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/drmP.h>
  23 #include "drm_internal.h"
  24
  25 #define to_drm_minor(d) dev_get_drvdata(d)
  26 #define to_drm_connector(d) dev_get_drvdata(d)
  27
  28 /**
  29  * DOC: overview
  30  *
  31  * DRM provides very little additional support to drivers for sysfs
  32  * interactions, beyond just all the standard stuff. Drivers who want to expose
  33  * additional sysfs properties and property groups can attach them at either
  34  * &drm_device.dev or &drm_connector.kdev.
  35  *
  36  * Registration is automatically handled when calling drm_dev_register(), or
  37  * drm_connector_register() in case of hot-plugged connectors. Unregistration is
  38  * also automatically handled by drm_dev_unregister() and
  39  * drm_connector_unregister().
  40  */
  41
  42 static struct device_type drm_sysfs_device_minor = {
  43         .name = "drm_minor"
  44 };
  45
  46 struct class *drm_class;
  47
  48 static char *drm_devnode(struct device *dev, umode_t *mode)
  49 {
  50         return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
  51 }
  52
  53 static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
  54
  55 /**
  56  * drm_sysfs_init - initialize sysfs helpers
  57  *
  58  * This is used to create the DRM class, which is the implicit parent of any
  59  * other top-level DRM sysfs objects.
  60  *
  61  * You must call drm_sysfs_destroy() to release the allocated resources.
  62  *
  63  * Return: 0 on success, negative error code on failure.
  64  */
  65 int drm_sysfs_init(void)
  66 {
  67         int err;
  68
  69         drm_class = class_create(THIS_MODULE, "drm");
  70         if (IS_ERR(drm_class))
  71                 return PTR_ERR(drm_class);
  72
  73         err = class_create_file(drm_class, &class_attr_version.attr);
  74         if (err) {
  75                 class_destroy(drm_class);
  76                 drm_class = NULL;
  77                 return err;
  78         }
  79
  80         drm_class->devnode = drm_devnode;
  81         return 0;
  82 }
  83
  84 /**
  85  * drm_sysfs_destroy - destroys DRM class
  86  *
  87  * Destroy the DRM device class.
  88  */
  89 void drm_sysfs_destroy(void)
  90 {
  91         if (IS_ERR_OR_NULL(drm_class))
  92                 return;
  93         class_remove_file(drm_class, &class_attr_version.attr);
  94         class_destroy(drm_class);
  95         drm_class = NULL;
  96 }
  97
  98 /*
  99  * Connector properties
 100  */
 101 static ssize_t status_store(struct device *device,
 102                            struct device_attribute *attr,
 103                            const char *buf, size_t count)
 104 {
 105         struct drm_connector *connector = to_drm_connector(device);
 106         struct drm_device *dev = connector->dev;
 107         enum drm_connector_force old_force;
 108         int ret;
 109
 110         ret = mutex_lock_interruptible(&dev->mode_config.mutex);
 111         if (ret)
 112                 return ret;
 113
 114         old_force = connector->force;
 115
 116         if (sysfs_streq(buf, "detect"))
 117                 connector->force = 0;
 118         else if (sysfs_streq(buf, "on"))
 119                 connector->force = DRM_FORCE_ON;
 120         else if (sysfs_streq(buf, "on-digital"))
 121                 connector->force = DRM_FORCE_ON_DIGITAL;
 122         else if (sysfs_streq(buf, "off"))
 123                 connector->force = DRM_FORCE_OFF;
 124         else
 125                 ret = -EINVAL;
 126
 127         if (old_force != connector->force || !connector->force) {
 128                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
 129                               connector->base.id,
 130                               connector->name,
 131                               old_force, connector->force);
 132
 133                 connector->funcs->fill_modes(connector,
 134                                              dev->mode_config.max_width,
 135                                              dev->mode_config.max_height);
 136         }
 137
 138         mutex_unlock(&dev->mode_config.mutex);
 139
 140         return ret ? ret : count;
 141 }
 142
 143 static ssize_t status_show(struct device *device,
 144                            struct device_attribute *attr,
 145                            char *buf)
 146 {
 147         struct drm_connector *connector = to_drm_connector(device);
 148         enum drm_connector_status status;
 149
 150         status = READ_ONCE(connector->status);
 151
 152         return snprintf(buf, PAGE_SIZE, "%s\n",
 153                         drm_get_connector_status_name(status));
 154 }
 155
 156 static ssize_t dpms_show(struct device *device,
 157                            struct device_attribute *attr,
 158                            char *buf)
 159 {
 160         struct drm_connector *connector = to_drm_connector(device);
 161         int dpms;
 162
 163         dpms = READ_ONCE(connector->dpms);
 164
 165         return snprintf(buf, PAGE_SIZE, "%s\n",
 166                         drm_get_dpms_name(dpms));
 167 }
 168
 169 static ssize_t enabled_show(struct device *device,
 170                             struct device_attribute *attr,
 171                            char *buf)
 172 {
 173         struct drm_connector *connector = to_drm_connector(device);
 174         bool enabled;
 175
 176         enabled = READ_ONCE(connector->encoder);
 177
 178         return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n");
 179 }
 180
 181 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
 182                          struct bin_attribute *attr, char *buf, loff_t off,
 183                          size_t count)
 184 {
 185         struct device *connector_dev = kobj_to_dev(kobj);
 186         struct drm_connector *connector = to_drm_connector(connector_dev);
 187         unsigned char *edid;
 188         size_t size;
 189         ssize_t ret = 0;
 190
 191         mutex_lock(&connector->dev->mode_config.mutex);
 192         if (!connector->edid_blob_ptr)
 193                 goto unlock;
 194
 195         edid = connector->edid_blob_ptr->data;
 196         size = connector->edid_blob_ptr->length;
 197         if (!edid)
 198                 goto unlock;
 199
 200         if (off >= size)
 201                 goto unlock;
 202
 203         if (off + count > size)
 204                 count = size - off;
 205         memcpy(buf, edid + off, count);
 206
 207         ret = count;
 208 unlock:
 209         mutex_unlock(&connector->dev->mode_config.mutex);
 210
 211         return ret;
 212 }
 213
 214 static ssize_t modes_show(struct device *device,
 215                            struct device_attribute *attr,
 216                            char *buf)
 217 {
 218         struct drm_connector *connector = to_drm_connector(device);
 219         struct drm_display_mode *mode;
 220         int written = 0;
 221
 222         mutex_lock(&connector->dev->mode_config.mutex);
 223         list_for_each_entry(mode, &connector->modes, head) {
 224                 written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
 225                                     mode->name);
 226         }
 227         mutex_unlock(&connector->dev->mode_config.mutex);
 228
 229         return written;
 230 }
 231
 232 static DEVICE_ATTR_RW(status);
 233 static DEVICE_ATTR_RO(enabled);
 234 static DEVICE_ATTR_RO(dpms);
 235 static DEVICE_ATTR_RO(modes);
 236
 237 static struct attribute *connector_dev_attrs[] = {
 238         &dev_attr_status.attr,
 239         &dev_attr_enabled.attr,
 240         &dev_attr_dpms.attr,
 241         &dev_attr_modes.attr,
 242         NULL
 243 };
 244
 245 static struct bin_attribute edid_attr = {
 246         .attr.name = "edid",
 247         .attr.mode = 0444,
 248         .size = 0,
 249         .read = edid_show,
 250 };
 251
 252 static struct bin_attribute *connector_bin_attrs[] = {
 253         &edid_attr,
 254         NULL
 255 };
 256
 257 static const struct attribute_group connector_dev_group = {
 258         .attrs = connector_dev_attrs,
 259         .bin_attrs = connector_bin_attrs,
 260 };
 261
 262 static const struct attribute_group *connector_dev_groups[] = {
 263         &connector_dev_group,
 264         NULL
 265 };
 266
 267 int drm_sysfs_connector_add(struct drm_connector *connector)
 268 {
 269         struct drm_device *dev = connector->dev;
 270
 271         if (connector->kdev)
 272                 return 0;
 273
 274         connector->kdev =
 275                 device_create_with_groups(drm_class, dev->primary->kdev, 0,
 276                                           connector, connector_dev_groups,
 277                                           "card%d-%s", dev->primary->index,
 278                                           connector->name);
 279         DRM_DEBUG("adding \"%s\" to sysfs\n",
 280                   connector->name);
 281
 282         if (IS_ERR(connector->kdev)) {
 283                 DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
 284                 return PTR_ERR(connector->kdev);
 285         }
 286
 287         /* Let userspace know we have a new connector */
 288         drm_sysfs_hotplug_event(dev);
 289
 290         return 0;
 291 }
 292
 293 void drm_sysfs_connector_remove(struct drm_connector *connector)
 294 {
 295         if (!connector->kdev)
 296                 return;
 297         DRM_DEBUG("removing \"%s\" from sysfs\n",
 298                   connector->name);
 299
 300         device_unregister(connector->kdev);
 301         connector->kdev = NULL;
 302 }
 303
 304 /**
 305  * drm_sysfs_hotplug_event - generate a DRM uevent
 306  * @dev: DRM device
 307  *
 308  * Send a uevent for the DRM device specified by @dev.  Currently we only
 309  * set HOTPLUG=1 in the uevent environment, but this could be expanded to
 310  * deal with other types of events.
 311  */
 312 void drm_sysfs_hotplug_event(struct drm_device *dev)
 313 {
 314         char *event_string = "HOTPLUG=1";
 315         char *envp[] = { event_string, NULL };
 316
 317         DRM_DEBUG("generating hotplug event\n");
 318
 319         kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
 320 }
 321 EXPORT_SYMBOL(drm_sysfs_hotplug_event);
 322
 323 static void drm_sysfs_release(struct device *dev)
 324 {
 325         kfree(dev);
 326 }
 327
 328 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 329 {
 330         const char *minor_str;
 331         struct device *kdev;
 332         int r;
 333
 334         if (minor->type == DRM_MINOR_CONTROL)
 335                 minor_str = "controlD%d";
 336         else if (minor->type == DRM_MINOR_RENDER)
 337                 minor_str = "renderD%d";
 338         else
 339                 minor_str = "card%d";
 340
 341         kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
 342         if (!kdev)
 343                 return ERR_PTR(-ENOMEM);
 344
 345         device_initialize(kdev);
 346         kdev->devt = MKDEV(DRM_MAJOR, minor->index);
 347         kdev->class = drm_class;
 348         kdev->type = &drm_sysfs_device_minor;
 349         kdev->parent = minor->dev->dev;
 350         kdev->release = drm_sysfs_release;
 351         dev_set_drvdata(kdev, minor);
 352
 353         r = dev_set_name(kdev, minor_str, minor->index);
 354         if (r < 0)
 355                 goto err_free;
 356
 357         return kdev;
 358
 359 err_free:
 360         put_device(kdev);
 361         return ERR_PTR(r);
 362 }
 363
 364 /**
 365  * drm_class_device_register - register new device with the DRM sysfs class
 366  * @dev: device to register
 367  *
 368  * Registers a new &struct device within the DRM sysfs class. Essentially only
 369  * used by ttm to have a place for its global settings. Drivers should never use
 370  * this.
 371  */
 372 int drm_class_device_register(struct device *dev)
 373 {
 374         if (!drm_class || IS_ERR(drm_class))
 375                 return -ENOENT;
 376
 377         dev->class = drm_class;
 378         return device_register(dev);
 379 }
 380 EXPORT_SYMBOL_GPL(drm_class_device_register);
 381
 382 /**
 383  * drm_class_device_unregister - unregister device with the DRM sysfs class
 384  * @dev: device to unregister
 385  *
 386  * Unregisters a &struct device from the DRM sysfs class. Essentially only used
 387  * by ttm to have a place for its global settings. Drivers should never use
 388  * this.
 389  */
 390 void drm_class_device_unregister(struct device *dev)
 391 {
 392         return device_unregister(dev);
 393 }
 394 EXPORT_SYMBOL_GPL(drm_class_device_unregister);