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
);