Merge branch 'clk-parent-rewrite' (early part) into clk-next

* 'clk-parent-rewrite' (early part):
  clk: Move of_clk_*() APIs into clk.c from clkdev.c
  clk: Inform the core about consumer devices
  clk: Introduce of_clk_get_hw_from_clkspec()
  clk: core: clarify the check for runtime PM
  clk: Combine __clk_get() and __clk_create_clk()

3 files changed, 230 insertions, 178 deletions

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index af3882f04080..14cbf239d9b2 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -57,6 +57,7 @@ struct clk_core {
         struct clk_core         *new_child;
         unsigned long           flags;
         bool                    orphan;
+        bool                    rpm_enabled;
         unsigned int            enable_count;
         unsigned int            prepare_count;
         unsigned int            protect_count;
@@ -81,6 +82,7 @@ struct clk_core {
 
 struct clk {
         struct clk_core *core;
+        struct device *dev;
         const char *dev_id;
         const char *con_id;
         unsigned long min_rate;
@@ -92,9 +94,9 @@ struct clk {
 /***           runtime pm          ***/
 static int clk_pm_runtime_get(struct clk_core *core)
 {
-        int ret = 0;
+        int ret;
 
-        if (!core->dev)
+        if (!core->rpm_enabled)
                 return 0;
 
         ret = pm_runtime_get_sync(core->dev);
@@ -103,7 +105,7 @@ static int clk_pm_runtime_get(struct clk_core *core)
 
 static void clk_pm_runtime_put(struct clk_core *core)
 {
-        if (!core->dev)
+        if (!core->rpm_enabled)
                 return;
 
         pm_runtime_put_sync(core->dev);
@@ -223,7 +225,7 @@ static bool clk_core_is_enabled(struct clk_core *core)
          * taking enable spinlock, but the below check is needed if one tries
          * to call it from other places.
          */
-        if (core->dev) {
+        if (core->rpm_enabled) {
                 pm_runtime_get_noresume(core->dev);
                 if (!pm_runtime_active(core->dev)) {
                         ret = false;
@@ -233,7 +235,7 @@ static bool clk_core_is_enabled(struct clk_core *core)
 
         ret = core->ops->is_enabled(core->hw);
 done:
-        if (core->dev)
+        if (core->rpm_enabled)
                 pm_runtime_put(core->dev);
 
         return ret;
@@ -3212,43 +3214,106 @@ unlock:
         return ret;
 }
 
-struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
+/**
+ * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
+ * @core: clk to add consumer to
+ * @clk: consumer to link to a clk
+ */
+static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
+{
+        clk_prepare_lock();
+        hlist_add_head(&clk->clks_node, &core->clks);
+        clk_prepare_unlock();
+}
+
+/**
+ * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
+ * @clk: consumer to unlink
+ */
+static void clk_core_unlink_consumer(struct clk *clk)
+{
+        lockdep_assert_held(&prepare_lock);
+        hlist_del(&clk->clks_node);
+}
+
+/**
+ * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
+ * @core: clk to allocate a consumer for
+ * @dev_id: string describing device name
+ * @con_id: connection ID string on device
+ *
+ * Returns: clk consumer left unlinked from the consumer list
+ */
+static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
                              const char *con_id)
 {
         struct clk *clk;
 
-        /* This is to allow this function to be chained to others */
-        if (IS_ERR_OR_NULL(hw))
-                return ERR_CAST(hw);
-
         clk = kzalloc(sizeof(*clk), GFP_KERNEL);
         if (!clk)
                 return ERR_PTR(-ENOMEM);
 
-        clk->core = hw->core;
+        clk->core = core;
         clk->dev_id = dev_id;
         clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
         clk->max_rate = ULONG_MAX;
 
-        clk_prepare_lock();
-        hlist_add_head(&clk->clks_node, &hw->core->clks);
-        clk_prepare_unlock();
-
         return clk;
 }
 
-/* keep in sync with __clk_put */
-void __clk_free_clk(struct clk *clk)
+/**
+ * free_clk - Free a clk consumer
+ * @clk: clk consumer to free
+ *
+ * Note, this assumes the clk has been unlinked from the clk_core consumer
+ * list.
+ */
+static void free_clk(struct clk *clk)
 {
-        clk_prepare_lock();
-        hlist_del(&clk->clks_node);
-        clk_prepare_unlock();
-
         kfree_const(clk->con_id);
         kfree(clk);
 }
 
 /**
+ * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
+ * a clk_hw
+ * @dev: clk consumer device
+ * @hw: clk_hw associated with the clk being consumed
+ * @dev_id: string describing device name
+ * @con_id: connection ID string on device
+ *
+ * This is the main function used to create a clk pointer for use by clk
+ * consumers. It connects a consumer to the clk_core and clk_hw structures
+ * used by the framework and clk provider respectively.
+ */
+struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
+                              const char *dev_id, const char *con_id)
+{
+        struct clk *clk;
+        struct clk_core *core;
+
+        /* This is to allow this function to be chained to others */
+        if (IS_ERR_OR_NULL(hw))
+                return ERR_CAST(hw);
+
+        core = hw->core;
+        clk = alloc_clk(core, dev_id, con_id);
+        if (IS_ERR(clk))
+                return clk;
+        clk->dev = dev;
+
+        if (!try_module_get(core->owner)) {
+                free_clk(clk);
+                return ERR_PTR(-ENOENT);
+        }
+
+        kref_get(&core->ref);
+        clk_core_link_consumer(core, clk);
+
+        return clk;
+}
+
+/**
  * clk_register - allocate a new clock, register it and return an opaque cookie
  * @dev: device that is registering this clock
  * @hw: link to hardware-specific clock data
@@ -3283,7 +3348,8 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
         core->ops = hw->init->ops;
 
         if (dev && pm_runtime_enabled(dev))
-                core->dev = dev;
+                core->rpm_enabled = true;
+        core->dev = dev;
         if (dev && dev->driver)
                 core->owner = dev->driver->owner;
         core->hw = hw;
@@ -3323,17 +3389,27 @@ struct clk *clk_register(struct device *dev, struct clk_hw *hw)
 
         INIT_HLIST_HEAD(&core->clks);
 
-        hw->clk = __clk_create_clk(hw, NULL, NULL);
+        /*
+         * Don't call clk_hw_create_clk() here because that would pin the
+         * provider module to itself and prevent it from ever being removed.
+         */
+        hw->clk = alloc_clk(core, NULL, NULL);
         if (IS_ERR(hw->clk)) {
                 ret = PTR_ERR(hw->clk);
                 goto fail_parents;
         }
 
+        clk_core_link_consumer(hw->core, hw->clk);
+
         ret = __clk_core_init(core);
         if (!ret)
                 return hw->clk;
 
-        __clk_free_clk(hw->clk);
+        clk_prepare_lock();
+        clk_core_unlink_consumer(hw->clk);
+        clk_prepare_unlock();
+
+        free_clk(hw->clk);
         hw->clk = NULL;
 
 fail_parents:
@@ -3604,20 +3680,7 @@ EXPORT_SYMBOL_GPL(devm_clk_hw_unregister);
 /*
  * clkdev helpers
  */
-int __clk_get(struct clk *clk)
-{
-        struct clk_core *core = !clk ? NULL : clk->core;
-
-        if (core) {
-                if (!try_module_get(core->owner))
-                        return 0;
 
-                kref_get(&core->ref);
-        }
-        return 1;
-}
-
-/* keep in sync with __clk_free_clk */
 void __clk_put(struct clk *clk)
 {
         struct module *owner;
@@ -3651,8 +3714,7 @@ void __clk_put(struct clk *clk)
 
         module_put(owner);
 
-        kfree_const(clk->con_id);
-        kfree(clk);
+        free_clk(clk);
 }
 
 /***        clk rate change notifiers        ***/
@@ -4009,6 +4071,49 @@ void devm_of_clk_del_provider(struct device *dev)
 }
 EXPORT_SYMBOL(devm_of_clk_del_provider);
 
+/*
+ * Beware the return values when np is valid, but no clock provider is found.
+ * If name == NULL, the function returns -ENOENT.
+ * If name != NULL, the function returns -EINVAL. This is because
+ * of_parse_phandle_with_args() is called even if of_property_match_string()
+ * returns an error.
+ */
+static int of_parse_clkspec(const struct device_node *np, int index,
+                            const char *name, struct of_phandle_args *out_args)
+{
+        int ret = -ENOENT;
+
+        /* Walk up the tree of devices looking for a clock property that matches */
+        while (np) {
+                /*
+                 * For named clocks, first look up the name in the
+                 * "clock-names" property.  If it cannot be found, then index
+                 * will be an error code and of_parse_phandle_with_args() will
+                 * return -EINVAL.
+                 */
+                if (name)
+                        index = of_property_match_string(np, "clock-names", name);
+                ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
+                                                 index, out_args);
+                if (!ret)
+                        break;
+                if (name && index >= 0)
+                        break;
+
+                /*
+                 * No matching clock found on this node.  If the parent node
+                 * has a "clock-ranges" property, then we can try one of its
+                 * clocks.
+                 */
+                np = np->parent;
+                if (np && !of_get_property(np, "clock-ranges", NULL))
+                        break;
+                index = 0;
+        }
+
+        return ret;
+}
+
 static struct clk_hw *
 __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
                               struct of_phandle_args *clkspec)
@@ -4024,36 +4129,26 @@ __of_clk_get_hw_from_provider(struct of_clk_provider *provider,
         return __clk_get_hw(clk);
 }
 
-struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
-                                       const char *dev_id, const char *con_id)
+static struct clk_hw *
+of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
 {
         struct of_clk_provider *provider;
-        struct clk *clk = ERR_PTR(-EPROBE_DEFER);
-        struct clk_hw *hw;
+        struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
 
         if (!clkspec)
                 return ERR_PTR(-EINVAL);
 
-        /* Check if we have such a provider in our array */
         mutex_lock(&of_clk_mutex);
         list_for_each_entry(provider, &of_clk_providers, link) {
                 if (provider->node == clkspec->np) {
                         hw = __of_clk_get_hw_from_provider(provider, clkspec);
-                        clk = __clk_create_clk(hw, dev_id, con_id);
-                }
-
-                if (!IS_ERR(clk)) {
-                        if (!__clk_get(clk)) {
-                                __clk_free_clk(clk);
-                                clk = ERR_PTR(-ENOENT);
-                        }
-
-                        break;
+                        if (!IS_ERR(hw))
+                                break;
                 }
         }
         mutex_unlock(&of_clk_mutex);
 
-        return clk;
+        return hw;
 }
 
 /**
@@ -4066,10 +4161,62 @@ struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
  */
 struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
 {
-        return __of_clk_get_from_provider(clkspec, NULL, __func__);
+        struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
+
+        return clk_hw_create_clk(NULL, hw, NULL, __func__);
 }
 EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
 
+struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
+                             const char *con_id)
+{
+        int ret;
+        struct clk_hw *hw;
+        struct of_phandle_args clkspec;
+
+        ret = of_parse_clkspec(np, index, con_id, &clkspec);
+        if (ret)
+                return ERR_PTR(ret);
+
+        hw = of_clk_get_hw_from_clkspec(&clkspec);
+        of_node_put(clkspec.np);
+
+        return hw;
+}
+
+static struct clk *__of_clk_get(struct device_node *np,
+                                int index, const char *dev_id,
+                                const char *con_id)
+{
+        struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
+
+        return clk_hw_create_clk(NULL, hw, dev_id, con_id);
+}
+
+struct clk *of_clk_get(struct device_node *np, int index)
+{
+        return __of_clk_get(np, index, np->full_name, NULL);
+}
+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)
+{
+        if (!np)
+                return ERR_PTR(-ENOENT);
+
+        return __of_clk_get(np, -1, np->full_name, name);
+}
+EXPORT_SYMBOL(of_clk_get_by_name);
+
 /**
  * of_clk_get_parent_count() - Count the number of clocks a device node has
  * @np: device node to count
diff --git a/drivers/clk/clk.h b/drivers/clk/clk.h
index b02f5e604e69..553f531cc232 100644
--- a/drivers/clk/clk.h
+++ b/drivers/clk/clk.h
@@ -5,31 +5,36 @@
  */
 
 struct clk_hw;
+struct device;
+struct of_phandle_args;
 
 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
-struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec,
-                                       const char *dev_id, const char *con_id);
+struct clk_hw *of_clk_get_hw(struct device_node *np,
+                                    int index, const char *con_id);
+#else /* !CONFIG_COMMON_CLK || !CONFIG_OF */
+static inline struct clk_hw *of_clk_get_hw(struct device_node *np,
+                                    int index, const char *con_id)
+{
+        return ERR_PTR(-ENOENT);
+}
 #endif
 
 #ifdef CONFIG_COMMON_CLK
-struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
-                             const char *con_id);
-void __clk_free_clk(struct clk *clk);
-int __clk_get(struct clk *clk);
+struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
+                              const char *dev_id, const char *con_id);
 void __clk_put(struct clk *clk);
 #else
 /* All these casts to avoid ifdefs in clkdev... */
 static inline struct clk *
-__clk_create_clk(struct clk_hw *hw, const char *dev_id, const char *con_id)
+clk_hw_create_clk(struct device *dev, struct clk_hw *hw, const char *dev_id,
+                  const char *con_id)
 {
         return (struct clk *)hw;
 }
-static inline void __clk_free_clk(struct clk *clk) { }
 static struct clk_hw *__clk_get_hw(struct clk *clk)
 {
         return (struct clk_hw *)clk;
 }
-static inline int __clk_get(struct clk *clk) { return 1; }
 static inline void __clk_put(struct clk *clk) { }
 
 #endif
diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
index 4cfe39636105..8c4435c53f09 100644
--- a/drivers/clk/clkdev.c
+++ b/drivers/clk/clkdev.c
@@ -27,105 +27,6 @@
 static LIST_HEAD(clocks);
 static DEFINE_MUTEX(clocks_mutex);
 
-#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
-static struct clk *__of_clk_get(struct device_node *np, int index,
-                               const char *dev_id, const char *con_id)
-{
-        struct of_phandle_args clkspec;
-        struct clk *clk;
-        int rc;
-
-        rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
-                                        &clkspec);
-        if (rc)
-                return ERR_PTR(rc);
-
-        clk = __of_clk_get_from_provider(&clkspec, dev_id, con_id);
-        of_node_put(clkspec.np);
-
-        return clk;
-}
-
-struct clk *of_clk_get(struct device_node *np, int index)
-{
-        return __of_clk_get(np, index, np->full_name, NULL);
-}
-EXPORT_SYMBOL(of_clk_get);
-
-/*
- * Beware the return values when np is valid, but no clock provider is found.
- * If name == NULL, the function returns -ENOENT.
- * If name != NULL, the function returns -EINVAL. This is because __of_clk_get()
- * is called even if of_property_match_string() returns an error.
- */
-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);
-
-        /* Walk up the tree of devices looking for a clock that matches */
-        while (np) {
-                int index = 0;
-
-                /*
-                 * For named clocks, first look up the name in the
-                 * "clock-names" property.  If it cannot be found, then
-                 * index will be an error code, and of_clk_get() will fail.
-                 */
-                if (name)
-                        index = of_property_match_string(np, "clock-names", name);
-                clk = __of_clk_get(np, index, dev_id, name);
-                if (!IS_ERR(clk)) {
-                        break;
-                } else if (name && index >= 0) {
-                        if (PTR_ERR(clk) != -EPROBE_DEFER)
-                                pr_err("ERROR: could not get clock %pOF:%s(%i)\n",
-                                        np, name ? name : "", index);
-                        return clk;
-                }
-
-                /*
-                 * No matching clock found on this node.  If the parent node
-                 * has a "clock-ranges" property, then we can try one of its
-                 * clocks.
-                 */
-                np = np->parent;
-                if (np && !of_get_property(np, "clock-ranges", NULL))
-                        break;
-        }
-
-        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
-
 /*
  * Find the correct struct clk for the device and connection ID.
  * We do slightly fuzzy matching here:
@@ -169,7 +70,8 @@ static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
         return cl;
 }
 
-struct clk *clk_get_sys(const char *dev_id, const char *con_id)
+static struct clk *__clk_get_sys(struct device *dev, const char *dev_id,
+                                 const char *con_id)
 {
         struct clk_lookup *cl;
         struct clk *clk = NULL;
@@ -180,35 +82,33 @@ struct clk *clk_get_sys(const char *dev_id, const char *con_id)
         if (!cl)
                 goto out;
 
-        clk = __clk_create_clk(cl->clk_hw, dev_id, con_id);
+        clk = clk_hw_create_clk(dev, cl->clk_hw, dev_id, con_id);
         if (IS_ERR(clk))
-                goto out;
-
-        if (!__clk_get(clk)) {
-                __clk_free_clk(clk);
                 cl = NULL;
-                goto out;
-        }
-
 out:
         mutex_unlock(&clocks_mutex);
 
         return cl ? clk : ERR_PTR(-ENOENT);
 }
+
+struct clk *clk_get_sys(const char *dev_id, const char *con_id)
+{
+        return __clk_get_sys(NULL, dev_id, con_id);
+}
 EXPORT_SYMBOL(clk_get_sys);
 
 struct clk *clk_get(struct device *dev, const char *con_id)
 {
         const char *dev_id = dev ? dev_name(dev) : NULL;
-        struct clk *clk;
+        struct clk_hw *hw;
 
         if (dev && dev->of_node) {
-                clk = __of_clk_get_by_name(dev->of_node, dev_id, con_id);
-                if (!IS_ERR(clk) || PTR_ERR(clk) == -EPROBE_DEFER)
-                        return clk;
+                hw = of_clk_get_hw(dev->of_node, 0, con_id);
+                if (!IS_ERR(hw) || PTR_ERR(hw) == -EPROBE_DEFER)
+                        return clk_hw_create_clk(dev, hw, dev_id, con_id);
         }
 
-        return clk_get_sys(dev_id, con_id);
+        return __clk_get_sys(dev, dev_id, con_id);
 }
 EXPORT_SYMBOL(clk_get);