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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/drmP.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>
41 
42 /**
43  * DOC: output probing helper overview
44  *
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.
48  *
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.
52  *
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.
56  */
57 
58 static bool drm_kms_helper_poll = true;
59 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
60 
drm_mode_validate_flag(struct drm_connector * connector,int flags)61 static void drm_mode_validate_flag(struct drm_connector *connector,
62 				   int flags)
63 {
64 	struct drm_display_mode *mode;
65 
66 	if (flags == (DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_INTERLACE |
67 		      DRM_MODE_FLAG_3D_MASK))
68 		return;
69 
70 	list_for_each_entry(mode, &connector->modes, head) {
71 		if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
72 				!(flags & DRM_MODE_FLAG_INTERLACE))
73 			mode->status = MODE_NO_INTERLACE;
74 		if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
75 				!(flags & DRM_MODE_FLAG_DBLSCAN))
76 			mode->status = MODE_NO_DBLESCAN;
77 		if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
78 				!(flags & DRM_MODE_FLAG_3D_MASK))
79 			mode->status = MODE_NO_STEREO;
80 	}
81 
82 	return;
83 }
84 
drm_helper_probe_add_cmdline_mode(struct drm_connector * connector)85 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
86 {
87 	struct drm_display_mode *mode;
88 
89 	if (!connector->cmdline_mode.specified)
90 		return 0;
91 
92 	mode = drm_mode_create_from_cmdline_mode(connector->dev,
93 						 &connector->cmdline_mode);
94 	if (mode == NULL)
95 		return 0;
96 
97 	drm_mode_probed_add(connector, mode);
98 	return 1;
99 }
100 
drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector * connector,uint32_t maxX,uint32_t maxY,bool merge_type_bits)101 static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector *connector,
102 							      uint32_t maxX, uint32_t maxY, bool merge_type_bits)
103 {
104 	struct drm_device *dev = connector->dev;
105 	struct drm_display_mode *mode;
106 	struct drm_connector_helper_funcs *connector_funcs =
107 		connector->helper_private;
108 	int count = 0;
109 	int mode_flags = 0;
110 	bool verbose_prune = true;
111 
112 	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
113 
114 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
115 			connector->name);
116 	/* set all modes to the unverified state */
117 	list_for_each_entry(mode, &connector->modes, head)
118 		mode->status = MODE_UNVERIFIED;
119 
120 	if (connector->force) {
121 		if (connector->force == DRM_FORCE_ON)
122 			connector->status = connector_status_connected;
123 		else
124 			connector->status = connector_status_disconnected;
125 		if (connector->funcs->force)
126 			connector->funcs->force(connector);
127 	} else {
128 		connector->status = connector->funcs->detect(connector, true);
129 	}
130 
131 	/* Re-enable polling in case the global poll config changed. */
132 	if (drm_kms_helper_poll != dev->mode_config.poll_running)
133 		drm_kms_helper_poll_enable(dev);
134 
135 	dev->mode_config.poll_running = drm_kms_helper_poll;
136 
137 	if (connector->status == connector_status_disconnected) {
138 		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
139 			connector->base.id, connector->name);
140 		drm_mode_connector_update_edid_property(connector, NULL);
141 		verbose_prune = false;
142 		goto prune;
143 	}
144 
145 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
146 	count = drm_load_edid_firmware(connector);
147 	if (count == 0)
148 #endif
149 	{
150 		if (connector->override_edid) {
151 			struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
152 
153 			count = drm_add_edid_modes(connector, edid);
154 			drm_edid_to_eld(connector, edid);
155 		} else
156 			count = (*connector_funcs->get_modes)(connector);
157 	}
158 
159 	if (count == 0 && connector->status == connector_status_connected)
160 		count = drm_add_modes_noedid(connector, 1024, 768);
161 	count += drm_helper_probe_add_cmdline_mode(connector);
162 	if (count == 0)
163 		goto prune;
164 
165 	drm_mode_connector_list_update(connector, merge_type_bits);
166 
167 	if (maxX && maxY)
168 		drm_mode_validate_size(dev, &connector->modes, maxX, maxY);
169 
170 	if (connector->interlace_allowed)
171 		mode_flags |= DRM_MODE_FLAG_INTERLACE;
172 	if (connector->doublescan_allowed)
173 		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
174 	if (connector->stereo_allowed)
175 		mode_flags |= DRM_MODE_FLAG_3D_MASK;
176 	drm_mode_validate_flag(connector, mode_flags);
177 
178 	list_for_each_entry(mode, &connector->modes, head) {
179 		if (mode->status == MODE_OK && connector_funcs->mode_valid)
180 			mode->status = connector_funcs->mode_valid(connector,
181 								   mode);
182 	}
183 
184 prune:
185 	drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
186 
187 	if (list_empty(&connector->modes))
188 		return 0;
189 
190 	list_for_each_entry(mode, &connector->modes, head)
191 		mode->vrefresh = drm_mode_vrefresh(mode);
192 
193 	drm_mode_sort(&connector->modes);
194 
195 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
196 			connector->name);
197 	list_for_each_entry(mode, &connector->modes, head) {
198 		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
199 		drm_mode_debug_printmodeline(mode);
200 	}
201 
202 	return count;
203 }
204 
205 /**
206  * drm_helper_probe_single_connector_modes - get complete set of display modes
207  * @connector: connector to probe
208  * @maxX: max width for modes
209  * @maxY: max height for modes
210  *
211  * Based on the helper callbacks implemented by @connector try to detect all
212  * valid modes.  Modes will first be added to the connector's probed_modes list,
213  * then culled (based on validity and the @maxX, @maxY parameters) and put into
214  * the normal modes list.
215  *
216  * Intended to be use as a generic implementation of the ->fill_modes()
217  * @connector vfunc for drivers that use the crtc helpers for output mode
218  * filtering and detection.
219  *
220  * Returns:
221  * The number of modes found on @connector.
222  */
drm_helper_probe_single_connector_modes(struct drm_connector * connector,uint32_t maxX,uint32_t maxY)223 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
224 					    uint32_t maxX, uint32_t maxY)
225 {
226 	return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, true);
227 }
228 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
229 
230 /**
231  * drm_helper_probe_single_connector_modes_nomerge - get complete set of display modes
232  * @connector: connector to probe
233  * @maxX: max width for modes
234  * @maxY: max height for modes
235  *
236  * This operates like drm_hehlper_probe_single_connector_modes except it
237  * replaces the mode bits instead of merging them for preferred modes.
238  */
drm_helper_probe_single_connector_modes_nomerge(struct drm_connector * connector,uint32_t maxX,uint32_t maxY)239 int drm_helper_probe_single_connector_modes_nomerge(struct drm_connector *connector,
240 					    uint32_t maxX, uint32_t maxY)
241 {
242 	return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, false);
243 }
244 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes_nomerge);
245 
246 /**
247  * drm_kms_helper_hotplug_event - fire off KMS hotplug events
248  * @dev: drm_device whose connector state changed
249  *
250  * This function fires off the uevent for userspace and also calls the
251  * output_poll_changed function, which is most commonly used to inform the fbdev
252  * emulation code and allow it to update the fbcon output configuration.
253  *
254  * Drivers should call this from their hotplug handling code when a change is
255  * detected. Note that this function does not do any output detection of its
256  * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
257  * driver already.
258  *
259  * This function must be called from process context with no mode
260  * setting locks held.
261  */
drm_kms_helper_hotplug_event(struct drm_device * dev)262 void drm_kms_helper_hotplug_event(struct drm_device *dev)
263 {
264 	/* send a uevent + call fbdev */
265 	drm_sysfs_hotplug_event(dev);
266 	if (dev->mode_config.funcs->output_poll_changed)
267 		dev->mode_config.funcs->output_poll_changed(dev);
268 }
269 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
270 
271 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
output_poll_execute(struct work_struct * work)272 static void output_poll_execute(struct work_struct *work)
273 {
274 	struct delayed_work *delayed_work = to_delayed_work(work);
275 	struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
276 	struct drm_connector *connector;
277 	enum drm_connector_status old_status;
278 	bool repoll = false, changed = false;
279 
280 	if (!drm_kms_helper_poll)
281 		return;
282 
283 	mutex_lock(&dev->mode_config.mutex);
284 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
285 
286 		/* Ignore forced connectors. */
287 		if (connector->force)
288 			continue;
289 
290 		/* Ignore HPD capable connectors and connectors where we don't
291 		 * want any hotplug detection at all for polling. */
292 		if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
293 			continue;
294 
295 		repoll = true;
296 
297 		old_status = connector->status;
298 		/* if we are connected and don't want to poll for disconnect
299 		   skip it */
300 		if (old_status == connector_status_connected &&
301 		    !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
302 			continue;
303 
304 		connector->status = connector->funcs->detect(connector, false);
305 		if (old_status != connector->status) {
306 			const char *old, *new;
307 
308 			old = drm_get_connector_status_name(old_status);
309 			new = drm_get_connector_status_name(connector->status);
310 
311 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
312 				      "status updated from %s to %s\n",
313 				      connector->base.id,
314 				      connector->name,
315 				      old, new);
316 
317 			changed = true;
318 		}
319 	}
320 
321 	mutex_unlock(&dev->mode_config.mutex);
322 
323 	if (changed)
324 		drm_kms_helper_hotplug_event(dev);
325 
326 	if (repoll)
327 		schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
328 }
329 
330 /**
331  * drm_kms_helper_poll_disable - disable output polling
332  * @dev: drm_device
333  *
334  * This function disables the output polling work.
335  *
336  * Drivers can call this helper from their device suspend implementation. It is
337  * not an error to call this even when output polling isn't enabled or arlready
338  * disabled.
339  */
drm_kms_helper_poll_disable(struct drm_device * dev)340 void drm_kms_helper_poll_disable(struct drm_device *dev)
341 {
342 	if (!dev->mode_config.poll_enabled)
343 		return;
344 	cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
345 }
346 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
347 
348 /**
349  * drm_kms_helper_poll_enable - re-enable output polling.
350  * @dev: drm_device
351  *
352  * This function re-enables the output polling work.
353  *
354  * Drivers can call this helper from their device resume implementation. It is
355  * an error to call this when the output polling support has not yet been set
356  * up.
357  */
drm_kms_helper_poll_enable(struct drm_device * dev)358 void drm_kms_helper_poll_enable(struct drm_device *dev)
359 {
360 	bool poll = false;
361 	struct drm_connector *connector;
362 
363 	if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
364 		return;
365 
366 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
367 		if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
368 					 DRM_CONNECTOR_POLL_DISCONNECT))
369 			poll = true;
370 	}
371 
372 	if (poll)
373 		schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
374 }
375 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
376 
377 /**
378  * drm_kms_helper_poll_init - initialize and enable output polling
379  * @dev: drm_device
380  *
381  * This function intializes and then also enables output polling support for
382  * @dev. Drivers which do not have reliable hotplug support in hardware can use
383  * this helper infrastructure to regularly poll such connectors for changes in
384  * their connection state.
385  *
386  * Drivers can control which connectors are polled by setting the
387  * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
388  * connectors where probing live outputs can result in visual distortion drivers
389  * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
390  * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
391  * completely ignored by the polling logic.
392  *
393  * Note that a connector can be both polled and probed from the hotplug handler,
394  * in case the hotplug interrupt is known to be unreliable.
395  */
drm_kms_helper_poll_init(struct drm_device * dev)396 void drm_kms_helper_poll_init(struct drm_device *dev)
397 {
398 	INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
399 	dev->mode_config.poll_enabled = true;
400 
401 	drm_kms_helper_poll_enable(dev);
402 }
403 EXPORT_SYMBOL(drm_kms_helper_poll_init);
404 
405 /**
406  * drm_kms_helper_poll_fini - disable output polling and clean it up
407  * @dev: drm_device
408  */
drm_kms_helper_poll_fini(struct drm_device * dev)409 void drm_kms_helper_poll_fini(struct drm_device *dev)
410 {
411 	drm_kms_helper_poll_disable(dev);
412 }
413 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
414 
415 /**
416  * drm_helper_hpd_irq_event - hotplug processing
417  * @dev: drm_device
418  *
419  * Drivers can use this helper function to run a detect cycle on all connectors
420  * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
421  * other connectors are ignored, which is useful to avoid reprobing fixed
422  * panels.
423  *
424  * This helper function is useful for drivers which can't or don't track hotplug
425  * interrupts for each connector.
426  *
427  * Drivers which support hotplug interrupts for each connector individually and
428  * which have a more fine-grained detect logic should bypass this code and
429  * directly call drm_kms_helper_hotplug_event() in case the connector state
430  * changed.
431  *
432  * This function must be called from process context with no mode
433  * setting locks held.
434  *
435  * Note that a connector can be both polled and probed from the hotplug handler,
436  * in case the hotplug interrupt is known to be unreliable.
437  */
drm_helper_hpd_irq_event(struct drm_device * dev)438 bool drm_helper_hpd_irq_event(struct drm_device *dev)
439 {
440 	struct drm_connector *connector;
441 	enum drm_connector_status old_status;
442 	bool changed = false;
443 
444 	if (!dev->mode_config.poll_enabled)
445 		return false;
446 
447 	mutex_lock(&dev->mode_config.mutex);
448 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
449 
450 		/* Only handle HPD capable connectors. */
451 		if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
452 			continue;
453 
454 		old_status = connector->status;
455 
456 		connector->status = connector->funcs->detect(connector, false);
457 		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
458 			      connector->base.id,
459 			      connector->name,
460 			      drm_get_connector_status_name(old_status),
461 			      drm_get_connector_status_name(connector->status));
462 		if (old_status != connector->status)
463 			changed = true;
464 	}
465 
466 	mutex_unlock(&dev->mode_config.mutex);
467 
468 	if (changed)
469 		drm_kms_helper_hotplug_event(dev);
470 
471 	return changed;
472 }
473 EXPORT_SYMBOL(drm_helper_hpd_irq_event);
474