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); 395