1 files changed, 173 insertions, 0 deletions
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
new file mode 100644
index 000000000000..b18b0e7888a8
--- /dev/null
+++ b/include/linux/clk-provider.h
@@ -0,0 +1,173 @@
+/*
+ *  linux/include/linux/clk-provider.h
+ *
+ *  Copyright (c) 2010-2011 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *  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_PROVIDER_H
+#define __LINUX_CLK_PROVIDER_H
+
+#include <linux/clk.h>
+
+#ifdef CONFIG_COMMON_CLK
+
+/**
+ * struct clk_hw - handle for traversing from a struct clk to its corresponding
+ * hardware-specific structure.  struct clk_hw should be declared within struct
+ * clk_foo and then referenced by the struct clk instance that uses struct
+ * clk_foo's clk_ops
+ *
+ * clk: pointer to the struct clk instance that points back to this struct
+ * clk_hw instance
+ */
+struct clk_hw {
+	struct clk *clk;
+};
+
+/*
+ * flags used across common struct clk.  these flags should only affect the
+ * top-level framework.  custom flags for dealing with hardware specifics
+ * belong in struct clk_foo
+ */
+#define CLK_SET_RATE_GATE	BIT(0) /* must be gated across rate change */
+#define CLK_SET_PARENT_GATE	BIT(1) /* must be gated across re-parent */
+#define CLK_SET_RATE_PARENT	BIT(2) /* propagate rate change up one level */
+#define CLK_IGNORE_UNUSED	BIT(3) /* do not gate even if unused */
+#define CLK_IS_ROOT		BIT(4) /* root clk, has no parent */
+
+/**
+ * struct clk_ops -  Callback operations for hardware clocks; these are to
+ * be provided by the clock implementation, and will be called by drivers
+ * through the clk_* api.
+ *
+ * @prepare:	Prepare the clock for enabling. This must not return until
+ * 		the clock is fully prepared, and it's safe to call clk_enable.
+ * 		This callback is intended to allow clock implementations to
+ * 		do any initialisation that may sleep. Called with
+ * 		prepare_lock held.
+ *
+ * @unprepare:	Release the clock from its prepared state. This will typically
+ * 		undo any work done in the @prepare callback. Called with
+ * 		prepare_lock held.
+ *
+ * @enable:	Enable the clock atomically. This must not return until the
+ * 		clock is generating a valid clock signal, usable by consumer
+ * 		devices. Called with enable_lock held. This function must not
+ * 		sleep.
+ *
+ * @disable:	Disable the clock atomically. Called with enable_lock held.
+ * 		This function must not sleep.
+ *
+ * @recalc_rate	Recalculate the rate of this clock, by quering hardware.  The
+ * 		parent rate is an input parameter.  It is up to the caller to
+ * 		insure that the prepare_mutex is held across this call.
+ * 		Returns the calculated rate.  Optional, but recommended - if
+ * 		this op is not set then clock rate will be initialized to 0.
+ *
+ * @round_rate:	Given a target rate as input, returns the closest rate actually
+ * 		supported by the clock.
+ *
+ * @get_parent:	Queries the hardware to determine the parent of a clock.  The
+ * 		return value is a u8 which specifies the index corresponding to
+ * 		the parent clock.  This index can be applied to either the
+ * 		.parent_names or .parents arrays.  In short, this function
+ * 		translates the parent value read from hardware into an array
+ * 		index.  Currently only called when the clock is initialized by
+ * 		__clk_init.  This callback is mandatory for clocks with
+ * 		multiple parents.  It is optional (and unnecessary) for clocks
+ * 		with 0 or 1 parents.
+ *
+ * @set_parent:	Change the input source of this clock; for clocks with multiple
+ * 		possible parents specify a new parent by passing in the index
+ * 		as a u8 corresponding to the parent in either the .parent_names
+ * 		or .parents arrays.  This function in affect translates an
+ * 		array index into the value programmed into the hardware.
+ * 		Returns 0 on success, -EERROR otherwise.
+ *
+ * @set_rate:	Change the rate of this clock. If this callback returns
+ * 		CLK_SET_RATE_PARENT, the rate change will be propagated to the
+ * 		parent clock (which may propagate again if the parent clock
+ * 		also sets this flag). The requested rate of the parent is
+ * 		passed back from the callback in the second 'unsigned long *'
+ * 		argument.  Note that it is up to the hardware clock's set_rate
+ * 		implementation to insure that clocks do not run out of spec
+ * 		when propgating the call to set_rate up to the parent.  One way
+ * 		to do this is to gate the clock (via clk_disable and/or
+ * 		clk_unprepare) before calling clk_set_rate, then ungating it
+ * 		afterward.  If your clock also has the CLK_GATE_SET_RATE flag
+ * 		set then this will insure safety.  Returns 0 on success,
+ * 		-EERROR otherwise.
+ *
+ * The clk_enable/clk_disable and clk_prepare/clk_unprepare pairs allow
+ * implementations to split any work between atomic (enable) and sleepable
+ * (prepare) contexts.  If enabling a clock requires code that might sleep,
+ * this must be done in clk_prepare.  Clock enable code that will never be
+ * called in a sleepable context may be implement in clk_enable.
+ *
+ * Typically, drivers will call clk_prepare when a clock may be needed later
+ * (eg. when a device is opened), and clk_enable when the clock is actually
+ * required (eg. from an interrupt). Note that clk_prepare MUST have been
+ * called before clk_enable.
+ */
+struct clk_ops {
+	int		(*prepare)(struct clk_hw *hw);
+	void		(*unprepare)(struct clk_hw *hw);
+	int		(*enable)(struct clk_hw *hw);
+	void		(*disable)(struct clk_hw *hw);
+	int		(*is_enabled)(struct clk_hw *hw);
+	unsigned long	(*recalc_rate)(struct clk_hw *hw,
+					unsigned long parent_rate);
+	long		(*round_rate)(struct clk_hw *hw, unsigned long,
+					unsigned long *);
+	int		(*set_parent)(struct clk_hw *hw, u8 index);
+	u8		(*get_parent)(struct clk_hw *hw);
+	int		(*set_rate)(struct clk_hw *hw, unsigned long);
+	void		(*init)(struct clk_hw *hw);
+};
+
+
+/**
+ * clk_register - allocate a new clock, register it and return an opaque cookie
+ * @dev: device that is registering this clock
+ * @name: clock name
+ * @ops: operations this clock supports
+ * @hw: link to hardware-specific clock data
+ * @parent_names: array of string names for all possible parents
+ * @num_parents: number of possible parents
+ * @flags: framework-level hints and quirks
+ *
+ * clk_register is the primary interface for populating the clock tree with new
+ * clock nodes.  It returns a pointer to the newly allocated struct clk which
+ * cannot be dereferenced by driver code but may be used in conjuction with the
+ * rest of the clock API.
+ */
+struct clk *clk_register(struct device *dev, const char *name,
+		const struct clk_ops *ops, struct clk_hw *hw,
+		char **parent_names, u8 num_parents, unsigned long flags);
+
+/* helper functions */
+const char *__clk_get_name(struct clk *clk);
+struct clk_hw *__clk_get_hw(struct clk *clk);
+u8 __clk_get_num_parents(struct clk *clk);
+struct clk *__clk_get_parent(struct clk *clk);
+inline int __clk_get_enable_count(struct clk *clk);
+inline int __clk_get_prepare_count(struct clk *clk);
+unsigned long __clk_get_rate(struct clk *clk);
+unsigned long __clk_get_flags(struct clk *clk);
+int __clk_is_enabled(struct clk *clk);
+struct clk *__clk_lookup(const char *name);
+
+/*
+ * FIXME clock api without lock protection
+ */
+int __clk_prepare(struct clk *clk);
+void __clk_unprepare(struct clk *clk);
+void __clk_reparent(struct clk *clk, struct clk *new_parent);
+unsigned long __clk_round_rate(struct clk *clk, unsigned long rate);
+
+#endif /* CONFIG_COMMON_CLK */
+#endif /* CLK_PROVIDER_H */