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_force old_force;
 171         int ret;
 172
 173         ret = mutex_lock_interruptible(&dev->mode_config.mutex);
 174         if (ret)
 175                 return ret;
 176
 177         old_force = connector->force;
 178
 179         if (sysfs_streq(buf, "detect"))
 180                 connector->force = 0;
 181         else if (sysfs_streq(buf, "on"))
 182                 connector->force = DRM_FORCE_ON;
 183         else if (sysfs_streq(buf, "on-digital"))
 184                 connector->force = DRM_FORCE_ON_DIGITAL;
 185         else if (sysfs_streq(buf, "off"))
 186                 connector->force = DRM_FORCE_OFF;
 187         else
 188                 ret = -EINVAL;
 189
 190         if (old_force != connector->force || !connector->force) {
 191                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
 192                               connector->base.id,
 193                               connector->name,
 194                               old_force, connector->force);
 195
 196                 connector->funcs->fill_modes(connector,
 197                                              dev->mode_config.max_width,
 198                                              dev->mode_config.max_height);
 199         }
 200
 201         mutex_unlock(&dev->mode_config.mutex);
 202
 203         return ret ? ret : count;
 204 }
 205
 206 static ssize_t status_show(struct device *device,
 207                            struct device_attribute *attr,
 208                            char *buf)
 209 {
 210         struct drm_connector *connector = to_drm_connector(device);
 211         enum drm_connector_status status;
 212
 213         status = READ_ONCE(connector->status);
 214
 215         return snprintf(buf, PAGE_SIZE, "%s\n",
 216                         drm_get_connector_status_name(status));
 217 }
 218
 219 static ssize_t dpms_show(struct device *device,
 220                            struct device_attribute *attr,
 221                            char *buf)
 222 {
 223         struct drm_connector *connector = to_drm_connector(device);
 224         int dpms;
 225
 226         dpms = READ_ONCE(connector->dpms);
 227
 228         return snprintf(buf, PAGE_SIZE, "%s\n",
 229                         drm_get_dpms_name(dpms));
 230 }
 231
 232 static ssize_t enabled_show(struct device *device,
 233                             struct device_attribute *attr,
 234                            char *buf)
 235 {
 236         struct drm_connector *connector = to_drm_connector(device);
 237         bool enabled;
 238
 239         enabled = READ_ONCE(connector->encoder);
 240
 241         return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n");
 242 }
 243
 244 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
 245                          struct bin_attribute *attr, char *buf, loff_t off,
 246                          size_t count)
 247 {
 248         struct device *connector_dev = kobj_to_dev(kobj);
 249         struct drm_connector *connector = to_drm_connector(connector_dev);
 250         unsigned char *edid;
 251         size_t size;
 252         ssize_t ret = 0;
 253
 254         mutex_lock(&connector->dev->mode_config.mutex);
 255         if (!connector->edid_blob_ptr)
 256                 goto unlock;
 257
 258         edid = connector->edid_blob_ptr->data;
 259         size = connector->edid_blob_ptr->length;
 260         if (!edid)
 261                 goto unlock;
 262
 263         if (off >= size)
 264                 goto unlock;
 265
 266         if (off + count > size)
 267                 count = size - off;
 268         memcpy(buf, edid + off, count);
 269
 270         ret = count;
 271 unlock:
 272         mutex_unlock(&connector->dev->mode_config.mutex);
 273
 274         return ret;
 275 }
 276
 277 static ssize_t modes_show(struct device *device,
 278                            struct device_attribute *attr,
 279                            char *buf)
 280 {
 281         struct drm_connector *connector = to_drm_connector(device);
 282         struct drm_display_mode *mode;
 283         int written = 0;
 284
 285         mutex_lock(&connector->dev->mode_config.mutex);
 286         list_for_each_entry(mode, &connector->modes, head) {
 287                 written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
 288                                     mode->name);
 289         }
 290         mutex_unlock(&connector->dev->mode_config.mutex);
 291
 292         return written;
 293 }
 294
 295 static DEVICE_ATTR_RW(status);
 296 static DEVICE_ATTR_RO(enabled);
 297 static DEVICE_ATTR_RO(dpms);
 298 static DEVICE_ATTR_RO(modes);
 299
 300 static struct attribute *connector_dev_attrs[] = {
 301         &dev_attr_status.attr,
 302         &dev_attr_enabled.attr,
 303         &dev_attr_dpms.attr,
 304         &dev_attr_modes.attr,
 305         NULL
 306 };
 307
 308 static struct bin_attribute edid_attr = {
 309         .attr.name = "edid",
 310         .attr.mode = 0444,
 311         .size = 0,
 312         .read = edid_show,
 313 };
 314
 315 static struct bin_attribute *connector_bin_attrs[] = {
 316         &edid_attr,
 317         NULL
 318 };
 319
 320 static const struct attribute_group connector_dev_group = {
 321         .attrs = connector_dev_attrs,
 322         .bin_attrs = connector_bin_attrs,
 323 };
 324
 325 static const struct attribute_group *connector_dev_groups[] = {
 326         &connector_dev_group,
 327         NULL
 328 };
 329
 330 /**
 331  * drm_sysfs_connector_add - add a connector to sysfs
 332  * @connector: connector to add
 333  *
 334  * Create a connector device in sysfs, along with its associated connector
 335  * properties (so far, connection status, dpms, mode list & edid) and
 336  * generate a hotplug event so userspace knows there's a new connector
 337  * available.
 338  */
 339 int drm_sysfs_connector_add(struct drm_connector *connector)
 340 {
 341         struct drm_device *dev = connector->dev;
 342
 343         if (connector->kdev)
 344                 return 0;
 345
 346         connector->kdev =
 347                 device_create_with_groups(drm_class, dev->primary->kdev, 0,
 348                                           connector, connector_dev_groups,
 349                                           "card%d-%s", dev->primary->index,
 350                                           connector->name);
 351         DRM_DEBUG("adding \"%s\" to sysfs\n",
 352                   connector->name);
 353
 354         if (IS_ERR(connector->kdev)) {
 355                 DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
 356                 return PTR_ERR(connector->kdev);
 357         }
 358
 359         /* Let userspace know we have a new connector */
 360         drm_sysfs_hotplug_event(dev);
 361
 362         return 0;
 363 }
 364
 365 /**
 366  * drm_sysfs_connector_remove - remove an connector device from sysfs
 367  * @connector: connector to remove
 368  *
 369  * Remove @connector and its associated attributes from sysfs.  Note that
 370  * the device model core will take care of sending the "remove" uevent
 371  * at this time, so we don't need to do it.
 372  *
 373  * Note:
 374  * This routine should only be called if the connector was previously
 375  * successfully registered.  If @connector hasn't been registered yet,
 376  * you'll likely see a panic somewhere deep in sysfs code when called.
 377  */
 378 void drm_sysfs_connector_remove(struct drm_connector *connector)
 379 {
 380         if (!connector->kdev)
 381                 return;
 382         DRM_DEBUG("removing \"%s\" from sysfs\n",
 383                   connector->name);
 384
 385         device_unregister(connector->kdev);
 386         connector->kdev = NULL;
 387 }
 388
 389 /**
 390  * drm_sysfs_hotplug_event - generate a DRM uevent
 391  * @dev: DRM device
 392  *
 393  * Send a uevent for the DRM device specified by @dev.  Currently we only
 394  * set HOTPLUG=1 in the uevent environment, but this could be expanded to
 395  * deal with other types of events.
 396  */
 397 void drm_sysfs_hotplug_event(struct drm_device *dev)
 398 {
 399         char *event_string = "HOTPLUG=1";
 400         char *envp[] = { event_string, NULL };
 401
 402         DRM_DEBUG("generating hotplug event\n");
 403
 404         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 405 }
 406 EXPORT_SYMBOL(drm_sysfs_hotplug_event);
 407
 408 static void drm_sysfs_release(struct device *dev)
 409 {
 410         kfree(dev);
 411 }
 412
 413 /**
 414  * drm_sysfs_minor_alloc() - Allocate sysfs device for given minor
 415  * @minor: minor to allocate sysfs device for
 416  *
 417  * This allocates a new sysfs device for @minor and returns it. The device is
 418  * not registered nor linked. The caller has to use device_add() and
 419  * device_del() to register and unregister it.
 420  *
 421  * Note that dev_get_drvdata() on the new device will return the minor.
 422  * However, the device does not hold a ref-count to the minor nor to the
 423  * underlying drm_device. This is unproblematic as long as you access the
 424  * private data only in sysfs callbacks. device_del() disables those
 425  * synchronously, so they cannot be called after you cleanup a minor.
 426  */
 427 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 428 {
 429         const char *minor_str;
 430         struct device *kdev;
 431         int r;
 432
 433         if (minor->type == DRM_MINOR_CONTROL)
 434                 minor_str = "controlD%d";
 435         else if (minor->type == DRM_MINOR_RENDER)
 436                 minor_str = "renderD%d";
 437         else
 438                 minor_str = "card%d";
 439
 440         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 441         if (!kdev)
 442                 return ERR_PTR(-ENOMEM);
 443
 444         device_initialize(kdev);
 445         kdev->devt = MKDEV(DRM_MAJOR, minor->index);
 446         kdev->class = drm_class;
 447         kdev->type = &drm_sysfs_device_minor;
 448         kdev->parent = minor->dev->dev;
 449         kdev->release = drm_sysfs_release;
 450         dev_set_drvdata(kdev, minor);
 451
 452         r = dev_set_name(kdev, minor_str, minor->index);
 453         if (r < 0)
 454                 goto err_free;
 455
 456         return kdev;
 457
 458 err_free:
 459         put_device(kdev);
 460         return ERR_PTR(r);
 461 }
 462
 463 /**
 464  * drm_class_device_register - Register a struct device in the drm class.
 465  *
 466  * @dev: pointer to struct device to register.
 467  *
 468  * @dev should have all relevant members pre-filled with the exception
 469  * of the class member. In particular, the device_type member must
 470  * be set.
 471  */
 472
 473 int drm_class_device_register(struct device *dev)
 474 {
 475         if (!drm_class || IS_ERR(drm_class))
 476                 return -ENOENT;
 477
 478         dev->class = drm_class;
 479         return device_register(dev);
 480 }
 481 EXPORT_SYMBOL_GPL(drm_class_device_register);
 482
 483 void drm_class_device_unregister(struct device *dev)
 484 {
 485         return device_unregister(dev);
 486 }
 487 EXPORT_SYMBOL_GPL(drm_class_device_unregister);