clk: Add common __clk_get(), __clk_put() implementations

Sylwester Nawrocki · Sylwester Nawrocki · commit ac2df527fb40 · 2013-12-04T17:19:44.000+01:00
This patch adds common __clk_get(), __clk_put() clkdev helpers that
replace their platform specific counterparts when the common clock
API is used.

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.

The owner module is assigned while the clock is being registered,
in functions _clk_register() and __clk_register().

Signed-off-by: Sylwester Nawrocki &lt;s.nawrocki@samsung.com&gt;
Signed-off-by: Kyungmin Park &lt;kyungmin.park@samsung.com&gt;
Acked-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
diff --git 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
@@ -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
@@ -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
@@ -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
@@ -1813,6 +1813,10 @@ struct clk *__clk_register(struct device *dev, struct clk_hw *hw)
 	clk->flags = hw->init->flags;
 	clk->parent_names = hw->init->parent_names;
 	clk->num_parents = hw->init->num_parents;
+	if (dev && dev->driver)
+		clk->owner = dev->driver->owner;
+	else
+		clk->owner = NULL;
 
 	ret = __clk_init(dev, clk);
 	if (ret)
@@ -1833,6 +1837,8 @@ static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)
 		goto fail_name;
 	}
 	clk->ops = hw->init->ops;
+	if (dev && dev->driver)
+		clk->owner = dev->driver->owner;
 	clk->hw = hw;
 	clk->flags = hw->init->flags;
 	clk->num_parents = hw->init->num_parents;
@@ -1973,6 +1979,26 @@ 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
@@ -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
@@ -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

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,9 @@ static inline struct clk_lookup_alloc *__clkdev_alloc(size_t size)`
`8`	`8`	`return kzalloc(size, GFP_KERNEL);`
`9`	`9`	`}`
`10`	`10`
	`11`	`+#ifndef CONFIG_COMMON_CLK`
`11`	`12`	`#define __clk_put(clk)`
`12`	`13`	`#define __clk_get(clk) ({ 1; })`
	`14`	`+#endif`
`13`	`15`
`14`	`16`	`#endif`
Original file line number	Diff line number	Diff line change
`@@ -14,8 +14,10 @@`
`14`	`14`
`15`	`15`	`#include <linux/slab.h>`
`16`	`16`
	`17`	`+#ifndef CONFIG_COMMON_CLK`
`17`	`18`	`#define __clk_get(clk) ({ 1; })`
`18`	`19`	`#define __clk_put(clk) do { } while (0)`
	`20`	`+#endif`
`19`	`21`
`20`	`22`	`static inline struct clk_lookup_alloc *__clkdev_alloc(size_t size)`
`21`	`23`	`{`
Original file line number	Diff line number	Diff line change
`@@ -25,7 +25,9 @@ static inline struct clk_lookup_alloc *__clkdev_alloc(size_t size)`
`25`	`25`	`return kzalloc(size, GFP_KERNEL);`
`26`	`26`	`}`
`27`	`27`
	`28`	`+#ifndef CONFIG_COMMON_CLK`
`28`	`29`	`#define __clk_put(clk)`
`29`	`30`	`#define __clk_get(clk) ({ 1; })`
	`31`	`+#endif`
`30`	`32`
`31`	`33`	`#endif /* __CLKDEV_H__ */`