xref: /netbsd-src/sys/external/bsd/drm2/dist/drm/drm_probe_helper.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
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 <asm/param.h>
33 #include <linux/export.h>
34 #include <linux/moduleparam.h>
35 
36 #include <drm/drmP.h>
37 #include <drm/drm_crtc.h>
38 #include <drm/drm_fourcc.h>
39 #include <drm/drm_crtc_helper.h>
40 #include <drm/drm_fb_helper.h>
41 #include <drm/drm_edid.h>
42 
43 /**
44  * DOC: output probing helper overview
45  *
46  * This library provides some helper code for output probing. It provides an
47  * implementation of the core connector->fill_modes interface with
48  * drm_helper_probe_single_connector_modes.
49  *
50  * It also provides support for polling connectors with a work item and for
51  * generic hotplug interrupt handling where the driver doesn't or cannot keep
52  * track of a per-connector hpd interrupt.
53  *
54  * This helper library can be used independently of the modeset helper library.
55  * Drivers can also overwrite different parts e.g. use their own hotplug
56  * handling code to avoid probing unrelated outputs.
57  */
58 
59 static bool drm_kms_helper_poll = true;
60 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
61 
62 static void drm_mode_validate_flag(struct drm_connector *connector,
63 				   int flags)
64 {
65 	struct drm_display_mode *mode;
66 
67 	if (flags == (DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_INTERLACE |
68 		      DRM_MODE_FLAG_3D_MASK))
69 		return;
70 
71 	list_for_each_entry(mode, &connector->modes, head) {
72 		if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
73 				!(flags & DRM_MODE_FLAG_INTERLACE))
74 			mode->status = MODE_NO_INTERLACE;
75 		if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
76 				!(flags & DRM_MODE_FLAG_DBLSCAN))
77 			mode->status = MODE_NO_DBLESCAN;
78 		if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
79 				!(flags & DRM_MODE_FLAG_3D_MASK))
80 			mode->status = MODE_NO_STEREO;
81 	}
82 
83 	return;
84 }
85 
86 /**
87  * drm_helper_probe_single_connector_modes - get complete set of display modes
88  * @connector: connector to probe
89  * @maxX: max width for modes
90  * @maxY: max height for modes
91  *
92  * Based on the helper callbacks implemented by @connector try to detect all
93  * valid modes.  Modes will first be added to the connector's probed_modes list,
94  * then culled (based on validity and the @maxX, @maxY parameters) and put into
95  * the normal modes list.
96  *
97  * Intended to be use as a generic implementation of the ->fill_modes()
98  * @connector vfunc for drivers that use the crtc helpers for output mode
99  * filtering and detection.
100  *
101  * Returns:
102  * The number of modes found on @connector.
103  */
104 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
105 					    uint32_t maxX, uint32_t maxY)
106 {
107 	struct drm_device *dev = connector->dev;
108 	struct drm_display_mode *mode;
109 	struct drm_connector_helper_funcs *connector_funcs =
110 		connector->helper_private;
111 	int count = 0;
112 	int mode_flags = 0;
113 	bool verbose_prune = true;
114 
115 	WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
116 
117 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
118 			drm_get_connector_name(connector));
119 	/* set all modes to the unverified state */
120 	list_for_each_entry(mode, &connector->modes, head)
121 		mode->status = MODE_UNVERIFIED;
122 
123 	if (connector->force) {
124 		if (connector->force == DRM_FORCE_ON)
125 			connector->status = connector_status_connected;
126 		else
127 			connector->status = connector_status_disconnected;
128 		if (connector->funcs->force)
129 			connector->funcs->force(connector);
130 	} else {
131 		connector->status = connector->funcs->detect(connector, true);
132 	}
133 
134 	/* Re-enable polling in case the global poll config changed. */
135 	if (drm_kms_helper_poll != dev->mode_config.poll_running)
136 		drm_kms_helper_poll_enable(dev);
137 
138 	dev->mode_config.poll_running = drm_kms_helper_poll;
139 
140 	if (connector->status == connector_status_disconnected) {
141 		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
142 			connector->base.id, drm_get_connector_name(connector));
143 		drm_mode_connector_update_edid_property(connector, NULL);
144 		verbose_prune = false;
145 		goto prune;
146 	}
147 
148 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
149 	count = drm_load_edid_firmware(connector);
150 	if (count == 0)
151 #endif
152 		count = (*connector_funcs->get_modes)(connector);
153 
154 	if (count == 0 && connector->status == connector_status_connected)
155 		count = drm_add_modes_noedid(connector, 1024, 768);
156 	if (count == 0)
157 		goto prune;
158 
159 	drm_mode_connector_list_update(connector);
160 
161 	if (maxX && maxY)
162 		drm_mode_validate_size(dev, &connector->modes, maxX, maxY);
163 
164 	if (connector->interlace_allowed)
165 		mode_flags |= DRM_MODE_FLAG_INTERLACE;
166 	if (connector->doublescan_allowed)
167 		mode_flags |= DRM_MODE_FLAG_DBLSCAN;
168 	if (connector->stereo_allowed)
169 		mode_flags |= DRM_MODE_FLAG_3D_MASK;
170 	drm_mode_validate_flag(connector, mode_flags);
171 
172 	list_for_each_entry(mode, &connector->modes, head) {
173 		if (mode->status == MODE_OK)
174 			mode->status = connector_funcs->mode_valid(connector,
175 								   mode);
176 	}
177 
178 prune:
179 	drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
180 
181 	if (list_empty(&connector->modes))
182 		return 0;
183 
184 	list_for_each_entry(mode, &connector->modes, head)
185 		mode->vrefresh = drm_mode_vrefresh(mode);
186 
187 	drm_mode_sort(&connector->modes);
188 
189 	DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
190 			drm_get_connector_name(connector));
191 	list_for_each_entry(mode, &connector->modes, head) {
192 		drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
193 		drm_mode_debug_printmodeline(mode);
194 	}
195 
196 	return count;
197 }
198 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
199 
200 /**
201  * drm_kms_helper_hotplug_event - fire off KMS hotplug events
202  * @dev: drm_device whose connector state changed
203  *
204  * This function fires off the uevent for userspace and also calls the
205  * output_poll_changed function, which is most commonly used to inform the fbdev
206  * emulation code and allow it to update the fbcon output configuration.
207  *
208  * Drivers should call this from their hotplug handling code when a change is
209  * detected. Note that this function does not do any output detection of its
210  * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
211  * driver already.
212  *
213  * This function must be called from process context with no mode
214  * setting locks held.
215  */
216 void drm_kms_helper_hotplug_event(struct drm_device *dev)
217 {
218 	/* send a uevent + call fbdev */
219 	drm_sysfs_hotplug_event(dev);
220 	if (dev->mode_config.funcs->output_poll_changed)
221 		dev->mode_config.funcs->output_poll_changed(dev);
222 }
223 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
224 
225 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
226 static void output_poll_execute(struct work_struct *work)
227 {
228 	struct delayed_work *delayed_work = to_delayed_work(work);
229 	struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
230 	struct drm_connector *connector;
231 	enum drm_connector_status old_status;
232 	bool repoll = false, changed = false;
233 
234 	if (!drm_kms_helper_poll)
235 		return;
236 
237 	mutex_lock(&dev->mode_config.mutex);
238 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
239 
240 		/* Ignore forced connectors. */
241 		if (connector->force)
242 			continue;
243 
244 		/* Ignore HPD capable connectors and connectors where we don't
245 		 * want any hotplug detection at all for polling. */
246 		if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
247 			continue;
248 
249 		repoll = true;
250 
251 		old_status = connector->status;
252 		/* if we are connected and don't want to poll for disconnect
253 		   skip it */
254 		if (old_status == connector_status_connected &&
255 		    !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
256 			continue;
257 
258 		connector->status = connector->funcs->detect(connector, false);
259 		if (old_status != connector->status) {
260 			const char *old, *new;
261 
262 			old = drm_get_connector_status_name(old_status);
263 			new = drm_get_connector_status_name(connector->status);
264 
265 			DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
266 				      "status updated from %s to %s\n",
267 				      connector->base.id,
268 				      drm_get_connector_name(connector),
269 				      old, new);
270 
271 			changed = true;
272 		}
273 	}
274 
275 	mutex_unlock(&dev->mode_config.mutex);
276 
277 	if (changed)
278 		drm_kms_helper_hotplug_event(dev);
279 
280 	if (repoll)
281 		schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
282 }
283 
284 /**
285  * drm_kms_helper_poll_disable - disable output polling
286  * @dev: drm_device
287  *
288  * This function disables the output polling work.
289  *
290  * Drivers can call this helper from their device suspend implementation. It is
291  * not an error to call this even when output polling isn't enabled or arlready
292  * disabled.
293  */
294 void drm_kms_helper_poll_disable(struct drm_device *dev)
295 {
296 	if (!dev->mode_config.poll_enabled)
297 		return;
298 	cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
299 }
300 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
301 
302 /**
303  * drm_kms_helper_poll_enable - re-enable output polling.
304  * @dev: drm_device
305  *
306  * This function re-enables the output polling work.
307  *
308  * Drivers can call this helper from their device resume implementation. It is
309  * an error to call this when the output polling support has not yet been set
310  * up.
311  */
312 void drm_kms_helper_poll_enable(struct drm_device *dev)
313 {
314 	bool poll = false;
315 	struct drm_connector *connector;
316 
317 	if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
318 		return;
319 
320 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
321 		if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
322 					 DRM_CONNECTOR_POLL_DISCONNECT))
323 			poll = true;
324 	}
325 
326 	if (poll)
327 		schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
328 }
329 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
330 
331 /**
332  * drm_kms_helper_poll_init - initialize and enable output polling
333  * @dev: drm_device
334  *
335  * This function intializes and then also enables output polling support for
336  * @dev. Drivers which do not have reliable hotplug support in hardware can use
337  * this helper infrastructure to regularly poll such connectors for changes in
338  * their connection state.
339  *
340  * Drivers can control which connectors are polled by setting the
341  * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
342  * connectors where probing live outputs can result in visual distortion drivers
343  * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
344  * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
345  * completely ignored by the polling logic.
346  *
347  * Note that a connector can be both polled and probed from the hotplug handler,
348  * in case the hotplug interrupt is known to be unreliable.
349  */
350 void drm_kms_helper_poll_init(struct drm_device *dev)
351 {
352 	INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
353 	dev->mode_config.poll_enabled = true;
354 
355 	drm_kms_helper_poll_enable(dev);
356 }
357 EXPORT_SYMBOL(drm_kms_helper_poll_init);
358 
359 /**
360  * drm_kms_helper_poll_fini - disable output polling and clean it up
361  * @dev: drm_device
362  */
363 void drm_kms_helper_poll_fini(struct drm_device *dev)
364 {
365 	drm_kms_helper_poll_disable(dev);
366 }
367 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
368 
369 /**
370  * drm_helper_hpd_irq_event - hotplug processing
371  * @dev: drm_device
372  *
373  * Drivers can use this helper function to run a detect cycle on all connectors
374  * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
375  * other connectors are ignored, which is useful to avoid reprobing fixed
376  * panels.
377  *
378  * This helper function is useful for drivers which can't or don't track hotplug
379  * interrupts for each connector.
380  *
381  * Drivers which support hotplug interrupts for each connector individually and
382  * which have a more fine-grained detect logic should bypass this code and
383  * directly call drm_kms_helper_hotplug_event() in case the connector state
384  * changed.
385  *
386  * This function must be called from process context with no mode
387  * setting locks held.
388  *
389  * Note that a connector can be both polled and probed from the hotplug handler,
390  * in case the hotplug interrupt is known to be unreliable.
391  */
392 bool drm_helper_hpd_irq_event(struct drm_device *dev)
393 {
394 	struct drm_connector *connector;
395 	enum drm_connector_status old_status;
396 	bool changed = false;
397 
398 	if (!dev->mode_config.poll_enabled)
399 		return false;
400 
401 	mutex_lock(&dev->mode_config.mutex);
402 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
403 
404 		/* Only handle HPD capable connectors. */
405 		if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
406 			continue;
407 
408 		old_status = connector->status;
409 
410 		connector->status = connector->funcs->detect(connector, false);
411 		DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
412 			      connector->base.id,
413 			      drm_get_connector_name(connector),
414 			      drm_get_connector_status_name(old_status),
415 			      drm_get_connector_status_name(connector->status));
416 		if (old_status != connector->status)
417 			changed = true;
418 	}
419 
420 	mutex_unlock(&dev->mode_config.mutex);
421 
422 	if (changed)
423 		drm_kms_helper_hotplug_event(dev);
424 
425 	return changed;
426 }
427 EXPORT_SYMBOL(drm_helper_hpd_irq_event);
428