drivers/gpu/drm/drm_probe_helper.c

   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 /**
  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  */
 103 int 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
 177 prune:
 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 }
 197 EXPORT_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  */
 215 void 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 }
 222 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
 223
 224 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
 225 static 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  */
 293 void 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 }
 299 EXPORT_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  */
 311 void 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 }
 328 EXPORT_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  */
 349 void 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 }
 356 EXPORT_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  */
 362 void drm_kms_helper_poll_fini(struct drm_device *dev)
 363 {
 364         drm_kms_helper_poll_disable(dev);
 365 }
 366 EXPORT_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  */
 391 bool 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 }
 426 EXPORT_SYMBOL(drm_helper_hpd_irq_event);