3 files changed, 308 insertions, 5 deletions

diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h
new file mode 100644
index 000000000000..e2cce6fa6046
--- /dev/null
+++ b/include/linux/clk-private.h
@@ -0,0 +1,72 @@
+/*
+ *  linux/include/linux/clk-private.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_PRIVATE_H
+#define __LINUX_CLK_PRIVATE_H
+
+#include <linux/clk-provider.h>
+#include <linux/list.h>
+
+/*
+ * WARNING: Do not include clk-private.h from any file that implements struct
+ * clk_ops.  Doing so is a layering violation!
+ *
+ * This header exists only to allow for statically initialized clock data.  Any
+ * static clock data must be defined in a separate file from the logic that
+ * implements the clock operations for that same data.
+ */
+
+#ifdef CONFIG_COMMON_CLK
+
+struct clk {
+        const char              *name;
+        const struct clk_ops    *ops;
+        struct clk_hw           *hw;
+        struct clk              *parent;
+        char                    **parent_names;
+        struct clk              **parents;
+        u8                      num_parents;
+        unsigned long           rate;
+        unsigned long           new_rate;
+        unsigned long           flags;
+        unsigned int            enable_count;
+        unsigned int            prepare_count;
+        struct hlist_head       children;
+        struct hlist_node       child_node;
+        unsigned int            notifier_count;
+#ifdef CONFIG_COMMON_CLK_DEBUG
+        struct dentry           *dentry;
+#endif
+};
+
+/**
+ * __clk_init - initialize the data structures in a struct clk
+ * @dev:        device initializing this clk, placeholder for now
+ * @clk:        clk being initialized
+ *
+ * Initializes the lists in struct clk, queries the hardware for the
+ * parent and rate and sets them both.
+ *
+ * Any struct clk passed into __clk_init must have the following members
+ * populated:
+ *      .name
+ *      .ops
+ *      .hw
+ *      .parent_names
+ *      .num_parents
+ *      .flags
+ *
+ * It is not necessary to call clk_register if __clk_init is used directly with
+ * statically initialized clock data.
+ */
+void __clk_init(struct device *dev, struct clk *clk);
+
+#endif /* CONFIG_COMMON_CLK */
+#endif /* CLK_PRIVATE_H */
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 */
diff --git a/include/linux/clk.h b/include/linux/clk.h
index b9d46fa154b4..b0252726df61 100644
--- a/include/linux/clk.h
+++ b/include/linux/clk.h
@@ -3,6 +3,7 @@
  *
  *  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
@@ -12,18 +13,75 @@
 #define __LINUX_CLK_H
 
 #include <linux/kernel.h>
+#include <linux/notifier.h>
 
 struct device;
 
-/*
- * The base API.
+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 - an machine class defined object / cookie.
+/**
+ * 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;
+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.