sh: clock framework update, fix count and kill off kref
This patch updates the clock framework use count code.
With this patch the enable() and disable() callbacks
only get called when counting from and to zero.
While at it the kref stuff gets replaced with an int.
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/include/asm/clock.h b/arch/sh/include/asm/clock.h
index 2f6c962..b1f2919 100644
--- a/arch/sh/include/asm/clock.h
+++ b/arch/sh/include/asm/clock.h
@@ -1,7 +1,6 @@
#ifndef __ASM_SH_CLOCK_H
#define __ASM_SH_CLOCK_H
-#include <linux/kref.h>
#include <linux/list.h>
#include <linux/seq_file.h>
#include <linux/clk.h>
@@ -28,7 +27,7 @@
struct clk *parent;
struct clk_ops *ops;
- struct kref kref;
+ int usecount;
unsigned long rate;
unsigned long flags;
@@ -37,6 +36,7 @@
#define CLK_ALWAYS_ENABLED (1 << 0)
#define CLK_RATE_PROPAGATES (1 << 1)
+#define CLK_NEEDS_INIT (1 << 2)
/* Should be defined by processor-specific code */
void arch_init_clk_ops(struct clk_ops **, int type);
diff --git a/arch/sh/kernel/cpu/clock.c b/arch/sh/kernel/cpu/clock.c
index 099373a..133dbe4 100644
--- a/arch/sh/kernel/cpu/clock.c
+++ b/arch/sh/kernel/cpu/clock.c
@@ -19,7 +19,6 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/list.h>
-#include <linux/kref.h>
#include <linux/kobject.h>
#include <linux/sysdev.h>
#include <linux/seq_file.h>
@@ -90,7 +89,7 @@
}
}
-static int __clk_enable(struct clk *clk)
+static void __clk_init(struct clk *clk)
{
/*
* See if this is the first time we're enabling the clock, some
@@ -100,19 +99,33 @@
* divisors to use before it can effectively recalc.
*/
- if (clk->flags & CLK_ALWAYS_ENABLED) {
- kref_get(&clk->kref);
- return 0;
- }
-
- if (unlikely(atomic_read(&clk->kref.refcount) == 1))
+ if (clk->flags & CLK_NEEDS_INIT) {
if (clk->ops && clk->ops->init)
clk->ops->init(clk);
- kref_get(&clk->kref);
+ clk->flags &= ~CLK_NEEDS_INIT;
+ }
+}
- if (likely(clk->ops && clk->ops->enable))
- clk->ops->enable(clk);
+static int __clk_enable(struct clk *clk)
+{
+ if (!clk)
+ return -EINVAL;
+
+ clk->usecount++;
+
+ /* nothing to do if always enabled */
+ if (clk->flags & CLK_ALWAYS_ENABLED)
+ return 0;
+
+ if (clk->usecount == 1) {
+ __clk_init(clk);
+
+ __clk_enable(clk->parent);
+
+ if (clk->ops && clk->ops->enable)
+ clk->ops->enable(clk);
+ }
return 0;
}
@@ -122,11 +135,6 @@
unsigned long flags;
int ret;
- if (!clk)
- return -EINVAL;
-
- clk_enable(clk->parent);
-
spin_lock_irqsave(&clock_lock, flags);
ret = __clk_enable(clk);
spin_unlock_irqrestore(&clock_lock, flags);
@@ -135,21 +143,23 @@
}
EXPORT_SYMBOL_GPL(clk_enable);
-static void clk_kref_release(struct kref *kref)
-{
- /* Nothing to do */
-}
-
static void __clk_disable(struct clk *clk)
{
- int count = kref_put(&clk->kref, clk_kref_release);
+ if (!clk)
+ return;
+
+ clk->usecount--;
+
+ WARN_ON(clk->usecount < 0);
if (clk->flags & CLK_ALWAYS_ENABLED)
return;
- if (!count) { /* count reaches zero, disable the clock */
+ if (clk->usecount == 0) {
if (likely(clk->ops && clk->ops->disable))
clk->ops->disable(clk);
+
+ __clk_disable(clk->parent);
}
}
@@ -157,14 +167,9 @@
{
unsigned long flags;
- if (!clk)
- return;
-
spin_lock_irqsave(&clock_lock, flags);
__clk_disable(clk);
spin_unlock_irqrestore(&clock_lock, flags);
-
- clk_disable(clk->parent);
}
EXPORT_SYMBOL_GPL(clk_disable);
@@ -173,14 +178,14 @@
mutex_lock(&clock_list_sem);
list_add(&clk->node, &clock_list);
- kref_init(&clk->kref);
+ clk->usecount = 0;
+ clk->flags |= CLK_NEEDS_INIT;
mutex_unlock(&clock_list_sem);
if (clk->flags & CLK_ALWAYS_ENABLED) {
+ __clk_init(clk);
pr_debug( "Clock '%s' is ALWAYS_ENABLED\n", clk->name);
- if (clk->ops && clk->ops->init)
- clk->ops->init(clk);
if (clk->ops && clk->ops->enable)
clk->ops->enable(clk);
pr_debug( "Enabled.");
@@ -356,7 +361,7 @@
p += sprintf(p, "%-12s\t: %ld.%02ldMHz\t%s\n", clk->name,
rate / 1000000, (rate % 1000000) / 10000,
((clk->flags & CLK_ALWAYS_ENABLED) ||
- (atomic_read(&clk->kref.refcount) != 1)) ?
+ clk->usecount > 0) ?
"enabled" : "disabled");
}