drivers/gpu/drm/drm_sysfs.c

   1
   2 /*
   3  * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
   4  *               extra sysfs attribute from DRM. Normal drm_sysfs_class
   5  *               does not allow adding attributes.
   6  *
   7  * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
   8  * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
   9  * Copyright (c) 2003-2004 IBM Corp.
  10  *
  11  * This file is released under the GPLv2
  12  *
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/kdev_t.h>
  17 #include <linux/gfp.h>
  18 #include <linux/err.h>
  19 #include <linux/export.h>
  20
  21 #include <drm/drm_sysfs.h>
  22 #include <drm/drm_core.h>
  23 #include <drm/drmP.h>
  24 #include "drm_internal.h"
  25
  26 #define to_drm_minor(d) dev_get_drvdata(d)
  27 #define to_drm_connector(d) dev_get_drvdata(d)
  28
  29 static struct device_type drm_sysfs_device_minor = {
  30         .name = "drm_minor"
  31 };
  32
  33 struct class *drm_class;
  34
  35 /**
  36  * __drm_class_suspend - internal DRM class suspend routine
  37  * @dev: Linux device to suspend
  38  * @state: power state to enter
  39  *
  40  * Just figures out what the actual struct drm_device associated with
  41  * @dev is and calls its suspend hook, if present.
  42  */
  43 static int __drm_class_suspend(struct device *dev, pm_message_t state)
  44 {
  45         if (dev->type == &drm_sysfs_device_minor) {
  46                 struct drm_minor *drm_minor = to_drm_minor(dev);
  47                 struct drm_device *drm_dev = drm_minor->dev;
  48
  49                 if (drm_minor->type == DRM_MINOR_LEGACY &&
  50                     !drm_core_check_feature(drm_dev, DRIVER_MODESET) &&
  51                     drm_dev->driver->suspend)
  52                         return drm_dev->driver->suspend(drm_dev, state);
  53         }
  54         return 0;
  55 }
  56
  57 /**
  58  * drm_class_suspend - internal DRM class suspend hook. Simply calls
  59  * __drm_class_suspend() with the correct pm state.
  60  * @dev: Linux device to suspend
  61  */
  62 static int drm_class_suspend(struct device *dev)
  63 {
  64         return __drm_class_suspend(dev, PMSG_SUSPEND);
  65 }
  66
  67 /**
  68  * drm_class_freeze - internal DRM class freeze hook. Simply calls
  69  * __drm_class_suspend() with the correct pm state.
  70  * @dev: Linux device to freeze
  71  */
  72 static int drm_class_freeze(struct device *dev)
  73 {
  74         return __drm_class_suspend(dev, PMSG_FREEZE);
  75 }
  76
  77 /**
  78  * drm_class_resume - DRM class resume hook
  79  * @dev: Linux device to resume
  80  *
  81  * Just figures out what the actual struct drm_device associated with
  82  * @dev is and calls its resume hook, if present.
  83  */
  84 static int drm_class_resume(struct device *dev)
  85 {
  86         if (dev->type == &drm_sysfs_device_minor) {
  87                 struct drm_minor *drm_minor = to_drm_minor(dev);
  88                 struct drm_device *drm_dev = drm_minor->dev;
  89
  90                 if (drm_minor->type == DRM_MINOR_LEGACY &&
  91                     !drm_core_check_feature(drm_dev, DRIVER_MODESET) &&
  92                     drm_dev->driver->resume)
  93                         return drm_dev->driver->resume(drm_dev);
  94         }
  95         return 0;
  96 }
  97
  98 static const struct dev_pm_ops drm_class_dev_pm_ops = {
  99         .suspend        = drm_class_suspend,
 100         .resume         = drm_class_resume,
 101         .freeze         = drm_class_freeze,
 102 };
 103
 104 static char *drm_devnode(struct device *dev, umode_t *mode)
 105 {
 106         return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
 107 }
 108
 109 static CLASS_ATTR_STRING(version, S_IRUGO,
 110                 CORE_NAME " "
 111                 __stringify(CORE_MAJOR) "."
 112                 __stringify(CORE_MINOR) "."
 113                 __stringify(CORE_PATCHLEVEL) " "
 114                 CORE_DATE);
 115
 116 /**
 117  * drm_sysfs_init - initialize sysfs helpers
 118  *
 119  * This is used to create the DRM class, which is the implicit parent of any
 120  * other top-level DRM sysfs objects.
 121  *
 122  * You must call drm_sysfs_destroy() to release the allocated resources.
 123  *
 124  * Return: 0 on success, negative error code on failure.
 125  */
 126 int drm_sysfs_init(void)
 127 {
 128         int err;
 129
 130         drm_class = class_create(THIS_MODULE, "drm");
 131         if (IS_ERR(drm_class))
 132                 return PTR_ERR(drm_class);
 133
 134         drm_class->pm = &drm_class_dev_pm_ops;
 135
 136         err = class_create_file(drm_class, &class_attr_version.attr);
 137         if (err) {
 138                 class_destroy(drm_class);
 139                 drm_class = NULL;
 140                 return err;
 141         }
 142
 143         drm_class->devnode = drm_devnode;
 144         return 0;
 145 }
 146
 147 /**
 148  * drm_sysfs_destroy - destroys DRM class
 149  *
 150  * Destroy the DRM device class.
 151  */
 152 void drm_sysfs_destroy(void)
 153 {
 154         if (IS_ERR_OR_NULL(drm_class))
 155                 return;
 156         class_remove_file(drm_class, &class_attr_version.attr);
 157         class_destroy(drm_class);
 158         drm_class = NULL;
 159 }
 160
 161 /*
 162  * Connector properties
 163  */
 164 static ssize_t status_store(struct device *device,
 165                            struct device_attribute *attr,
 166                            const char *buf, size_t count)
 167 {
 168         struct drm_connector *connector = to_drm_connector(device);
 169         struct drm_device *dev = connector->dev;
 170         enum drm_connector_status old_status;
 171         int ret;
 172
 173         ret = mutex_lock_interruptible(&dev->mode_config.mutex);
 174         if (ret)
 175                 return ret;
 176
 177         old_status = connector->status;
 178
 179         if (sysfs_streq(buf, "detect")) {
 180                 connector->force = 0;
 181                 connector->status = connector->funcs->detect(connector, true);
 182         } else if (sysfs_streq(buf, "on")) {
 183                 connector->force = DRM_FORCE_ON;
 184         } else if (sysfs_streq(buf, "on-digital")) {
 185                 connector->force = DRM_FORCE_ON_DIGITAL;
 186         } else if (sysfs_streq(buf, "off")) {
 187                 connector->force = DRM_FORCE_OFF;
 188         } else
 189                 ret = -EINVAL;
 190
 191         if (ret == 0 && connector->force) {
 192                 if (connector->force == DRM_FORCE_ON ||
 193                     connector->force == DRM_FORCE_ON_DIGITAL)
 194                         connector->status = connector_status_connected;
 195                 else
 196                         connector->status = connector_status_disconnected;
 197                 if (connector->funcs->force)
 198                         connector->funcs->force(connector);
 199         }
 200
 201         if (old_status != connector->status) {
 202                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
 203                               connector->base.id,
 204                               connector->name,
 205                               old_status, connector->status);
 206
 207                 dev->mode_config.delayed_event = true;
 208                 if (dev->mode_config.poll_enabled)
 209                         schedule_delayed_work(&dev->mode_config.output_poll_work,
 210                                               0);
 211         }
 212
 213         mutex_unlock(&dev->mode_config.mutex);
 214
 215         return ret ? ret : count;
 216 }
 217
 218 static ssize_t status_show(struct device *device,
 219                            struct device_attribute *attr,
 220                            char *buf)
 221 {
 222         struct drm_connector *connector = to_drm_connector(device);
 223
 224         return snprintf(buf, PAGE_SIZE, "%s\n",
 225                         drm_get_connector_status_name(connector->status));
 226 }
 227
 228 static ssize_t dpms_show(struct device *device,
 229                            struct device_attribute *attr,
 230                            char *buf)
 231 {
 232         struct drm_connector *connector = to_drm_connector(device);
 233         int dpms;
 234
 235         dpms = READ_ONCE(connector->dpms);
 236
 237         return snprintf(buf, PAGE_SIZE, "%s\n",
 238                         drm_get_dpms_name(dpms));
 239 }
 240
 241 static ssize_t enabled_show(struct device *device,
 242                             struct device_attribute *attr,
 243                            char *buf)
 244 {
 245         struct drm_connector *connector = to_drm_connector(device);
 246
 247         return snprintf(buf, PAGE_SIZE, "%s\n", connector->encoder ? "enabled" :
 248                         "disabled");
 249 }
 250
 251 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
 252                          struct bin_attribute *attr, char *buf, loff_t off,
 253                          size_t count)
 254 {
 255         struct device *connector_dev = container_of(kobj, struct device, kobj);
 256         struct drm_connector *connector = to_drm_connector(connector_dev);
 257         unsigned char *edid;
 258         size_t size;
 259
 260         if (!connector->edid_blob_ptr)
 261                 return 0;
 262
 263         edid = connector->edid_blob_ptr->data;
 264         size = connector->edid_blob_ptr->length;
 265         if (!edid)
 266                 return 0;
 267
 268         if (off >= size)
 269                 return 0;
 270
 271         if (off + count > size)
 272                 count = size - off;
 273         memcpy(buf, edid + off, count);
 274
 275         return count;
 276 }
 277
 278 static ssize_t modes_show(struct device *device,
 279                            struct device_attribute *attr,
 280                            char *buf)
 281 {
 282         struct drm_connector *connector = to_drm_connector(device);
 283         struct drm_display_mode *mode;
 284         int written = 0;
 285
 286         list_for_each_entry(mode, &connector->modes, head) {
 287                 written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
 288                                     mode->name);
 289         }
 290
 291         return written;
 292 }
 293
 294 static ssize_t tv_subconnector_show(struct device *device,
 295                                     struct device_attribute *attr,
 296                                     char *buf)
 297 {
 298         struct drm_connector *connector = to_drm_connector(device);
 299         struct drm_device *dev = connector->dev;
 300         struct drm_property *prop;
 301         uint64_t subconnector;
 302         int ret;
 303
 304         prop = dev->mode_config.tv_subconnector_property;
 305         if (!prop) {
 306                 DRM_ERROR("Unable to find subconnector property\n");
 307                 return 0;
 308         }
 309
 310         ret = drm_object_property_get_value(&connector->base, prop, &subconnector);
 311         if (ret)
 312                 return 0;
 313
 314         return snprintf(buf, PAGE_SIZE, "%s",
 315                         drm_get_tv_subconnector_name((int)subconnector));
 316 }
 317
 318 static ssize_t tv_select_subconnector_show(struct device *device,
 319                                            struct device_attribute *attr,
 320                                            char *buf)
 321 {
 322         struct drm_connector *connector = to_drm_connector(device);
 323         struct drm_device *dev = connector->dev;
 324         struct drm_property *prop;
 325         uint64_t subconnector;
 326         int ret;
 327
 328         prop = dev->mode_config.tv_select_subconnector_property;
 329         if (!prop) {
 330                 DRM_ERROR("Unable to find select subconnector property\n");
 331                 return 0;
 332         }
 333
 334         ret = drm_object_property_get_value(&connector->base, prop, &subconnector);
 335         if (ret)
 336                 return 0;
 337
 338         return snprintf(buf, PAGE_SIZE, "%s",
 339                         drm_get_tv_select_name((int)subconnector));
 340 }
 341
 342 static ssize_t dvii_subconnector_show(struct device *device,
 343                                       struct device_attribute *attr,
 344                                       char *buf)
 345 {
 346         struct drm_connector *connector = to_drm_connector(device);
 347         struct drm_device *dev = connector->dev;
 348         struct drm_property *prop;
 349         uint64_t subconnector;
 350         int ret;
 351
 352         prop = dev->mode_config.dvi_i_subconnector_property;
 353         if (!prop) {
 354                 DRM_ERROR("Unable to find subconnector property\n");
 355                 return 0;
 356         }
 357
 358         ret = drm_object_property_get_value(&connector->base, prop, &subconnector);
 359         if (ret)
 360                 return 0;
 361
 362         return snprintf(buf, PAGE_SIZE, "%s",
 363                         drm_get_dvi_i_subconnector_name((int)subconnector));
 364 }
 365
 366 static ssize_t dvii_select_subconnector_show(struct device *device,
 367                                              struct device_attribute *attr,
 368                                              char *buf)
 369 {
 370         struct drm_connector *connector = to_drm_connector(device);
 371         struct drm_device *dev = connector->dev;
 372         struct drm_property *prop;
 373         uint64_t subconnector;
 374         int ret;
 375
 376         prop = dev->mode_config.dvi_i_select_subconnector_property;
 377         if (!prop) {
 378                 DRM_ERROR("Unable to find select subconnector property\n");
 379                 return 0;
 380         }
 381
 382         ret = drm_object_property_get_value(&connector->base, prop, &subconnector);
 383         if (ret)
 384                 return 0;
 385
 386         return snprintf(buf, PAGE_SIZE, "%s",
 387                         drm_get_dvi_i_select_name((int)subconnector));
 388 }
 389
 390 static DEVICE_ATTR_RW(status);
 391 static DEVICE_ATTR_RO(enabled);
 392 static DEVICE_ATTR_RO(dpms);
 393 static DEVICE_ATTR_RO(modes);
 394
 395 static struct attribute *connector_dev_attrs[] = {
 396         &dev_attr_status.attr,
 397         &dev_attr_enabled.attr,
 398         &dev_attr_dpms.attr,
 399         &dev_attr_modes.attr,
 400         NULL
 401 };
 402
 403 static DEVICE_ATTR_RO(tv_subconnector);
 404 static DEVICE_ATTR_RO(tv_select_subconnector);
 405
 406 static struct attribute *connector_tv_dev_attrs[] = {
 407         &dev_attr_tv_subconnector.attr,
 408         &dev_attr_tv_select_subconnector.attr,
 409         NULL
 410 };
 411
 412 static DEVICE_ATTR_RO(dvii_subconnector);
 413 static DEVICE_ATTR_RO(dvii_select_subconnector);
 414
 415 static struct attribute *connector_dvii_dev_attrs[] = {
 416         &dev_attr_dvii_subconnector.attr,
 417         &dev_attr_dvii_select_subconnector.attr,
 418         NULL
 419 };
 420
 421 /* Connector type related helpers */
 422 static int kobj_connector_type(struct kobject *kobj)
 423 {
 424         struct device *dev = kobj_to_dev(kobj);
 425         struct drm_connector *connector = to_drm_connector(dev);
 426
 427         return connector->connector_type;
 428 }
 429
 430 static umode_t connector_is_dvii(struct kobject *kobj,
 431                                  struct attribute *attr, int idx)
 432 {
 433         return kobj_connector_type(kobj) == DRM_MODE_CONNECTOR_DVII ?
 434                 attr->mode : 0;
 435 }
 436
 437 static umode_t connector_is_tv(struct kobject *kobj,
 438                                struct attribute *attr, int idx)
 439 {
 440         switch (kobj_connector_type(kobj)) {
 441         case DRM_MODE_CONNECTOR_Composite:
 442         case DRM_MODE_CONNECTOR_SVIDEO:
 443         case DRM_MODE_CONNECTOR_Component:
 444         case DRM_MODE_CONNECTOR_TV:
 445                 return attr->mode;
 446         }
 447
 448         return 0;
 449 }
 450
 451 static struct bin_attribute edid_attr = {
 452         .attr.name = "edid",
 453         .attr.mode = 0444,
 454         .size = 0,
 455         .read = edid_show,
 456 };
 457
 458 static struct bin_attribute *connector_bin_attrs[] = {
 459         &edid_attr,
 460         NULL
 461 };
 462
 463 static const struct attribute_group connector_dev_group = {
 464         .attrs = connector_dev_attrs,
 465         .bin_attrs = connector_bin_attrs,
 466 };
 467
 468 static const struct attribute_group connector_tv_dev_group = {
 469         .attrs = connector_tv_dev_attrs,
 470         .is_visible = connector_is_tv,
 471 };
 472
 473 static const struct attribute_group connector_dvii_dev_group = {
 474         .attrs = connector_dvii_dev_attrs,
 475         .is_visible = connector_is_dvii,
 476 };
 477
 478 static const struct attribute_group *connector_dev_groups[] = {
 479         &connector_dev_group,
 480         &connector_tv_dev_group,
 481         &connector_dvii_dev_group,
 482         NULL
 483 };
 484
 485 /**
 486  * drm_sysfs_connector_add - add a connector to sysfs
 487  * @connector: connector to add
 488  *
 489  * Create a connector device in sysfs, along with its associated connector
 490  * properties (so far, connection status, dpms, mode list & edid) and
 491  * generate a hotplug event so userspace knows there's a new connector
 492  * available.
 493  */
 494 int drm_sysfs_connector_add(struct drm_connector *connector)
 495 {
 496         struct drm_device *dev = connector->dev;
 497
 498         if (connector->kdev)
 499                 return 0;
 500
 501         connector->kdev =
 502                 device_create_with_groups(drm_class, dev->primary->kdev, 0,
 503                                           connector, connector_dev_groups,
 504                                           "card%d-%s", dev->primary->index,
 505                                           connector->name);
 506         DRM_DEBUG("adding \"%s\" to sysfs\n",
 507                   connector->name);
 508
 509         if (IS_ERR(connector->kdev)) {
 510                 DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
 511                 return PTR_ERR(connector->kdev);
 512         }
 513
 514         /* Let userspace know we have a new connector */
 515         drm_sysfs_hotplug_event(dev);
 516
 517         return 0;
 518 }
 519
 520 /**
 521  * drm_sysfs_connector_remove - remove an connector device from sysfs
 522  * @connector: connector to remove
 523  *
 524  * Remove @connector and its associated attributes from sysfs.  Note that
 525  * the device model core will take care of sending the "remove" uevent
 526  * at this time, so we don't need to do it.
 527  *
 528  * Note:
 529  * This routine should only be called if the connector was previously
 530  * successfully registered.  If @connector hasn't been registered yet,
 531  * you'll likely see a panic somewhere deep in sysfs code when called.
 532  */
 533 void drm_sysfs_connector_remove(struct drm_connector *connector)
 534 {
 535         if (!connector->kdev)
 536                 return;
 537         DRM_DEBUG("removing \"%s\" from sysfs\n",
 538                   connector->name);
 539
 540         device_unregister(connector->kdev);
 541         connector->kdev = NULL;
 542 }
 543
 544 /**
 545  * drm_sysfs_hotplug_event - generate a DRM uevent
 546  * @dev: DRM device
 547  *
 548  * Send a uevent for the DRM device specified by @dev.  Currently we only
 549  * set HOTPLUG=1 in the uevent environment, but this could be expanded to
 550  * deal with other types of events.
 551  */
 552 void drm_sysfs_hotplug_event(struct drm_device *dev)
 553 {
 554         char *event_string = "HOTPLUG=1";
 555         char *envp[] = { event_string, NULL };
 556
 557         DRM_DEBUG("generating hotplug event\n");
 558
 559         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 560 }
 561 EXPORT_SYMBOL(drm_sysfs_hotplug_event);
 562
 563 static void drm_sysfs_release(struct device *dev)
 564 {
 565         kfree(dev);
 566 }
 567
 568 /**
 569  * drm_sysfs_minor_alloc() - Allocate sysfs device for given minor
 570  * @minor: minor to allocate sysfs device for
 571  *
 572  * This allocates a new sysfs device for @minor and returns it. The device is
 573  * not registered nor linked. The caller has to use device_add() and
 574  * device_del() to register and unregister it.
 575  *
 576  * Note that dev_get_drvdata() on the new device will return the minor.
 577  * However, the device does not hold a ref-count to the minor nor to the
 578  * underlying drm_device. This is unproblematic as long as you access the
 579  * private data only in sysfs callbacks. device_del() disables those
 580  * synchronously, so they cannot be called after you cleanup a minor.
 581  */
 582 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 583 {
 584         const char *minor_str;
 585         struct device *kdev;
 586         int r;
 587
 588         if (minor->type == DRM_MINOR_CONTROL)
 589                 minor_str = "controlD%d";
 590         else if (minor->type == DRM_MINOR_RENDER)
 591                 minor_str = "renderD%d";
 592         else
 593                 minor_str = "card%d";
 594
 595         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 596         if (!kdev)
 597                 return ERR_PTR(-ENOMEM);
 598
 599         device_initialize(kdev);
 600         kdev->devt = MKDEV(DRM_MAJOR, minor->index);
 601         kdev->class = drm_class;
 602         kdev->type = &drm_sysfs_device_minor;
 603         kdev->parent = minor->dev->dev;
 604         kdev->release = drm_sysfs_release;
 605         dev_set_drvdata(kdev, minor);
 606
 607         r = dev_set_name(kdev, minor_str, minor->index);
 608         if (r < 0)
 609                 goto err_free;
 610
 611         return kdev;
 612
 613 err_free:
 614         put_device(kdev);
 615         return ERR_PTR(r);
 616 }
 617
 618 /**
 619  * drm_class_device_register - Register a struct device in the drm class.
 620  *
 621  * @dev: pointer to struct device to register.
 622  *
 623  * @dev should have all relevant members pre-filled with the exception
 624  * of the class member. In particular, the device_type member must
 625  * be set.
 626  */
 627
 628 int drm_class_device_register(struct device *dev)
 629 {
 630         if (!drm_class || IS_ERR(drm_class))
 631                 return -ENOENT;
 632
 633         dev->class = drm_class;
 634         return device_register(dev);
 635 }
 636 EXPORT_SYMBOL_GPL(drm_class_device_register);
 637
 638 void drm_class_device_unregister(struct device *dev)
 639 {
 640         return device_unregister(dev);
 641 }
 642 EXPORT_SYMBOL_GPL(drm_class_device_unregister);