prune = false;
294 if (connector->override_edid) {
295 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
297 count = drm_add_edid_modes(connector, edid);
298 drm_edid_to_eld(connector, edid);
300 count = drm_load_edid_firmware(connector);
302 count = (*connector_funcs->get_modes)(connector);
305 if (count == 0 && connector->status == connector_status_connected)
306 count = drm_add_modes_noedid(connector, 1024, 768);
307 count += drm_helper_probe_add_cmdline_mode(connector);
311 drm_mode_connector_list_update(connector);
313 if (connector->interlace_allowed)
314 mode_flags |= DRM_MODE_FLAG_INTERLACE;
315 if (connector->doublescan_allowed)
316 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
317 if (connector->stereo_allowed)
318 mode_flags |= DRM_MODE_FLAG_3D_MASK;
320 list_for_each_entry(mode, &connector->modes, head) {
321 if (mode->status == MODE_OK)
322 mode->status = drm_mode_validate_basic(mode);
324 if (mode->status == MODE_OK)
325 mode->status = drm_mode_validate_size(mode, maxX, maxY);
327 if (mode->status == MODE_OK)
328 mode->status = drm_mode_validate_flag(mode, mode_flags);
330 if (mode->status == MODE_OK && connector_funcs->mode_valid)
331 mode->status = connector_funcs->mode_valid(connector,
336 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
338 if (list_empty(&connector->modes))
341 list_for_each_entry(mode, &connector->modes, head)
342 mode->vrefresh = drm_mode_vrefresh(mode);
344 drm_mode_sort(&connector->modes);
346 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
348 list_for_each_entry(mode, &connector->modes, head) {
349 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
350 drm_mode_debug_printmodeline(mode);
355 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
358 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
359 * @dev: drm_device whose connector state changed
361 * This function fires off the uevent for userspace and also calls the
362 * output_poll_changed function, which is most commonly used to inform the fbdev
363 * emulation code and allow it to update the fbcon output configuration.
365 * Drivers should call this from their hotplug handling code when a change is
366 * detected. Note that this function does not do any output detection of its
367 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
370 * This function must be called from process context with no mode
371 * setting locks held.
373 void drm_kms_helper_hotplug_event(struct drm_device *dev)
375 /* send a uevent + call fbdev */
376 drm_sysfs_hotplug_event(dev);
377 if (dev->mode_config.funcs->output_poll_changed)
378 dev->mode_config.funcs->output_poll_changed(dev);
380 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
382 static void output_poll_execute(struct work_struct *work)
384 struct delayed_work *delayed_work = to_delayed_work(work);
385 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
386 struct drm_connector *connector;
387 enum drm_connector_status old_status;
388 bool repoll = false, changed;
390 if (!dev->mode_config.poll_enabled)
393 /* Pick up any changes detected by the probe functions. */
394 changed = dev->mode_config.delayed_event;
395 dev->mode_config.delayed_event = false;
397 if (!drm_kms_helper_poll)
400 mutex_lock(&dev->mode_config.mutex);
401 drm_for_each_connector(connector, dev) {
403 /* Ignore forced connectors. */
404 if (connector->force)
407 /* Ignore HPD capable connectors and connectors where we don't
408 * want any hotplug detection at all for polling. */
409 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
412 old_status = connector->status;
413 /* if we are connected and don't want to poll for disconnect
415 if (old_status == connector_status_connected &&
416 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
421 connector->status = connector->funcs->detect(connector, false);
422 if (old_status != connector->status) {
423 const char *old, *new;
426 * The poll work sets force=false when calling detect so
427 * that drivers can avoid to do disruptive tests (e.g.
428 * when load detect cycles could cause flickering on
429 * other, running displays). This bears the risk that we
430 * flip-flop between unknown here in the poll work and
431 * the real state when userspace forces a full detect
432 * call after receiving a hotplug event due to this
435 * Hence clamp an unknown detect status to the old
438 if (connector->status == connector_status_unknown) {
439 connector->status = old_status;
443 old = drm_get_connector_status_name(old_status);
444 new = drm_get_connector_status_name(connector->status);
446 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
447 "status updated from %s to %s\n",
456 mutex_unlock(&dev->mode_config.mutex);
460 drm_kms_helper_hotplug_event(dev);
463 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
467 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
469 * Determine if %current task is an output poll worker. This can be used
470 * to select distinct code paths for output polling versus other contexts.
472 * One use case is to avoid a deadlock between the output poll worker and
473 * the autosuspend worker wherein the latter waits for polling to finish
474 * upon calling drm_kms_helper_poll_disable(), while the former waits for
475 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
476 * connector ->detect hook.
478 bool drm_kms_helper_is_poll_worker(void)
480 struct work_struct *work = current_work();
482 return work && work->func == output_poll_execute;
484 EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
487 * drm_kms_helper_poll_disable - disable output polling
490 * This function disables the output polling work.
492 * Drivers can call this helper from their device suspend implementation. It is
493 * not an error to call this even when output polling isn't enabled or arlready
496 void drm_kms_helper_poll_disable(struct drm_device *dev)
498 if (!dev->mode_config.poll_enabled)
500 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
502 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
505 * drm_kms_helper_poll_enable - re-enable output polling.
508 * This function re-enables the output polling work.
510 * Drivers can call this helper from their device resume implementation. It is
511 * an error to call this when the output polling support has not yet been set
514 void drm_kms_helper_poll_enable(struct drm_device *dev)
516 mutex_lock(&dev->mode_config.mutex);
517 drm_kms_helper_poll_enable_locked(dev);
518 mutex_unlock(&dev->mode_config.mutex);
520 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
523 * drm_kms_helper_poll_init - initialize and enable output polling
526 * This function intializes and then also enables output polling support for
527 * @dev. Drivers which do not have reliable hotplug support in hardware can use
528 * this helper infrastructure to regularly poll such connectors for changes in
529 * their connection state.
531 * Drivers can control which connectors are polled by setting the
532 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
533 * connectors where probing live outputs can result in visual distortion drivers
534 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
535 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
536 * completely ignored by the polling logic.
538 * Note that a connector can be both polled and probed from the hotplug handler,
539 * in case the hotplug interrupt is known to be unreliable.
541 void drm_kms_helper_poll_init(struct drm_device *dev)
543 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
544 dev->mode_config.poll_enabled = true;
546 drm_kms_helper_poll_enable(dev);
548 EXPORT_SYMBOL(drm_kms_helper_poll_init);
551 * drm_kms_helper_poll_fini - disable output polling and clean it up
554 void drm_kms_helper_poll_fini(struct drm_device *dev)
556 if (!dev->mode_config.poll_enabled)
559 dev->mode_config.poll_enabled = false;
560 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
562 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
565 * drm_helper_hpd_irq_event - hotplug processing
568 * Drivers can use this helper function to run a detect cycle on all connectors
569 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
570 * other connectors are ignored, which is useful to avoid reprobing fixed
573 * This helper function is useful for drivers which can't or don't track hotplug
574 * interrupts for each connector.
576 * Drivers which support hotplug interrupts for each connector individually and
577 * which have a more fine-grained detect logic should bypass this code and
578 * directly call drm_kms_helper_hotplug_event() in case the connector state
581 * This function must be called from process context with no mode
582 * setting locks held.
584 * Note that a connector can be both polled and probed from the hotplug handler,
585 * in case the hotplug interrupt is known to be unreliable.
587 bool drm_helper_hpd_irq_event(struct drm_device *dev)
589 struct drm_connector *connector;
590 enum drm_connector_status old_status;
591 bool changed = false;
593 if (!dev->mode_config.poll_enabled)
596 mutex_lock(&dev->mode_config.mutex);
597 drm_for_each_connector(connector, dev) {
599 /* Only handle HPD capable connectors. */
600 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
603 old_status = connector->status;
605 connector->status = connector->funcs->detect(connector, false);
606 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
609 drm_get_connector_status_name(old_status),
610 drm_get_connector_status_name(connector->status));
611 if (old_status != connector->status)
615 mutex_unlock(&dev->mode_config.mutex);
618 drm_kms_helper_hotplug_event(dev);
622 EXPORT_SYMBOL(drm_helper_hpd_irq_event);