4 * Copyright (C) 2008 Russell King.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * Helper for the clk API to assist looking up a struct clk.
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/device.h>
16 #include <linux/list.h>
17 #include <linux/errno.h>
18 #include <linux/err.h>
19 #include <linux/string.h>
20 #include <linux/mutex.h>
21 #include <linux/clk.h>
22 #include <linux/clkdev.h>
24 #include <ubi_uboot.h>
25 #include <asm/arch/clock.h>
27 static LIST_HEAD(clocks);
28 static DEFINE_MUTEX(clocks_mutex);
31 * Find the correct struct clk for the device and connection ID.
32 * We do slightly fuzzy matching here:
33 * An entry with a NULL ID is assumed to be a wildcard.
34 * If an entry has a device ID, it must match
35 * If an entry has a connection ID, it must match
36 * Then we take the most specific entry - with the following
37 * order of precedence: dev+con > dev only > con only.
39 static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
41 struct clk_lookup *p, *cl = NULL;
44 list_for_each_entry(p, &clocks, node) {
47 if (!dev_id || strcmp(p->dev_id, dev_id))
52 if (!con_id || strcmp(p->con_id, con_id))
68 struct clk *clk_get_sys(const char *dev_id, const char *con_id)
70 struct clk_lookup *cl;
72 mutex_lock(&clocks_mutex);
73 cl = clk_find(dev_id, con_id);
74 //if (cl && !__clk_get(cl->clk))
76 mutex_unlock(&clocks_mutex);
78 return cl ? cl->clk : ERR_PTR(-ENOENT);
80 EXPORT_SYMBOL(clk_get_sys);
82 struct clk *clk_get(struct device *dev, const char *con_id)
84 //const char *dev_id = dev ? dev_name(dev) : NULL;
86 return clk_get_sys(NULL, con_id);
88 EXPORT_SYMBOL(clk_get);
90 void clk_put(struct clk *clk)
94 EXPORT_SYMBOL(clk_put);
96 void clkdev_add(struct clk_lookup *cl)
98 mutex_lock(&clocks_mutex);
99 list_add_tail(&cl->node, &clocks);
100 mutex_unlock(&clocks_mutex);
102 EXPORT_SYMBOL(clkdev_add);