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 drm_setup_hdcp_srm(drm_class); 82 return 0; 83 } 84 85 /** 86 * drm_sysfs_destroy - destroys DRM class 87 * 88 * Destroy the DRM device class. 89 */ 90 void drm_sysfs_destroy(void) 91 { 92 if (IS_ERR_OR_NULL(drm_class)) 93 return; 94 drm_teardown_hdcp_srm(drm_class); 95 class_remove_file(drm_class, &class_attr_version.attr); 96 class_destroy(drm_class); 97 drm_class = NULL; 98 } 99 100 /* 101 * Connector properties 102 */ 103 static ssize_t status_store(struct device *device, 104 struct device_attribute *attr, 105 const char *buf, size_t count) 106 { 107 struct drm_connector *connector = to_drm_connector(device); 108 struct drm_device *dev = connector->dev; 109 enum drm_connector_force old_force; 110 int ret; 111 112 ret = mutex_lock_interruptible(&dev->mode_config.mutex); 113 if (ret) 114 return ret; 115 116 old_force = connector->force; 117 118 if (sysfs_streq(buf, "detect")) 119 connector->force = 0; 120 else if (sysfs_streq(buf, "on")) 121 connector->force = DRM_FORCE_ON; 122 else if (sysfs_streq(buf, "on-digital")) 123 connector->force = DRM_FORCE_ON_DIGITAL; 124 else if (sysfs_streq(buf, "off")) 125 connector->force = DRM_FORCE_OFF; 126 else 127 ret = -EINVAL; 128 129 if (old_force != connector->force || !connector->force) { 130 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n", 131 connector->base.id, 132 connector->name, 133 old_force, connector->force); 134 135 connector->funcs->fill_modes(connector, 136 dev->mode_config.max_width, 137 dev->mode_config.max_height); 138 } 139 140 mutex_unlock(&dev->mode_config.mutex); 141 142 return ret ? ret : count; 143 } 144 145 static ssize_t status_show(struct device *device, 146 struct device_attribute *attr, 147 char *buf) 148 { 149 struct drm_connector *connector = to_drm_connector(device); 150 enum drm_connector_status status; 151 152 status = READ_ONCE(connector->status); 153 154 return snprintf(buf, PAGE_SIZE, "%s\n", 155 drm_get_connector_status_name(status)); 156 } 157 158 static ssize_t dpms_show(struct device *device, 159 struct device_attribute *attr, 160 char *buf) 161 { 162 struct drm_connector *connector = to_drm_connector(device); 163 int dpms; 164 165 dpms = READ_ONCE(connector->dpms); 166 167 return snprintf(buf, PAGE_SIZE, "%s\n", 168 drm_get_dpms_name(dpms)); 169 } 170 171 static ssize_t enabled_show(struct device *device, 172 struct device_attribute *attr, 173 char *buf) 174 { 175 struct drm_connector *connector = to_drm_connector(device); 176 bool enabled; 177 178 enabled = READ_ONCE(connector->encoder); 179 180 return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n"); 181 } 182 183 static ssize_t edid_show(struct file *filp, struct kobject *kobj, 184 struct bin_attribute *attr, char *buf, loff_t off, 185 size_t count) 186 { 187 struct device *connector_dev = kobj_to_dev(kobj); 188 struct drm_connector *connector = to_drm_connector(connector_dev); 189 unsigned char *edid; 190 size_t size; 191 ssize_t ret = 0; 192 193 mutex_lock(&connector->dev->mode_config.mutex); 194 if (!connector->edid_blob_ptr) 195 goto unlock; 196 197 edid = connector->edid_blob_ptr->data; 198 size = connector->edid_blob_ptr->length; 199 if (!edid) 200 goto unlock; 201 202 if (off >= size) 203 goto unlock; 204 205 if (off + count > size) 206 count = size - off; 207 memcpy(buf, edid + off, count); 208 209 ret = count; 210 unlock: 211 mutex_unlock(&connector->dev->mode_config.mutex); 212 213 return ret; 214 } 215 216 static ssize_t modes_show(struct device *device, 217 struct device_attribute *attr, 218 char *buf) 219 { 220 struct drm_connector *connector = to_drm_connector(device); 221 struct drm_display_mode *mode; 222 int written = 0; 223 224 mutex_lock(&connector->dev->mode_config.mutex); 225 list_for_each_entry(mode, &connector->modes, head) { 226 written += snprintf(buf + written, PAGE_SIZE - written, "%s\n", 227 mode->name); 228 } 229 mutex_unlock(&connector->dev->mode_config.mutex); 230 231 return written; 232 } 233 234 static DEVICE_ATTR_RW(status); 235 static DEVICE_ATTR_RO(enabled); 236 static DEVICE_ATTR_RO(dpms); 237 static DEVICE_ATTR_RO(modes); 238 239 static struct attribute *connector_dev_attrs[] = { 240 &dev_attr_status.attr, 241 &dev_attr_enabled.attr, 242 &dev_attr_dpms.attr, 243 &dev_attr_modes.attr, 244 NULL 245 }; 246 247 static struct bin_attribute edid_attr = { 248 .attr.name = "edid", 249 .attr.mode = 0444, 250 .size = 0, 251 .read = edid_show, 252 }; 253 254 static struct bin_attribute *connector_bin_attrs[] = { 255 &edid_attr, 256 NULL 257 }; 258 259 static const struct attribute_group connector_dev_group = { 260 .attrs = connector_dev_attrs, 261 .bin_attrs = connector_bin_attrs, 262 }; 263 264 static const struct attribute_group *connector_dev_groups[] = { 265 &connector_dev_group, 266 NULL 267 }; 268 269 int drm_sysfs_connector_add(struct drm_connector *connector) 270 { 271 struct drm_device *dev = connector->dev; 272 273 if (connector->kdev) 274 return 0; 275 276 connector->kdev = 277 device_create_with_groups(drm_class, dev->primary->kdev, 0, 278 connector, connector_dev_groups, 279 "card%d-%s", dev->primary->index, 280 connector->name); 281 DRM_DEBUG("adding \"%s\" to sysfs\n", 282 connector->name); 283 284 if (IS_ERR(connector->kdev)) { 285 DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev)); 286 return PTR_ERR(connector->kdev); 287 } 288 289 /* Let userspace know we have a new connector */ 290 drm_sysfs_hotplug_event(dev); 291 292 return 0; 293 } 294 295 void drm_sysfs_connector_remove(struct drm_connector *connector) 296 { 297 if (!connector->kdev) 298 return; 299 DRM_DEBUG("removing \"%s\" from sysfs\n", 300 connector->name); 301 302 device_unregister(connector->kdev); 303 connector->kdev = NULL; 304 } 305 306 void drm_sysfs_lease_event(struct drm_device *dev) 307 { 308 char *event_string = "LEASE=1"; 309 char *envp[] = { event_string, NULL }; 310 311 DRM_DEBUG("generating lease event\n"); 312 313 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp); 314 } 315 316 /** 317 * drm_sysfs_hotplug_event - generate a DRM uevent 318 * @dev: DRM device 319 * 320 * Send a uevent for the DRM device specified by @dev. Currently we only 321 * set HOTPLUG=1 in the uevent environment, but this could be expanded to 322 * deal with other types of events. 323 */ 324 void drm_sysfs_hotplug_event(struct drm_device *dev) 325 { 326 char *event_string = "HOTPLUG=1"; 327 char *envp[] = { event_string, NULL }; 328 329 DRM_DEBUG("generating hotplug event\n"); 330 331 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp); 332 } 333 EXPORT_SYMBOL(drm_sysfs_hotplug_event); 334 335 static void drm_sysfs_release(struct device *dev) 336 { 337 kfree(dev); 338 } 339 340 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor) 341 { 342 const char *minor_str; 343 struct device *kdev; 344 int r; 345 346 if (minor->type == DRM_MINOR_RENDER) 347 minor_str = "renderD%d"; 348 else 349 minor_str = "card%d"; 350 351 kdev = kzalloc(sizeof(*kdev), GFP_KERNEL); 352 if (!kdev) 353 return ERR_PTR(-ENOMEM); 354 355 device_initialize(kdev); 356 kdev->devt = MKDEV(DRM_MAJOR, minor->index); 357 kdev->class = drm_class; 358 kdev->type = &drm_sysfs_device_minor; 359 kdev->parent = minor->dev->dev; 360 kdev->release = drm_sysfs_release; 361 dev_set_drvdata(kdev, minor); 362 363 r = dev_set_name(kdev, minor_str, minor->index); 364 if (r < 0) 365 goto err_free; 366 367 return kdev; 368 369 err_free: 370 put_device(kdev); 371 return ERR_PTR(r); 372 } 373 374 /** 375 * drm_class_device_register - register new device with the DRM sysfs class 376 * @dev: device to register 377 * 378 * Registers a new &struct device within the DRM sysfs class. Essentially only 379 * used by ttm to have a place for its global settings. Drivers should never use 380 * this. 381 */ 382 int drm_class_device_register(struct device *dev) 383 { 384 if (!drm_class || IS_ERR(drm_class)) 385 return -ENOENT; 386 387 dev->class = drm_class; 388 return device_register(dev); 389 } 390 EXPORT_SYMBOL_GPL(drm_class_device_register); 391 392 /** 393 * drm_class_device_unregister - unregister device with the DRM sysfs class 394 * @dev: device to unregister 395 * 396 * Unregisters a &struct device from the DRM sysfs class. Essentially only used 397 * by ttm to have a place for its global settings. Drivers should never use 398 * this. 399 */ 400 void drm_class_device_unregister(struct device *dev) 401 { 402 return device_unregister(dev); 403 } 404 EXPORT_SYMBOL_GPL(drm_class_device_unregister); 405