diff options
Diffstat (limited to 'arch/arm/mach-ns9xxx/clock.c')
-rw-r--r-- | arch/arm/mach-ns9xxx/clock.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/arch/arm/mach-ns9xxx/clock.c b/arch/arm/mach-ns9xxx/clock.c new file mode 100644 index 000000000000..f8639161068f --- /dev/null +++ b/arch/arm/mach-ns9xxx/clock.c | |||
@@ -0,0 +1,215 @@ | |||
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> | ||
17 | |||
18 | #include <asm/semaphore.h> | ||
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 */ | ||