[PATCH v6 3/5] clk: Add common __clk_get(), __clk_put() implementations

Sylwester Nawrocki
2013-08-30T14:53:20Z

This patch adds common __clk_get(), __clk_put() clkdev helpers which
replace their platform specific counterparts when the common clock
API is enabled.

The owner module pointer field is added to struct clk so a reference
to the clock supplier module can be taken by the clock consumers.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
Changes since v5:
- none.

Changes since v4:
- dropped unnecessary struct module forward declaration from
clk-provider.h

Changes since v3:
- dropped exporting of __clk_get(), __clk_put().

Changes since v2:
- fixed handling of NULL clock pointers in __clk_get(), __clk_put();
---
arch/arm/include/asm/clkdev.h | 2 ++
arch/blackfin/include/asm/clkdev.h | 2 ++
arch/mips/include/asm/clkdev.h | 2 ++
arch/sh/include/asm/clkdev.h | 2 ++
drivers/clk/clk.c | 20 ++++++++++++++++++++
include/linux/clk-private.h | 3 +++
include/linux/clkdev.h | 5 +++++
7 files changed, 36 insertions(+)

diff --git a/arch/arm/include/asm/clkdev.h b/arch/arm/include/asm/clkdev.h
index 80751c1..4e8a4b2 100644
--- a/arch/arm/include/asm/clkdev.h
+++ b/arch/arm/include/asm/clkdev.h
@@ -14,12 +14,14 @@

#include <linux/slab.h>

+#ifndef CONFIG_COMMON_CLK
#ifdef CONFIG_HAVE_MACH_CLKDEV
#include <mach/clkdev.h>
#else
#define __clk_get(clk) ({ 1; })
#define __clk_put(clk) do { } while (0)
#endif
+#endif

static inline struct clk_lookup_alloc *__clkdev_alloc(size_t size)
{
diff --git a/arch/blackfin/include/asm/clkdev.h b/arch/blackfin/include/asm/clkdev.h
index 9053bed..7ac2436 100644
--- a/arch/blackfin/include/asm/clkdev.h
+++ b/arch/blackfin/include/asm/clkdev.h
@@ -8,7 +8,9 @@ static inline struct clk_lookup_alloc *__clkdev_alloc(size_t size)
return kzalloc(size, GFP_KERNEL);
}

+#ifndef CONFIG_COMMON_CLK
#define __clk_put(clk)
#define __clk_get(clk) ({ 1; })
+#endif

#endif
diff --git a/arch/mips/include/asm/clkdev.h b/arch/mips/include/asm/clkdev.h
index 2624754..1b3ad7b 100644
--- a/arch/mips/include/asm/clkdev.h
+++ b/arch/mips/include/asm/clkdev.h
@@ -14,8 +14,10 @@

#include <linux/slab.h>

+#ifndef CONFIG_COMMON_CLK
#define __clk_get(clk) ({ 1; })
#define __clk_put(clk) do { } while (0)
+#endif

static inline struct clk_lookup_alloc *__clkdev_alloc(size_t size)
{
diff --git a/arch/sh/include/asm/clkdev.h b/arch/sh/include/asm/clkdev.h
index 6ba9186..c419014 100644
--- a/arch/sh/include/asm/clkdev.h
+++ b/arch/sh/include/asm/clkdev.h
@@ -25,7 +25,9 @@ static inline struct clk_lookup_alloc *__clkdev_alloc(size_t size)
return kzalloc(size, GFP_KERNEL);
}

+#ifndef CONFIG_COMMON_CLK
#define __clk_put(clk)
#define __clk_get(clk) ({ 1; })
+#endif

#endif /* __CLKDEV_H__ */
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 8f18564..dcf061a 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1965,6 +1965,26 @@ void devm_clk_unregister(struct device *dev, struct clk *clk)
}
EXPORT_SYMBOL_GPL(devm_clk_unregister);

+/*
+ * clkdev helpers
+ */
+int __clk_get(struct clk *clk)
+{
+ if (clk && !try_module_get(clk->owner))
+ return 0;
+
+ return 1;
+}
+
+void __clk_put(struct clk *clk)
+{
+ if (WARN_ON_ONCE(IS_ERR(clk)))
+ return;
+
+ if (clk)
+ module_put(clk->owner);
+}
+
/*** clk rate change notifiers ***/

/**
diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h
index 8138c94..8cb1865 100644
--- a/include/linux/clk-private.h
+++ b/include/linux/clk-private.h
@@ -25,10 +25,13 @@

#ifdef CONFIG_COMMON_CLK

+struct module;
+
struct clk {
const char *name;
const struct clk_ops *ops;
struct clk_hw *hw;
+ struct module *owner;
struct clk *parent;
const char **parent_names;
struct clk **parents;
diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h
index a6a6f60..94bad77 100644
--- a/include/linux/clkdev.h
+++ b/include/linux/clkdev.h
@@ -43,4 +43,9 @@ int clk_add_alias(const char *, const char *, char *, struct device *);
int clk_register_clkdev(struct clk *, const char *, const char *, ...);
int clk_register_clkdevs(struct clk *, struct clk_lookup *, size_t);

+#ifdef CONFIG_COMMON_CLK
+int __clk_get(struct clk *clk);
+void __clk_put(struct clk *clk);
+#endif
+
#endif
--
1.7.9.5