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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /include/linux/clk.h
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'include/linux/clk.h')
-rw-r--r--include/linux/clk.h281
1 files changed, 281 insertions, 0 deletions
diff --git a/include/linux/clk.h b/include/linux/clk.h
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--- /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 <mturquette@linaro.org>
+ *
+ * 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 <linux/kernel.h>
+#include <linux/notifier.h>
+
+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