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.
58 static bool drm_kms_helper_poll = true;
59 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
61 static enum drm_mode_status
62 drm_mode_validate_flag(const struct drm_display_mode *mode,
65 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
66 !(flags & DRM_MODE_FLAG_INTERLACE))
67 return MODE_NO_INTERLACE;
69 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
70 !(flags & DRM_MODE_FLAG_DBLSCAN))
71 return MODE_NO_DBLESCAN;
73 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
74 !(flags & DRM_MODE_FLAG_3D_MASK))
75 return MODE_NO_STEREO;
80 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
82 struct drm_display_mode *mode;
84 if (!connector->cmdline_mode.specified)
87 mode = drm_mode_create_from_cmdline_mode(connector->dev,
88 &connector->cmdline_mode);
92 drm_mode_probed_add(connector, mode);
96 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
97 static void __drm_kms_helper_poll_enable(struct drm_device *dev)
100 struct drm_connector *connector;
102 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
104 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
107 drm_for_each_connector(connector, dev) {
108 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
109 DRM_CONNECTOR_POLL_DISCONNECT))
114 schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
117 static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector *connector,
118 uint32_t maxX, uint32_t maxY, bool merge_type_bits)
120 struct drm_device *dev = connector->dev;
121 struct drm_display_mode *mode;
122 const struct drm_connector_helper_funcs *connector_funcs =
123 connector->helper_private;
126 bool verbose_prune = true;
127 enum drm_connector_status old_status;
129 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
131 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
133 /* set all modes to the unverified state */
134 list_for_each_entry(mode, &connector->modes, head)
135 mode->status = MODE_UNVERIFIED;
137 if (connector->force) {
138 if (connector->force == DRM_FORCE_ON ||
139 connector->force == DRM_FORCE_ON_DIGITAL)
140 connector->status = connector_status_connected;
142 connector->status = connector_status_disconnected;
143 if (connector->funcs->force)
144 connector->funcs->force(connector);
146 old_status = connector->status;
148 connector->status = connector->funcs->detect(connector, true);
151 * Normally either the driver's hpd code or the poll loop should
152 * pick up any changes and fire the hotplug event. But if
153 * userspace sneaks in a probe, we might miss a change. Hence
154 * check here, and if anything changed start the hotplug code.
156 if (old_status != connector->status) {
157 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
160 old_status, connector->status);
163 * The hotplug event code might call into the fb
164 * helpers, and so expects that we do not hold any
165 * locks. Fire up the poll struct instead, it will
166 * disable itself again.
168 dev->mode_config.delayed_event = true;
169 if (dev->mode_config.poll_enabled)
170 schedule_delayed_work(&dev->mode_config.output_poll_work,
175 /* Re-enable polling in case the global poll config changed. */
176 if (drm_kms_helper_poll != dev->mode_config.poll_running)
177 __drm_kms_helper_poll_enable(dev);
179 dev->mode_config.poll_running = drm_kms_helper_poll;
181 if (connector->status == connector_status_disconnected) {
182 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
183 connector->base.id, connector->name);
184 drm_mode_connector_update_edid_property(connector, NULL);
185 verbose_prune = false;
189 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
190 count = drm_load_edid_firmware(connector);
194 if (connector->override_edid) {
195 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
197 count = drm_add_edid_modes(connector, edid);
198 drm_edid_to_eld(connector, edid);
200 count = (*connector_funcs->get_modes)(connector);
203 if (count == 0 && connector->status == connector_status_connected)
204 count = drm_add_modes_noedid(connector, 1024, 768);
205 count += drm_helper_probe_add_cmdline_mode(connector);
209 drm_mode_connector_list_update(connector, merge_type_bits);
211 if (connector->interlace_allowed)
212 mode_flags |= DRM_MODE_FLAG_INTERLACE;
213 if (connector->doublescan_allowed)
214 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
215 if (connector->stereo_allowed)
216 mode_flags |= DRM_MODE_FLAG_3D_MASK;
218 list_for_each_entry(mode, &connector->modes, head) {
219 mode->status = drm_mode_validate_basic(mode);
221 if (mode->status == MODE_OK)
222 mode->status = drm_mode_validate_size(mode, maxX, maxY);
224 if (mode->status == MODE_OK)
225 mode->status = drm_mode_validate_flag(mode, mode_flags);
227 if (mode->status == MODE_OK && connector_funcs->mode_valid)
228 mode->status = connector_funcs->mode_valid(connector,
233 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
235 if (list_empty(&connector->modes))
238 list_for_each_entry(mode, &connector->modes, head)
239 mode->vrefresh = drm_mode_vrefresh(mode);
241 drm_mode_sort(&connector->modes);
243 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
245 list_for_each_entry(mode, &connector->modes, head) {
246 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
247 drm_mode_debug_printmodeline(mode);
254 * drm_helper_probe_single_connector_modes - get complete set of display modes
255 * @connector: connector to probe
256 * @maxX: max width for modes
257 * @maxY: max height for modes
259 * Based on the helper callbacks implemented by @connector try to detect all
260 * valid modes. Modes will first be added to the connector's probed_modes list,
261 * then culled (based on validity and the @maxX, @maxY parameters) and put into
262 * the normal modes list.
264 * Intended to be use as a generic implementation of the ->fill_modes()
265 * @connector vfunc for drivers that use the crtc helpers for output mode
266 * filtering and detection.
269 * The number of modes found on @connector.
271 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
272 uint32_t maxX, uint32_t maxY)
274 return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, true);
276 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
279 * drm_helper_probe_single_connector_modes_nomerge - get complete set of display modes
280 * @connector: connector to probe
281 * @maxX: max width for modes
282 * @maxY: max height for modes
284 * This operates like drm_hehlper_probe_single_connector_modes except it
285 * replaces the mode bits instead of merging them for preferred modes.
287 int drm_helper_probe_single_connector_modes_nomerge(struct drm_connector *connector,
288 uint32_t maxX, uint32_t maxY)
290 return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, false);
292 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes_nomerge);
295 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
296 * @dev: drm_device whose connector state changed
298 * This function fires off the uevent for userspace and also calls the
299 * output_poll_changed function, which is most commonly used to inform the fbdev
300 * emulation code and allow it to update the fbcon output configuration.
302 * Drivers should call this from their hotplug handling code when a change is
303 * detected. Note that this function does not do any output detection of its
304 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
307 * This function must be called from process context with no mode
308 * setting locks held.
310 void drm_kms_helper_hotplug_event(struct drm_device *dev)
312 /* send a uevent + call fbdev */
313 drm_sysfs_hotplug_event(dev);
314 if (dev->mode_config.funcs->output_poll_changed)
315 dev->mode_config.funcs->output_poll_changed(dev);
317 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
319 static void output_poll_execute(struct work_struct *work)
321 struct delayed_work *delayed_work = to_delayed_work(work);
322 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
323 struct drm_connector *connector;
324 enum drm_connector_status old_status;
325 bool repoll = false, changed;
327 /* Pick up any changes detected by the probe functions. */
328 changed = dev->mode_config.delayed_event;
329 dev->mode_config.delayed_event = false;
331 if (!drm_kms_helper_poll)
334 mutex_lock(&dev->mode_config.mutex);
335 drm_for_each_connector(connector, dev) {
337 /* Ignore forced connectors. */
338 if (connector->force)
341 /* Ignore HPD capable connectors and connectors where we don't
342 * want any hotplug detection at all for polling. */
343 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
346 old_status = connector->status;
347 /* if we are connected and don't want to poll for disconnect
349 if (old_status == connector_status_connected &&
350 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
355 connector->status = connector->funcs->detect(connector, false);
356 if (old_status != connector->status) {
357 const char *old, *new;
360 * The poll work sets force=false when calling detect so
361 * that drivers can avoid to do disruptive tests (e.g.
362 * when load detect cycles could cause flickering on
363 * other, running displays). This bears the risk that we
364 * flip-flop between unknown here in the poll work and
365 * the real state when userspace forces a full detect
366 * call after receiving a hotplug event due to this
369 * Hence clamp an unknown detect status to the old
372 if (connector->status == connector_status_unknown) {
373 connector->status = old_status;
377 old = drm_get_connector_status_name(old_status);
378 new = drm_get_connector_status_name(connector->status);
380 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
381 "status updated from %s to %s\n",
390 mutex_unlock(&dev->mode_config.mutex);
394 drm_kms_helper_hotplug_event(dev);
397 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
401 * drm_kms_helper_poll_disable - disable output polling
404 * This function disables the output polling work.
406 * Drivers can call this helper from their device suspend implementation. It is
407 * not an error to call this even when output polling isn't enabled or arlready
410 void drm_kms_helper_poll_disable(struct drm_device *dev)
412 if (!dev->mode_config.poll_enabled)
414 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
416 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
419 * drm_kms_helper_poll_enable - re-enable output polling.
422 * This function re-enables the output polling work.
424 * Drivers can call this helper from their device resume implementation. It is
425 * an error to call this when the output polling support has not yet been set
428 void drm_kms_helper_poll_enable(struct drm_device *dev)
430 mutex_lock(&dev->mode_config.mutex);
431 __drm_kms_helper_poll_enable(dev);
432 mutex_unlock(&dev->mode_config.mutex);
434 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
437 * drm_kms_helper_poll_init - initialize and enable output polling
440 * This function intializes and then also enables output polling support for
441 * @dev. Drivers which do not have reliable hotplug support in hardware can use
442 * this helper infrastructure to regularly poll such connectors for changes in
443 * their connection state.
445 * Drivers can control which connectors are polled by setting the
446 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
447 * connectors where probing live outputs can result in visual distortion drivers
448 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
449 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
450 * completely ignored by the polling logic.
452 * Note that a connector can be both polled and probed from the hotplug handler,
453 * in case the hotplug interrupt is known to be unreliable.
455 void drm_kms_helper_poll_init(struct drm_device *dev)
457 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
458 dev->mode_config.poll_enabled = true;
460 drm_kms_helper_poll_enable(dev);
462 EXPORT_SYMBOL(drm_kms_helper_poll_init);
465 * drm_kms_helper_poll_fini - disable output polling and clean it up
468 void drm_kms_helper_poll_fini(struct drm_device *dev)
470 drm_kms_helper_poll_disable(dev);
472 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
475 * drm_helper_hpd_irq_event - hotplug processing
478 * Drivers can use this helper function to run a detect cycle on all connectors
479 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
480 * other connectors are ignored, which is useful to avoid reprobing fixed
483 * This helper function is useful for drivers which can't or don't track hotplug
484 * interrupts for each connector.
486 * Drivers which support hotplug interrupts for each connector individually and
487 * which have a more fine-grained detect logic should bypass this code and
488 * directly call drm_kms_helper_hotplug_event() in case the connector state
491 * This function must be called from process context with no mode
492 * setting locks held.
494 * Note that a connector can be both polled and probed from the hotplug handler,
495 * in case the hotplug interrupt is known to be unreliable.
497 bool drm_helper_hpd_irq_event(struct drm_device *dev)
499 struct drm_connector *connector;
500 enum drm_connector_status old_status;
501 bool changed = false;
503 if (!dev->mode_config.poll_enabled)
506 mutex_lock(&dev->mode_config.mutex);
507 drm_for_each_connector(connector, dev) {
509 /* Only handle HPD capable connectors. */
510 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
513 old_status = connector->status;
515 connector->status = connector->funcs->detect(connector, false);
516 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
519 drm_get_connector_status_name(old_status),
520 drm_get_connector_status_name(connector->status));
521 if (old_status != connector->status)
525 mutex_unlock(&dev->mode_config.mutex);
528 drm_kms_helper_hotplug_event(dev);
532 EXPORT_SYMBOL(drm_helper_hpd_irq_event);