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1/*
2 * linux/include/asm-arm/hardware/clock.h
3 *
4 * Copyright (C) 2004 ARM Limited.
5 * Written by Deep Blue Solutions Limited.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11#ifndef ASMARM_CLOCK_H
12#define ASMARM_CLOCK_H
13
14struct device;
15
16/*
17 * The base API.
18 */
19
20
21/*
22 * struct clk - an machine class defined object / cookie.
23 */
24struct clk;
25
26/**
27 * clk_get - lookup and obtain a reference to a clock producer.
28 * @dev: device for clock "consumer"
29 * @id: device ID
30 *
31 * Returns a struct clk corresponding to the clock producer, or
32 * valid IS_ERR() condition containing errno.
33 */
34struct clk *clk_get(struct device *dev, const char *id);
35
36/**
37 * clk_enable - inform the system when the clock source should be running.
38 * @clk: clock source
39 *
40 * If the clock can not be enabled/disabled, this should return success.
41 *
42 * Returns success (0) or negative errno.
43 */
44int clk_enable(struct clk *clk);
45
46/**
47 * clk_disable - inform the system when the clock source is no longer required.
48 * @clk: clock source
49 */
50void clk_disable(struct clk *clk);
51
52/**
53 * clk_use - increment the use count
54 * @clk: clock source
55 *
56 * Returns success (0) or negative errno.
57 */
58int clk_use(struct clk *clk);
59
60/**
61 * clk_unuse - decrement the use count
62 * @clk: clock source
63 */
64void clk_unuse(struct clk *clk);
65
66/**
67 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
68 * This is only valid once the clock source has been enabled.
69 * @clk: clock source
70 */
71unsigned long clk_get_rate(struct clk *clk);
72
73/**
74 * clk_put - "free" the clock source
75 * @clk: clock source
76 */
77void clk_put(struct clk *clk);
78
79
80/*
81 * The remaining APIs are optional for machine class support.
82 */
83
84
85/**
86 * clk_round_rate - adjust a rate to the exact rate a clock can provide
87 * @clk: clock source
88 * @rate: desired clock rate in Hz
89 *
90 * Returns rounded clock rate in Hz, or negative errno.
91 */
92long clk_round_rate(struct clk *clk, unsigned long rate);
93
94/**
95 * clk_set_rate - set the clock rate for a clock source
96 * @clk: clock source
97 * @rate: desired clock rate in Hz
98 *
99 * Returns success (0) or negative errno.
100 */
101int clk_set_rate(struct clk *clk, unsigned long rate);
102
103/**
104 * clk_set_parent - set the parent clock source for this clock
105 * @clk: clock source
106 * @parent: parent clock source
107 *
108 * Returns success (0) or negative errno.
109 */
110int clk_set_parent(struct clk *clk, struct clk *parent);
111
112/**
113 * clk_get_parent - get the parent clock source for this clock
114 * @clk: clock source
115 *
116 * Returns struct clk corresponding to parent clock source, or
117 * valid IS_ERR() condition containing errno.
118 */
119struct clk *clk_get_parent(struct clk *clk);
120
121#endif