2 * drm_sysfs.c - Modifications to drm_sysfs_class.c to support
3 * extra sysfs attribute from DRM. Normal drm_sysfs_class
4 * does not allow adding attributes.
6 * Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
7 * Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
8 * Copyright (c) 2003-2004 IBM Corp.
10 * This file is released under the GPLv2
14 #include <linux/config.h>
15 #include <linux/device.h>
16 #include <linux/kdev_t.h>
17 #include <linux/err.h>
21 struct drm_sysfs_class {
22 struct class_device_attribute attr;
25 #define to_drm_sysfs_class(d) container_of(d, struct drm_sysfs_class, class)
28 struct list_head node;
30 struct class_device class_dev;
32 #define to_simple_dev(d) container_of(d, struct simple_dev, class_dev)
34 static LIST_HEAD(simple_dev_list);
35 static spinlock_t simple_dev_list_lock = SPIN_LOCK_UNLOCKED;
37 static void release_simple_dev(struct class_device *class_dev)
39 struct simple_dev *s_dev = to_simple_dev(class_dev);
43 static ssize_t show_dev(struct class_device *class_dev, char *buf)
45 struct simple_dev *s_dev = to_simple_dev(class_dev);
46 return print_dev_t(buf, s_dev->dev);
49 static void drm_sysfs_class_release(struct class *class)
51 struct drm_sysfs_class *cs = to_drm_sysfs_class(class);
55 /* Display the version of drm_core. This doesn't work right in current design */
56 static ssize_t version_show(struct class *dev, char *buf)
58 return sprintf(buf, "%s %d.%d.%d %s\n", DRIVER_NAME, DRIVER_MAJOR,
59 DRIVER_MINOR, DRIVER_PATCHLEVEL, DRIVER_DATE);
61 static CLASS_ATTR(version, S_IRUGO, version_show, NULL);
64 * drm_sysfs_create - create a struct drm_sysfs_class structure
65 * @owner: pointer to the module that is to "own" this struct drm_sysfs_class
66 * @name: pointer to a string for the name of this class.
68 * This is used to create a struct drm_sysfs_class pointer that can then be used
69 * in calls to drm_sysfs_device_add().
71 * Note, the pointer created here is to be destroyed when finished by making a
72 * call to drm_sysfs_destroy().
74 struct drm_sysfs_class *drm_sysfs_create(struct module *owner, char *name)
76 struct drm_sysfs_class *cs;
79 cs = kmalloc(sizeof(*cs), GFP_KERNEL);
84 memset(cs, 0x00, sizeof(*cs));
86 cs->class.name = name;
87 cs->class.class_release = drm_sysfs_class_release;
88 cs->class.release = release_simple_dev;
90 cs->attr.attr.name = "dev";
91 cs->attr.attr.mode = S_IRUGO;
92 cs->attr.attr.owner = owner;
93 cs->attr.show = show_dev;
94 cs->attr.store = NULL;
96 retval = class_register(&cs->class);
99 class_create_file(&cs->class, &class_attr_version);
105 return ERR_PTR(retval);
109 * drm_sysfs_destroy - destroys a struct drm_sysfs_class structure
110 * @cs: pointer to the struct drm_sysfs_class that is to be destroyed
112 * Note, the pointer to be destroyed must have been created with a call to
113 * drm_sysfs_create().
115 void drm_sysfs_destroy(struct drm_sysfs_class *cs)
117 if ((cs == NULL) || (IS_ERR(cs)))
120 class_unregister(&cs->class);
124 * drm_sysfs_device_add - adds a class device to sysfs for a character driver
125 * @cs: pointer to the struct drm_sysfs_class that this device should be registered to.
126 * @dev: the dev_t for the device to be added.
127 * @device: a pointer to a struct device that is assiociated with this class device.
128 * @fmt: string for the class device's name
130 * A struct class_device will be created in sysfs, registered to the specified
131 * class. A "dev" file will be created, showing the dev_t for the device. The
132 * pointer to the struct class_device will be returned from the call. Any further
133 * sysfs files that might be required can be created using this pointer.
134 * Note: the struct drm_sysfs_class passed to this function must have previously been
135 * created with a call to drm_sysfs_create().
137 struct class_device *drm_sysfs_device_add(struct drm_sysfs_class *cs, dev_t dev, struct device *device, const char *fmt, ...)
140 struct simple_dev *s_dev = NULL;
143 if ((cs == NULL) || (IS_ERR(cs))) {
148 s_dev = kmalloc(sizeof(*s_dev), GFP_KERNEL);
153 memset(s_dev, 0x00, sizeof(*s_dev));
156 s_dev->class_dev.dev = device;
157 s_dev->class_dev.class = &cs->class;
160 vsnprintf(s_dev->class_dev.class_id, BUS_ID_SIZE, fmt, args);
162 retval = class_device_register(&s_dev->class_dev);
166 class_device_create_file(&s_dev->class_dev, &cs->attr);
168 spin_lock(&simple_dev_list_lock);
169 list_add(&s_dev->node, &simple_dev_list);
170 spin_unlock(&simple_dev_list_lock);
172 return &s_dev->class_dev;
176 return ERR_PTR(retval);
180 * drm_sysfs_device_remove - removes a class device that was created with drm_sysfs_device_add()
181 * @dev: the dev_t of the device that was previously registered.
183 * This call unregisters and cleans up a class device that was created with a
184 * call to drm_sysfs_device_add()
186 void drm_sysfs_device_remove(dev_t dev)
188 struct simple_dev *s_dev = NULL;
191 spin_lock(&simple_dev_list_lock);
192 list_for_each_entry(s_dev, &simple_dev_list, node) {
193 if (s_dev->dev == dev) {
199 list_del(&s_dev->node);
200 spin_unlock(&simple_dev_list_lock);
201 class_device_unregister(&s_dev->class_dev);
203 spin_unlock(&simple_dev_list_lock);