From 871480933a1c28f8a9fed4c4d34d06c439a7a422 Mon Sep 17 00:00:00 2001 From: Srikant Patnaik Date: Sun, 11 Jan 2015 12:28:04 +0530 Subject: Moved, renamed, and deleted files The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure. --- include/linux/clk.h | 281 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 281 insertions(+) create mode 100644 include/linux/clk.h (limited to 'include/linux/clk.h') diff --git a/include/linux/clk.h b/include/linux/clk.h new file mode 100644 index 00000000..b0252726 --- /dev/null +++ b/include/linux/clk.h @@ -0,0 +1,281 @@ +/* + * linux/include/linux/clk.h + * + * Copyright (C) 2004 ARM Limited. + * Written by Deep Blue Solutions Limited. + * Copyright (C) 2011-2012 Linaro Ltd + * + * 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. + */ +#ifndef __LINUX_CLK_H +#define __LINUX_CLK_H + +#include +#include + +struct device; + +struct clk; + +#ifdef CONFIG_COMMON_CLK + +/** + * DOC: clk notifier callback types + * + * PRE_RATE_CHANGE - called immediately before the clk rate is changed, + * to indicate that the rate change will proceed. Drivers must + * immediately terminate any operations that will be affected by the + * rate change. Callbacks may either return NOTIFY_DONE or + * NOTIFY_STOP. + * + * ABORT_RATE_CHANGE: called if the rate change failed for some reason + * after PRE_RATE_CHANGE. In this case, all registered notifiers on + * the clk will be called with ABORT_RATE_CHANGE. Callbacks must + * always return NOTIFY_DONE. + * + * POST_RATE_CHANGE - called after the clk rate change has successfully + * completed. Callbacks must always return NOTIFY_DONE. + * + */ +#define PRE_RATE_CHANGE BIT(0) +#define POST_RATE_CHANGE BIT(1) +#define ABORT_RATE_CHANGE BIT(2) + +/** + * struct clk_notifier - associate a clk with a notifier + * @clk: struct clk * to associate the notifier with + * @notifier_head: a blocking_notifier_head for this clk + * @node: linked list pointers + * + * A list of struct clk_notifier is maintained by the notifier code. + * An entry is created whenever code registers the first notifier on a + * particular @clk. Future notifiers on that @clk are added to the + * @notifier_head. + */ +struct clk_notifier { + struct clk *clk; + struct srcu_notifier_head notifier_head; + struct list_head node; +}; + +/** + * struct clk_notifier_data - rate data to pass to the notifier callback + * @clk: struct clk * being changed + * @old_rate: previous rate of this clk + * @new_rate: new rate of this clk + * + * For a pre-notifier, old_rate is the clk's rate before this rate + * change, and new_rate is what the rate will be in the future. For a + * post-notifier, old_rate and new_rate are both set to the clk's + * current rate (this was done to optimize the implementation). + */ +struct clk_notifier_data { + struct clk *clk; + unsigned long old_rate; + unsigned long new_rate; +}; + +int clk_notifier_register(struct clk *clk, struct notifier_block *nb); + +int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb); + +#endif /* !CONFIG_COMMON_CLK */ + +/** + * clk_get - lookup and obtain a reference to a clock producer. + * @dev: device for clock "consumer" + * @id: clock comsumer ID + * + * Returns a struct clk corresponding to the clock producer, or + * 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.) + * + * Drivers must assume that the clock source is not enabled. + * + * clk_get should not be called from within interrupt context. + */ +struct clk *clk_get(struct device *dev, const char *id); + +/** + * clk_prepare - prepare a clock source + * @clk: clock source + * + * This prepares the clock source for use. + * + * Must not be called from within atomic context. + */ +#ifdef CONFIG_HAVE_CLK_PREPARE +int clk_prepare(struct clk *clk); +#else +static inline int clk_prepare(struct clk *clk) +{ + might_sleep(); + return 0; +} +#endif + +/** + * 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. + * + * May be called from atomic contexts. + * + * 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 + * + * Inform the system that a clock source is no longer required by + * a driver and may be shut down. + * + * May be called from atomic contexts. + * + * 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. + */ +void clk_disable(struct clk *clk); + + +/** + * clk_unprepare - undo preparation of a clock source + * @clk: clock source + * + * This undoes a previously prepared clock. The caller must balance + * the number of prepare and unprepare calls. + * + * Must not be called from within atomic context. + */ +#ifdef CONFIG_HAVE_CLK_PREPARE +void clk_unprepare(struct clk *clk); +#else +static inline void clk_unprepare(struct clk *clk) +{ + might_sleep(); +} +#endif + +/* clk_prepare_enable helps cases using clk_enable in non-atomic context. */ +static inline int clk_prepare_enable(struct clk *clk) +{ + int ret; + + ret = clk_prepare(clk); + if (ret) + return ret; + ret = clk_enable(clk); + if (ret) + clk_unprepare(clk); + + return ret; +} + +/* clk_disable_unprepare helps cases using clk_disable in non-atomic context. */ +static inline void clk_disable_unprepare(struct clk *clk) +{ + clk_disable(clk); + clk_unprepare(clk); +} + +/** + * 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 + * + * 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. + * + * clk_put should not be called from within interrupt context. + */ +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); + +/** + * clk_get_sys - get a clock based upon the device name + * @dev_id: device name + * @con_id: connection ID + * + * Returns a struct clk corresponding to the clock producer, or + * valid IS_ERR() condition containing errno. The implementation + * uses @dev_id and @con_id to determine the clock consumer, and + * thereby the clock producer. In contrast to clk_get() this function + * takes the device name instead of the device itself for identification. + * + * Drivers must assume that the clock source is not enabled. + * + * clk_get_sys should not be called from within interrupt context. + */ +struct clk *clk_get_sys(const char *dev_id, const char *con_id); + +/** + * clk_add_alias - add a new clock alias + * @alias: name for clock alias + * @alias_dev_name: device name + * @id: platform specific clock name + * @dev: device + * + * Allows using generic clock names for drivers by adding a new alias. + * Assumes clkdev, see clkdev.h for more info. + */ +int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, + struct device *dev); + +#endif -- cgit