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 &drm_connector_funcs.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 - re-enable output polling.
121 * This function re-enables the output polling work, after it has been
122 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
125 * Drivers can call this helper from their device resume implementation. It is
126 * an error to call this when the output polling support has not yet been set
129 * Note that calls to enable and disable polling must be strictly ordered, which
130 * is automatically the case when they're only call from suspend/resume
133 void drm_kms_helper_poll_enable(struct drm_device *dev)
136 struct drm_connector *connector;
137 struct drm_connector_list_iter conn_iter;
138 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
140 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
143 drm_connector_list_iter_begin(dev, &conn_iter);
144 drm_for_each_connector_iter(connector, &conn_iter) {
145 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
146 DRM_CONNECTOR_POLL_DISCONNECT))
149 drm_connector_list_iter_end(&conn_iter);
151 if (dev->mode_config.delayed_event) {
155 * Use short (1s) delay to handle the initial delayed event.
156 * This delay should not be needed, but Optimus/nouveau will
157 * fail in a mysterious way if the delayed event is handled as
158 * soon as possible like it is done in
159 * drm_helper_probe_single_connector_modes() in case the poll
160 * was enabled before.
167 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
169 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
171 static enum drm_connector_status
172 drm_connector_detect(struct drm_connector *connector, bool force)
174 return connector->funcs->detect ?
175 connector->funcs->detect(connector, force) :
176 connector_status_connected;
180 * drm_helper_probe_single_connector_modes - get complete set of display modes
181 * @connector: connector to probe
182 * @maxX: max width for modes
183 * @maxY: max height for modes
185 * Based on the helper callbacks implemented by @connector in struct
186 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
187 * be added to the connector's probed_modes list, then culled (based on validity
188 * and the @maxX, @maxY parameters) and put into the normal modes list.
190 * Intended to be used as a generic implementation of the
191 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
192 * for output mode filtering and detection.
194 * The basic procedure is as follows
196 * 1. All modes currently on the connector's modes list are marked as stale
198 * 2. New modes are added to the connector's probed_modes list with
199 * drm_mode_probed_add(). New modes start their life with status as OK.
200 * Modes are added from a single source using the following priority order.
202 * - debugfs 'override_edid' (used for testing only)
203 * - firmware EDID (drm_load_edid_firmware())
204 * - &drm_connector_helper_funcs.get_modes vfunc
205 * - if the connector status is connector_status_connected, standard
206 * VESA DMT modes up to 1024x768 are automatically added
207 * (drm_add_modes_noedid())
209 * Finally modes specified via the kernel command line (video=...) are
210 * added in addition to what the earlier probes produced
211 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
212 * using the VESA GTF/CVT formulas.
214 * 3. Modes are moved from the probed_modes list to the modes list. Potential
215 * duplicates are merged together (see drm_mode_connector_list_update()).
216 * After this step the probed_modes list will be empty again.
218 * 4. Any non-stale mode on the modes list then undergoes validation
220 * - drm_mode_validate_basic() performs basic sanity checks
221 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
223 * - drm_mode_validate_flag() checks the modes against basic connector
224 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
225 * - the optional &drm_connector_helper_funcs.mode_valid helper can perform
226 * driver and/or hardware specific checks
228 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
229 * accompanied by a debug message indicating the reason for the mode's
230 * rejection (see drm_mode_prune_invalid()).
233 * The number of modes found on @connector.
235 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
236 uint32_t maxX, uint32_t maxY)
238 struct drm_device *dev = connector->dev;
239 struct drm_display_mode *mode;
240 const struct drm_connector_helper_funcs *connector_funcs =
241 connector->helper_private;
244 bool verbose_prune = true;
245 enum drm_connector_status old_status;
247 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
249 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
251 /* set all old modes to the stale state */
252 list_for_each_entry(mode, &connector->modes, head)
253 mode->status = MODE_STALE;
255 old_status = connector->status;
257 if (connector->force) {
258 if (connector->force == DRM_FORCE_ON ||
259 connector->force == DRM_FORCE_ON_DIGITAL)
260 connector->status = connector_status_connected;
262 connector->status = connector_status_disconnected;
263 if (connector->funcs->force)
264 connector->funcs->force(connector);
266 connector->status = drm_connector_detect(connector, true);
270 * Normally either the driver's hpd code or the poll loop should
271 * pick up any changes and fire the hotplug event. But if
272 * userspace sneaks in a probe, we might miss a change. Hence
273 * check here, and if anything changed start the hotplug code.
275 if (old_status != connector->status) {
276 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
279 drm_get_connector_status_name(old_status),
280 drm_get_connector_status_name(connector->status));
283 * The hotplug event code might call into the fb
284 * helpers, and so expects that we do not hold any
285 * locks. Fire up the poll struct instead, it will
286 * disable itself again.
288 dev->mode_config.delayed_event = true;
289 if (dev->mode_config.poll_enabled)
290 schedule_delayed_work(&dev->mode_config.output_poll_work,
294 /* Re-enable polling in case the global poll config changed. */
295 if (drm_kms_helper_poll != dev->mode_config.poll_running)
296 drm_kms_helper_poll_enable(dev);
298 dev->mode_config.poll_running = drm_kms_helper_poll;
300 if (connector->status == connector_status_disconnected) {
301 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
302 connector->base.id, connector->name);
303 drm_mode_connector_update_edid_property(connector, NULL);
304 verbose_prune = false;
308 if (connector->override_edid) {
309 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
311 count = drm_add_edid_modes(connector, edid);
312 drm_edid_to_eld(connector, edid);
314 struct edid *edid = drm_load_edid_firmware(connector);
315 if (!IS_ERR_OR_NULL(edid)) {
316 drm_mode_connector_update_edid_property(connector, edid);
317 count = drm_add_edid_modes(connector, edid);
318 drm_edid_to_eld(connector, edid);
322 count = (*connector_funcs->get_modes)(connector);
325 if (count == 0 && connector->status == connector_status_connected)
326 count = drm_add_modes_noedid(connector, 1024, 768);
327 count += drm_helper_probe_add_cmdline_mode(connector);
331 drm_mode_connector_list_update(connector);
333 if (connector->interlace_allowed)
334 mode_flags |= DRM_MODE_FLAG_INTERLACE;
335 if (connector->doublescan_allowed)
336 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
337 if (connector->stereo_allowed)
338 mode_flags |= DRM_MODE_FLAG_3D_MASK;
340 list_for_each_entry(mode, &connector->modes, head) {
341 if (mode->status == MODE_OK)
342 mode->status = drm_mode_validate_basic(mode);
344 if (mode->status == MODE_OK)
345 mode->status = drm_mode_validate_size(mode, maxX, maxY);
347 if (mode->status == MODE_OK)
348 mode->status = drm_mode_validate_flag(mode, mode_flags);
350 if (mode->status == MODE_OK && connector_funcs->mode_valid)
351 mode->status = connector_funcs->mode_valid(connector,
356 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
358 if (list_empty(&connector->modes))
361 list_for_each_entry(mode, &connector->modes, head)
362 mode->vrefresh = drm_mode_vrefresh(mode);
364 drm_mode_sort(&connector->modes);
366 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
368 list_for_each_entry(mode, &connector->modes, head) {
369 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
370 drm_mode_debug_printmodeline(mode);
375 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
378 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
379 * @dev: drm_device whose connector state changed
381 * This function fires off the uevent for userspace and also calls the
382 * output_poll_changed function, which is most commonly used to inform the fbdev
383 * emulation code and allow it to update the fbcon output configuration.
385 * Drivers should call this from their hotplug handling code when a change is
386 * detected. Note that this function does not do any output detection of its
387 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
390 * This function must be called from process context with no mode
391 * setting locks held.
393 void drm_kms_helper_hotplug_event(struct drm_device *dev)
395 /* send a uevent + call fbdev */
396 drm_sysfs_hotplug_event(dev);
397 if (dev->mode_config.funcs->output_poll_changed)
398 dev->mode_config.funcs->output_poll_changed(dev);
400 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
402 static void output_poll_execute(struct work_struct *work)
404 struct delayed_work *delayed_work = to_delayed_work(work);
405 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
406 struct drm_connector *connector;
407 struct drm_connector_list_iter conn_iter;
408 enum drm_connector_status old_status;
409 bool repoll = false, changed;
411 /* Pick up any changes detected by the probe functions. */
412 changed = dev->mode_config.delayed_event;
413 dev->mode_config.delayed_event = false;
415 if (!drm_kms_helper_poll)
418 if (!mutex_trylock(&dev->mode_config.mutex)) {
423 drm_connector_list_iter_begin(dev, &conn_iter);
424 drm_for_each_connector_iter(connector, &conn_iter) {
425 /* Ignore forced connectors. */
426 if (connector->force)
429 /* Ignore HPD capable connectors and connectors where we don't
430 * want any hotplug detection at all for polling. */
431 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
434 old_status = connector->status;
435 /* if we are connected and don't want to poll for disconnect
437 if (old_status == connector_status_connected &&
438 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
443 connector->status = drm_connector_detect(connector, false);
444 if (old_status != connector->status) {
445 const char *old, *new;
448 * The poll work sets force=false when calling detect so
449 * that drivers can avoid to do disruptive tests (e.g.
450 * when load detect cycles could cause flickering on
451 * other, running displays). This bears the risk that we
452 * flip-flop between unknown here in the poll work and
453 * the real state when userspace forces a full detect
454 * call after receiving a hotplug event due to this
457 * Hence clamp an unknown detect status to the old
460 if (connector->status == connector_status_unknown) {
461 connector->status = old_status;
465 old = drm_get_connector_status_name(old_status);
466 new = drm_get_connector_status_name(connector->status);
468 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
469 "status updated from %s to %s\n",
477 drm_connector_list_iter_end(&conn_iter);
479 mutex_unlock(&dev->mode_config.mutex);
483 drm_kms_helper_hotplug_event(dev);
486 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
490 * drm_kms_helper_poll_disable - disable output polling
493 * This function disables the output polling work.
495 * Drivers can call this helper from their device suspend implementation. It is
496 * not an error to call this even when output polling isn't enabled or already
497 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
499 * Note that calls to enable and disable polling must be strictly ordered, which
500 * is automatically the case when they're only call from suspend/resume
503 void drm_kms_helper_poll_disable(struct drm_device *dev)
505 if (!dev->mode_config.poll_enabled)
507 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
509 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
512 * drm_kms_helper_poll_init - initialize and enable output polling
515 * This function intializes and then also enables output polling support for
516 * @dev. Drivers which do not have reliable hotplug support in hardware can use
517 * this helper infrastructure to regularly poll such connectors for changes in
518 * their connection state.
520 * Drivers can control which connectors are polled by setting the
521 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
522 * connectors where probing live outputs can result in visual distortion drivers
523 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
524 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
525 * completely ignored by the polling logic.
527 * Note that a connector can be both polled and probed from the hotplug handler,
528 * in case the hotplug interrupt is known to be unreliable.
530 void drm_kms_helper_poll_init(struct drm_device *dev)
532 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
533 dev->mode_config.poll_enabled = true;
535 drm_kms_helper_poll_enable(dev);
537 EXPORT_SYMBOL(drm_kms_helper_poll_init);
540 * drm_kms_helper_poll_fini - disable output polling and clean it up
543 void drm_kms_helper_poll_fini(struct drm_device *dev)
545 drm_kms_helper_poll_disable(dev);
547 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
550 * drm_helper_hpd_irq_event - hotplug processing
553 * Drivers can use this helper function to run a detect cycle on all connectors
554 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
555 * other connectors are ignored, which is useful to avoid reprobing fixed
558 * This helper function is useful for drivers which can't or don't track hotplug
559 * interrupts for each connector.
561 * Drivers which support hotplug interrupts for each connector individually and
562 * which have a more fine-grained detect logic should bypass this code and
563 * directly call drm_kms_helper_hotplug_event() in case the connector state
566 * This function must be called from process context with no mode
567 * setting locks held.
569 * Note that a connector can be both polled and probed from the hotplug handler,
570 * in case the hotplug interrupt is known to be unreliable.
572 bool drm_helper_hpd_irq_event(struct drm_device *dev)
574 struct drm_connector *connector;
575 struct drm_connector_list_iter conn_iter;
576 enum drm_connector_status old_status;
577 bool changed = false;
579 if (!dev->mode_config.poll_enabled)
582 mutex_lock(&dev->mode_config.mutex);
583 drm_connector_list_iter_begin(dev, &conn_iter);
584 drm_for_each_connector_iter(connector, &conn_iter) {
585 /* Only handle HPD capable connectors. */
586 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
589 old_status = connector->status;
591 connector->status = drm_connector_detect(connector, false);
592 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
595 drm_get_connector_status_name(old_status),
596 drm_get_connector_status_name(connector->status));
597 if (old_status != connector->status)
600 drm_connector_list_iter_end(&conn_iter);
601 mutex_unlock(&dev->mode_config.mutex);
604 drm_kms_helper_hotplug_event(dev);
608 EXPORT_SYMBOL(drm_helper_hpd_irq_event);