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