clk: Make clk API return per-user struct clk instances

Moves clock state to struct clk_core, but takes care to change as little API as
possible.

struct clk_hw still has a pointer to a struct clk, which is the
implementation's per-user clk instance, for backwards compatibility.

The struct clk that clk_get_parent() returns isn't owned by the caller, but by
the clock implementation, so the former shouldn't call clk_put() on it.

Because some boards in mach-omap2 still register clocks statically, their clock
registration had to be updated to take into account that the clock information
is stored in struct clk_core now.
Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: adapted clk_has_parent to struct clk_core
                        applied OMAP3+ DPLL fix from Tero & Tony]

arch/arm/mach-omap2/clock.h

@@ -40,23 +40,29 @@ struct omap_clk {
 struct clockdomain;
 
 #define DEFINE_STRUCT_CLK(_name, _parent_array_name, _clkops_name)	\
-	static struct clk _name = {				\
+	static struct clk_core _name##_core = {			\
 		.name = #_name,					\
 		.hw = &_name##_hw.hw,				\
 		.parent_names = _parent_array_name,		\
 		.num_parents = ARRAY_SIZE(_parent_array_name),	\
 		.ops = &_clkops_name,				\
+	};							\
+	static struct clk _name = {				\
+		.core = &_name##_core,				\
 	};
 
 #define DEFINE_STRUCT_CLK_FLAGS(_name, _parent_array_name,	\
 				_clkops_name, _flags)		\
-	static struct clk _name = {				\
+	static struct clk_core _name##_core = {			\
 		.name = #_name,					\
 		.hw = &_name##_hw.hw,				\
 		.parent_names = _parent_array_name,		\
 		.num_parents = ARRAY_SIZE(_parent_array_name),	\
 		.ops = &_clkops_name,				\
 		.flags = _flags,				\
+	};							\
+	static struct clk _name = {				\
+		.core = &_name##_core,				\
 	};
 
 #define DEFINE_STRUCT_CLK_HW_OMAP(_name, _clkdm_name)		\
@@ -248,6 +254,7 @@ extern const struct clksel_rate gpt_32k_rates[];
 extern const struct clksel_rate gpt_sys_rates[];
 extern const struct clksel_rate gfx_l3_rates[];
 extern const struct clksel_rate dsp_ick_rates[];
+extern struct clk_core dummy_ck_core;
 extern struct clk dummy_ck;
 
 extern const struct clk_hw_omap_ops clkhwops_iclk_wait;

arch/arm/mach-omap2/clock_common_data.c

@@ -119,8 +119,11 @@ const struct clksel_rate div31_1to31_rates[] = {
 
 static struct clk_ops dummy_ck_ops = {};
 
-struct clk dummy_ck = {
+struct clk_core dummy_ck_core = {
 	.name = "dummy_clk",
 	.ops = &dummy_ck_ops,
 	.flags = CLK_IS_BASIC,
 };
+struct clk dummy_ck = {
+	.core = &dummy_ck_core,
+};

arch/arm/mach-omap2/dpll3xxx.c

@@ -410,7 +410,7 @@ int omap3_noncore_dpll_enable(struct clk_hw *hw)
 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
 	int r;
 	struct dpll_data *dd;
-	struct clk *parent;
+	struct clk_hw *parent;
 
 	dd = clk->dpll_data;
 	if (!dd)
@@ -427,13 +427,13 @@ int omap3_noncore_dpll_enable(struct clk_hw *hw)
 		}
 	}
 
-	parent = __clk_get_parent(hw->clk);
+	parent = __clk_get_hw(__clk_get_parent(hw->clk));
 
 	if (__clk_get_rate(hw->clk) == __clk_get_rate(dd->clk_bypass)) {
-		WARN_ON(parent != dd->clk_bypass);
+		WARN_ON(parent != __clk_get_hw(dd->clk_bypass));
 		r = _omap3_noncore_dpll_bypass(clk);
 	} else {
-		WARN_ON(parent != dd->clk_ref);
+		WARN_ON(parent != __clk_get_hw(dd->clk_ref));
 		r = _omap3_noncore_dpll_lock(clk);
 	}
 
@@ -549,7 +549,8 @@ int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate,
 	if (!dd)
 		return -EINVAL;
 
-	if (__clk_get_parent(hw->clk) != dd->clk_ref)
+	if (__clk_get_hw(__clk_get_parent(hw->clk)) !=
+	    __clk_get_hw(dd->clk_ref))
 		return -EINVAL;
 
 	if (dd->last_rounded_rate == 0)

drivers/clk/clk.h

@@ -9,9 +9,14 @@
  * published by the Free Software Foundation.
  */
 
+struct clk_hw;
+
 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
 struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec);
 struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec);
 void of_clk_lock(void);
 void of_clk_unlock(void);
 #endif
+
+struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
+			     const char *con_id);

drivers/clk/clkdev.c

@@ -19,6 +19,7 @@
 #include <linux/mutex.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
+#include <linux/clk-provider.h>
 #include <linux/of.h>
 
 #include "clk.h"
@@ -53,7 +54,7 @@ struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec)
 	return clk;
 }
 
-struct clk *of_clk_get(struct device_node *np, int index)
+static struct clk *__of_clk_get(struct device_node *np, int index)
 {
 	struct of_phandle_args clkspec;
 	struct clk *clk;
@@ -69,20 +70,24 @@ struct clk *of_clk_get(struct device_node *np, int index)
 
 	clk = of_clk_get_by_clkspec(&clkspec);
 	of_node_put(clkspec.np);
+
+	return clk;
+}
+
+struct clk *of_clk_get(struct device_node *np, int index)
+{
+	struct clk *clk = __of_clk_get(np, index);
+
+	if (!IS_ERR(clk))
+		clk = __clk_create_clk(__clk_get_hw(clk), np->full_name, NULL);
+
 	return clk;
 }
 EXPORT_SYMBOL(of_clk_get);
 
-/**
- * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
- * @np: pointer to clock consumer node
- * @name: name of consumer's clock input, or NULL for the first clock reference
- *
- * This function parses the clocks and clock-names properties,
- * and uses them to look up the struct clk from the registered list of clock
- * providers.
- */
-struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
+static struct clk *__of_clk_get_by_name(struct device_node *np,
+					const char *dev_id,
+					const char *name)
 {
 	struct clk *clk = ERR_PTR(-ENOENT);
 
@@ -97,9 +102,11 @@ struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
 		 */
 		if (name)
 			index = of_property_match_string(np, "clock-names", name);
-		clk = of_clk_get(np, index);
-		if (!IS_ERR(clk))
+		clk = __of_clk_get(np, index);
+		if (!IS_ERR(clk)) {
+			clk = __clk_create_clk(__clk_get_hw(clk), dev_id, name);
 			break;
+		}
 		else if (name && index >= 0) {
 			if (PTR_ERR(clk) != -EPROBE_DEFER)
 				pr_err("ERROR: could not get clock %s:%s(%i)\n",
@@ -119,7 +126,33 @@ struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
 
 	return clk;
 }
+
+/**
+ * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
+ * @np: pointer to clock consumer node
+ * @name: name of consumer's clock input, or NULL for the first clock reference
+ *
+ * This function parses the clocks and clock-names properties,
+ * and uses them to look up the struct clk from the registered list of clock
+ * providers.
+ */
+struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
+{
+	if (!np)
+		return ERR_PTR(-ENOENT);
+
+	return __of_clk_get_by_name(np, np->full_name, name);
+}
 EXPORT_SYMBOL(of_clk_get_by_name);
+
+#else /* defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) */
+
+static struct clk *__of_clk_get_by_name(struct device_node *np,
+					const char *dev_id,
+					const char *name)
+{
+	return ERR_PTR(-ENOENT);
+}
 #endif
 
 /*
@@ -168,14 +201,29 @@ static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
 struct clk *clk_get_sys(const char *dev_id, const char *con_id)
 {
 	struct clk_lookup *cl;
+	struct clk *clk = NULL;
 
 	mutex_lock(&clocks_mutex);
+
 	cl = clk_find(dev_id, con_id);
-	if (cl && !__clk_get(cl->clk))
+	if (!cl)
+		goto out;
+
+	if (!__clk_get(cl->clk)) {
 		cl = NULL;
+		goto out;
+	}
+
+#if defined(CONFIG_COMMON_CLK)
+	clk = __clk_create_clk(__clk_get_hw(cl->clk), dev_id, con_id);
+#else
+	clk = cl->clk;
+#endif
+
+out:
 	mutex_unlock(&clocks_mutex);
 
-	return cl ? cl->clk : ERR_PTR(-ENOENT);
+	return cl ? clk : ERR_PTR(-ENOENT);
 }
 EXPORT_SYMBOL(clk_get_sys);
 
@@ -185,10 +233,8 @@ struct clk *clk_get(struct device *dev, const char *con_id)
 	struct clk *clk;
 
 	if (dev) {
-		clk = of_clk_get_by_name(dev->of_node, con_id);
-		if (!IS_ERR(clk))
-			return clk;
-		if (PTR_ERR(clk) == -EPROBE_DEFER)
+		clk = __of_clk_get_by_name(dev->of_node, dev_id, con_id);
+		if (!IS_ERR(clk) || PTR_ERR(clk) == -EPROBE_DEFER)
 			return clk;
 	}
 

include/linux/clk-private.h

@@ -28,20 +28,20 @@
 
 struct module;
 
-struct clk {
+struct clk_core {
 	const char		*name;
 	const struct clk_ops	*ops;
 	struct clk_hw		*hw;
 	struct module		*owner;
-	struct clk		*parent;
+	struct clk_core		*parent;
 	const char		**parent_names;
-	struct clk		**parents;
+	struct clk_core		**parents;
 	u8			num_parents;
 	u8			new_parent_index;
 	unsigned long		rate;
 	unsigned long		new_rate;
-	struct clk		*new_parent;
-	struct clk		*new_child;
+	struct clk_core		*new_parent;
+	struct clk_core		*new_child;
 	unsigned long		flags;
 	unsigned int		enable_count;
 	unsigned int		prepare_count;
@@ -57,6 +57,12 @@ struct clk {
 	struct kref		ref;
 };
 
+struct clk {
+	struct clk_core	*core;
+	const char *dev_id;
+	const char *con_id;
+};
+
 /*
  * DOC: Basic clock implementations common to many platforms
  *
@@ -69,6 +75,9 @@ struct clk {
 #define DEFINE_CLK(_name, _ops, _flags, _parent_names,		\
 		_parents)					\
 	static struct clk _name = {				\
+		.core = &_name##_core				\
+	};							\
+	static struct clk_core _name##_core = {			\
 		.name = #_name,					\
 		.ops = &_ops,					\
 		.hw = &_name##_hw.hw,				\
@@ -81,9 +90,11 @@ struct clk {
 #define DEFINE_CLK_FIXED_RATE(_name, _flags, _rate,		\
 				_fixed_rate_flags)		\
 	static struct clk _name;				\
+	static struct clk_core _name##_core;			\
 	static const char *_name##_parent_names[] = {};		\
 	static struct clk_fixed_rate _name##_hw = {		\
 		.hw = {						\
+			.core = &_name##_core,			\
 			.clk = &_name,				\
 		},						\
 		.fixed_rate = _rate,				\
@@ -96,14 +107,16 @@ struct clk {
 				_flags, _reg, _bit_idx,		\
 				_gate_flags, _lock)		\
 	static struct clk _name;				\
+	static struct clk_core _name##_core;			\
 	static const char *_name##_parent_names[] = {		\
 		_parent_name,					\
 	};							\
-	static struct clk *_name##_parents[] = {		\
+	static struct clk_core *_name##_parents[] = {		\
 		_parent_ptr,					\
 	};							\
 	static struct clk_gate _name##_hw = {			\
 		.hw = {						\
+			.core = &_name##_core,			\
 			.clk = &_name,				\
 		},						\
 		.reg = _reg,					\
@@ -118,14 +131,16 @@ struct clk {
 				_flags, _reg, _shift, _width,	\
 				_divider_flags, _table, _lock)	\
 	static struct clk _name;				\
+	static struct clk_core _name##_core;			\
 	static const char *_name##_parent_names[] = {		\
 		_parent_name,					\
 	};							\
-	static struct clk *_name##_parents[] = {		\
+	static struct clk_core *_name##_parents[] = {		\
 		_parent_ptr,					\
 	};							\
 	static struct clk_divider _name##_hw = {		\
 		.hw = {						\
+			.core = &_name##_core,			\
 			.clk = &_name,				\
 		},						\
 		.reg = _reg,					\
@@ -157,8 +172,10 @@ struct clk {
 				_reg, _shift, _width,		\
 				_mux_flags, _lock)		\
 	static struct clk _name;				\
+	static struct clk_core _name##_core;			\
 	static struct clk_mux _name##_hw = {			\
 		.hw = {						\
+			.core = &_name##_core,			\
 			.clk = &_name,				\
 		},						\
 		.reg = _reg,					\
@@ -174,14 +191,16 @@ struct clk {
 				_parent_ptr, _flags,		\
 				_mult, _div)			\
 	static struct clk _name;				\
+	static struct clk_core _name##_core;			\
 	static const char *_name##_parent_names[] = {		\
 		_parent_name,					\
 	};							\
-	static struct clk *_name##_parents[] = {		\
+	static struct clk_core *_name##_parents[] = {		\
 		_parent_ptr,					\
 	};							\
 	static struct clk_fixed_factor _name##_hw = {		\
 		.hw = {						\
+			.core = &_name##_core,			\
 			.clk = &_name,				\
 		},						\
 		.mult = _mult,					\

include/linux/clk-provider.h

@@ -33,6 +33,7 @@
 #define CLK_GET_ACCURACY_NOCACHE BIT(8) /* do not use the cached clk accuracy */
 
 struct clk_hw;
+struct clk_core;
 struct dentry;
 
 /**
@@ -216,13 +217,17 @@ struct clk_init_data {
  * clk_foo and then referenced by the struct clk instance that uses struct
  * clk_foo's clk_ops
  *
- * @clk: pointer to the struct clk instance that points back to this struct
- * clk_hw instance
+ * @core: pointer to the struct clk_core instance that points back to this
+ * struct clk_hw instance
+ *
+ * @clk: pointer to the per-user struct clk instance that can be used to call
+ * into the clk API
  *
  * @init: pointer to struct clk_init_data that contains the init data shared
  * with the common clock framework.
  */
 struct clk_hw {
+	struct clk_core *core;
 	struct clk *clk;
 	const struct clk_init_data *init;
 };
@@ -577,9 +582,6 @@ long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
 /*
  * FIXME clock api without lock protection
  */
-int __clk_prepare(struct clk *clk);
-void __clk_unprepare(struct clk *clk);
-void __clk_reparent(struct clk *clk, struct clk *new_parent);
 unsigned long __clk_round_rate(struct clk *clk, unsigned long rate);
 
 struct of_device_id;