xref: /linux/drivers/gpu/drm/drm_probe_helper.c (revision 446d0f48)
1 /*
2  * Copyright (c) 2006-2008 Intel Corporation
3  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
4  *
5  * DRM core CRTC related functions
6  *
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.
16  *
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
23  * OF THIS SOFTWARE.
24  *
25  * Authors:
26  *      Keith Packard
27  *	Eric Anholt <eric@anholt.net>
28  *      Dave Airlie <airlied@linux.ie>
29  *      Jesse Barnes <jesse.barnes@intel.com>
30  */
31 
32 #include <linux/export.h>
33 #include <linux/moduleparam.h>
34 
35 #include <drm/drm_bridge.h>
36 #include <drm/drm_client.h>
37 #include <drm/drm_crtc.h>
38 #include <drm/drm_edid.h>
39 #include <drm/drm_fourcc.h>
40 #include <drm/drm_managed.h>
41 #include <drm/drm_modeset_helper_vtables.h>
42 #include <drm/drm_print.h>
43 #include <drm/drm_probe_helper.h>
44 #include <drm/drm_sysfs.h>
45 
46 #include "drm_crtc_helper_internal.h"
47 
48 /**
49  * DOC: output probing helper overview
50  *
51  * This library provides some helper code for output probing. It provides an
52  * implementation of the core &drm_connector_funcs.fill_modes interface with
53  * drm_helper_probe_single_connector_modes().
54  *
55  * It also provides support for polling connectors with a work item and for
56  * generic hotplug interrupt handling where the driver doesn't or cannot keep
57  * track of a per-connector hpd interrupt.
58  *
59  * This helper library can be used independently of the modeset helper library.
60  * Drivers can also overwrite different parts e.g. use their own hotplug
61  * handling code to avoid probing unrelated outputs.
62  *
63  * The probe helpers share the function table structures with other display
64  * helper libraries. See &struct drm_connector_helper_funcs for the details.
65  */
66 
67 static bool drm_kms_helper_poll = true;
68 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
69 
70 static enum drm_mode_status
drm_mode_validate_flag(const struct drm_display_mode * mode,int flags)71 drm_mode_validate_flag(const struct drm_display_mode *mode,
72 		       int flags)
73 {
74 	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
75 	    !(flags & DRM_MODE_FLAG_INTERLACE))
76 		return MODE_NO_INTERLACE;
77 
78 	if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
79 	    !(flags & DRM_MODE_FLAG_DBLSCAN))
80 		return MODE_NO_DBLESCAN;
81 
82 	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
83 	    !(flags & DRM_MODE_FLAG_3D_MASK))
84 		return MODE_NO_STEREO;
85 
86 	return MODE_OK;
87 }
88 
89 static int
drm_mode_validate_pipeline(struct drm_display_mode * mode,struct drm_connector * connector,struct drm_modeset_acquire_ctx * ctx,enum drm_mode_status * status)90 drm_mode_validate_pipeline(struct drm_display_mode *mode,
91 			   struct drm_connector *connector,
92 			   struct drm_modeset_acquire_ctx *ctx,
93 			   enum drm_mode_status *status)
94 {
95 	struct drm_device *dev = connector->dev;
96 	struct drm_encoder *encoder;
97 	int ret;
98 
99 	/* Step 1: Validate against connector */
100 	ret = drm_connector_mode_valid(connector, mode, ctx, status);
101 	if (ret || *status != MODE_OK)
102 		return ret;
103 
104 	/* Step 2: Validate against encoders and crtcs */
105 	drm_connector_for_each_possible_encoder(connector, encoder) {
106 		struct drm_bridge *bridge;
107 		struct drm_crtc *crtc;
108 
109 		*status = drm_encoder_mode_valid(encoder, mode);
110 		if (*status != MODE_OK) {
111 			/* No point in continuing for crtc check as this encoder
112 			 * will not accept the mode anyway. If all encoders
113 			 * reject the mode then, at exit, ret will not be
114 			 * MODE_OK. */
115 			continue;
116 		}
117 
118 		bridge = drm_bridge_chain_get_first_bridge(encoder);
119 		*status = drm_bridge_chain_mode_valid(bridge,
120 						      &connector->display_info,
121 						      mode);
122 		if (*status != MODE_OK) {
123 			/* There is also no point in continuing for crtc check
124 			 * here. */
125 			continue;
126 		}
127 
128 		drm_for_each_crtc(crtc, dev) {
129 			if (!drm_encoder_crtc_ok(encoder, crtc))
130 				continue;
131 
132 			*status = drm_crtc_mode_valid(crtc, mode);
133 			if (*status == MODE_OK) {
134 				/* If we get to this point there is at least
135 				 * one combination of encoder+crtc that works
136 				 * for this mode. Lets return now. */
137 				return 0;
138 			}
139 		}
140 	}
141 
142 	return 0;
143 }
144 
drm_helper_probe_add_cmdline_mode(struct drm_connector * connector)145 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
146 {
147 	struct drm_cmdline_mode *cmdline_mode;
148 	struct drm_display_mode *mode;
149 
150 	cmdline_mode = &connector->cmdline_mode;
151 	if (!cmdline_mode->specified)
152 		return 0;
153 
154 	/* Only add a GTF mode if we find no matching probed modes */
155 	list_for_each_entry(mode, &connector->probed_modes, head) {
156 		if (mode->hdisplay != cmdline_mode->xres ||
157 		    mode->vdisplay != cmdline_mode->yres)
158 			continue;
159 
160 		if (cmdline_mode->refresh_specified) {
161 			/* The probed mode's vrefresh is set until later */
162 			if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
163 				continue;
164 		}
165 
166 		/* Mark the matching mode as being preferred by the user */
167 		mode->type |= DRM_MODE_TYPE_USERDEF;
168 		return 0;
169 	}
170 
171 	mode = drm_mode_create_from_cmdline_mode(connector->dev,
172 						 cmdline_mode);
173 	if (mode == NULL)
174 		return 0;
175 
176 	drm_mode_probed_add(connector, mode);
177 	return 1;
178 }
179 
drm_crtc_mode_valid(struct drm_crtc * crtc,const struct drm_display_mode * mode)180 enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
181 					 const struct drm_display_mode *mode)
182 {
183 	const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
184 
185 	if (!crtc_funcs || !crtc_funcs->mode_valid)
186 		return MODE_OK;
187 
188 	return crtc_funcs->mode_valid(crtc, mode);
189 }
190 
drm_encoder_mode_valid(struct drm_encoder * encoder,const struct drm_display_mode * mode)191 enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
192 					    const struct drm_display_mode *mode)
193 {
194 	const struct drm_encoder_helper_funcs *encoder_funcs =
195 		encoder->helper_private;
196 
197 	if (!encoder_funcs || !encoder_funcs->mode_valid)
198 		return MODE_OK;
199 
200 	return encoder_funcs->mode_valid(encoder, mode);
201 }
202 
203 int
drm_connector_mode_valid(struct drm_connector * connector,struct drm_display_mode * mode,struct drm_modeset_acquire_ctx * ctx,enum drm_mode_status * status)204 drm_connector_mode_valid(struct drm_connector *connector,
205 			 struct drm_display_mode *mode,
206 			 struct drm_modeset_acquire_ctx *ctx,
207 			 enum drm_mode_status *status)
208 {
209 	const struct drm_connector_helper_funcs *connector_funcs =
210 		connector->helper_private;
211 	int ret = 0;
212 
213 	if (!connector_funcs)
214 		*status = MODE_OK;
215 	else if (connector_funcs->mode_valid_ctx)
216 		ret = connector_funcs->mode_valid_ctx(connector, mode, ctx,
217 						      status);
218 	else if (connector_funcs->mode_valid)
219 		*status = connector_funcs->mode_valid(connector, mode);
220 	else
221 		*status = MODE_OK;
222 
223 	return ret;
224 }
225 
drm_kms_helper_disable_hpd(struct drm_device * dev)226 static void drm_kms_helper_disable_hpd(struct drm_device *dev)
227 {
228 	struct drm_connector *connector;
229 	struct drm_connector_list_iter conn_iter;
230 
231 	drm_connector_list_iter_begin(dev, &conn_iter);
232 	drm_for_each_connector_iter(connector, &conn_iter) {
233 		const struct drm_connector_helper_funcs *funcs =
234 			connector->helper_private;
235 
236 		if (funcs && funcs->disable_hpd)
237 			funcs->disable_hpd(connector);
238 	}
239 	drm_connector_list_iter_end(&conn_iter);
240 }
241 
drm_kms_helper_enable_hpd(struct drm_device * dev)242 static bool drm_kms_helper_enable_hpd(struct drm_device *dev)
243 {
244 	bool poll = false;
245 	struct drm_connector *connector;
246 	struct drm_connector_list_iter conn_iter;
247 
248 	drm_connector_list_iter_begin(dev, &conn_iter);
249 	drm_for_each_connector_iter(connector, &conn_iter) {
250 		const struct drm_connector_helper_funcs *funcs =
251 			connector->helper_private;
252 
253 		if (funcs && funcs->enable_hpd)
254 			funcs->enable_hpd(connector);
255 
256 		if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
257 					 DRM_CONNECTOR_POLL_DISCONNECT))
258 			poll = true;
259 	}
260 	drm_connector_list_iter_end(&conn_iter);
261 
262 	return poll;
263 }
264 
265 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
reschedule_output_poll_work(struct drm_device * dev)266 static void reschedule_output_poll_work(struct drm_device *dev)
267 {
268 	unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
269 
270 	if (dev->mode_config.delayed_event)
271 		/*
272 		 * FIXME:
273 		 *
274 		 * Use short (1s) delay to handle the initial delayed event.
275 		 * This delay should not be needed, but Optimus/nouveau will
276 		 * fail in a mysterious way if the delayed event is handled as
277 		 * soon as possible like it is done in
278 		 * drm_helper_probe_single_connector_modes() in case the poll
279 		 * was enabled before.
280 		 */
281 		delay = HZ;
282 
283 	schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
284 }
285 
286 /**
287  * drm_kms_helper_poll_enable - re-enable output polling.
288  * @dev: drm_device
289  *
290  * This function re-enables the output polling work, after it has been
291  * temporarily disabled using drm_kms_helper_poll_disable(), for example over
292  * suspend/resume.
293  *
294  * Drivers can call this helper from their device resume implementation. It is
295  * not an error to call this even when output polling isn't enabled.
296  *
297  * If device polling was never initialized before, this call will trigger a
298  * warning and return.
299  *
300  * Note that calls to enable and disable polling must be strictly ordered, which
301  * is automatically the case when they're only call from suspend/resume
302  * callbacks.
303  */
drm_kms_helper_poll_enable(struct drm_device * dev)304 void drm_kms_helper_poll_enable(struct drm_device *dev)
305 {
306 	if (drm_WARN_ON_ONCE(dev, !dev->mode_config.poll_enabled) ||
307 	    !drm_kms_helper_poll || dev->mode_config.poll_running)
308 		return;
309 
310 	if (drm_kms_helper_enable_hpd(dev) ||
311 	    dev->mode_config.delayed_event)
312 		reschedule_output_poll_work(dev);
313 
314 	dev->mode_config.poll_running = true;
315 }
316 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
317 
318 /**
319  * drm_kms_helper_poll_reschedule - reschedule the output polling work
320  * @dev: drm_device
321  *
322  * This function reschedules the output polling work, after polling for a
323  * connector has been enabled.
324  *
325  * Drivers must call this helper after enabling polling for a connector by
326  * setting %DRM_CONNECTOR_POLL_CONNECT / %DRM_CONNECTOR_POLL_DISCONNECT flags
327  * in drm_connector::polled. Note that after disabling polling by clearing these
328  * flags for a connector will stop the output polling work automatically if
329  * the polling is disabled for all other connectors as well.
330  *
331  * The function can be called only after polling has been enabled by calling
332  * drm_kms_helper_poll_init() / drm_kms_helper_poll_enable().
333  */
drm_kms_helper_poll_reschedule(struct drm_device * dev)334 void drm_kms_helper_poll_reschedule(struct drm_device *dev)
335 {
336 	if (dev->mode_config.poll_running)
337 		reschedule_output_poll_work(dev);
338 }
339 EXPORT_SYMBOL(drm_kms_helper_poll_reschedule);
340 
341 static enum drm_connector_status
drm_helper_probe_detect_ctx(struct drm_connector * connector,bool force)342 drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
343 {
344 	const struct drm_connector_helper_funcs *funcs = connector->helper_private;
345 	struct drm_modeset_acquire_ctx ctx;
346 	int ret;
347 
348 	drm_modeset_acquire_init(&ctx, 0);
349 
350 retry:
351 	ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
352 	if (!ret) {
353 		if (funcs->detect_ctx)
354 			ret = funcs->detect_ctx(connector, &ctx, force);
355 		else if (connector->funcs->detect)
356 			ret = connector->funcs->detect(connector, force);
357 		else
358 			ret = connector_status_connected;
359 	}
360 
361 	if (ret == -EDEADLK) {
362 		drm_modeset_backoff(&ctx);
363 		goto retry;
364 	}
365 
366 	if (WARN_ON(ret < 0))
367 		ret = connector_status_unknown;
368 
369 	if (ret != connector->status)
370 		connector->epoch_counter += 1;
371 
372 	drm_modeset_drop_locks(&ctx);
373 	drm_modeset_acquire_fini(&ctx);
374 
375 	return ret;
376 }
377 
378 /**
379  * drm_helper_probe_detect - probe connector status
380  * @connector: connector to probe
381  * @ctx: acquire_ctx, or NULL to let this function handle locking.
382  * @force: Whether destructive probe operations should be performed.
383  *
384  * This function calls the detect callbacks of the connector.
385  * This function returns &drm_connector_status, or
386  * if @ctx is set, it might also return -EDEADLK.
387  */
388 int
drm_helper_probe_detect(struct drm_connector * connector,struct drm_modeset_acquire_ctx * ctx,bool force)389 drm_helper_probe_detect(struct drm_connector *connector,
390 			struct drm_modeset_acquire_ctx *ctx,
391 			bool force)
392 {
393 	const struct drm_connector_helper_funcs *funcs = connector->helper_private;
394 	struct drm_device *dev = connector->dev;
395 	int ret;
396 
397 	if (!ctx)
398 		return drm_helper_probe_detect_ctx(connector, force);
399 
400 	ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
401 	if (ret)
402 		return ret;
403 
404 	if (funcs->detect_ctx)
405 		ret = funcs->detect_ctx(connector, ctx, force);
406 	else if (connector->funcs->detect)
407 		ret = connector->funcs->detect(connector, force);
408 	else
409 		ret = connector_status_connected;
410 
411 	if (ret != connector->status)
412 		connector->epoch_counter += 1;
413 
414 	return ret;
415 }
416 EXPORT_SYMBOL(drm_helper_probe_detect);
417 
drm_helper_probe_get_modes(struct drm_connector * connector)418 static int drm_helper_probe_get_modes(struct drm_connector *connector)
419 {
420 	const struct drm_connector_helper_funcs *connector_funcs =
421 		connector->helper_private;
422 	int count;
423 
424 	count = connector_funcs->get_modes(connector);
425 
426 	/* The .get_modes() callback should not return negative values. */
427 	if (count < 0) {
428 		drm_err(connector->dev, ".get_modes() returned %pe\n",
429 			ERR_PTR(count));
430 		count = 0;
431 	}
432 
433 	/*
434 	 * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
435 	 * override/firmware EDID.
436 	 */
437 	if (count == 0 && connector->status == connector_status_connected)
438 		count = drm_edid_override_connector_update(connector);
439 
440 	return count;
441 }
442 
__drm_helper_update_and_validate(struct drm_connector * connector,uint32_t maxX,uint32_t maxY,struct drm_modeset_acquire_ctx * ctx)443 static int __drm_helper_update_and_validate(struct drm_connector *connector,
444 					    uint32_t maxX, uint32_t maxY,
445 					    struct drm_modeset_acquire_ctx *ctx)
446 {
447 	struct drm_device *dev = connector->dev;
448 	struct drm_display_mode *mode;
449 	int mode_flags = 0;
450 	int ret;
451 
452 	drm_connector_list_update(connector);
453 
454 	if (connector->interlace_allowed)
455 		mode_flags |= DRM_MODE_FLAG_INTERLACE;
456 	if (connector->doublescan_allowed)
457 		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
458 	if (connector->stereo_allowed)
459 		mode_flags |= DRM_MODE_FLAG_3D_MASK;
460 
461 	list_for_each_entry(mode, &connector->modes, head) {
462 		if (mode->status != MODE_OK)
463 			continue;
464 
465 		mode->status = drm_mode_validate_driver(dev, mode);
466 		if (mode->status != MODE_OK)
467 			continue;
468 
469 		mode->status = drm_mode_validate_size(mode, maxX, maxY);
470 		if (mode->status != MODE_OK)
471 			continue;
472 
473 		mode->status = drm_mode_validate_flag(mode, mode_flags);
474 		if (mode->status != MODE_OK)
475 			continue;
476 
477 		mode->status = drm_mode_validate_ycbcr420(mode, connector);
478 		if (mode->status != MODE_OK)
479 			continue;
480 
481 		ret = drm_mode_validate_pipeline(mode, connector, ctx,
482 						 &mode->status);
483 		if (ret) {
484 			drm_dbg_kms(dev,
485 				    "drm_mode_validate_pipeline failed: %d\n",
486 				    ret);
487 
488 			if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK))
489 				mode->status = MODE_ERROR;
490 			else
491 				return -EDEADLK;
492 		}
493 	}
494 
495 	return 0;
496 }
497 
498 /**
499  * drm_helper_probe_single_connector_modes - get complete set of display modes
500  * @connector: connector to probe
501  * @maxX: max width for modes
502  * @maxY: max height for modes
503  *
504  * Based on the helper callbacks implemented by @connector in struct
505  * &drm_connector_helper_funcs try to detect all valid modes.  Modes will first
506  * be added to the connector's probed_modes list, then culled (based on validity
507  * and the @maxX, @maxY parameters) and put into the normal modes list.
508  *
509  * Intended to be used as a generic implementation of the
510  * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
511  * for output mode filtering and detection.
512  *
513  * The basic procedure is as follows
514  *
515  * 1. All modes currently on the connector's modes list are marked as stale
516  *
517  * 2. New modes are added to the connector's probed_modes list with
518  *    drm_mode_probed_add(). New modes start their life with status as OK.
519  *    Modes are added from a single source using the following priority order.
520  *
521  *    - &drm_connector_helper_funcs.get_modes vfunc
522  *    - if the connector status is connector_status_connected, standard
523  *      VESA DMT modes up to 1024x768 are automatically added
524  *      (drm_add_modes_noedid())
525  *
526  *    Finally modes specified via the kernel command line (video=...) are
527  *    added in addition to what the earlier probes produced
528  *    (drm_helper_probe_add_cmdline_mode()). These modes are generated
529  *    using the VESA GTF/CVT formulas.
530  *
531  * 3. Modes are moved from the probed_modes list to the modes list. Potential
532  *    duplicates are merged together (see drm_connector_list_update()).
533  *    After this step the probed_modes list will be empty again.
534  *
535  * 4. Any non-stale mode on the modes list then undergoes validation
536  *
537  *    - drm_mode_validate_basic() performs basic sanity checks
538  *    - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
539  *      (if specified)
540  *    - drm_mode_validate_flag() checks the modes against basic connector
541  *      capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
542  *    - the optional &drm_connector_helper_funcs.mode_valid or
543  *      &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
544  *      and/or sink specific checks
545  *    - the optional &drm_crtc_helper_funcs.mode_valid,
546  *      &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
547  *      helpers can perform driver and/or source specific checks which are also
548  *      enforced by the modeset/atomic helpers
549  *
550  * 5. Any mode whose status is not OK is pruned from the connector's modes list,
551  *    accompanied by a debug message indicating the reason for the mode's
552  *    rejection (see drm_mode_prune_invalid()).
553  *
554  * Returns:
555  * The number of modes found on @connector.
556  */
drm_helper_probe_single_connector_modes(struct drm_connector * connector,uint32_t maxX,uint32_t maxY)557 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
558 					    uint32_t maxX, uint32_t maxY)
559 {
560 	struct drm_device *dev = connector->dev;
561 	struct drm_display_mode *mode;
562 	int count = 0, ret;
563 	enum drm_connector_status old_status;
564 	struct drm_modeset_acquire_ctx ctx;
565 
566 	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
567 
568 	drm_modeset_acquire_init(&ctx, 0);
569 
570 	drm_dbg_kms(dev, "[CONNECTOR:%d:%s]\n", connector->base.id,
571 		    connector->name);
572 
573 retry:
574 	ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
575 	if (ret == -EDEADLK) {
576 		drm_modeset_backoff(&ctx);
577 		goto retry;
578 	} else
579 		WARN_ON(ret < 0);
580 
581 	/* set all old modes to the stale state */
582 	list_for_each_entry(mode, &connector->modes, head)
583 		mode->status = MODE_STALE;
584 
585 	old_status = connector->status;
586 
587 	if (connector->force) {
588 		if (connector->force == DRM_FORCE_ON ||
589 		    connector->force == DRM_FORCE_ON_DIGITAL)
590 			connector->status = connector_status_connected;
591 		else
592 			connector->status = connector_status_disconnected;
593 		if (connector->funcs->force)
594 			connector->funcs->force(connector);
595 	} else {
596 		ret = drm_helper_probe_detect(connector, &ctx, true);
597 
598 		if (ret == -EDEADLK) {
599 			drm_modeset_backoff(&ctx);
600 			goto retry;
601 		} else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
602 			ret = connector_status_unknown;
603 
604 		connector->status = ret;
605 	}
606 
607 	/*
608 	 * Normally either the driver's hpd code or the poll loop should
609 	 * pick up any changes and fire the hotplug event. But if
610 	 * userspace sneaks in a probe, we might miss a change. Hence
611 	 * check here, and if anything changed start the hotplug code.
612 	 */
613 	if (old_status != connector->status) {
614 		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
615 			    connector->base.id, connector->name,
616 			    drm_get_connector_status_name(old_status),
617 			    drm_get_connector_status_name(connector->status));
618 
619 		/*
620 		 * The hotplug event code might call into the fb
621 		 * helpers, and so expects that we do not hold any
622 		 * locks. Fire up the poll struct instead, it will
623 		 * disable itself again.
624 		 */
625 		dev->mode_config.delayed_event = true;
626 		if (dev->mode_config.poll_enabled)
627 			mod_delayed_work(system_wq,
628 					 &dev->mode_config.output_poll_work,
629 					 0);
630 	}
631 
632 	/*
633 	 * Re-enable polling in case the global poll config changed but polling
634 	 * is still initialized.
635 	 */
636 	if (dev->mode_config.poll_enabled)
637 		drm_kms_helper_poll_enable(dev);
638 
639 	if (connector->status == connector_status_disconnected) {
640 		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] disconnected\n",
641 			    connector->base.id, connector->name);
642 		drm_connector_update_edid_property(connector, NULL);
643 		drm_mode_prune_invalid(dev, &connector->modes, false);
644 		goto exit;
645 	}
646 
647 	count = drm_helper_probe_get_modes(connector);
648 
649 	if (count == 0 && (connector->status == connector_status_connected ||
650 			   connector->status == connector_status_unknown)) {
651 		count = drm_add_modes_noedid(connector, 1024, 768);
652 
653 		/*
654 		 * Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a
655 		 * Link CTS specifies that 640x480 (the official "failsafe"
656 		 * mode) needs to be the default if there's no EDID.
657 		 */
658 		if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort)
659 			drm_set_preferred_mode(connector, 640, 480);
660 	}
661 	count += drm_helper_probe_add_cmdline_mode(connector);
662 	if (count != 0) {
663 		ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
664 		if (ret == -EDEADLK) {
665 			drm_modeset_backoff(&ctx);
666 			goto retry;
667 		}
668 	}
669 
670 	drm_mode_prune_invalid(dev, &connector->modes, true);
671 
672 	/*
673 	 * Displayport spec section 5.2.1.2 ("Video Timing Format") says that
674 	 * all detachable sinks shall support 640x480 @60Hz as a fail safe
675 	 * mode. If all modes were pruned, perhaps because they need more
676 	 * lanes or a higher pixel clock than available, at least try to add
677 	 * in 640x480.
678 	 */
679 	if (list_empty(&connector->modes) &&
680 	    connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
681 		count = drm_add_modes_noedid(connector, 640, 480);
682 		ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
683 		if (ret == -EDEADLK) {
684 			drm_modeset_backoff(&ctx);
685 			goto retry;
686 		}
687 		drm_mode_prune_invalid(dev, &connector->modes, true);
688 	}
689 
690 exit:
691 	drm_modeset_drop_locks(&ctx);
692 	drm_modeset_acquire_fini(&ctx);
693 
694 	if (list_empty(&connector->modes))
695 		return 0;
696 
697 	drm_mode_sort(&connector->modes);
698 
699 	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] probed modes:\n",
700 		    connector->base.id, connector->name);
701 
702 	list_for_each_entry(mode, &connector->modes, head) {
703 		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
704 		drm_dbg_kms(dev, "Probed mode: " DRM_MODE_FMT "\n",
705 			    DRM_MODE_ARG(mode));
706 	}
707 
708 	return count;
709 }
710 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
711 
712 /**
713  * drm_kms_helper_hotplug_event - fire off KMS hotplug events
714  * @dev: drm_device whose connector state changed
715  *
716  * This function fires off the uevent for userspace and also calls the
717  * client hotplug function, which is most commonly used to inform the fbdev
718  * emulation code and allow it to update the fbcon output configuration.
719  *
720  * Drivers should call this from their hotplug handling code when a change is
721  * detected. Note that this function does not do any output detection of its
722  * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
723  * driver already.
724  *
725  * This function must be called from process context with no mode
726  * setting locks held.
727  *
728  * If only a single connector has changed, consider calling
729  * drm_kms_helper_connector_hotplug_event() instead.
730  */
drm_kms_helper_hotplug_event(struct drm_device * dev)731 void drm_kms_helper_hotplug_event(struct drm_device *dev)
732 {
733 	drm_sysfs_hotplug_event(dev);
734 	drm_client_dev_hotplug(dev);
735 }
736 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
737 
738 /**
739  * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
740  * @connector: drm_connector which has changed
741  *
742  * This is the same as drm_kms_helper_hotplug_event(), except it fires a more
743  * fine-grained uevent for a single connector.
744  */
drm_kms_helper_connector_hotplug_event(struct drm_connector * connector)745 void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector)
746 {
747 	struct drm_device *dev = connector->dev;
748 
749 	drm_sysfs_connector_hotplug_event(connector);
750 	drm_client_dev_hotplug(dev);
751 }
752 EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event);
753 
output_poll_execute(struct work_struct * work)754 static void output_poll_execute(struct work_struct *work)
755 {
756 	struct delayed_work *delayed_work = to_delayed_work(work);
757 	struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
758 	struct drm_connector *connector;
759 	struct drm_connector_list_iter conn_iter;
760 	enum drm_connector_status old_status;
761 	bool repoll = false, changed;
762 	u64 old_epoch_counter;
763 
764 	if (!dev->mode_config.poll_enabled)
765 		return;
766 
767 	/* Pick up any changes detected by the probe functions. */
768 	changed = dev->mode_config.delayed_event;
769 	dev->mode_config.delayed_event = false;
770 
771 	if (!drm_kms_helper_poll) {
772 		if (dev->mode_config.poll_running) {
773 			drm_kms_helper_disable_hpd(dev);
774 			dev->mode_config.poll_running = false;
775 		}
776 		goto out;
777 	}
778 
779 	if (!mutex_trylock(&dev->mode_config.mutex)) {
780 		repoll = true;
781 		goto out;
782 	}
783 
784 	drm_connector_list_iter_begin(dev, &conn_iter);
785 	drm_for_each_connector_iter(connector, &conn_iter) {
786 		/* Ignore forced connectors. */
787 		if (connector->force)
788 			continue;
789 
790 		/* Ignore HPD capable connectors and connectors where we don't
791 		 * want any hotplug detection at all for polling. */
792 		if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
793 			continue;
794 
795 		old_status = connector->status;
796 		/* if we are connected and don't want to poll for disconnect
797 		   skip it */
798 		if (old_status == connector_status_connected &&
799 		    !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
800 			continue;
801 
802 		repoll = true;
803 
804 		old_epoch_counter = connector->epoch_counter;
805 		connector->status = drm_helper_probe_detect(connector, NULL, false);
806 		if (old_epoch_counter != connector->epoch_counter) {
807 			const char *old, *new;
808 
809 			/*
810 			 * The poll work sets force=false when calling detect so
811 			 * that drivers can avoid to do disruptive tests (e.g.
812 			 * when load detect cycles could cause flickering on
813 			 * other, running displays). This bears the risk that we
814 			 * flip-flop between unknown here in the poll work and
815 			 * the real state when userspace forces a full detect
816 			 * call after receiving a hotplug event due to this
817 			 * change.
818 			 *
819 			 * Hence clamp an unknown detect status to the old
820 			 * value.
821 			 */
822 			if (connector->status == connector_status_unknown) {
823 				connector->status = old_status;
824 				continue;
825 			}
826 
827 			old = drm_get_connector_status_name(old_status);
828 			new = drm_get_connector_status_name(connector->status);
829 
830 			drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
831 				    connector->base.id, connector->name,
832 				    old, new);
833 			drm_dbg_kms(dev, "[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
834 				    connector->base.id, connector->name,
835 				    old_epoch_counter, connector->epoch_counter);
836 
837 			changed = true;
838 		}
839 	}
840 	drm_connector_list_iter_end(&conn_iter);
841 
842 	mutex_unlock(&dev->mode_config.mutex);
843 
844 out:
845 	if (changed)
846 		drm_kms_helper_hotplug_event(dev);
847 
848 	if (repoll)
849 		schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
850 }
851 
852 /**
853  * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
854  *
855  * Determine if %current task is an output poll worker.  This can be used
856  * to select distinct code paths for output polling versus other contexts.
857  *
858  * One use case is to avoid a deadlock between the output poll worker and
859  * the autosuspend worker wherein the latter waits for polling to finish
860  * upon calling drm_kms_helper_poll_disable(), while the former waits for
861  * runtime suspend to finish upon calling pm_runtime_get_sync() in a
862  * connector ->detect hook.
863  */
drm_kms_helper_is_poll_worker(void)864 bool drm_kms_helper_is_poll_worker(void)
865 {
866 	struct work_struct *work = current_work();
867 
868 	return work && work->func == output_poll_execute;
869 }
870 EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
871 
872 /**
873  * drm_kms_helper_poll_disable - disable output polling
874  * @dev: drm_device
875  *
876  * This function disables the output polling work.
877  *
878  * Drivers can call this helper from their device suspend implementation. It is
879  * not an error to call this even when output polling isn't enabled or already
880  * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
881  *
882  * If however, the polling was never initialized, this call will trigger a
883  * warning and return.
884  *
885  * Note that calls to enable and disable polling must be strictly ordered, which
886  * is automatically the case when they're only call from suspend/resume
887  * callbacks.
888  */
drm_kms_helper_poll_disable(struct drm_device * dev)889 void drm_kms_helper_poll_disable(struct drm_device *dev)
890 {
891 	if (drm_WARN_ON(dev, !dev->mode_config.poll_enabled))
892 		return;
893 
894 	if (dev->mode_config.poll_running)
895 		drm_kms_helper_disable_hpd(dev);
896 
897 	cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
898 
899 	dev->mode_config.poll_running = false;
900 }
901 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
902 
903 /**
904  * drm_kms_helper_poll_init - initialize and enable output polling
905  * @dev: drm_device
906  *
907  * This function initializes and then also enables output polling support for
908  * @dev. Drivers which do not have reliable hotplug support in hardware can use
909  * this helper infrastructure to regularly poll such connectors for changes in
910  * their connection state.
911  *
912  * Drivers can control which connectors are polled by setting the
913  * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
914  * connectors where probing live outputs can result in visual distortion drivers
915  * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
916  * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
917  * completely ignored by the polling logic.
918  *
919  * Note that a connector can be both polled and probed from the hotplug handler,
920  * in case the hotplug interrupt is known to be unreliable.
921  */
drm_kms_helper_poll_init(struct drm_device * dev)922 void drm_kms_helper_poll_init(struct drm_device *dev)
923 {
924 	INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
925 	dev->mode_config.poll_enabled = true;
926 
927 	drm_kms_helper_poll_enable(dev);
928 }
929 EXPORT_SYMBOL(drm_kms_helper_poll_init);
930 
931 /**
932  * drm_kms_helper_poll_fini - disable output polling and clean it up
933  * @dev: drm_device
934  */
drm_kms_helper_poll_fini(struct drm_device * dev)935 void drm_kms_helper_poll_fini(struct drm_device *dev)
936 {
937 	if (!dev->mode_config.poll_enabled)
938 		return;
939 
940 	drm_kms_helper_poll_disable(dev);
941 
942 	dev->mode_config.poll_enabled = false;
943 }
944 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
945 
drm_kms_helper_poll_init_release(struct drm_device * dev,void * res)946 static void drm_kms_helper_poll_init_release(struct drm_device *dev, void *res)
947 {
948 	drm_kms_helper_poll_fini(dev);
949 }
950 
951 /**
952  * drmm_kms_helper_poll_init - initialize and enable output polling
953  * @dev: drm_device
954  *
955  * This function initializes and then also enables output polling support for
956  * @dev similar to drm_kms_helper_poll_init(). Polling will automatically be
957  * cleaned up when the DRM device goes away.
958  *
959  * See drm_kms_helper_poll_init() for more information.
960  *
961  * Returns:
962  * 0 on success, or a negative errno code otherwise.
963  */
drmm_kms_helper_poll_init(struct drm_device * dev)964 int drmm_kms_helper_poll_init(struct drm_device *dev)
965 {
966 	drm_kms_helper_poll_init(dev);
967 
968 	return drmm_add_action_or_reset(dev, drm_kms_helper_poll_init_release, dev);
969 }
970 EXPORT_SYMBOL(drmm_kms_helper_poll_init);
971 
check_connector_changed(struct drm_connector * connector)972 static bool check_connector_changed(struct drm_connector *connector)
973 {
974 	struct drm_device *dev = connector->dev;
975 	enum drm_connector_status old_status;
976 	u64 old_epoch_counter;
977 
978 	/* Only handle HPD capable connectors. */
979 	drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD));
980 
981 	drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
982 
983 	old_status = connector->status;
984 	old_epoch_counter = connector->epoch_counter;
985 	connector->status = drm_helper_probe_detect(connector, NULL, false);
986 
987 	if (old_epoch_counter == connector->epoch_counter) {
988 		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
989 			    connector->base.id,
990 			    connector->name,
991 			    connector->epoch_counter);
992 
993 		return false;
994 	}
995 
996 	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
997 		    connector->base.id,
998 		    connector->name,
999 		    drm_get_connector_status_name(old_status),
1000 		    drm_get_connector_status_name(connector->status));
1001 
1002 	drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
1003 		    connector->base.id,
1004 		    connector->name,
1005 		    old_epoch_counter,
1006 		    connector->epoch_counter);
1007 
1008 	return true;
1009 }
1010 
1011 /**
1012  * drm_connector_helper_hpd_irq_event - hotplug processing
1013  * @connector: drm_connector
1014  *
1015  * Drivers can use this helper function to run a detect cycle on a connector
1016  * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
1017  *
1018  * This helper function is useful for drivers which can track hotplug
1019  * interrupts for a single connector. Drivers that want to send a
1020  * hotplug event for all connectors or can't track hotplug interrupts
1021  * per connector need to use drm_helper_hpd_irq_event().
1022  *
1023  * This function must be called from process context with no mode
1024  * setting locks held.
1025  *
1026  * Note that a connector can be both polled and probed from the hotplug
1027  * handler, in case the hotplug interrupt is known to be unreliable.
1028  *
1029  * Returns:
1030  * A boolean indicating whether the connector status changed or not
1031  */
drm_connector_helper_hpd_irq_event(struct drm_connector * connector)1032 bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector)
1033 {
1034 	struct drm_device *dev = connector->dev;
1035 	bool changed;
1036 
1037 	mutex_lock(&dev->mode_config.mutex);
1038 	changed = check_connector_changed(connector);
1039 	mutex_unlock(&dev->mode_config.mutex);
1040 
1041 	if (changed) {
1042 		drm_kms_helper_connector_hotplug_event(connector);
1043 		drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Sent hotplug event\n",
1044 			    connector->base.id,
1045 			    connector->name);
1046 	}
1047 
1048 	return changed;
1049 }
1050 EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event);
1051 
1052 /**
1053  * drm_helper_hpd_irq_event - hotplug processing
1054  * @dev: drm_device
1055  *
1056  * Drivers can use this helper function to run a detect cycle on all connectors
1057  * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
1058  * other connectors are ignored, which is useful to avoid reprobing fixed
1059  * panels.
1060  *
1061  * This helper function is useful for drivers which can't or don't track hotplug
1062  * interrupts for each connector.
1063  *
1064  * Drivers which support hotplug interrupts for each connector individually and
1065  * which have a more fine-grained detect logic can use
1066  * drm_connector_helper_hpd_irq_event(). Alternatively, they should bypass this
1067  * code and directly call drm_kms_helper_hotplug_event() in case the connector
1068  * state changed.
1069  *
1070  * This function must be called from process context with no mode
1071  * setting locks held.
1072  *
1073  * Note that a connector can be both polled and probed from the hotplug handler,
1074  * in case the hotplug interrupt is known to be unreliable.
1075  *
1076  * Returns:
1077  * A boolean indicating whether the connector status changed or not
1078  */
drm_helper_hpd_irq_event(struct drm_device * dev)1079 bool drm_helper_hpd_irq_event(struct drm_device *dev)
1080 {
1081 	struct drm_connector *connector, *first_changed_connector = NULL;
1082 	struct drm_connector_list_iter conn_iter;
1083 	int changed = 0;
1084 
1085 	if (!dev->mode_config.poll_enabled)
1086 		return false;
1087 
1088 	mutex_lock(&dev->mode_config.mutex);
1089 	drm_connector_list_iter_begin(dev, &conn_iter);
1090 	drm_for_each_connector_iter(connector, &conn_iter) {
1091 		/* Only handle HPD capable connectors. */
1092 		if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
1093 			continue;
1094 
1095 		if (check_connector_changed(connector)) {
1096 			if (!first_changed_connector) {
1097 				drm_connector_get(connector);
1098 				first_changed_connector = connector;
1099 			}
1100 
1101 			changed++;
1102 		}
1103 	}
1104 	drm_connector_list_iter_end(&conn_iter);
1105 	mutex_unlock(&dev->mode_config.mutex);
1106 
1107 	if (changed == 1)
1108 		drm_kms_helper_connector_hotplug_event(first_changed_connector);
1109 	else if (changed > 0)
1110 		drm_kms_helper_hotplug_event(dev);
1111 
1112 	if (first_changed_connector)
1113 		drm_connector_put(first_changed_connector);
1114 
1115 	return changed;
1116 }
1117 EXPORT_SYMBOL(drm_helper_hpd_irq_event);
1118 
1119 /**
1120  * drm_crtc_helper_mode_valid_fixed - Validates a display mode
1121  * @crtc: the crtc
1122  * @mode: the mode to validate
1123  * @fixed_mode: the display hardware's mode
1124  *
1125  * Returns:
1126  * MODE_OK on success, or another mode-status code otherwise.
1127  */
drm_crtc_helper_mode_valid_fixed(struct drm_crtc * crtc,const struct drm_display_mode * mode,const struct drm_display_mode * fixed_mode)1128 enum drm_mode_status drm_crtc_helper_mode_valid_fixed(struct drm_crtc *crtc,
1129 						      const struct drm_display_mode *mode,
1130 						      const struct drm_display_mode *fixed_mode)
1131 {
1132 	if (mode->hdisplay != fixed_mode->hdisplay && mode->vdisplay != fixed_mode->vdisplay)
1133 		return MODE_ONE_SIZE;
1134 	else if (mode->hdisplay != fixed_mode->hdisplay)
1135 		return MODE_ONE_WIDTH;
1136 	else if (mode->vdisplay != fixed_mode->vdisplay)
1137 		return MODE_ONE_HEIGHT;
1138 
1139 	return MODE_OK;
1140 }
1141 EXPORT_SYMBOL(drm_crtc_helper_mode_valid_fixed);
1142 
1143 /**
1144  * drm_connector_helper_get_modes_fixed - Duplicates a display mode for a connector
1145  * @connector: the connector
1146  * @fixed_mode: the display hardware's mode
1147  *
1148  * This function duplicates a display modes for a connector. Drivers for hardware
1149  * that only supports a single fixed mode can use this function in their connector's
1150  * get_modes helper.
1151  *
1152  * Returns:
1153  * The number of created modes.
1154  */
drm_connector_helper_get_modes_fixed(struct drm_connector * connector,const struct drm_display_mode * fixed_mode)1155 int drm_connector_helper_get_modes_fixed(struct drm_connector *connector,
1156 					 const struct drm_display_mode *fixed_mode)
1157 {
1158 	struct drm_device *dev = connector->dev;
1159 	struct drm_display_mode *mode;
1160 
1161 	mode = drm_mode_duplicate(dev, fixed_mode);
1162 	if (!mode) {
1163 		drm_err(dev, "Failed to duplicate mode " DRM_MODE_FMT "\n",
1164 			DRM_MODE_ARG(fixed_mode));
1165 		return 0;
1166 	}
1167 
1168 	if (mode->name[0] == '\0')
1169 		drm_mode_set_name(mode);
1170 
1171 	mode->type |= DRM_MODE_TYPE_PREFERRED;
1172 	drm_mode_probed_add(connector, mode);
1173 
1174 	if (mode->width_mm)
1175 		connector->display_info.width_mm = mode->width_mm;
1176 	if (mode->height_mm)
1177 		connector->display_info.height_mm = mode->height_mm;
1178 
1179 	return 1;
1180 }
1181 EXPORT_SYMBOL(drm_connector_helper_get_modes_fixed);
1182 
1183 /**
1184  * drm_connector_helper_get_modes - Read EDID and update connector.
1185  * @connector: The connector
1186  *
1187  * Read the EDID using drm_edid_read() (which requires that connector->ddc is
1188  * set), and update the connector using the EDID.
1189  *
1190  * This can be used as the "default" connector helper .get_modes() hook if the
1191  * driver does not need any special processing. This is sets the example what
1192  * custom .get_modes() hooks should do regarding EDID read and connector update.
1193  *
1194  * Returns: Number of modes.
1195  */
drm_connector_helper_get_modes(struct drm_connector * connector)1196 int drm_connector_helper_get_modes(struct drm_connector *connector)
1197 {
1198 	const struct drm_edid *drm_edid;
1199 	int count;
1200 
1201 	drm_edid = drm_edid_read(connector);
1202 
1203 	/*
1204 	 * Unconditionally update the connector. If the EDID was read
1205 	 * successfully, fill in the connector information derived from the
1206 	 * EDID. Otherwise, if the EDID is NULL, clear the connector
1207 	 * information.
1208 	 */
1209 	drm_edid_connector_update(connector, drm_edid);
1210 
1211 	count = drm_edid_connector_add_modes(connector);
1212 
1213 	drm_edid_free(drm_edid);
1214 
1215 	return count;
1216 }
1217 EXPORT_SYMBOL(drm_connector_helper_get_modes);
1218 
1219 /**
1220  * drm_connector_helper_tv_get_modes - Fills the modes availables to a TV connector
1221  * @connector: The connector
1222  *
1223  * Fills the available modes for a TV connector based on the supported
1224  * TV modes, and the default mode expressed by the kernel command line.
1225  *
1226  * This can be used as the default TV connector helper .get_modes() hook
1227  * if the driver does not need any special processing.
1228  *
1229  * Returns:
1230  * The number of modes added to the connector.
1231  */
drm_connector_helper_tv_get_modes(struct drm_connector * connector)1232 int drm_connector_helper_tv_get_modes(struct drm_connector *connector)
1233 {
1234 	struct drm_device *dev = connector->dev;
1235 	struct drm_property *tv_mode_property =
1236 		dev->mode_config.tv_mode_property;
1237 	struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
1238 	unsigned int ntsc_modes = BIT(DRM_MODE_TV_MODE_NTSC) |
1239 		BIT(DRM_MODE_TV_MODE_NTSC_443) |
1240 		BIT(DRM_MODE_TV_MODE_NTSC_J) |
1241 		BIT(DRM_MODE_TV_MODE_PAL_M);
1242 	unsigned int pal_modes = BIT(DRM_MODE_TV_MODE_PAL) |
1243 		BIT(DRM_MODE_TV_MODE_PAL_N) |
1244 		BIT(DRM_MODE_TV_MODE_SECAM);
1245 	unsigned int tv_modes[2] = { UINT_MAX, UINT_MAX };
1246 	unsigned int i, supported_tv_modes = 0;
1247 
1248 	if (!tv_mode_property)
1249 		return 0;
1250 
1251 	for (i = 0; i < tv_mode_property->num_values; i++)
1252 		supported_tv_modes |= BIT(tv_mode_property->values[i]);
1253 
1254 	if (((supported_tv_modes & ntsc_modes) &&
1255 	     (supported_tv_modes & pal_modes)) ||
1256 	    (supported_tv_modes & BIT(DRM_MODE_TV_MODE_MONOCHROME))) {
1257 		uint64_t default_mode;
1258 
1259 		if (drm_object_property_get_default_value(&connector->base,
1260 							  tv_mode_property,
1261 							  &default_mode))
1262 			return 0;
1263 
1264 		if (cmdline->tv_mode_specified)
1265 			default_mode = cmdline->tv_mode;
1266 
1267 		if (BIT(default_mode) & ntsc_modes) {
1268 			tv_modes[0] = DRM_MODE_TV_MODE_NTSC;
1269 			tv_modes[1] = DRM_MODE_TV_MODE_PAL;
1270 		} else {
1271 			tv_modes[0] = DRM_MODE_TV_MODE_PAL;
1272 			tv_modes[1] = DRM_MODE_TV_MODE_NTSC;
1273 		}
1274 	} else if (supported_tv_modes & ntsc_modes) {
1275 		tv_modes[0] = DRM_MODE_TV_MODE_NTSC;
1276 	} else if (supported_tv_modes & pal_modes) {
1277 		tv_modes[0] = DRM_MODE_TV_MODE_PAL;
1278 	} else {
1279 		return 0;
1280 	}
1281 
1282 	for (i = 0; i < ARRAY_SIZE(tv_modes); i++) {
1283 		struct drm_display_mode *mode;
1284 
1285 		if (tv_modes[i] == DRM_MODE_TV_MODE_NTSC)
1286 			mode = drm_mode_analog_ntsc_480i(dev);
1287 		else if (tv_modes[i] == DRM_MODE_TV_MODE_PAL)
1288 			mode = drm_mode_analog_pal_576i(dev);
1289 		else
1290 			break;
1291 		if (!mode)
1292 			return i;
1293 		if (!i)
1294 			mode->type |= DRM_MODE_TYPE_PREFERRED;
1295 		drm_mode_probed_add(connector, mode);
1296 	}
1297 
1298 	return i;
1299 }
1300 EXPORT_SYMBOL(drm_connector_helper_tv_get_modes);
1301 
1302 /**
1303  * drm_connector_helper_detect_from_ddc - Read EDID and detect connector status.
1304  * @connector: The connector
1305  * @ctx: Acquire context
1306  * @force: Perform screen-destructive operations, if necessary
1307  *
1308  * Detects the connector status by reading the EDID using drm_probe_ddc(),
1309  * which requires connector->ddc to be set. Returns connector_status_connected
1310  * on success or connector_status_disconnected on failure.
1311  *
1312  * Returns:
1313  * The connector status as defined by enum drm_connector_status.
1314  */
drm_connector_helper_detect_from_ddc(struct drm_connector * connector,struct drm_modeset_acquire_ctx * ctx,bool force)1315 int drm_connector_helper_detect_from_ddc(struct drm_connector *connector,
1316 					 struct drm_modeset_acquire_ctx *ctx,
1317 					 bool force)
1318 {
1319 	struct i2c_adapter *ddc = connector->ddc;
1320 
1321 	if (!ddc)
1322 		return connector_status_unknown;
1323 
1324 	if (drm_probe_ddc(ddc))
1325 		return connector_status_connected;
1326 
1327 	return connector_status_disconnected;
1328 }
1329 EXPORT_SYMBOL(drm_connector_helper_detect_from_ddc);
1330