aboutsummaryrefslogtreecommitdiff
path: root/drivers/clk/clk.c
diff options
context:
space:
mode:
authorSylwester Nawrocki <s.nawrocki@samsung.com>2013-08-23 17:03:43 +0200
committerSylwester Nawrocki <s.nawrocki@samsung.com>2013-12-04 17:19:30 +0100
commitd6782c263661abd6c7e8a375141d69fdc457f9e1 (patch)
tree4e43750d3ddbcbe1de3696e1bcbe50e3e982acc2 /drivers/clk/clk.c
parent4eadfc38c4d6e30775d3764f9a1a3098789d2acc (diff)
clk: Provide not locked variant of of_clk_get_from_provider()
Add helper functions for the of_clk_providers list locking and an unlocked variant of of_clk_get_from_provider(). These functions are intended to be used in the clkdev to avoid race condition in the device tree based clock look up in clk_get(). Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r--drivers/clk/clk.c38
1 files changed, 30 insertions, 8 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 77fcd069c64..c687dc8d0b6 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -21,6 +21,8 @@
#include <linux/init.h>
#include <linux/sched.h>
+#include "clk.h"
+
static DEFINE_SPINLOCK(enable_lock);
static DEFINE_MUTEX(prepare_lock);
@@ -2111,7 +2113,18 @@ static const struct of_device_id __clk_of_table_sentinel
__used __section(__clk_of_table_end);
static LIST_HEAD(of_clk_providers);
-static DEFINE_MUTEX(of_clk_lock);
+static DEFINE_MUTEX(of_clk_mutex);
+
+/* of_clk_provider list locking helpers */
+void of_clk_lock(void)
+{
+ mutex_lock(&of_clk_mutex);
+}
+
+void of_clk_unlock(void)
+{
+ mutex_unlock(&of_clk_mutex);
+}
struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
void *data)
@@ -2155,9 +2168,9 @@ int of_clk_add_provider(struct device_node *np,
cp->data = data;
cp->get = clk_src_get;
- mutex_lock(&of_clk_lock);
+ mutex_lock(&of_clk_mutex);
list_add(&cp->link, &of_clk_providers);
- mutex_unlock(&of_clk_lock);
+ mutex_unlock(&of_clk_mutex);
pr_debug("Added clock from %s\n", np->full_name);
return 0;
@@ -2172,7 +2185,7 @@ void of_clk_del_provider(struct device_node *np)
{
struct of_clk_provider *cp;
- mutex_lock(&of_clk_lock);
+ mutex_lock(&of_clk_mutex);
list_for_each_entry(cp, &of_clk_providers, link) {
if (cp->node == np) {
list_del(&cp->link);
@@ -2181,24 +2194,33 @@ void of_clk_del_provider(struct device_node *np)
break;
}
}
- mutex_unlock(&of_clk_lock);
+ mutex_unlock(&of_clk_mutex);
}
EXPORT_SYMBOL_GPL(of_clk_del_provider);
-struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
+struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec)
{
struct of_clk_provider *provider;
struct clk *clk = ERR_PTR(-ENOENT);
/* Check if we have such a provider in our array */
- mutex_lock(&of_clk_lock);
list_for_each_entry(provider, &of_clk_providers, link) {
if (provider->node == clkspec->np)
clk = provider->get(clkspec, provider->data);
if (!IS_ERR(clk))
break;
}
- mutex_unlock(&of_clk_lock);
+
+ return clk;
+}
+
+struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
+{
+ struct clk *clk;
+
+ mutex_lock(&of_clk_mutex);
+ clk = __of_clk_get_from_provider(clkspec);
+ mutex_unlock(&of_clk_mutex);
return clk;
}