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1da177e4 LT |
1 | /* |
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. | |
5 | * | |
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. | |
9 | * | |
10 | * This file is released under the GPLv2 | |
11 | * | |
12 | */ | |
13 | ||
14 | #include <linux/config.h> | |
15 | #include <linux/device.h> | |
16 | #include <linux/kdev_t.h> | |
17 | #include <linux/err.h> | |
4e57b681 TS |
18 | #include <linux/slab.h> |
19 | #include <linux/string.h> | |
1da177e4 LT |
20 | |
21 | #include "drm_core.h" | |
f210973b | 22 | #include "drmP.h" |
1da177e4 LT |
23 | |
24 | struct drm_sysfs_class { | |
25 | struct class_device_attribute attr; | |
26 | struct class class; | |
27 | }; | |
28 | #define to_drm_sysfs_class(d) container_of(d, struct drm_sysfs_class, class) | |
29 | ||
30 | struct simple_dev { | |
31 | struct list_head node; | |
32 | dev_t dev; | |
33 | struct class_device class_dev; | |
34 | }; | |
35 | #define to_simple_dev(d) container_of(d, struct simple_dev, class_dev) | |
36 | ||
37 | static LIST_HEAD(simple_dev_list); | |
38 | static DEFINE_SPINLOCK(simple_dev_list_lock); | |
39 | ||
40 | static void release_simple_dev(struct class_device *class_dev) | |
41 | { | |
42 | struct simple_dev *s_dev = to_simple_dev(class_dev); | |
43 | kfree(s_dev); | |
44 | } | |
45 | ||
46 | static ssize_t show_dev(struct class_device *class_dev, char *buf) | |
47 | { | |
48 | struct simple_dev *s_dev = to_simple_dev(class_dev); | |
49 | return print_dev_t(buf, s_dev->dev); | |
50 | } | |
51 | ||
52 | static void drm_sysfs_class_release(struct class *class) | |
53 | { | |
54 | struct drm_sysfs_class *cs = to_drm_sysfs_class(class); | |
55 | kfree(cs); | |
56 | } | |
57 | ||
58 | /* Display the version of drm_core. This doesn't work right in current design */ | |
59 | static ssize_t version_show(struct class *dev, char *buf) | |
60 | { | |
61 | return sprintf(buf, "%s %d.%d.%d %s\n", CORE_NAME, CORE_MAJOR, | |
62 | CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE); | |
63 | } | |
64 | ||
65 | static CLASS_ATTR(version, S_IRUGO, version_show, NULL); | |
66 | ||
67 | /** | |
68 | * drm_sysfs_create - create a struct drm_sysfs_class structure | |
69 | * @owner: pointer to the module that is to "own" this struct drm_sysfs_class | |
70 | * @name: pointer to a string for the name of this class. | |
71 | * | |
72 | * This is used to create a struct drm_sysfs_class pointer that can then be used | |
73 | * in calls to drm_sysfs_device_add(). | |
74 | * | |
75 | * Note, the pointer created here is to be destroyed when finished by making a | |
76 | * call to drm_sysfs_destroy(). | |
77 | */ | |
78 | struct drm_sysfs_class *drm_sysfs_create(struct module *owner, char *name) | |
79 | { | |
80 | struct drm_sysfs_class *cs; | |
81 | int retval; | |
82 | ||
83 | cs = kmalloc(sizeof(*cs), GFP_KERNEL); | |
84 | if (!cs) { | |
85 | retval = -ENOMEM; | |
86 | goto error; | |
87 | } | |
88 | memset(cs, 0x00, sizeof(*cs)); | |
89 | ||
90 | cs->class.name = name; | |
91 | cs->class.class_release = drm_sysfs_class_release; | |
92 | cs->class.release = release_simple_dev; | |
93 | ||
94 | cs->attr.attr.name = "dev"; | |
95 | cs->attr.attr.mode = S_IRUGO; | |
96 | cs->attr.attr.owner = owner; | |
97 | cs->attr.show = show_dev; | |
98 | cs->attr.store = NULL; | |
99 | ||
100 | retval = class_register(&cs->class); | |
101 | if (retval) | |
102 | goto error; | |
103 | class_create_file(&cs->class, &class_attr_version); | |
104 | ||
105 | return cs; | |
106 | ||
107 | error: | |
108 | kfree(cs); | |
109 | return ERR_PTR(retval); | |
110 | } | |
111 | ||
112 | /** | |
113 | * drm_sysfs_destroy - destroys a struct drm_sysfs_class structure | |
114 | * @cs: pointer to the struct drm_sysfs_class that is to be destroyed | |
115 | * | |
116 | * Note, the pointer to be destroyed must have been created with a call to | |
117 | * drm_sysfs_create(). | |
118 | */ | |
119 | void drm_sysfs_destroy(struct drm_sysfs_class *cs) | |
120 | { | |
121 | if ((cs == NULL) || (IS_ERR(cs))) | |
122 | return; | |
123 | ||
124 | class_unregister(&cs->class); | |
125 | } | |
126 | ||
127 | /** | |
128 | * drm_sysfs_device_add - adds a class device to sysfs for a character driver | |
129 | * @cs: pointer to the struct drm_sysfs_class that this device should be registered to. | |
130 | * @dev: the dev_t for the device to be added. | |
131 | * @device: a pointer to a struct device that is assiociated with this class device. | |
132 | * @fmt: string for the class device's name | |
133 | * | |
134 | * A struct class_device will be created in sysfs, registered to the specified | |
135 | * class. A "dev" file will be created, showing the dev_t for the device. The | |
136 | * pointer to the struct class_device will be returned from the call. Any further | |
137 | * sysfs files that might be required can be created using this pointer. | |
138 | * Note: the struct drm_sysfs_class passed to this function must have previously been | |
139 | * created with a call to drm_sysfs_create(). | |
140 | */ | |
141 | struct class_device *drm_sysfs_device_add(struct drm_sysfs_class *cs, dev_t dev, | |
142 | struct device *device, | |
143 | const char *fmt, ...) | |
144 | { | |
145 | va_list args; | |
146 | struct simple_dev *s_dev = NULL; | |
147 | int retval; | |
148 | ||
149 | if ((cs == NULL) || (IS_ERR(cs))) { | |
150 | retval = -ENODEV; | |
151 | goto error; | |
152 | } | |
153 | ||
154 | s_dev = kmalloc(sizeof(*s_dev), GFP_KERNEL); | |
155 | if (!s_dev) { | |
156 | retval = -ENOMEM; | |
157 | goto error; | |
158 | } | |
159 | memset(s_dev, 0x00, sizeof(*s_dev)); | |
160 | ||
161 | s_dev->dev = dev; | |
162 | s_dev->class_dev.dev = device; | |
163 | s_dev->class_dev.class = &cs->class; | |
164 | ||
165 | va_start(args, fmt); | |
166 | vsnprintf(s_dev->class_dev.class_id, BUS_ID_SIZE, fmt, args); | |
167 | va_end(args); | |
168 | retval = class_device_register(&s_dev->class_dev); | |
169 | if (retval) | |
170 | goto error; | |
171 | ||
172 | class_device_create_file(&s_dev->class_dev, &cs->attr); | |
173 | ||
174 | spin_lock(&simple_dev_list_lock); | |
175 | list_add(&s_dev->node, &simple_dev_list); | |
176 | spin_unlock(&simple_dev_list_lock); | |
177 | ||
178 | return &s_dev->class_dev; | |
179 | ||
180 | error: | |
181 | kfree(s_dev); | |
182 | return ERR_PTR(retval); | |
183 | } | |
184 | ||
185 | /** | |
186 | * drm_sysfs_device_remove - removes a class device that was created with drm_sysfs_device_add() | |
187 | * @dev: the dev_t of the device that was previously registered. | |
188 | * | |
189 | * This call unregisters and cleans up a class device that was created with a | |
190 | * call to drm_sysfs_device_add() | |
191 | */ | |
192 | void drm_sysfs_device_remove(dev_t dev) | |
193 | { | |
194 | struct simple_dev *s_dev = NULL; | |
195 | int found = 0; | |
196 | ||
197 | spin_lock(&simple_dev_list_lock); | |
198 | list_for_each_entry(s_dev, &simple_dev_list, node) { | |
199 | if (s_dev->dev == dev) { | |
200 | found = 1; | |
201 | break; | |
202 | } | |
203 | } | |
204 | if (found) { | |
205 | list_del(&s_dev->node); | |
206 | spin_unlock(&simple_dev_list_lock); | |
207 | class_device_unregister(&s_dev->class_dev); | |
208 | } else { | |
209 | spin_unlock(&simple_dev_list_lock); | |
210 | } | |
211 | } |