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