drivers/gpu/drm/drm_sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2
   3 /*
   4  * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
   5  *               extra sysfs attribute from DRM. Normal drm_sysfs_class
   6  *               does not allow adding attributes.
   7  *
   8  * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
   9  * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
  10  * Copyright (c) 2003-2004 IBM Corp.
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/component.h>
  15 #include <linux/device.h>
  16 #include <linux/err.h>
  17 #include <linux/export.h>
  18 #include <linux/gfp.h>
  19 #include <linux/i2c.h>
  20 #include <linux/kdev_t.h>
  21 #include <linux/property.h>
  22 #include <linux/slab.h>
  23
  24 #include <drm/drm_accel.h>
  25 #include <drm/drm_connector.h>
  26 #include <drm/drm_device.h>
  27 #include <drm/drm_file.h>
  28 #include <drm/drm_modes.h>
  29 #include <drm/drm_print.h>
  30 #include <drm/drm_property.h>
  31 #include <drm/drm_sysfs.h>
  32
  33 #include "drm_internal.h"
  34 #include "drm_crtc_internal.h"
  35
  36 #define to_drm_minor(d) dev_get_drvdata(d)
  37 #define to_drm_connector(d) dev_get_drvdata(d)
  38
  39 /**
  40  * DOC: overview
  41  *
  42  * DRM provides very little additional support to drivers for sysfs
  43  * interactions, beyond just all the standard stuff. Drivers who want to expose
  44  * additional sysfs properties and property groups can attach them at either
  45  * &drm_device.dev or &drm_connector.kdev.
  46  *
  47  * Registration is automatically handled when calling drm_dev_register(), or
  48  * drm_connector_register() in case of hot-plugged connectors. Unregistration is
  49  * also automatically handled by drm_dev_unregister() and
  50  * drm_connector_unregister().
  51  */
  52
  53 static struct device_type drm_sysfs_device_minor = {
  54         .name = "drm_minor"
  55 };
  56
  57 static struct device_type drm_sysfs_device_connector = {
  58         .name = "drm_connector",
  59 };
  60
  61 struct class *drm_class;
  62
  63 #ifdef CONFIG_ACPI
  64 static bool drm_connector_acpi_bus_match(struct device *dev)
  65 {
  66         return dev->type == &drm_sysfs_device_connector;
  67 }
  68
  69 static struct acpi_device *drm_connector_acpi_find_companion(struct device *dev)
  70 {
  71         struct drm_connector *connector = to_drm_connector(dev);
  72
  73         return to_acpi_device_node(connector->fwnode);
  74 }
  75
  76 static struct acpi_bus_type drm_connector_acpi_bus = {
  77         .name = "drm_connector",
  78         .match = drm_connector_acpi_bus_match,
  79         .find_companion = drm_connector_acpi_find_companion,
  80 };
  81
  82 static void drm_sysfs_acpi_register(void)
  83 {
  84         register_acpi_bus_type(&drm_connector_acpi_bus);
  85 }
  86
  87 static void drm_sysfs_acpi_unregister(void)
  88 {
  89         unregister_acpi_bus_type(&drm_connector_acpi_bus);
  90 }
  91 #else
  92 static void drm_sysfs_acpi_register(void) { }
  93 static void drm_sysfs_acpi_unregister(void) { }
  94 #endif
  95
  96 static char *drm_devnode(const struct device *dev, umode_t *mode)
  97 {
  98         return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
  99 }
 100
 101 static int typec_connector_bind(struct device *dev,
 102                                 struct device *typec_connector, void *data)
 103 {
 104         int ret;
 105
 106         ret = sysfs_create_link(&dev->kobj, &typec_connector->kobj, "typec_connector");
 107         if (ret)
 108                 return ret;
 109
 110         ret = sysfs_create_link(&typec_connector->kobj, &dev->kobj, "drm_connector");
 111         if (ret)
 112                 sysfs_remove_link(&dev->kobj, "typec_connector");
 113
 114         return ret;
 115 }
 116
 117 static void typec_connector_unbind(struct device *dev,
 118                                    struct device *typec_connector, void *data)
 119 {
 120         sysfs_remove_link(&typec_connector->kobj, "drm_connector");
 121         sysfs_remove_link(&dev->kobj, "typec_connector");
 122 }
 123
 124 static const struct component_ops typec_connector_ops = {
 125         .bind = typec_connector_bind,
 126         .unbind = typec_connector_unbind,
 127 };
 128
 129 static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
 130
 131 /**
 132  * drm_sysfs_init - initialize sysfs helpers
 133  *
 134  * This is used to create the DRM class, which is the implicit parent of any
 135  * other top-level DRM sysfs objects.
 136  *
 137  * You must call drm_sysfs_destroy() to release the allocated resources.
 138  *
 139  * Return: 0 on success, negative error code on failure.
 140  */
 141 int drm_sysfs_init(void)
 142 {
 143         int err;
 144
 145         drm_class = class_create("drm");
 146         if (IS_ERR(drm_class))
 147                 return PTR_ERR(drm_class);
 148
 149         err = class_create_file(drm_class, &class_attr_version.attr);
 150         if (err) {
 151                 class_destroy(drm_class);
 152                 drm_class = NULL;
 153                 return err;
 154         }
 155
 156         drm_class->devnode = drm_devnode;
 157
 158         drm_sysfs_acpi_register();
 159         return 0;
 160 }
 161
 162 /**
 163  * drm_sysfs_destroy - destroys DRM class
 164  *
 165  * Destroy the DRM device class.
 166  */
 167 void drm_sysfs_destroy(void)
 168 {
 169         if (IS_ERR_OR_NULL(drm_class))
 170                 return;
 171         drm_sysfs_acpi_unregister();
 172         class_remove_file(drm_class, &class_attr_version.attr);
 173         class_destroy(drm_class);
 174         drm_class = NULL;
 175 }
 176
 177 static void drm_sysfs_release(struct device *dev)
 178 {
 179         kfree(dev);
 180 }
 181
 182 /*
 183  * Connector properties
 184  */
 185 static ssize_t status_store(struct device *device,
 186                            struct device_attribute *attr,
 187                            const char *buf, size_t count)
 188 {
 189         struct drm_connector *connector = to_drm_connector(device);
 190         struct drm_device *dev = connector->dev;
 191         enum drm_connector_force old_force;
 192         int ret;
 193
 194         ret = mutex_lock_interruptible(&dev->mode_config.mutex);
 195         if (ret)
 196                 return ret;
 197
 198         old_force = connector->force;
 199
 200         if (sysfs_streq(buf, "detect"))
 201                 connector->force = 0;
 202         else if (sysfs_streq(buf, "on"))
 203                 connector->force = DRM_FORCE_ON;
 204         else if (sysfs_streq(buf, "on-digital"))
 205                 connector->force = DRM_FORCE_ON_DIGITAL;
 206         else if (sysfs_streq(buf, "off"))
 207                 connector->force = DRM_FORCE_OFF;
 208         else
 209                 ret = -EINVAL;
 210
 211         if (old_force != connector->force || !connector->force) {
 212                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
 213                               connector->base.id,
 214                               connector->name,
 215                               old_force, connector->force);
 216
 217                 connector->funcs->fill_modes(connector,
 218                                              dev->mode_config.max_width,
 219                                              dev->mode_config.max_height);
 220         }
 221
 222         mutex_unlock(&dev->mode_config.mutex);
 223
 224         return ret ? ret : count;
 225 }
 226
 227 static ssize_t status_show(struct device *device,
 228                            struct device_attribute *attr,
 229                            char *buf)
 230 {
 231         struct drm_connector *connector = to_drm_connector(device);
 232         enum drm_connector_status status;
 233
 234         status = READ_ONCE(connector->status);
 235
 236         return sysfs_emit(buf, "%s\n",
 237                           drm_get_connector_status_name(status));
 238 }
 239
 240 static ssize_t dpms_show(struct device *device,
 241                            struct device_attribute *attr,
 242                            char *buf)
 243 {
 244         struct drm_connector *connector = to_drm_connector(device);
 245         int dpms;
 246
 247         dpms = READ_ONCE(connector->dpms);
 248
 249         return sysfs_emit(buf, "%s\n", drm_get_dpms_name(dpms));
 250 }
 251
 252 static ssize_t enabled_show(struct device *device,
 253                             struct device_attribute *attr,
 254                            char *buf)
 255 {
 256         struct drm_connector *connector = to_drm_connector(device);
 257         bool enabled;
 258
 259         enabled = READ_ONCE(connector->encoder);
 260
 261         return sysfs_emit(buf, enabled ? "enabled\n" : "disabled\n");
 262 }
 263
 264 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
 265                          struct bin_attribute *attr, char *buf, loff_t off,
 266                          size_t count)
 267 {
 268         struct device *connector_dev = kobj_to_dev(kobj);
 269         struct drm_connector *connector = to_drm_connector(connector_dev);
 270         unsigned char *edid;
 271         size_t size;
 272         ssize_t ret = 0;
 273
 274         mutex_lock(&connector->dev->mode_config.mutex);
 275         if (!connector->edid_blob_ptr)
 276                 goto unlock;
 277
 278         edid = connector->edid_blob_ptr->data;
 279         size = connector->edid_blob_ptr->length;
 280         if (!edid)
 281                 goto unlock;
 282
 283         if (off >= size)
 284                 goto unlock;
 285
 286         if (off + count > size)
 287                 count = size - off;
 288         memcpy(buf, edid + off, count);
 289
 290         ret = count;
 291 unlock:
 292         mutex_unlock(&connector->dev->mode_config.mutex);
 293
 294         return ret;
 295 }
 296
 297 static ssize_t modes_show(struct device *device,
 298                            struct device_attribute *attr,
 299                            char *buf)
 300 {
 301         struct drm_connector *connector = to_drm_connector(device);
 302         struct drm_display_mode *mode;
 303         int written = 0;
 304
 305         mutex_lock(&connector->dev->mode_config.mutex);
 306         list_for_each_entry(mode, &connector->modes, head) {
 307                 written += scnprintf(buf + written, PAGE_SIZE - written, "%s\n",
 308                                     mode->name);
 309         }
 310         mutex_unlock(&connector->dev->mode_config.mutex);
 311
 312         return written;
 313 }
 314
 315 static ssize_t connector_id_show(struct device *device,
 316                                  struct device_attribute *attr,
 317                                  char *buf)
 318 {
 319         struct drm_connector *connector = to_drm_connector(device);
 320
 321         return sysfs_emit(buf, "%d\n", connector->base.id);
 322 }
 323
 324 static DEVICE_ATTR_RW(status);
 325 static DEVICE_ATTR_RO(enabled);
 326 static DEVICE_ATTR_RO(dpms);
 327 static DEVICE_ATTR_RO(modes);
 328 static DEVICE_ATTR_RO(connector_id);
 329
 330 static struct attribute *connector_dev_attrs[] = {
 331         &dev_attr_status.attr,
 332         &dev_attr_enabled.attr,
 333         &dev_attr_dpms.attr,
 334         &dev_attr_modes.attr,
 335         &dev_attr_connector_id.attr,
 336         NULL
 337 };
 338
 339 static struct bin_attribute edid_attr = {
 340         .attr.name = "edid",
 341         .attr.mode = 0444,
 342         .size = 0,
 343         .read = edid_show,
 344 };
 345
 346 static struct bin_attribute *connector_bin_attrs[] = {
 347         &edid_attr,
 348         NULL
 349 };
 350
 351 static const struct attribute_group connector_dev_group = {
 352         .attrs = connector_dev_attrs,
 353         .bin_attrs = connector_bin_attrs,
 354 };
 355
 356 static const struct attribute_group *connector_dev_groups[] = {
 357         &connector_dev_group,
 358         NULL
 359 };
 360
 361 int drm_sysfs_connector_add(struct drm_connector *connector)
 362 {
 363         struct drm_device *dev = connector->dev;
 364         struct device *kdev;
 365         int r;
 366
 367         if (connector->kdev)
 368                 return 0;
 369
 370         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 371         if (!kdev)
 372                 return -ENOMEM;
 373
 374         device_initialize(kdev);
 375         kdev->class = drm_class;
 376         kdev->type = &drm_sysfs_device_connector;
 377         kdev->parent = dev->primary->kdev;
 378         kdev->groups = connector_dev_groups;
 379         kdev->release = drm_sysfs_release;
 380         dev_set_drvdata(kdev, connector);
 381
 382         r = dev_set_name(kdev, "card%d-%s", dev->primary->index, connector->name);
 383         if (r)
 384                 goto err_free;
 385
 386         DRM_DEBUG("adding \"%s\" to sysfs\n",
 387                   connector->name);
 388
 389         r = device_add(kdev);
 390         if (r) {
 391                 drm_err(dev, "failed to register connector device: %d\n", r);
 392                 goto err_free;
 393         }
 394
 395         connector->kdev = kdev;
 396
 397         if (dev_fwnode(kdev)) {
 398                 r = component_add(kdev, &typec_connector_ops);
 399                 if (r)
 400                         drm_err(dev, "failed to add component to create link to typec connector\n");
 401         }
 402
 403         if (connector->ddc)
 404                 return sysfs_create_link(&connector->kdev->kobj,
 405                                  &connector->ddc->dev.kobj, "ddc");
 406
 407         return 0;
 408
 409 err_free:
 410         put_device(kdev);
 411         return r;
 412 }
 413
 414 void drm_sysfs_connector_remove(struct drm_connector *connector)
 415 {
 416         if (!connector->kdev)
 417                 return;
 418
 419         if (connector->ddc)
 420                 sysfs_remove_link(&connector->kdev->kobj, "ddc");
 421
 422         if (dev_fwnode(connector->kdev))
 423                 component_del(connector->kdev, &typec_connector_ops);
 424
 425         DRM_DEBUG("removing \"%s\" from sysfs\n",
 426                   connector->name);
 427
 428         device_unregister(connector->kdev);
 429         connector->kdev = NULL;
 430 }
 431
 432 void drm_sysfs_lease_event(struct drm_device *dev)
 433 {
 434         char *event_string = "LEASE=1";
 435         char *envp[] = { event_string, NULL };
 436
 437         DRM_DEBUG("generating lease event\n");
 438
 439         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 440 }
 441
 442 /**
 443  * drm_sysfs_hotplug_event - generate a DRM uevent
 444  * @dev: DRM device
 445  *
 446  * Send a uevent for the DRM device specified by @dev.  Currently we only
 447  * set HOTPLUG=1 in the uevent environment, but this could be expanded to
 448  * deal with other types of events.
 449  *
 450  * Any new uapi should be using the drm_sysfs_connector_status_event()
 451  * for uevents on connector status change.
 452  */
 453 void drm_sysfs_hotplug_event(struct drm_device *dev)
 454 {
 455         char *event_string = "HOTPLUG=1";
 456         char *envp[] = { event_string, NULL };
 457
 458         DRM_DEBUG("generating hotplug event\n");
 459
 460         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 461 }
 462 EXPORT_SYMBOL(drm_sysfs_hotplug_event);
 463
 464 /**
 465  * drm_sysfs_connector_hotplug_event - generate a DRM uevent for any connector
 466  * change
 467  * @connector: connector which has changed
 468  *
 469  * Send a uevent for the DRM connector specified by @connector. This will send
 470  * a uevent with the properties HOTPLUG=1 and CONNECTOR.
 471  */
 472 void drm_sysfs_connector_hotplug_event(struct drm_connector *connector)
 473 {
 474         struct drm_device *dev = connector->dev;
 475         char hotplug_str[] = "HOTPLUG=1", conn_id[21];
 476         char *envp[] = { hotplug_str, conn_id, NULL };
 477
 478         snprintf(conn_id, sizeof(conn_id),
 479                  "CONNECTOR=%u", connector->base.id);
 480
 481         drm_dbg_kms(connector->dev,
 482                     "[CONNECTOR:%d:%s] generating connector hotplug event\n",
 483                     connector->base.id, connector->name);
 484
 485         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 486 }
 487 EXPORT_SYMBOL(drm_sysfs_connector_hotplug_event);
 488
 489 /**
 490  * drm_sysfs_connector_property_event - generate a DRM uevent for connector
 491  * property change
 492  * @connector: connector on which property changed
 493  * @property: connector property which has changed.
 494  *
 495  * Send a uevent for the specified DRM connector and property.  Currently we
 496  * set HOTPLUG=1 and connector id along with the attached property id
 497  * related to the change.
 498  */
 499 void drm_sysfs_connector_property_event(struct drm_connector *connector,
 500                                         struct drm_property *property)
 501 {
 502         struct drm_device *dev = connector->dev;
 503         char hotplug_str[] = "HOTPLUG=1", conn_id[21], prop_id[21];
 504         char *envp[4] = { hotplug_str, conn_id, prop_id, NULL };
 505
 506         WARN_ON(!drm_mode_obj_find_prop_id(&connector->base,
 507                                            property->base.id));
 508
 509         snprintf(conn_id, ARRAY_SIZE(conn_id),
 510                  "CONNECTOR=%u", connector->base.id);
 511         snprintf(prop_id, ARRAY_SIZE(prop_id),
 512                  "PROPERTY=%u", property->base.id);
 513
 514         drm_dbg_kms(connector->dev,
 515                     "[CONNECTOR:%d:%s] generating connector property event for [PROP:%d:%s]\n",
 516                     connector->base.id, connector->name,
 517                     property->base.id, property->name);
 518
 519         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 520 }
 521 EXPORT_SYMBOL(drm_sysfs_connector_property_event);
 522
 523 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 524 {
 525         const char *minor_str;
 526         struct device *kdev;
 527         int r;
 528
 529         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 530         if (!kdev)
 531                 return ERR_PTR(-ENOMEM);
 532
 533         device_initialize(kdev);
 534
 535         if (minor->type == DRM_MINOR_ACCEL) {
 536                 minor_str = "accel%d";
 537                 accel_set_device_instance_params(kdev, minor->index);
 538         } else {
 539                 if (minor->type == DRM_MINOR_RENDER)
 540                         minor_str = "renderD%d";
 541                 else
 542                         minor_str = "card%d";
 543
 544                 kdev->devt = MKDEV(DRM_MAJOR, minor->index);
 545                 kdev->class = drm_class;
 546                 kdev->type = &drm_sysfs_device_minor;
 547         }
 548
 549         kdev->parent = minor->dev->dev;
 550         kdev->release = drm_sysfs_release;
 551         dev_set_drvdata(kdev, minor);
 552
 553         r = dev_set_name(kdev, minor_str, minor->index);
 554         if (r < 0)
 555                 goto err_free;
 556
 557         return kdev;
 558
 559 err_free:
 560         put_device(kdev);
 561         return ERR_PTR(r);
 562 }
 563
 564 /**
 565  * drm_class_device_register - register new device with the DRM sysfs class
 566  * @dev: device to register
 567  *
 568  * Registers a new &struct device within the DRM sysfs class. Essentially only
 569  * used by ttm to have a place for its global settings. Drivers should never use
 570  * this.
 571  */
 572 int drm_class_device_register(struct device *dev)
 573 {
 574         if (!drm_class || IS_ERR(drm_class))
 575                 return -ENOENT;
 576
 577         dev->class = drm_class;
 578         return device_register(dev);
 579 }
 580 EXPORT_SYMBOL_GPL(drm_class_device_register);
 581
 582 /**
 583  * drm_class_device_unregister - unregister device with the DRM sysfs class
 584  * @dev: device to unregister
 585  *
 586  * Unregisters a &struct device from the DRM sysfs class. Essentially only used
 587  * by ttm to have a place for its global settings. Drivers should never use
 588  * this.
 589  */
 590 void drm_class_device_unregister(struct device *dev)
 591 {
 592         return device_unregister(dev);
 593 }
 594 EXPORT_SYMBOL_GPL(drm_class_device_unregister);