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_dbg_kms(dev, "[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
 213                             connector->base.id, connector->name,
 214                             old_force, connector->force);
 215
 216                 connector->funcs->fill_modes(connector,
 217                                              dev->mode_config.max_width,
 218                                              dev->mode_config.max_height);
 219         }
 220
 221         mutex_unlock(&dev->mode_config.mutex);
 222
 223         return ret ? ret : count;
 224 }
 225
 226 static ssize_t status_show(struct device *device,
 227                            struct device_attribute *attr,
 228                            char *buf)
 229 {
 230         struct drm_connector *connector = to_drm_connector(device);
 231         enum drm_connector_status status;
 232
 233         status = READ_ONCE(connector->status);
 234
 235         return sysfs_emit(buf, "%s\n",
 236                           drm_get_connector_status_name(status));
 237 }
 238
 239 static ssize_t dpms_show(struct device *device,
 240                            struct device_attribute *attr,
 241                            char *buf)
 242 {
 243         struct drm_connector *connector = to_drm_connector(device);
 244         int dpms;
 245
 246         dpms = READ_ONCE(connector->dpms);
 247
 248         return sysfs_emit(buf, "%s\n", drm_get_dpms_name(dpms));
 249 }
 250
 251 static ssize_t enabled_show(struct device *device,
 252                             struct device_attribute *attr,
 253                            char *buf)
 254 {
 255         struct drm_connector *connector = to_drm_connector(device);
 256         bool enabled;
 257
 258         enabled = READ_ONCE(connector->encoder);
 259
 260         return sysfs_emit(buf, enabled ? "enabled\n" : "disabled\n");
 261 }
 262
 263 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
 264                          struct bin_attribute *attr, char *buf, loff_t off,
 265                          size_t count)
 266 {
 267         struct device *connector_dev = kobj_to_dev(kobj);
 268         struct drm_connector *connector = to_drm_connector(connector_dev);
 269         ssize_t ret;
 270
 271         ret = drm_edid_connector_property_show(connector, buf, off, count);
 272
 273         return ret;
 274 }
 275
 276 static ssize_t modes_show(struct device *device,
 277                            struct device_attribute *attr,
 278                            char *buf)
 279 {
 280         struct drm_connector *connector = to_drm_connector(device);
 281         struct drm_display_mode *mode;
 282         int written = 0;
 283
 284         mutex_lock(&connector->dev->mode_config.mutex);
 285         list_for_each_entry(mode, &connector->modes, head) {
 286                 written += scnprintf(buf + written, PAGE_SIZE - written, "%s\n",
 287                                     mode->name);
 288         }
 289         mutex_unlock(&connector->dev->mode_config.mutex);
 290
 291         return written;
 292 }
 293
 294 static ssize_t connector_id_show(struct device *device,
 295                                  struct device_attribute *attr,
 296                                  char *buf)
 297 {
 298         struct drm_connector *connector = to_drm_connector(device);
 299
 300         return sysfs_emit(buf, "%d\n", connector->base.id);
 301 }
 302
 303 static DEVICE_ATTR_RW(status);
 304 static DEVICE_ATTR_RO(enabled);
 305 static DEVICE_ATTR_RO(dpms);
 306 static DEVICE_ATTR_RO(modes);
 307 static DEVICE_ATTR_RO(connector_id);
 308
 309 static struct attribute *connector_dev_attrs[] = {
 310         &dev_attr_status.attr,
 311         &dev_attr_enabled.attr,
 312         &dev_attr_dpms.attr,
 313         &dev_attr_modes.attr,
 314         &dev_attr_connector_id.attr,
 315         NULL
 316 };
 317
 318 static struct bin_attribute edid_attr = {
 319         .attr.name = "edid",
 320         .attr.mode = 0444,
 321         .size = 0,
 322         .read = edid_show,
 323 };
 324
 325 static struct bin_attribute *connector_bin_attrs[] = {
 326         &edid_attr,
 327         NULL
 328 };
 329
 330 static const struct attribute_group connector_dev_group = {
 331         .attrs = connector_dev_attrs,
 332         .bin_attrs = connector_bin_attrs,
 333 };
 334
 335 static const struct attribute_group *connector_dev_groups[] = {
 336         &connector_dev_group,
 337         NULL
 338 };
 339
 340 int drm_sysfs_connector_add(struct drm_connector *connector)
 341 {
 342         struct drm_device *dev = connector->dev;
 343         struct device *kdev;
 344         int r;
 345
 346         if (connector->kdev)
 347                 return 0;
 348
 349         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 350         if (!kdev)
 351                 return -ENOMEM;
 352
 353         device_initialize(kdev);
 354         kdev->class = drm_class;
 355         kdev->type = &drm_sysfs_device_connector;
 356         kdev->parent = dev->primary->kdev;
 357         kdev->groups = connector_dev_groups;
 358         kdev->release = drm_sysfs_release;
 359         dev_set_drvdata(kdev, connector);
 360
 361         r = dev_set_name(kdev, "card%d-%s", dev->primary->index, connector->name);
 362         if (r)
 363                 goto err_free;
 364
 365         drm_dbg_kms(dev, "[CONNECTOR:%d:%s] adding connector to sysfs\n",
 366                     connector->base.id, connector->name);
 367
 368         r = device_add(kdev);
 369         if (r) {
 370                 drm_err(dev, "failed to register connector device: %d\n", r);
 371                 goto err_free;
 372         }
 373
 374         connector->kdev = kdev;
 375
 376         if (dev_fwnode(kdev)) {
 377                 r = component_add(kdev, &typec_connector_ops);
 378                 if (r)
 379                         drm_err(dev, "failed to add component to create link to typec connector\n");
 380         }
 381
 382         return 0;
 383
 384 err_free:
 385         put_device(kdev);
 386         return r;
 387 }
 388
 389 int drm_sysfs_connector_add_late(struct drm_connector *connector)
 390 {
 391         if (connector->ddc)
 392                 return sysfs_create_link(&connector->kdev->kobj,
 393                                          &connector->ddc->dev.kobj, "ddc");
 394
 395         return 0;
 396 }
 397
 398 void drm_sysfs_connector_remove_early(struct drm_connector *connector)
 399 {
 400         if (connector->ddc)
 401                 sysfs_remove_link(&connector->kdev->kobj, "ddc");
 402 }
 403
 404 void drm_sysfs_connector_remove(struct drm_connector *connector)
 405 {
 406         if (!connector->kdev)
 407                 return;
 408
 409         if (dev_fwnode(connector->kdev))
 410                 component_del(connector->kdev, &typec_connector_ops);
 411
 412         drm_dbg_kms(connector->dev,
 413                     "[CONNECTOR:%d:%s] removing connector from sysfs\n",
 414                     connector->base.id, connector->name);
 415
 416         device_unregister(connector->kdev);
 417         connector->kdev = NULL;
 418 }
 419
 420 void drm_sysfs_lease_event(struct drm_device *dev)
 421 {
 422         char *event_string = "LEASE=1";
 423         char *envp[] = { event_string, NULL };
 424
 425         drm_dbg_lease(dev, "generating lease event\n");
 426
 427         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 428 }
 429
 430 /**
 431  * drm_sysfs_hotplug_event - generate a DRM uevent
 432  * @dev: DRM device
 433  *
 434  * Send a uevent for the DRM device specified by @dev.  Currently we only
 435  * set HOTPLUG=1 in the uevent environment, but this could be expanded to
 436  * deal with other types of events.
 437  *
 438  * Any new uapi should be using the drm_sysfs_connector_status_event()
 439  * for uevents on connector status change.
 440  */
 441 void drm_sysfs_hotplug_event(struct drm_device *dev)
 442 {
 443         char *event_string = "HOTPLUG=1";
 444         char *envp[] = { event_string, NULL };
 445
 446         drm_dbg_kms(dev, "generating hotplug event\n");
 447
 448         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 449 }
 450 EXPORT_SYMBOL(drm_sysfs_hotplug_event);
 451
 452 /**
 453  * drm_sysfs_connector_hotplug_event - generate a DRM uevent for any connector
 454  * change
 455  * @connector: connector which has changed
 456  *
 457  * Send a uevent for the DRM connector specified by @connector. This will send
 458  * a uevent with the properties HOTPLUG=1 and CONNECTOR.
 459  */
 460 void drm_sysfs_connector_hotplug_event(struct drm_connector *connector)
 461 {
 462         struct drm_device *dev = connector->dev;
 463         char hotplug_str[] = "HOTPLUG=1", conn_id[21];
 464         char *envp[] = { hotplug_str, conn_id, NULL };
 465
 466         snprintf(conn_id, sizeof(conn_id),
 467                  "CONNECTOR=%u", connector->base.id);
 468
 469         drm_dbg_kms(connector->dev,
 470                     "[CONNECTOR:%d:%s] generating connector hotplug event\n",
 471                     connector->base.id, connector->name);
 472
 473         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 474 }
 475 EXPORT_SYMBOL(drm_sysfs_connector_hotplug_event);
 476
 477 /**
 478  * drm_sysfs_connector_property_event - generate a DRM uevent for connector
 479  * property change
 480  * @connector: connector on which property changed
 481  * @property: connector property which has changed.
 482  *
 483  * Send a uevent for the specified DRM connector and property.  Currently we
 484  * set HOTPLUG=1 and connector id along with the attached property id
 485  * related to the change.
 486  */
 487 void drm_sysfs_connector_property_event(struct drm_connector *connector,
 488                                         struct drm_property *property)
 489 {
 490         struct drm_device *dev = connector->dev;
 491         char hotplug_str[] = "HOTPLUG=1", conn_id[21], prop_id[21];
 492         char *envp[4] = { hotplug_str, conn_id, prop_id, NULL };
 493
 494         WARN_ON(!drm_mode_obj_find_prop_id(&connector->base,
 495                                            property->base.id));
 496
 497         snprintf(conn_id, ARRAY_SIZE(conn_id),
 498                  "CONNECTOR=%u", connector->base.id);
 499         snprintf(prop_id, ARRAY_SIZE(prop_id),
 500                  "PROPERTY=%u", property->base.id);
 501
 502         drm_dbg_kms(connector->dev,
 503                     "[CONNECTOR:%d:%s] generating connector property event for [PROP:%d:%s]\n",
 504                     connector->base.id, connector->name,
 505                     property->base.id, property->name);
 506
 507         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 508 }
 509 EXPORT_SYMBOL(drm_sysfs_connector_property_event);
 510
 511 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 512 {
 513         const char *minor_str;
 514         struct device *kdev;
 515         int r;
 516
 517         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 518         if (!kdev)
 519                 return ERR_PTR(-ENOMEM);
 520
 521         device_initialize(kdev);
 522
 523         if (minor->type == DRM_MINOR_ACCEL) {
 524                 minor_str = "accel%d";
 525                 accel_set_device_instance_params(kdev, minor->index);
 526         } else {
 527                 if (minor->type == DRM_MINOR_RENDER)
 528                         minor_str = "renderD%d";
 529                 else
 530                         minor_str = "card%d";
 531
 532                 kdev->devt = MKDEV(DRM_MAJOR, minor->index);
 533                 kdev->class = drm_class;
 534                 kdev->type = &drm_sysfs_device_minor;
 535         }
 536
 537         kdev->parent = minor->dev->dev;
 538         kdev->release = drm_sysfs_release;
 539         dev_set_drvdata(kdev, minor);
 540
 541         r = dev_set_name(kdev, minor_str, minor->index);
 542         if (r < 0)
 543                 goto err_free;
 544
 545         return kdev;
 546
 547 err_free:
 548         put_device(kdev);
 549         return ERR_PTR(r);
 550 }
 551
 552 /**
 553  * drm_class_device_register - register new device with the DRM sysfs class
 554  * @dev: device to register
 555  *
 556  * Registers a new &struct device within the DRM sysfs class. Essentially only
 557  * used by ttm to have a place for its global settings. Drivers should never use
 558  * this.
 559  */
 560 int drm_class_device_register(struct device *dev)
 561 {
 562         if (!drm_class || IS_ERR(drm_class))
 563                 return -ENOENT;
 564
 565         dev->class = drm_class;
 566         return device_register(dev);
 567 }
 568 EXPORT_SYMBOL_GPL(drm_class_device_register);
 569
 570 /**
 571  * drm_class_device_unregister - unregister device with the DRM sysfs class
 572  * @dev: device to unregister
 573  *
 574  * Unregisters a &struct device from the DRM sysfs class. Essentially only used
 575  * by ttm to have a place for its global settings. Drivers should never use
 576  * this.
 577  */
 578 void drm_class_device_unregister(struct device *dev)
 579 {
 580         return device_unregister(dev);
 581 }
 582 EXPORT_SYMBOL_GPL(drm_class_device_unregister);