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