diff --git a/arch/Kconfig b/arch/Kconfig
index 8bf0fa6..212bd3c 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -165,6 +165,9 @@ config HAVE_MIXED_BREAKPOINTS_REGS
config HAVE_USER_RETURN_NOTIFIER
bool
+config USE_COMMON_STRUCT_CLK
+ bool
+
config HAVE_PERF_EVENTS_NMI
bool
help
diff --git a/include/linux/clk.h b/include/linux/clk.h
index 1d37f42..95c49b1 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) 2010 Jeremy Kerr <jeremy.kerr@canonical.com>
*
* 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
@@ -11,18 +12,169 @@
#ifndef __LINUX_CLK_H
#define __LINUX_CLK_H
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+
struct device;
-/*
- * The base API.
+#ifdef CONFIG_USE_COMMON_STRUCT_CLK
+
+#define CLK_ATOMIC 0x1
+
+/* If we're using the common struct clk, we define the base clk object here */
+
+/**
+ * struct clk - hardware independent clock structure
+ * @ops: implementation-specific ops for this clock
+ * @enable_count: count of clk_enable() calls active on this clock
+ * @flags: platform-independent flags
+ * @lock: lock for enable/disable or other HW-specific ops
+ *
+ * The base clock object, used by drivers for hardware-independent manipulation
+ * of clock lines. This will be 'subclassed' by device-specific implementations,
+ * which add device-specific data to struct clk. For example:
+ *
+ * struct clk_foo {
+ * struct clk;
+ * [device specific fields]
+ * };
+ *
+ * The clock driver code will manage the device-specific data, and pass
+ * clk_foo.clk to the common clock code. The clock driver will be called
+ * through the @ops callbacks.
+ *
+ * The @lock member provides either a spinlock or a mutex to protect (at least)
+ * @enable_count. The type of lock used will depend on @flags; if CLK_ATOMIC is
+ * set, then the core clock code will use a spinlock, otherwise a mutex. This
+ * lock will be acquired during clk_enable and clk_disable, so for atomic
+ * clocks, these ops callbacks must not sleep.
+ *
+ * The choice of atomic or non-atomic clock depends on how the clock is enabled.
+ * Typically, you'll want to use a non-atomic clock. For clocks that need to be
+ * enabled/disabled in interrupt context, use CLK_ATOMIC. Note that atomic
+ * clocks with parents will typically cascade enable/disable operations to
+ * their parent, so the parent of an atomic clock *must* be atomic too.
+ */
+struct clk {
+ const struct clk_ops *ops;
+ unsigned int enable_count;
+ int flags;
+ union {
+ struct mutex mutex;
+ spinlock_t spinlock;
+ } lock;
+};
+
+/* static initialiser for non-atomic clocks */
+#define INIT_CLK(name, o) { \
+ .ops = &o, \
+ .enable_count = 0, \
+ .flags = 0, \
+ .lock.mutex = __MUTEX_INITIALIZER(name.lock.mutex), \
+}
+
+/* static initialiser for atomic clocks */
+#define INIT_CLK_ATOMIC(name, o) { \
+ .ops = &o, \
+ .enable_count = 0, \
+ .flags = CLK_ATOMIC, \
+ .lock.spinlock = __SPIN_LOCK_UNLOCKED(name.lock.spinlock), \
+}
+
+/**
+ * struct clk_ops - Callback operations for clocks; these are to be provided
+ * by the clock implementation, and will be called by drivers through the clk_*
+ * API.
+ *
+ * @enable: Enable the clock. This must not return until the clock is
+ * generating a valid clock signal, usable by consumer devices.
+ * Called with clk->lock held.
+ *
+ * @disable: Disable the clock. Called with clk->lock held.
+ *
+ * @get: Called by the core clock code when a device driver acquires a
+ * clock via clk_get(). Optional.
+ *
+ * @put: Called by the core clock code when a devices driver releases a
+ * clock via clk_put(). Optional.
+ *
+ * For other callbacks, see the corresponding clk_* functions. Parameters and
+ * return values are passed directly from/to these API functions, or
+ * -ENOSYS (or zero, in the case of clk_get_rate) is returned if the callback
+ * is NULL, see kernel/clk.c for implementation details. All are optional.
*/
+struct clk_ops {
+ int (*enable)(struct clk *);
+ void (*disable)(struct clk *);
+ int (*get)(struct clk *);
+ void (*put)(struct clk *);
+ unsigned long (*get_rate)(struct clk *);
+ long (*round_rate)(struct clk *, unsigned long);
+ int (*set_rate)(struct clk *, unsigned long);
+ int (*set_parent)(struct clk *, struct clk *);
+ struct clk * (*get_parent)(struct clk *);
+};
+static inline void __clk_lock(struct clk *clk)
+{
+ if (clk->flags & CLK_ATOMIC)
+ spin_lock(&clk->lock.spinlock);
+ else
+ mutex_lock(&clk->lock.mutex);
+}
+
+static inline void __clk_unlock(struct clk *clk)
+{
+ if (clk->flags & CLK_ATOMIC)
+ spin_unlock(&clk->lock.spinlock);
+ else
+ mutex_unlock(&clk->lock.mutex);
+}
+
+/**
+ * __clk_get - update clock-specific refcounter
+ *
+ * @clk: The clock to refcount
+ *
+ * Before a clock is returned from clk_get, this function should be called
+ * to update any clock-specific refcounting.
+ *
+ * Returns non-zero on success, zero on failure.
+ *
+ * Drivers should not need this function; it is only needed by the
+ * arch-specific clk_get() implementations.
+ */
+int __clk_get(struct clk *clk);
+
+/**
+ * clk_common_init - initialise a clock for driver usage
+ *
+ * @clk: The clock to initialise
+ *
+ * Used for runtime intialization of clocks; you don't need to call this
+ * if your clock has been (statically) initialized with INIT_CLK.
+ */
+static inline void clk_common_init(struct clk *clk)
+{
+ clk->enable_count = 0;
+ if (clk->flags & CLK_ATOMIC)
+ spin_lock_init(&clk->lock.spinlock);
+ else
+ mutex_init(&clk->lock.mutex);
+}
+
+#else /* !CONFIG_USE_COMMON_STRUCT_CLK */
/*
- * struct clk - an machine class defined object / cookie.
+ * Global clock object, actual structure is declared per-machine
*/
struct clk;
+static inline void clk_common_init(struct clk *clk) { }
+
+#endif /* !CONFIG_USE_COMMON_STRUCT_CLK */
+
/**
* clk_get - lookup and obtain a reference to a clock producer.
* @dev: device for clock "consumer"@@ -83,12 +235,6 @@ unsigned long clk_get_rate(struct clk *clk);
*/
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
diff --git a/kernel/Makefile b/kernel/Makefile
index 0b5ff08..01383a0 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o
obj-$(CONFIG_PADATA) += padata.o
+obj-$(CONFIG_USE_COMMON_STRUCT_CLK) += clk.o
ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
diff --git a/kernel/clk.c b/kernel/clk.c
new file mode 100644
index 0000000..8de8fe3
--- /dev/null
+++ b/kernel/clk.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2010 Canonical Ltd <jeremy.kerr@canonical.com>
+ *
+ * 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.
+ *
+ * Standard functionality for the common clock API.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+
+int clk_enable(struct clk *clk)
+{
+ int ret = 0;
+
+ if (!clk->ops->enable)
+ return 0;
+
+ __clk_lock(clk);
+ if (!clk->enable_count)
+ ret = clk->ops->enable(clk);
+
+ if (!ret)
+ clk->enable_count++;
+ __clk_unlock(clk);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(clk_enable);
+
+void clk_disable(struct clk *clk)
+{
+ if (!clk->ops->disable)
+ return;
+
+ __clk_lock(clk);
+
+ WARN_ON(!clk->enable_count);
+
+ if (!--clk->enable_count)
+ clk->ops->disable(clk);
+
+ __clk_unlock(clk);
+}
+EXPORT_SYMBOL_GPL(clk_disable);
+
+unsigned long clk_get_rate(struct clk *clk)
+{
+ if (clk->ops->get_rate)
+ return clk->ops->get_rate(clk);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(clk_get_rate);
+
+int __clk_get(struct clk *clk)
+{
+ if (clk->ops->get)
+ return clk->ops->get(clk);
+ return 1;
+}
+EXPORT_SYMBOL_GPL(__clk_get);
+
+void clk_put(struct clk *clk)
+{
+ if (clk->ops->put)
+ clk->ops->put(clk);
+}
+EXPORT_SYMBOL_GPL(clk_put);
+
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+ if (clk->ops->round_rate)
+ return clk->ops->round_rate(clk, rate);
+ return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(clk_round_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+ if (clk->ops->set_rate)
+ return clk->ops->set_rate(clk, rate);
+ return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(clk_set_rate);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+ if (clk->ops->set_parent)
+ return clk->ops->set_parent(clk, parent);
+ return -ENOSYS;
+}
+EXPORT_SYMBOL_GPL(clk_set_parent);
+
+struct clk *clk_get_parent(struct clk *clk)
+{
+ if (clk->ops->get_parent)
+ return clk->ops->get_parent(clk);
+ return ERR_PTR(-ENOSYS);
+}
+EXPORT_SYMBOL_GPL(clk_get_parent);