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