drm/doc: Remove duplicate "by"
[linux-block.git] / drivers / gpu / drm / drm_probe_helper.c
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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
58static bool drm_kms_helper_poll = true;
59module_param_named(poll, drm_kms_helper_poll, bool, 0600);
60
61static 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
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85static 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
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101static int drm_helper_probe_single_connector_modes_merge_bits(struct drm_connector *connector,
102 uint32_t maxX, uint32_t maxY, bool merge_type_bits)
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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,
25933820 115 connector->name);
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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) {
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121 if (connector->force == DRM_FORCE_ON ||
122 connector->force == DRM_FORCE_ON_DIGITAL)
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123 connector->status = connector_status_connected;
124 else
125 connector->status = connector_status_disconnected;
126 if (connector->funcs->force)
127 connector->funcs->force(connector);
128 } else {
129 connector->status = connector->funcs->detect(connector, true);
130 }
131
132 /* Re-enable polling in case the global poll config changed. */
133 if (drm_kms_helper_poll != dev->mode_config.poll_running)
134 drm_kms_helper_poll_enable(dev);
135
136 dev->mode_config.poll_running = drm_kms_helper_poll;
137
138 if (connector->status == connector_status_disconnected) {
139 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
25933820 140 connector->base.id, connector->name);
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141 drm_mode_connector_update_edid_property(connector, NULL);
142 verbose_prune = false;
143 goto prune;
144 }
145
146#ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
147 count = drm_load_edid_firmware(connector);
148 if (count == 0)
149#endif
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150 {
151 if (connector->override_edid) {
152 struct edid *edid = (struct edid *) connector->edid_blob_ptr->data;
153
154 count = drm_add_edid_modes(connector, edid);
155 } else
156 count = (*connector_funcs->get_modes)(connector);
157 }
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158
159 if (count == 0 && connector->status == connector_status_connected)
160 count = drm_add_modes_noedid(connector, 1024, 768);
eaf99c74 161 count += drm_helper_probe_add_cmdline_mode(connector);
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162 if (count == 0)
163 goto prune;
164
b87577b7 165 drm_mode_connector_list_update(connector, merge_type_bits);
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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) {
f9b0e251 179 if (mode->status == MODE_OK && connector_funcs->mode_valid)
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180 mode->status = connector_funcs->mode_valid(connector,
181 mode);
182 }
183
184prune:
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,
25933820 196 connector->name);
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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}
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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 */
223int 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}
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228EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
229
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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 */
239int 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}
244EXPORT_SYMBOL(drm_helper_probe_single_connector_modes_nomerge);
245
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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 */
262void 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}
269EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
270
271#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
272static 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,
25933820 314 connector->name,
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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 */
340void 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}
346EXPORT_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 */
358void 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}
375EXPORT_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 */
396void 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}
403EXPORT_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 */
409void drm_kms_helper_poll_fini(struct drm_device *dev)
410{
411 drm_kms_helper_poll_disable(dev);
412}
413EXPORT_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 */
438bool 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,
25933820 459 connector->name,
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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}
473EXPORT_SYMBOL(drm_helper_hpd_irq_event);