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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> | |
18 | ||
19 | #include "drm_core.h" | |
20 | ||
21 | struct drm_sysfs_class { | |
22 | struct class_device_attribute attr; | |
23 | struct class class; | |
24 | }; | |
25 | #define to_drm_sysfs_class(d) container_of(d, struct drm_sysfs_class, class) | |
26 | ||
27 | struct simple_dev { | |
28 | struct list_head node; | |
29 | dev_t dev; | |
30 | struct class_device class_dev; | |
31 | }; | |
32 | #define to_simple_dev(d) container_of(d, struct simple_dev, class_dev) | |
33 | ||
34 | static LIST_HEAD(simple_dev_list); | |
35 | static DEFINE_SPINLOCK(simple_dev_list_lock); | |
36 | ||
37 | static void release_simple_dev(struct class_device *class_dev) | |
38 | { | |
39 | struct simple_dev *s_dev = to_simple_dev(class_dev); | |
40 | kfree(s_dev); | |
41 | } | |
42 | ||
43 | static ssize_t show_dev(struct class_device *class_dev, char *buf) | |
44 | { | |
45 | struct simple_dev *s_dev = to_simple_dev(class_dev); | |
46 | return print_dev_t(buf, s_dev->dev); | |
47 | } | |
48 | ||
49 | static void drm_sysfs_class_release(struct class *class) | |
50 | { | |
51 | struct drm_sysfs_class *cs = to_drm_sysfs_class(class); | |
52 | kfree(cs); | |
53 | } | |
54 | ||
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) | |
57 | { | |
58 | return sprintf(buf, "%s %d.%d.%d %s\n", CORE_NAME, CORE_MAJOR, | |
59 | CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE); | |
60 | } | |
61 | ||
62 | static CLASS_ATTR(version, S_IRUGO, version_show, NULL); | |
63 | ||
64 | /** | |
65 | * drm_sysfs_create - create a struct drm_sysfs_class structure | |
66 | * @owner: pointer to the module that is to "own" this struct drm_sysfs_class | |
67 | * @name: pointer to a string for the name of this class. | |
68 | * | |
69 | * This is used to create a struct drm_sysfs_class pointer that can then be used | |
70 | * in calls to drm_sysfs_device_add(). | |
71 | * | |
72 | * Note, the pointer created here is to be destroyed when finished by making a | |
73 | * call to drm_sysfs_destroy(). | |
74 | */ | |
75 | struct drm_sysfs_class *drm_sysfs_create(struct module *owner, char *name) | |
76 | { | |
77 | struct drm_sysfs_class *cs; | |
78 | int retval; | |
79 | ||
80 | cs = kmalloc(sizeof(*cs), GFP_KERNEL); | |
81 | if (!cs) { | |
82 | retval = -ENOMEM; | |
83 | goto error; | |
84 | } | |
85 | memset(cs, 0x00, sizeof(*cs)); | |
86 | ||
87 | cs->class.name = name; | |
88 | cs->class.class_release = drm_sysfs_class_release; | |
89 | cs->class.release = release_simple_dev; | |
90 | ||
91 | cs->attr.attr.name = "dev"; | |
92 | cs->attr.attr.mode = S_IRUGO; | |
93 | cs->attr.attr.owner = owner; | |
94 | cs->attr.show = show_dev; | |
95 | cs->attr.store = NULL; | |
96 | ||
97 | retval = class_register(&cs->class); | |
98 | if (retval) | |
99 | goto error; | |
100 | class_create_file(&cs->class, &class_attr_version); | |
101 | ||
102 | return cs; | |
103 | ||
104 | error: | |
105 | kfree(cs); | |
106 | return ERR_PTR(retval); | |
107 | } | |
108 | ||
109 | /** | |
110 | * drm_sysfs_destroy - destroys a struct drm_sysfs_class structure | |
111 | * @cs: pointer to the struct drm_sysfs_class that is to be destroyed | |
112 | * | |
113 | * Note, the pointer to be destroyed must have been created with a call to | |
114 | * drm_sysfs_create(). | |
115 | */ | |
116 | void drm_sysfs_destroy(struct drm_sysfs_class *cs) | |
117 | { | |
118 | if ((cs == NULL) || (IS_ERR(cs))) | |
119 | return; | |
120 | ||
121 | class_unregister(&cs->class); | |
122 | } | |
123 | ||
124 | /** | |
125 | * drm_sysfs_device_add - adds a class device to sysfs for a character driver | |
126 | * @cs: pointer to the struct drm_sysfs_class that this device should be registered to. | |
127 | * @dev: the dev_t for the device to be added. | |
128 | * @device: a pointer to a struct device that is assiociated with this class device. | |
129 | * @fmt: string for the class device's name | |
130 | * | |
131 | * A struct class_device will be created in sysfs, registered to the specified | |
132 | * class. A "dev" file will be created, showing the dev_t for the device. The | |
133 | * pointer to the struct class_device will be returned from the call. Any further | |
134 | * sysfs files that might be required can be created using this pointer. | |
135 | * Note: the struct drm_sysfs_class passed to this function must have previously been | |
136 | * created with a call to drm_sysfs_create(). | |
137 | */ | |
138 | struct class_device *drm_sysfs_device_add(struct drm_sysfs_class *cs, dev_t dev, | |
139 | struct device *device, | |
140 | const char *fmt, ...) | |
141 | { | |
142 | va_list args; | |
143 | struct simple_dev *s_dev = NULL; | |
144 | int retval; | |
145 | ||
146 | if ((cs == NULL) || (IS_ERR(cs))) { | |
147 | retval = -ENODEV; | |
148 | goto error; | |
149 | } | |
150 | ||
151 | s_dev = kmalloc(sizeof(*s_dev), GFP_KERNEL); | |
152 | if (!s_dev) { | |
153 | retval = -ENOMEM; | |
154 | goto error; | |
155 | } | |
156 | memset(s_dev, 0x00, sizeof(*s_dev)); | |
157 | ||
158 | s_dev->dev = dev; | |
159 | s_dev->class_dev.dev = device; | |
160 | s_dev->class_dev.class = &cs->class; | |
161 | ||
162 | va_start(args, fmt); | |
163 | vsnprintf(s_dev->class_dev.class_id, BUS_ID_SIZE, fmt, args); | |
164 | va_end(args); | |
165 | retval = class_device_register(&s_dev->class_dev); | |
166 | if (retval) | |
167 | goto error; | |
168 | ||
169 | class_device_create_file(&s_dev->class_dev, &cs->attr); | |
170 | ||
171 | spin_lock(&simple_dev_list_lock); | |
172 | list_add(&s_dev->node, &simple_dev_list); | |
173 | spin_unlock(&simple_dev_list_lock); | |
174 | ||
175 | return &s_dev->class_dev; | |
176 | ||
177 | error: | |
178 | kfree(s_dev); | |
179 | return ERR_PTR(retval); | |
180 | } | |
181 | ||
182 | /** | |
183 | * drm_sysfs_device_remove - removes a class device that was created with drm_sysfs_device_add() | |
184 | * @dev: the dev_t of the device that was previously registered. | |
185 | * | |
186 | * This call unregisters and cleans up a class device that was created with a | |
187 | * call to drm_sysfs_device_add() | |
188 | */ | |
189 | void drm_sysfs_device_remove(dev_t dev) | |
190 | { | |
191 | struct simple_dev *s_dev = NULL; | |
192 | int found = 0; | |
193 | ||
194 | spin_lock(&simple_dev_list_lock); | |
195 | list_for_each_entry(s_dev, &simple_dev_list, node) { | |
196 | if (s_dev->dev == dev) { | |
197 | found = 1; | |
198 | break; | |
199 | } | |
200 | } | |
201 | if (found) { | |
202 | list_del(&s_dev->node); | |
203 | spin_unlock(&simple_dev_list_lock); | |
204 | class_device_unregister(&s_dev->class_dev); | |
205 | } else { | |
206 | spin_unlock(&simple_dev_list_lock); | |
207 | } | |
208 | } |