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
) {
151 schedule_delayed_work(&dev
->mode_config
.output_poll_work
, delay
);
153 EXPORT_SYMBOL(drm_kms_helper_poll_enable_locked
);
156 * drm_helper_probe_single_connector_modes - get complete set of display modes
157 * @connector: connector to probe
158 * @maxX: max width for modes
159 * @maxY: max height for modes
161 * Based on the helper callbacks implemented by @connector in struct
162 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
163 * be added to the connector's probed_modes list, then culled (based on validity
164 * and the @maxX, @maxY parameters) and put into the normal modes list.
166 * Intended to be used as a generic implementation of the ->fill_modes()
167 * @connector vfunc for drivers that use the CRTC helpers for output mode
168 * filtering and detection.
170 * The basic procedure is as follows
172 * 1. All modes currently on the connector's modes list are marked as stale
174 * 2. New modes are added to the connector's probed_modes list with
175 * drm_mode_probed_add(). New modes start their life with status as OK.
176 * Modes are added from a single source using the following priority order.
178 * - debugfs 'override_edid' (used for testing only)
179 * - firmware EDID (drm_load_edid_firmware())
180 * - connector helper ->get_modes() vfunc
181 * - if the connector status is connector_status_connected, standard
182 * VESA DMT modes up to 1024x768 are automatically added
183 * (drm_add_modes_noedid())
185 * Finally modes specified via the kernel command line (video=...) are
186 * added in addition to what the earlier probes produced
187 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
188 * using the VESA GTF/CVT formulas.
190 * 3. Modes are moved from the probed_modes list to the modes list. Potential
191 * duplicates are merged together (see drm_mode_connector_list_update()).
192 * After this step the probed_modes list will be empty again.
194 * 4. Any non-stale mode on the modes list then undergoes validation
196 * - drm_mode_validate_basic() performs basic sanity checks
197 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
199 * - drm_mode_validate_flag() checks the modes againt basic connector
200 * capabilites (interlace_allowed,doublescan_allowed,stereo_allowed)
201 * - the optional connector ->mode_valid() helper can perform driver and/or
202 * hardware specific checks
204 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
205 * accompanied by a debug message indicating the reason for the mode's
206 * rejection (see drm_mode_prune_invalid()).
209 * The number of modes found on @connector.
211 int drm_helper_probe_single_connector_modes(struct drm_connector
*connector
,
212 uint32_t maxX
, uint32_t maxY
)
214 struct drm_device
*dev
= connector
->dev
;
215 struct drm_display_mode
*mode
;
216 const struct drm_connector_helper_funcs
*connector_funcs
=
217 connector
->helper_private
;
220 bool verbose_prune
= true;
221 enum drm_connector_status old_status
;
223 WARN_ON(!mutex_is_locked(&dev
->mode_config
.mutex
));
225 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector
->base
.id
,
227 /* set all old modes to the stale state */
228 list_for_each_entry(mode
, &connector
->modes
, head
)
229 mode
->status
= MODE_STALE
;
231 old_status
= connector
->status
;
233 if (connector
->force
) {
234 if (connector
->force
== DRM_FORCE_ON
||
235 connector
->force
== DRM_FORCE_ON_DIGITAL
)
236 connector
->status
= connector_status_connected
;
238 connector
->status
= connector_status_disconnected
;
239 if (connector
->funcs
->force
)
240 connector
->funcs
->force(connector
);
242 connector
->status
= connector
->funcs
->detect(connector
, true);
246 * Normally either the driver's hpd code or the poll loop should
247 * pick up any changes and fire the hotplug event. But if
248 * userspace sneaks in a probe, we might miss a change. Hence
249 * check here, and if anything changed start the hotplug code.
251 if (old_status
!= connector
->status
) {
252 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
255 drm_get_connector_status_name(old_status
),
256 drm_get_connector_status_name(connector
->status
));
259 * The hotplug event code might call into the fb
260 * helpers, and so expects that we do not hold any
261 * locks. Fire up the poll struct instead, it will
262 * disable itself again.
264 dev
->mode_config
.delayed_event
= true;
265 if (dev
->mode_config
.poll_enabled
)
266 schedule_delayed_work(&dev
->mode_config
.output_poll_work
,
270 /* Re-enable polling in case the global poll config changed. */
271 if (drm_kms_helper_poll
!= dev
->mode_config
.poll_running
)
272 drm_kms_helper_poll_enable_locked(dev
);
274 dev
->mode_config
.poll_running
= drm_kms_helper_poll
;
276 if (connector
->status
== connector_status_disconnected
) {
277 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
278 connector
->base
.id
, connector
->name
);
279 drm_mode_connector_update_edid_property(connector
, NULL
);
280 verbose_prune
= false;
284 if (connector
->override_edid
) {
285 struct edid
*edid
= (struct edid
*) connector
->edid_blob_ptr
->data
;
287 count
= drm_add_edid_modes(connector
, edid
);
288 drm_edid_to_eld(connector
, edid
);
290 count
= drm_load_edid_firmware(connector
);
292 count
= (*connector_funcs
->get_modes
)(connector
);
295 if (count
== 0 && connector
->status
== connector_status_connected
)
296 count
= drm_add_modes_noedid(connector
, 1024, 768);
297 count
+= drm_helper_probe_add_cmdline_mode(connector
);
301 drm_mode_connector_list_update(connector
);
303 if (connector
->interlace_allowed
)
304 mode_flags
|= DRM_MODE_FLAG_INTERLACE
;
305 if (connector
->doublescan_allowed
)
306 mode_flags
|= DRM_MODE_FLAG_DBLSCAN
;
307 if (connector
->stereo_allowed
)
308 mode_flags
|= DRM_MODE_FLAG_3D_MASK
;
310 list_for_each_entry(mode
, &connector
->modes
, head
) {
311 if (mode
->status
== MODE_OK
)
312 mode
->status
= drm_mode_validate_basic(mode
);
314 if (mode
->status
== MODE_OK
)
315 mode
->status
= drm_mode_validate_size(mode
, maxX
, maxY
);
317 if (mode
->status
== MODE_OK
)
318 mode
->status
= drm_mode_validate_flag(mode
, mode_flags
);
320 if (mode
->status
== MODE_OK
&& connector_funcs
->mode_valid
)
321 mode
->status
= connector_funcs
->mode_valid(connector
,
326 drm_mode_prune_invalid(dev
, &connector
->modes
, verbose_prune
);
328 if (list_empty(&connector
->modes
))
331 list_for_each_entry(mode
, &connector
->modes
, head
)
332 mode
->vrefresh
= drm_mode_vrefresh(mode
);
334 drm_mode_sort(&connector
->modes
);
336 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector
->base
.id
,
338 list_for_each_entry(mode
, &connector
->modes
, head
) {
339 drm_mode_set_crtcinfo(mode
, CRTC_INTERLACE_HALVE_V
);
340 drm_mode_debug_printmodeline(mode
);
345 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes
);
348 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
349 * @dev: drm_device whose connector state changed
351 * This function fires off the uevent for userspace and also calls the
352 * output_poll_changed function, which is most commonly used to inform the fbdev
353 * emulation code and allow it to update the fbcon output configuration.
355 * Drivers should call this from their hotplug handling code when a change is
356 * detected. Note that this function does not do any output detection of its
357 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
360 * This function must be called from process context with no mode
361 * setting locks held.
363 void drm_kms_helper_hotplug_event(struct drm_device
*dev
)
365 /* send a uevent + call fbdev */
366 drm_sysfs_hotplug_event(dev
);
367 if (dev
->mode_config
.funcs
->output_poll_changed
)
368 dev
->mode_config
.funcs
->output_poll_changed(dev
);
370 EXPORT_SYMBOL(drm_kms_helper_hotplug_event
);
372 static void output_poll_execute(struct work_struct
*work
)
374 struct delayed_work
*delayed_work
= to_delayed_work(work
);
375 struct drm_device
*dev
= container_of(delayed_work
, struct drm_device
, mode_config
.output_poll_work
);
376 struct drm_connector
*connector
;
377 enum drm_connector_status old_status
;
378 bool repoll
= false, changed
;
380 /* Pick up any changes detected by the probe functions. */
381 changed
= dev
->mode_config
.delayed_event
;
382 dev
->mode_config
.delayed_event
= false;
384 if (!drm_kms_helper_poll
)
387 mutex_lock(&dev
->mode_config
.mutex
);
388 drm_for_each_connector(connector
, dev
) {
390 /* Ignore forced connectors. */
391 if (connector
->force
)
394 /* Ignore HPD capable connectors and connectors where we don't
395 * want any hotplug detection at all for polling. */
396 if (!connector
->polled
|| connector
->polled
== DRM_CONNECTOR_POLL_HPD
)
399 old_status
= connector
->status
;
400 /* if we are connected and don't want to poll for disconnect
402 if (old_status
== connector_status_connected
&&
403 !(connector
->polled
& DRM_CONNECTOR_POLL_DISCONNECT
))
408 connector
->status
= connector
->funcs
->detect(connector
, false);
409 if (old_status
!= connector
->status
) {
410 const char *old
, *new;
413 * The poll work sets force=false when calling detect so
414 * that drivers can avoid to do disruptive tests (e.g.
415 * when load detect cycles could cause flickering on
416 * other, running displays). This bears the risk that we
417 * flip-flop between unknown here in the poll work and
418 * the real state when userspace forces a full detect
419 * call after receiving a hotplug event due to this
422 * Hence clamp an unknown detect status to the old
425 if (connector
->status
== connector_status_unknown
) {
426 connector
->status
= old_status
;
430 old
= drm_get_connector_status_name(old_status
);
431 new = drm_get_connector_status_name(connector
->status
);
433 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
434 "status updated from %s to %s\n",
443 mutex_unlock(&dev
->mode_config
.mutex
);
447 drm_kms_helper_hotplug_event(dev
);
450 schedule_delayed_work(delayed_work
, DRM_OUTPUT_POLL_PERIOD
);
454 * drm_kms_helper_poll_disable - disable output polling
457 * This function disables the output polling work.
459 * Drivers can call this helper from their device suspend implementation. It is
460 * not an error to call this even when output polling isn't enabled or arlready
463 void drm_kms_helper_poll_disable(struct drm_device
*dev
)
465 if (!dev
->mode_config
.poll_enabled
)
467 cancel_delayed_work_sync(&dev
->mode_config
.output_poll_work
);
469 EXPORT_SYMBOL(drm_kms_helper_poll_disable
);
472 * drm_kms_helper_poll_enable - re-enable output polling.
475 * This function re-enables the output polling work.
477 * Drivers can call this helper from their device resume implementation. It is
478 * an error to call this when the output polling support has not yet been set
481 void drm_kms_helper_poll_enable(struct drm_device
*dev
)
483 mutex_lock(&dev
->mode_config
.mutex
);
484 drm_kms_helper_poll_enable_locked(dev
);
485 mutex_unlock(&dev
->mode_config
.mutex
);
487 EXPORT_SYMBOL(drm_kms_helper_poll_enable
);
490 * drm_kms_helper_poll_init - initialize and enable output polling
493 * This function intializes and then also enables output polling support for
494 * @dev. Drivers which do not have reliable hotplug support in hardware can use
495 * this helper infrastructure to regularly poll such connectors for changes in
496 * their connection state.
498 * Drivers can control which connectors are polled by setting the
499 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
500 * connectors where probing live outputs can result in visual distortion drivers
501 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
502 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
503 * completely ignored by the polling logic.
505 * Note that a connector can be both polled and probed from the hotplug handler,
506 * in case the hotplug interrupt is known to be unreliable.
508 void drm_kms_helper_poll_init(struct drm_device
*dev
)
510 INIT_DELAYED_WORK(&dev
->mode_config
.output_poll_work
, output_poll_execute
);
511 dev
->mode_config
.poll_enabled
= true;
513 drm_kms_helper_poll_enable(dev
);
515 EXPORT_SYMBOL(drm_kms_helper_poll_init
);
518 * drm_kms_helper_poll_fini - disable output polling and clean it up
521 void drm_kms_helper_poll_fini(struct drm_device
*dev
)
523 drm_kms_helper_poll_disable(dev
);
525 EXPORT_SYMBOL(drm_kms_helper_poll_fini
);
528 * drm_helper_hpd_irq_event - hotplug processing
531 * Drivers can use this helper function to run a detect cycle on all connectors
532 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
533 * other connectors are ignored, which is useful to avoid reprobing fixed
536 * This helper function is useful for drivers which can't or don't track hotplug
537 * interrupts for each connector.
539 * Drivers which support hotplug interrupts for each connector individually and
540 * which have a more fine-grained detect logic should bypass this code and
541 * directly call drm_kms_helper_hotplug_event() in case the connector state
544 * This function must be called from process context with no mode
545 * setting locks held.
547 * Note that a connector can be both polled and probed from the hotplug handler,
548 * in case the hotplug interrupt is known to be unreliable.
550 bool drm_helper_hpd_irq_event(struct drm_device
*dev
)
552 struct drm_connector
*connector
;
553 enum drm_connector_status old_status
;
554 bool changed
= false;
556 if (!dev
->mode_config
.poll_enabled
)
559 mutex_lock(&dev
->mode_config
.mutex
);
560 drm_for_each_connector(connector
, dev
) {
562 /* Only handle HPD capable connectors. */
563 if (!(connector
->polled
& DRM_CONNECTOR_POLL_HPD
))
566 old_status
= connector
->status
;
568 connector
->status
= connector
->funcs
->detect(connector
, false);
569 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
572 drm_get_connector_status_name(old_status
),
573 drm_get_connector_status_name(connector
->status
));
574 if (old_status
!= connector
->status
)
578 mutex_unlock(&dev
->mode_config
.mutex
);
581 drm_kms_helper_hotplug_event(dev
);
585 EXPORT_SYMBOL(drm_helper_hpd_irq_event
);