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04c366f0 UKK |
1 | /* |
2 | * arch/arm/mach-ns9xxx/clock.c | |
3 | * | |
4 | * Copyright (C) 2007 by Digi International Inc. | |
5 | * All rights reserved. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License version 2 as published by | |
9 | * the Free Software Foundation. | |
10 | */ | |
11 | #include <linux/err.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/list.h> | |
14 | #include <linux/clk.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/platform_device.h> | |
6310e472 | 17 | #include <linux/semaphore.h> |
04c366f0 | 18 | |
04c366f0 UKK |
19 | #include "clock.h" |
20 | ||
21 | static LIST_HEAD(clocks); | |
22 | static DEFINE_SPINLOCK(clk_lock); | |
23 | ||
24 | struct clk *clk_get(struct device *dev, const char *id) | |
25 | { | |
26 | struct clk *p, *ret = NULL, *retgen = NULL; | |
27 | unsigned long flags; | |
28 | int idno; | |
29 | ||
30 | if (dev == NULL || dev->bus != &platform_bus_type) | |
31 | idno = -1; | |
32 | else | |
33 | idno = to_platform_device(dev)->id; | |
34 | ||
35 | spin_lock_irqsave(&clk_lock, flags); | |
36 | list_for_each_entry(p, &clocks, node) { | |
37 | if (strcmp(id, p->name) == 0) { | |
38 | if (p->id == idno) { | |
39 | if (!try_module_get(p->owner)) | |
40 | continue; | |
41 | ret = p; | |
42 | break; | |
43 | } else if (p->id == -1) | |
44 | /* remember match with id == -1 in case there is | |
45 | * no clock for idno */ | |
46 | retgen = p; | |
47 | } | |
48 | } | |
49 | ||
50 | if (!ret && retgen && try_module_get(retgen->owner)) | |
51 | ret = retgen; | |
52 | ||
53 | if (ret) | |
54 | ++ret->refcount; | |
55 | ||
56 | spin_unlock_irqrestore(&clk_lock, flags); | |
57 | ||
58 | return ret ? ret : ERR_PTR(-ENOENT); | |
59 | } | |
60 | EXPORT_SYMBOL(clk_get); | |
61 | ||
62 | void clk_put(struct clk *clk) | |
63 | { | |
64 | module_put(clk->owner); | |
65 | --clk->refcount; | |
66 | } | |
67 | EXPORT_SYMBOL(clk_put); | |
68 | ||
69 | static int clk_enable_unlocked(struct clk *clk) | |
70 | { | |
71 | int ret = 0; | |
72 | if (clk->parent) { | |
73 | ret = clk_enable_unlocked(clk->parent); | |
74 | if (ret) | |
75 | return ret; | |
76 | } | |
77 | ||
78 | if (clk->usage++ == 0 && clk->endisable) | |
79 | ret = clk->endisable(clk, 1); | |
80 | ||
81 | return ret; | |
82 | } | |
83 | ||
84 | int clk_enable(struct clk *clk) | |
85 | { | |
86 | int ret; | |
87 | unsigned long flags; | |
88 | ||
89 | spin_lock_irqsave(&clk_lock, flags); | |
90 | ||
91 | ret = clk_enable_unlocked(clk); | |
92 | ||
93 | spin_unlock_irqrestore(&clk_lock, flags); | |
94 | ||
95 | return ret; | |
96 | } | |
97 | EXPORT_SYMBOL(clk_enable); | |
98 | ||
99 | static void clk_disable_unlocked(struct clk *clk) | |
100 | { | |
101 | if (--clk->usage == 0 && clk->endisable) | |
102 | clk->endisable(clk, 0); | |
103 | ||
104 | if (clk->parent) | |
105 | clk_disable_unlocked(clk->parent); | |
106 | } | |
107 | ||
108 | void clk_disable(struct clk *clk) | |
109 | { | |
110 | unsigned long flags; | |
111 | ||
112 | spin_lock_irqsave(&clk_lock, flags); | |
113 | ||
114 | clk_disable_unlocked(clk); | |
115 | ||
116 | spin_unlock_irqrestore(&clk_lock, flags); | |
117 | } | |
118 | EXPORT_SYMBOL(clk_disable); | |
119 | ||
120 | unsigned long clk_get_rate(struct clk *clk) | |
121 | { | |
122 | if (clk->get_rate) | |
123 | return clk->get_rate(clk); | |
124 | ||
125 | if (clk->rate) | |
126 | return clk->rate; | |
127 | ||
128 | if (clk->parent) | |
129 | return clk_get_rate(clk->parent); | |
130 | ||
131 | return 0; | |
132 | } | |
133 | EXPORT_SYMBOL(clk_get_rate); | |
134 | ||
135 | int clk_register(struct clk *clk) | |
136 | { | |
137 | unsigned long flags; | |
138 | ||
139 | spin_lock_irqsave(&clk_lock, flags); | |
140 | ||
141 | list_add(&clk->node, &clocks); | |
142 | ||
143 | if (clk->parent) | |
144 | ++clk->parent->refcount; | |
145 | ||
146 | spin_unlock_irqrestore(&clk_lock, flags); | |
147 | ||
148 | return 0; | |
149 | } | |
150 | ||
151 | int clk_unregister(struct clk *clk) | |
152 | { | |
153 | int ret = 0; | |
154 | unsigned long flags; | |
155 | ||
156 | spin_lock_irqsave(&clk_lock, flags); | |
157 | ||
158 | if (clk->usage || clk->refcount) | |
159 | ret = -EBUSY; | |
160 | else | |
161 | list_del(&clk->node); | |
162 | ||
163 | if (clk->parent) | |
164 | --clk->parent->refcount; | |
165 | ||
166 | spin_unlock_irqrestore(&clk_lock, flags); | |
167 | ||
168 | return ret; | |
169 | } | |
170 | ||
171 | #if defined CONFIG_DEBUG_FS | |
172 | ||
173 | #include <linux/debugfs.h> | |
174 | #include <linux/seq_file.h> | |
175 | ||
176 | static int clk_debugfs_show(struct seq_file *s, void *null) | |
177 | { | |
178 | unsigned long flags; | |
179 | struct clk *p; | |
180 | ||
181 | spin_lock_irqsave(&clk_lock, flags); | |
182 | ||
183 | list_for_each_entry(p, &clocks, node) | |
184 | seq_printf(s, "%s.%d: usage=%lu refcount=%lu rate=%lu\n", | |
185 | p->name, p->id, p->usage, p->refcount, | |
186 | p->usage ? clk_get_rate(p) : 0); | |
187 | ||
188 | spin_unlock_irqrestore(&clk_lock, flags); | |
189 | ||
190 | return 0; | |
191 | } | |
192 | ||
193 | static int clk_debugfs_open(struct inode *inode, struct file *file) | |
194 | { | |
195 | return single_open(file, clk_debugfs_show, NULL); | |
196 | } | |
197 | ||
198 | static struct file_operations clk_debugfs_operations = { | |
199 | .open = clk_debugfs_open, | |
200 | .read = seq_read, | |
201 | .llseek = seq_lseek, | |
202 | .release = single_release, | |
203 | }; | |
204 | ||
205 | static int __init clk_debugfs_init(void) | |
206 | { | |
207 | struct dentry *dentry; | |
208 | ||
209 | dentry = debugfs_create_file("clk", S_IFREG | S_IRUGO, NULL, NULL, | |
210 | &clk_debugfs_operations); | |
211 | return IS_ERR(dentry) ? PTR_ERR(dentry) : 0; | |
212 | } | |
213 | subsys_initcall(clk_debugfs_init); | |
214 | ||
215 | #endif /* if defined CONFIG_DEBUG_FS */ |