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 static struct device_type drm_sysfs_device_minor = { 29 .name = "drm_minor" 30 }; 31 32 struct class *drm_class; 33 34 static char *drm_devnode(struct device *dev, umode_t *mode) 35 { 36 return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev)); 37 } 38 39 static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810"); 40 41 /** 42 * drm_sysfs_init - initialize sysfs helpers 43 * 44 * This is used to create the DRM class, which is the implicit parent of any 45 * other top-level DRM sysfs objects. 46 * 47 * You must call drm_sysfs_destroy() to release the allocated resources. 48 * 49 * Return: 0 on success, negative error code on failure. 50 */ 51 int drm_sysfs_init(void) 52 { 53 int err; 54 55 drm_class = class_create(THIS_MODULE, "drm"); 56 if (IS_ERR(drm_class)) 57 return PTR_ERR(drm_class); 58 59 err = class_create_file(drm_class, &class_attr_version.attr); 60 if (err) { 61 class_destroy(drm_class); 62 drm_class = NULL; 63 return err; 64 } 65 66 drm_class->devnode = drm_devnode; 67 return 0; 68 } 69 70 /** 71 * drm_sysfs_destroy - destroys DRM class 72 * 73 * Destroy the DRM device class. 74 */ 75 void drm_sysfs_destroy(void) 76 { 77 if (IS_ERR_OR_NULL(drm_class)) 78 return; 79 class_remove_file(drm_class, &class_attr_version.attr); 80 class_destroy(drm_class); 81 drm_class = NULL; 82 } 83 84 /* 85 * Connector properties 86 */ 87 static ssize_t status_store(struct device *device, 88 struct device_attribute *attr, 89 const char *buf, size_t count) 90 { 91 struct drm_connector *connector = to_drm_connector(device); 92 struct drm_device *dev = connector->dev; 93 enum drm_connector_force old_force; 94 int ret; 95 96 ret = mutex_lock_interruptible(&dev->mode_config.mutex); 97 if (ret) 98 return ret; 99 100 old_force = connector->force; 101 102 if (sysfs_streq(buf, "detect")) 103 connector->force = 0; 104 else if (sysfs_streq(buf, "on")) 105 connector->force = DRM_FORCE_ON; 106 else if (sysfs_streq(buf, "on-digital")) 107 connector->force = DRM_FORCE_ON_DIGITAL; 108 else if (sysfs_streq(buf, "off")) 109 connector->force = DRM_FORCE_OFF; 110 else 111 ret = -EINVAL; 112 113 if (old_force != connector->force || !connector->force) { 114 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n", 115 connector->base.id, 116 connector->name, 117 old_force, connector->force); 118 119 connector->funcs->fill_modes(connector, 120 dev->mode_config.max_width, 121 dev->mode_config.max_height); 122 } 123 124 mutex_unlock(&dev->mode_config.mutex); 125 126 return ret ? ret : count; 127 } 128 129 static ssize_t status_show(struct device *device, 130 struct device_attribute *attr, 131 char *buf) 132 { 133 struct drm_connector *connector = to_drm_connector(device); 134 enum drm_connector_status status; 135 136 status = READ_ONCE(connector->status); 137 138 return snprintf(buf, PAGE_SIZE, "%s\n", 139 drm_get_connector_status_name(status)); 140 } 141 142 static ssize_t dpms_show(struct device *device, 143 struct device_attribute *attr, 144 char *buf) 145 { 146 struct drm_connector *connector = to_drm_connector(device); 147 int dpms; 148 149 dpms = READ_ONCE(connector->dpms); 150 151 return snprintf(buf, PAGE_SIZE, "%s\n", 152 drm_get_dpms_name(dpms)); 153 } 154 155 static ssize_t enabled_show(struct device *device, 156 struct device_attribute *attr, 157 char *buf) 158 { 159 struct drm_connector *connector = to_drm_connector(device); 160 bool enabled; 161 162 enabled = READ_ONCE(connector->encoder); 163 164 return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n"); 165 } 166 167 static ssize_t edid_show(struct file *filp, struct kobject *kobj, 168 struct bin_attribute *attr, char *buf, loff_t off, 169 size_t count) 170 { 171 struct device *connector_dev = kobj_to_dev(kobj); 172 struct drm_connector *connector = to_drm_connector(connector_dev); 173 unsigned char *edid; 174 size_t size; 175 ssize_t ret = 0; 176 177 mutex_lock(&connector->dev->mode_config.mutex); 178 if (!connector->edid_blob_ptr) 179 goto unlock; 180 181 edid = connector->edid_blob_ptr->data; 182 size = connector->edid_blob_ptr->length; 183 if (!edid) 184 goto unlock; 185 186 if (off >= size) 187 goto unlock; 188 189 if (off + count > size) 190 count = size - off; 191 memcpy(buf, edid + off, count); 192 193 ret = count; 194 unlock: 195 mutex_unlock(&connector->dev->mode_config.mutex); 196 197 return ret; 198 } 199 200 static ssize_t modes_show(struct device *device, 201 struct device_attribute *attr, 202 char *buf) 203 { 204 struct drm_connector *connector = to_drm_connector(device); 205 struct drm_display_mode *mode; 206 int written = 0; 207 208 mutex_lock(&connector->dev->mode_config.mutex); 209 list_for_each_entry(mode, &connector->modes, head) { 210 written += snprintf(buf + written, PAGE_SIZE - written, "%s\n", 211 mode->name); 212 } 213 mutex_unlock(&connector->dev->mode_config.mutex); 214 215 return written; 216 } 217 218 static DEVICE_ATTR_RW(status); 219 static DEVICE_ATTR_RO(enabled); 220 static DEVICE_ATTR_RO(dpms); 221 static DEVICE_ATTR_RO(modes); 222 223 static struct attribute *connector_dev_attrs[] = { 224 &dev_attr_status.attr, 225 &dev_attr_enabled.attr, 226 &dev_attr_dpms.attr, 227 &dev_attr_modes.attr, 228 NULL 229 }; 230 231 static struct bin_attribute edid_attr = { 232 .attr.name = "edid", 233 .attr.mode = 0444, 234 .size = 0, 235 .read = edid_show, 236 }; 237 238 static struct bin_attribute *connector_bin_attrs[] = { 239 &edid_attr, 240 NULL 241 }; 242 243 static const struct attribute_group connector_dev_group = { 244 .attrs = connector_dev_attrs, 245 .bin_attrs = connector_bin_attrs, 246 }; 247 248 static const struct attribute_group *connector_dev_groups[] = { 249 &connector_dev_group, 250 NULL 251 }; 252 253 /** 254 * drm_sysfs_connector_add - add a connector to sysfs 255 * @connector: connector to add 256 * 257 * Create a connector device in sysfs, along with its associated connector 258 * properties (so far, connection status, dpms, mode list & edid) and 259 * generate a hotplug event so userspace knows there's a new connector 260 * available. 261 */ 262 int drm_sysfs_connector_add(struct drm_connector *connector) 263 { 264 struct drm_device *dev = connector->dev; 265 266 if (connector->kdev) 267 return 0; 268 269 connector->kdev = 270 device_create_with_groups(drm_class, dev->primary->kdev, 0, 271 connector, connector_dev_groups, 272 "card%d-%s", dev->primary->index, 273 connector->name); 274 DRM_DEBUG("adding \"%s\" to sysfs\n", 275 connector->name); 276 277 if (IS_ERR(connector->kdev)) { 278 DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev)); 279 return PTR_ERR(connector->kdev); 280 } 281 282 /* Let userspace know we have a new connector */ 283 drm_sysfs_hotplug_event(dev); 284 285 return 0; 286 } 287 288 /** 289 * drm_sysfs_connector_remove - remove an connector device from sysfs 290 * @connector: connector to remove 291 * 292 * Remove @connector and its associated attributes from sysfs. Note that 293 * the device model core will take care of sending the "remove" uevent 294 * at this time, so we don't need to do it. 295 * 296 * Note: 297 * This routine should only be called if the connector was previously 298 * successfully registered. If @connector hasn't been registered yet, 299 * you'll likely see a panic somewhere deep in sysfs code when called. 300 */ 301 void drm_sysfs_connector_remove(struct drm_connector *connector) 302 { 303 if (!connector->kdev) 304 return; 305 DRM_DEBUG("removing \"%s\" from sysfs\n", 306 connector->name); 307 308 device_unregister(connector->kdev); 309 connector->kdev = NULL; 310 } 311 312 /** 313 * drm_sysfs_hotplug_event - generate a DRM uevent 314 * @dev: DRM device 315 * 316 * Send a uevent for the DRM device specified by @dev. Currently we only 317 * set HOTPLUG=1 in the uevent environment, but this could be expanded to 318 * deal with other types of events. 319 */ 320 void drm_sysfs_hotplug_event(struct drm_device *dev) 321 { 322 char *event_string = "HOTPLUG=1"; 323 char *envp[] = { event_string, NULL }; 324 325 DRM_DEBUG("generating hotplug event\n"); 326 327 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp); 328 } 329 EXPORT_SYMBOL(drm_sysfs_hotplug_event); 330 331 static void drm_sysfs_release(struct device *dev) 332 { 333 kfree(dev); 334 } 335 336 /** 337 * drm_sysfs_minor_alloc() - Allocate sysfs device for given minor 338 * @minor: minor to allocate sysfs device for 339 * 340 * This allocates a new sysfs device for @minor and returns it. The device is 341 * not registered nor linked. The caller has to use device_add() and 342 * device_del() to register and unregister it. 343 * 344 * Note that dev_get_drvdata() on the new device will return the minor. 345 * However, the device does not hold a ref-count to the minor nor to the 346 * underlying drm_device. This is unproblematic as long as you access the 347 * private data only in sysfs callbacks. device_del() disables those 348 * synchronously, so they cannot be called after you cleanup a minor. 349 */ 350 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor) 351 { 352 const char *minor_str; 353 struct device *kdev; 354 int r; 355 356 if (minor->type == DRM_MINOR_CONTROL) 357 minor_str = "controlD%d"; 358 else if (minor->type == DRM_MINOR_RENDER) 359 minor_str = "renderD%d"; 360 else 361 minor_str = "card%d"; 362 363 kdev = kzalloc(sizeof(*kdev), GFP_KERNEL); 364 if (!kdev) 365 return ERR_PTR(-ENOMEM); 366 367 device_initialize(kdev); 368 kdev->devt = MKDEV(DRM_MAJOR, minor->index); 369 kdev->class = drm_class; 370 kdev->type = &drm_sysfs_device_minor; 371 kdev->parent = minor->dev->dev; 372 kdev->release = drm_sysfs_release; 373 dev_set_drvdata(kdev, minor); 374 375 r = dev_set_name(kdev, minor_str, minor->index); 376 if (r < 0) 377 goto err_free; 378 379 return kdev; 380 381 err_free: 382 put_device(kdev); 383 return ERR_PTR(r); 384 } 385 386 /** 387 * drm_class_device_register - Register a struct device in the drm class. 388 * 389 * @dev: pointer to struct device to register. 390 * 391 * @dev should have all relevant members pre-filled with the exception 392 * of the class member. In particular, the device_type member must 393 * be set. 394 */ 395 396 int drm_class_device_register(struct device *dev) 397 { 398 if (!drm_class || IS_ERR(drm_class)) 399 return -ENOENT; 400 401 dev->class = drm_class; 402 return device_register(dev); 403 } 404 EXPORT_SYMBOL_GPL(drm_class_device_register); 405 406 void drm_class_device_unregister(struct device *dev) 407 { 408 return device_unregister(dev); 409 } 410 EXPORT_SYMBOL_GPL(drm_class_device_unregister); 411