]>
git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - include/linux/clk.h
2 * linux/include/linux/clk.h
4 * Copyright (C) 2004 ARM Limited.
5 * Written by Deep Blue Solutions Limited.
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.
22 * struct clk - an machine class defined object / cookie.
27 * clk_get - lookup and obtain a reference to a clock producer.
28 * @dev: device for clock "consumer"
29 * @id: clock comsumer ID
31 * Returns a struct clk corresponding to the clock producer, or
32 * valid IS_ERR() condition containing errno. The implementation
33 * uses @dev and @id to determine the clock consumer, and thereby
34 * the clock producer. (IOW, @id may be identical strings, but
35 * clk_get may return different clock producers depending on @dev.)
37 * Drivers must assume that the clock source is not enabled.
39 struct clk
*clk_get(struct device
*dev
, const char *id
);
42 * clk_enable - inform the system when the clock source should be running.
45 * If the clock can not be enabled/disabled, this should return success.
47 * Returns success (0) or negative errno.
49 int clk_enable(struct clk
*clk
);
52 * clk_disable - inform the system when the clock source is no longer required.
55 * Inform the system that a clock source is no longer required by
56 * a driver and may be shut down.
58 * Implementation detail: if the clock source is shared between
59 * multiple drivers, clk_enable() calls must be balanced by the
60 * same number of clk_disable() calls for the clock source to be
63 void clk_disable(struct clk
*clk
);
66 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
67 * This is only valid once the clock source has been enabled.
70 unsigned long clk_get_rate(struct clk
*clk
);
73 * clk_put - "free" the clock source
76 * Note: drivers must ensure that all clk_enable calls made on this
77 * clock source are balanced by clk_disable calls prior to calling
80 void clk_put(struct clk
*clk
);
84 * The remaining APIs are optional for machine class support.
89 * clk_round_rate - adjust a rate to the exact rate a clock can provide
91 * @rate: desired clock rate in Hz
93 * Returns rounded clock rate in Hz, or negative errno.
95 long clk_round_rate(struct clk
*clk
, unsigned long rate
);
98 * clk_set_rate - set the clock rate for a clock source
100 * @rate: desired clock rate in Hz
102 * Returns success (0) or negative errno.
104 int clk_set_rate(struct clk
*clk
, unsigned long rate
);
107 * clk_set_parent - set the parent clock source for this clock
109 * @parent: parent clock source
111 * Returns success (0) or negative errno.
113 int clk_set_parent(struct clk
*clk
, struct clk
*parent
);
116 * clk_get_parent - get the parent clock source for this clock
119 * Returns struct clk corresponding to parent clock source, or
120 * valid IS_ERR() condition containing errno.
122 struct clk
*clk_get_parent(struct clk
*clk
);