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
58static bool drm_kms_helper_poll = true;
59module_param_named(poll, drm_kms_helper_poll, bool, 0600);
60
61static enum drm_mode_status
62drm_mode_validate_flag(const struct drm_display_mode *mode,
63		       int flags)
64{
65	if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
66	    !(flags & DRM_MODE_FLAG_INTERLACE))
67		return MODE_NO_INTERLACE;
68
69	if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
70	    !(flags & DRM_MODE_FLAG_DBLSCAN))
71		return MODE_NO_DBLESCAN;
72
73	if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
74	    !(flags & DRM_MODE_FLAG_3D_MASK))
75		return MODE_NO_STEREO;
76
77	return MODE_OK;
78}
79
80static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
81{
82	struct drm_display_mode *mode;
83
84	if (!connector->cmdline_mode.specified)
85		return 0;
86
87	mode = drm_mode_create_from_cmdline_mode(connector->dev,
88						 &connector->cmdline_mode);
89	if (mode == NULL)
90		return 0;
91
92	drm_mode_probed_add(connector, mode);
93	return 1;
94}
95
96static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector *connector,
97							      uint32_t maxX, uint32_t maxY, bool merge_type_bits)
98{
99	struct drm_device *dev = connector->dev;
100	struct drm_display_mode *mode;
101	const struct drm_connector_helper_funcs *connector_funcs =
102		connector->helper_private;
103	int count = 0;
104	int mode_flags = 0;
105	bool verbose_prune = true;
106	enum drm_connector_status old_status;
107
108	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
109
110	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
111			connector->name);
112	/* set all modes to the unverified state */
113	list_for_each_entry(mode, &connector->modes, head)
114		mode->status = MODE_UNVERIFIED;
115
116	if (connector->force) {
117		if (connector->force == DRM_FORCE_ON ||
118		    connector->force == DRM_FORCE_ON_DIGITAL)
119			connector->status = connector_status_connected;
120		else
121			connector->status = connector_status_disconnected;
122		if (connector->funcs->force)
123			connector->funcs->force(connector);
124	} else {
125		old_status = connector->status;
126
127		connector->status = connector->funcs->detect(connector, true);
128
129		/*
130		 * Normally either the driver's hpd code or the poll loop should
131		 * pick up any changes and fire the hotplug event. But if
132		 * userspace sneaks in a probe, we might miss a change. Hence
133		 * check here, and if anything changed start the hotplug code.
134		 */
135		if (old_status != connector->status) {
136			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
137				      connector->base.id,
138				      connector->name,
139				      old_status, connector->status);
140
141			/*
142			 * The hotplug event code might call into the fb
143			 * helpers, and so expects that we do not hold any
144			 * locks. Fire up the poll struct instead, it will
145			 * disable itself again.
146			 */
147			dev->mode_config.delayed_event = true;
148			if (dev->mode_config.poll_enabled)
149				schedule_delayed_work(&dev->mode_config.output_poll_work,
150						      0);
151		}
152	}
153
154	/* Re-enable polling in case the global poll config changed. */
155	if (drm_kms_helper_poll != dev->mode_config.poll_running)
156		drm_kms_helper_poll_enable(dev);
157
158	dev->mode_config.poll_running = drm_kms_helper_poll;
159
160	if (connector->status == connector_status_disconnected) {
161		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
162			connector->base.id, connector->name);
163		drm_mode_connector_update_edid_property(connector, NULL);
164		verbose_prune = false;
165		goto prune;
166	}
167
168#ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
169	count = drm_load_edid_firmware(connector);
170	if (count == 0)
171#endif
172	{
173		if (connector->override_edid) {
174			struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
175
176			count = drm_add_edid_modes(connector, edid);
177			drm_edid_to_eld(connector, edid);
178		} else
179			count = (*connector_funcs->get_modes)(connector);
180	}
181
182	if (count == 0 && connector->status == connector_status_connected)
183		count = drm_add_modes_noedid(connector, 1024, 768);
184	count += drm_helper_probe_add_cmdline_mode(connector);
185	if (count == 0)
186		goto prune;
187
188	drm_mode_connector_list_update(connector, merge_type_bits);
189
190	if (connector->interlace_allowed)
191		mode_flags |= DRM_MODE_FLAG_INTERLACE;
192	if (connector->doublescan_allowed)
193		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
194	if (connector->stereo_allowed)
195		mode_flags |= DRM_MODE_FLAG_3D_MASK;
196
197	list_for_each_entry(mode, &connector->modes, head) {
198		if (mode->status == MODE_OK)
199			mode->status = drm_mode_validate_basic(mode);
200
201		if (mode->status == MODE_OK)
202			mode->status = drm_mode_validate_size(mode, maxX, maxY);
203
204		if (mode->status == MODE_OK)
205			mode->status = drm_mode_validate_flag(mode, mode_flags);
206
207		if (mode->status == MODE_OK && connector_funcs->mode_valid)
208			mode->status = connector_funcs->mode_valid(connector,
209								   mode);
210	}
211
212prune:
213	drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
214
215	if (list_empty(&connector->modes))
216		return 0;
217
218	list_for_each_entry(mode, &connector->modes, head)
219		mode->vrefresh = drm_mode_vrefresh(mode);
220
221	drm_mode_sort(&connector->modes);
222
223	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
224			connector->name);
225	list_for_each_entry(mode, &connector->modes, head) {
226		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
227		drm_mode_debug_printmodeline(mode);
228	}
229
230	return count;
231}
232
233/**
234 * drm_helper_probe_single_connector_modes - get complete set of display modes
235 * @connector: connector to probe
236 * @maxX: max width for modes
237 * @maxY: max height for modes
238 *
239 * Based on the helper callbacks implemented by @connector try to detect all
240 * valid modes.  Modes will first be added to the connector's probed_modes list,
241 * then culled (based on validity and the @maxX, @maxY parameters) and put into
242 * the normal modes list.
243 *
244 * Intended to be use as a generic implementation of the ->fill_modes()
245 * @connector vfunc for drivers that use the crtc helpers for output mode
246 * filtering and detection.
247 *
248 * Returns:
249 * The number of modes found on @connector.
250 */
251int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
252					    uint32_t maxX, uint32_t maxY)
253{
254	return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, true);
255}
256EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
257
258/**
259 * drm_helper_probe_single_connector_modes_nomerge - get complete set of display modes
260 * @connector: connector to probe
261 * @maxX: max width for modes
262 * @maxY: max height for modes
263 *
264 * This operates like drm_hehlper_probe_single_connector_modes except it
265 * replaces the mode bits instead of merging them for preferred modes.
266 */
267int drm_helper_probe_single_connector_modes_nomerge(struct drm_connector *connector,
268					    uint32_t maxX, uint32_t maxY)
269{
270	return drm_helper_probe_single_connector_modes_merge_bits(connector, maxX, maxY, false);
271}
272EXPORT_SYMBOL(drm_helper_probe_single_connector_modes_nomerge);
273
274/**
275 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
276 * @dev: drm_device whose connector state changed
277 *
278 * This function fires off the uevent for userspace and also calls the
279 * output_poll_changed function, which is most commonly used to inform the fbdev
280 * emulation code and allow it to update the fbcon output configuration.
281 *
282 * Drivers should call this from their hotplug handling code when a change is
283 * detected. Note that this function does not do any output detection of its
284 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
285 * driver already.
286 *
287 * This function must be called from process context with no mode
288 * setting locks held.
289 */
290void drm_kms_helper_hotplug_event(struct drm_device *dev)
291{
292	/* send a uevent + call fbdev */
293	drm_sysfs_hotplug_event(dev);
294	if (dev->mode_config.funcs->output_poll_changed)
295		dev->mode_config.funcs->output_poll_changed(dev);
296}
297EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
298
299#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
300static void output_poll_execute(struct work_struct *work)
301{
302	struct delayed_work *delayed_work = to_delayed_work(work);
303	struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
304	struct drm_connector *connector;
305	enum drm_connector_status old_status;
306	bool repoll = false, changed;
307
308	/* Pick up any changes detected by the probe functions. */
309	changed = dev->mode_config.delayed_event;
310	dev->mode_config.delayed_event = false;
311
312	if (!drm_kms_helper_poll)
313		goto out;
314
315	mutex_lock(&dev->mode_config.mutex);
316	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
317
318		/* Ignore forced connectors. */
319		if (connector->force)
320			continue;
321
322		/* Ignore HPD capable connectors and connectors where we don't
323		 * want any hotplug detection at all for polling. */
324		if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
325			continue;
326
327		repoll = true;
328
329		old_status = connector->status;
330		/* if we are connected and don't want to poll for disconnect
331		   skip it */
332		if (old_status == connector_status_connected &&
333		    !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
334			continue;
335
336		connector->status = connector->funcs->detect(connector, false);
337		if (old_status != connector->status) {
338			const char *old, *new;
339
340			/*
341			 * The poll work sets force=false when calling detect so
342			 * that drivers can avoid to do disruptive tests (e.g.
343			 * when load detect cycles could cause flickering on
344			 * other, running displays). This bears the risk that we
345			 * flip-flop between unknown here in the poll work and
346			 * the real state when userspace forces a full detect
347			 * call after receiving a hotplug event due to this
348			 * change.
349			 *
350			 * Hence clamp an unknown detect status to the old
351			 * value.
352			 */
353			if (connector->status == connector_status_unknown) {
354				connector->status = old_status;
355				continue;
356			}
357
358			old = drm_get_connector_status_name(old_status);
359			new = drm_get_connector_status_name(connector->status);
360
361			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
362				      "status updated from %s to %s\n",
363				      connector->base.id,
364				      connector->name,
365				      old, new);
366
367			changed = true;
368		}
369	}
370
371	mutex_unlock(&dev->mode_config.mutex);
372
373out:
374	if (changed)
375		drm_kms_helper_hotplug_event(dev);
376
377	if (repoll)
378		schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
379}
380
381/**
382 * drm_kms_helper_poll_disable - disable output polling
383 * @dev: drm_device
384 *
385 * This function disables the output polling work.
386 *
387 * Drivers can call this helper from their device suspend implementation. It is
388 * not an error to call this even when output polling isn't enabled or arlready
389 * disabled.
390 */
391void drm_kms_helper_poll_disable(struct drm_device *dev)
392{
393	if (!dev->mode_config.poll_enabled)
394		return;
395	cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
396}
397EXPORT_SYMBOL(drm_kms_helper_poll_disable);
398
399/**
400 * drm_kms_helper_poll_enable - re-enable output polling.
401 * @dev: drm_device
402 *
403 * This function re-enables the output polling work.
404 *
405 * Drivers can call this helper from their device resume implementation. It is
406 * an error to call this when the output polling support has not yet been set
407 * up.
408 */
409void drm_kms_helper_poll_enable(struct drm_device *dev)
410{
411	bool poll = false;
412	struct drm_connector *connector;
413
414	if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
415		return;
416
417	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
418		if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
419					 DRM_CONNECTOR_POLL_DISCONNECT))
420			poll = true;
421	}
422
423	if (poll)
424		schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
425}
426EXPORT_SYMBOL(drm_kms_helper_poll_enable);
427
428/**
429 * drm_kms_helper_poll_init - initialize and enable output polling
430 * @dev: drm_device
431 *
432 * This function intializes and then also enables output polling support for
433 * @dev. Drivers which do not have reliable hotplug support in hardware can use
434 * this helper infrastructure to regularly poll such connectors for changes in
435 * their connection state.
436 *
437 * Drivers can control which connectors are polled by setting the
438 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
439 * connectors where probing live outputs can result in visual distortion drivers
440 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
441 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
442 * completely ignored by the polling logic.
443 *
444 * Note that a connector can be both polled and probed from the hotplug handler,
445 * in case the hotplug interrupt is known to be unreliable.
446 */
447void drm_kms_helper_poll_init(struct drm_device *dev)
448{
449	INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
450	dev->mode_config.poll_enabled = true;
451
452	drm_kms_helper_poll_enable(dev);
453}
454EXPORT_SYMBOL(drm_kms_helper_poll_init);
455
456/**
457 * drm_kms_helper_poll_fini - disable output polling and clean it up
458 * @dev: drm_device
459 */
460void drm_kms_helper_poll_fini(struct drm_device *dev)
461{
462	drm_kms_helper_poll_disable(dev);
463}
464EXPORT_SYMBOL(drm_kms_helper_poll_fini);
465
466/**
467 * drm_helper_hpd_irq_event - hotplug processing
468 * @dev: drm_device
469 *
470 * Drivers can use this helper function to run a detect cycle on all connectors
471 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
472 * other connectors are ignored, which is useful to avoid reprobing fixed
473 * panels.
474 *
475 * This helper function is useful for drivers which can't or don't track hotplug
476 * interrupts for each connector.
477 *
478 * Drivers which support hotplug interrupts for each connector individually and
479 * which have a more fine-grained detect logic should bypass this code and
480 * directly call drm_kms_helper_hotplug_event() in case the connector state
481 * changed.
482 *
483 * This function must be called from process context with no mode
484 * setting locks held.
485 *
486 * Note that a connector can be both polled and probed from the hotplug handler,
487 * in case the hotplug interrupt is known to be unreliable.
488 */
489bool drm_helper_hpd_irq_event(struct drm_device *dev)
490{
491	struct drm_connector *connector;
492	enum drm_connector_status old_status;
493	bool changed = false;
494
495	if (!dev->mode_config.poll_enabled)
496		return false;
497
498	mutex_lock(&dev->mode_config.mutex);
499	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
500
501		/* Only handle HPD capable connectors. */
502		if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
503			continue;
504
505		old_status = connector->status;
506
507		connector->status = connector->funcs->detect(connector, false);
508		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
509			      connector->base.id,
510			      connector->name,
511			      drm_get_connector_status_name(old_status),
512			      drm_get_connector_status_name(connector->status));
513		if (old_status != connector->status)
514			changed = true;
515	}
516
517	mutex_unlock(&dev->mode_config.mutex);
518
519	if (changed)
520		drm_kms_helper_hotplug_event(dev);
521
522	return changed;
523}
524EXPORT_SYMBOL(drm_helper_hpd_irq_event);
525