1 // SPDX-License-Identifier: GPL-2.0-only
4 * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
5 * extra sysfs attribute from DRM. Normal drm_sysfs_class
6 * does not allow adding attributes.
8 * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
9 * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
10 * Copyright (c) 2003-2004 IBM Corp.
13 #include <linux/device.h>
14 #include <linux/kdev_t.h>
15 #include <linux/gfp.h>
16 #include <linux/err.h>
17 #include <linux/export.h>
19 #include <drm/drm_sysfs.h>
21 #include "drm_internal.h"
23 #define to_drm_minor(d) dev_get_drvdata(d)
24 #define to_drm_connector(d) dev_get_drvdata(d)
29 * DRM provides very little additional support to drivers for sysfs
30 * interactions, beyond just all the standard stuff. Drivers who want to expose
31 * additional sysfs properties and property groups can attach them at either
32 * &drm_device.dev or &drm_connector.kdev.
34 * Registration is automatically handled when calling drm_dev_register(), or
35 * drm_connector_register() in case of hot-plugged connectors. Unregistration is
36 * also automatically handled by drm_dev_unregister() and
37 * drm_connector_unregister().
40 static struct device_type drm_sysfs_device_minor = {
44 struct class *drm_class;
46 static char *drm_devnode(struct device *dev, umode_t *mode)
48 return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
51 static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
54 * drm_sysfs_init - initialize sysfs helpers
56 * This is used to create the DRM class, which is the implicit parent of any
57 * other top-level DRM sysfs objects.
59 * You must call drm_sysfs_destroy() to release the allocated resources.
61 * Return: 0 on success, negative error code on failure.
63 int drm_sysfs_init(void)
67 drm_class = class_create(THIS_MODULE, "drm");
68 if (IS_ERR(drm_class))
69 return PTR_ERR(drm_class);
71 err = class_create_file(drm_class, &class_attr_version.attr);
73 class_destroy(drm_class);
78 drm_class->devnode = drm_devnode;
83 * drm_sysfs_destroy - destroys DRM class
85 * Destroy the DRM device class.
87 void drm_sysfs_destroy(void)
89 if (IS_ERR_OR_NULL(drm_class))
91 class_remove_file(drm_class, &class_attr_version.attr);
92 class_destroy(drm_class);
97 * Connector properties
99 static ssize_t status_store(struct device *device,
100 struct device_attribute *attr,
101 const char *buf, size_t count)
103 struct drm_connector *connector = to_drm_connector(device);
104 struct drm_device *dev = connector->dev;
105 enum drm_connector_force old_force;
108 ret = mutex_lock_interruptible(&dev->mode_config.mutex);
112 old_force = connector->force;
114 if (sysfs_streq(buf, "detect"))
115 connector->force = 0;
116 else if (sysfs_streq(buf, "on"))
117 connector->force = DRM_FORCE_ON;
118 else if (sysfs_streq(buf, "on-digital"))
119 connector->force = DRM_FORCE_ON_DIGITAL;
120 else if (sysfs_streq(buf, "off"))
121 connector->force = DRM_FORCE_OFF;
125 if (old_force != connector->force || !connector->force) {
126 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
129 old_force, connector->force);
131 connector->funcs->fill_modes(connector,
132 dev->mode_config.max_width,
133 dev->mode_config.max_height);
136 mutex_unlock(&dev->mode_config.mutex);
138 return ret ? ret : count;
141 static ssize_t status_show(struct device *device,
142 struct device_attribute *attr,
145 struct drm_connector *connector = to_drm_connector(device);
146 enum drm_connector_status status;
148 status = READ_ONCE(connector->status);
150 return snprintf(buf, PAGE_SIZE, "%s\n",
151 drm_get_connector_status_name(status));
154 static ssize_t dpms_show(struct device *device,
155 struct device_attribute *attr,
158 struct drm_connector *connector = to_drm_connector(device);
161 dpms = READ_ONCE(connector->dpms);
163 return snprintf(buf, PAGE_SIZE, "%s\n",
164 drm_get_dpms_name(dpms));
167 static ssize_t enabled_show(struct device *device,
168 struct device_attribute *attr,
171 struct drm_connector *connector = to_drm_connector(device);
174 enabled = READ_ONCE(connector->encoder);
176 return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n");
179 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
180 struct bin_attribute *attr, char *buf, loff_t off,
183 struct device *connector_dev = kobj_to_dev(kobj);
184 struct drm_connector *connector = to_drm_connector(connector_dev);
189 mutex_lock(&connector->dev->mode_config.mutex);
190 if (!connector->edid_blob_ptr)
193 edid = connector->edid_blob_ptr->data;
194 size = connector->edid_blob_ptr->length;
201 if (off + count > size)
203 memcpy(buf, edid + off, count);
207 mutex_unlock(&connector->dev->mode_config.mutex);
212 static ssize_t modes_show(struct device *device,
213 struct device_attribute *attr,
216 struct drm_connector *connector = to_drm_connector(device);
217 struct drm_display_mode *mode;
220 mutex_lock(&connector->dev->mode_config.mutex);
221 list_for_each_entry(mode, &connector->modes, head) {
222 written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
225 mutex_unlock(&connector->dev->mode_config.mutex);
230 static DEVICE_ATTR_RW(status);
231 static DEVICE_ATTR_RO(enabled);
232 static DEVICE_ATTR_RO(dpms);
233 static DEVICE_ATTR_RO(modes);
235 static struct attribute *connector_dev_attrs[] = {
236 &dev_attr_status.attr,
237 &dev_attr_enabled.attr,
239 &dev_attr_modes.attr,
243 static struct bin_attribute edid_attr = {
250 static struct bin_attribute *connector_bin_attrs[] = {
255 static const struct attribute_group connector_dev_group = {
256 .attrs = connector_dev_attrs,
257 .bin_attrs = connector_bin_attrs,
260 static const struct attribute_group *connector_dev_groups[] = {
261 &connector_dev_group,
265 int drm_sysfs_connector_add(struct drm_connector *connector)
267 struct drm_device *dev = connector->dev;
273 device_create_with_groups(drm_class, dev->primary->kdev, 0,
274 connector, connector_dev_groups,
275 "card%d-%s", dev->primary->index,
277 DRM_DEBUG("adding \"%s\" to sysfs\n",
280 if (IS_ERR(connector->kdev)) {
281 DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
282 return PTR_ERR(connector->kdev);
285 /* Let userspace know we have a new connector */
286 drm_sysfs_hotplug_event(dev);
291 void drm_sysfs_connector_remove(struct drm_connector *connector)
293 if (!connector->kdev)
295 DRM_DEBUG("removing \"%s\" from sysfs\n",
298 device_unregister(connector->kdev);
299 connector->kdev = NULL;
302 void drm_sysfs_lease_event(struct drm_device *dev)
304 char *event_string = "LEASE=1";
305 char *envp[] = { event_string, NULL };
307 DRM_DEBUG("generating lease event\n");
309 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
313 * drm_sysfs_hotplug_event - generate a DRM uevent
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.
320 void drm_sysfs_hotplug_event(struct drm_device *dev)
322 char *event_string = "HOTPLUG=1";
323 char *envp[] = { event_string, NULL };
325 DRM_DEBUG("generating hotplug event\n");
327 kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
329 EXPORT_SYMBOL(drm_sysfs_hotplug_event);
331 static void drm_sysfs_release(struct device *dev)
336 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
338 const char *minor_str;
342 if (minor->type == DRM_MINOR_RENDER)
343 minor_str = "renderD%d";
345 minor_str = "card%d";
347 kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
349 return ERR_PTR(-ENOMEM);
351 device_initialize(kdev);
352 kdev->devt = MKDEV(DRM_MAJOR, minor->index);
353 kdev->class = drm_class;
354 kdev->type = &drm_sysfs_device_minor;
355 kdev->parent = minor->dev->dev;
356 kdev->release = drm_sysfs_release;
357 dev_set_drvdata(kdev, minor);
359 r = dev_set_name(kdev, minor_str, minor->index);
371 * drm_class_device_register - register new device with the DRM sysfs class
372 * @dev: device to register
374 * Registers a new &struct device within the DRM sysfs class. Essentially only
375 * used by ttm to have a place for its global settings. Drivers should never use
378 int drm_class_device_register(struct device *dev)
380 if (!drm_class || IS_ERR(drm_class))
383 dev->class = drm_class;
384 return device_register(dev);
386 EXPORT_SYMBOL_GPL(drm_class_device_register);
389 * drm_class_device_unregister - unregister device with the DRM sysfs class
390 * @dev: device to unregister
392 * Unregisters a &struct device from the DRM sysfs class. Essentially only used
393 * by ttm to have a place for its global settings. Drivers should never use
396 void drm_class_device_unregister(struct device *dev)
398 return device_unregister(dev);
400 EXPORT_SYMBOL_GPL(drm_class_device_unregister);