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include/linux/clk.h
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/* |
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* linux/include/linux/clk.h |
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* * Copyright (C) 2004 ARM Limited. * Written by Deep Blue Solutions Limited. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ |
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#ifndef __LINUX_CLK_H #define __LINUX_CLK_H |
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struct device; /* * The base API. */ /* * struct clk - an machine class defined object / cookie. */ struct clk; /** * clk_get - lookup and obtain a reference to a clock producer. * @dev: device for clock "consumer" |
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* @id: clock comsumer ID |
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* * Returns a struct clk corresponding to the clock producer, or |
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* valid IS_ERR() condition containing errno. The implementation * uses @dev and @id to determine the clock consumer, and thereby * the clock producer. (IOW, @id may be identical strings, but * clk_get may return different clock producers depending on @dev.) |
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* * Drivers must assume that the clock source is not enabled. |
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*/ struct clk *clk_get(struct device *dev, const char *id); /** * clk_enable - inform the system when the clock source should be running. * @clk: clock source * * If the clock can not be enabled/disabled, this should return success. * * Returns success (0) or negative errno. */ int clk_enable(struct clk *clk); /** * clk_disable - inform the system when the clock source is no longer required. * @clk: clock source |
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* * Inform the system that a clock source is no longer required by * a driver and may be shut down. * * Implementation detail: if the clock source is shared between * multiple drivers, clk_enable() calls must be balanced by the * same number of clk_disable() calls for the clock source to be * disabled. |
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*/ void clk_disable(struct clk *clk); /** |
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* clk_get_rate - obtain the current clock rate (in Hz) for a clock source. * This is only valid once the clock source has been enabled. * @clk: clock source */ unsigned long clk_get_rate(struct clk *clk); /** * clk_put - "free" the clock source * @clk: clock source |
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* * Note: drivers must ensure that all clk_enable calls made on this * clock source are balanced by clk_disable calls prior to calling * this function. |
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*/ void clk_put(struct clk *clk); /* * The remaining APIs are optional for machine class support. */ /** * clk_round_rate - adjust a rate to the exact rate a clock can provide * @clk: clock source * @rate: desired clock rate in Hz * * Returns rounded clock rate in Hz, or negative errno. */ long clk_round_rate(struct clk *clk, unsigned long rate); /** * clk_set_rate - set the clock rate for a clock source * @clk: clock source * @rate: desired clock rate in Hz * * Returns success (0) or negative errno. */ int clk_set_rate(struct clk *clk, unsigned long rate); /** * clk_set_parent - set the parent clock source for this clock * @clk: clock source * @parent: parent clock source * * Returns success (0) or negative errno. */ int clk_set_parent(struct clk *clk, struct clk *parent); /** * clk_get_parent - get the parent clock source for this clock * @clk: clock source * * Returns struct clk corresponding to parent clock source, or * valid IS_ERR() condition containing errno. */ struct clk *clk_get_parent(struct clk *clk); #endif |