diff options
-rw-r--r-- | drivers/clk/clk.c | 121 | ||||
-rw-r--r-- | include/linux/clk-private.h | 2 |
2 files changed, 120 insertions, 3 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index baa2f66a7d19..da7b33e4c5a2 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -345,6 +345,21 @@ out: return ret; } + /** + * clk_debug_unregister - remove a clk node from the debugfs clk tree + * @clk: the clk being removed from the debugfs clk tree + * + * Dynamically removes a clk and all it's children clk nodes from the + * debugfs clk tree if clk->dentry points to debugfs created by + * clk_debug_register in __clk_init. + * + * Caller must hold prepare_lock. + */ +static void clk_debug_unregister(struct clk *clk) +{ + debugfs_remove_recursive(clk->dentry); +} + /** * clk_debug_reparent - reparent clk node in the debugfs clk tree * @clk: the clk being reparented @@ -435,6 +450,9 @@ static inline int clk_debug_register(struct clk *clk) { return 0; } static inline void clk_debug_reparent(struct clk *clk, struct clk *new_parent) { } +static inline void clk_debug_unregister(struct clk *clk) +{ +} #endif /* caller must hold prepare_lock */ @@ -1778,6 +1796,7 @@ int __clk_init(struct device *dev, struct clk *clk) clk_debug_register(clk); + kref_init(&clk->ref); out: clk_prepare_unlock(); @@ -1913,13 +1932,104 @@ fail_out: } EXPORT_SYMBOL_GPL(clk_register); +/* + * Free memory allocated for a clock. + * Caller must hold prepare_lock. + */ +static void __clk_release(struct kref *ref) +{ + struct clk *clk = container_of(ref, struct clk, ref); + int i = clk->num_parents; + + kfree(clk->parents); + while (--i >= 0) + kfree(clk->parent_names[i]); + + kfree(clk->parent_names); + kfree(clk->name); + kfree(clk); +} + +/* + * Empty clk_ops for unregistered clocks. These are used temporarily + * after clk_unregister() was called on a clock and until last clock + * consumer calls clk_put() and the struct clk object is freed. + */ +static int clk_nodrv_prepare_enable(struct clk_hw *hw) +{ + return -ENXIO; +} + +static void clk_nodrv_disable_unprepare(struct clk_hw *hw) +{ + WARN_ON_ONCE(1); +} + +static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + return -ENXIO; +} + +static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) +{ + return -ENXIO; +} + +static const struct clk_ops clk_nodrv_ops = { + .enable = clk_nodrv_prepare_enable, + .disable = clk_nodrv_disable_unprepare, + .prepare = clk_nodrv_prepare_enable, + .unprepare = clk_nodrv_disable_unprepare, + .set_rate = clk_nodrv_set_rate, + .set_parent = clk_nodrv_set_parent, +}; + /** * clk_unregister - unregister a currently registered clock * @clk: clock to unregister - * - * Currently unimplemented. */ -void clk_unregister(struct clk *clk) {} +void clk_unregister(struct clk *clk) +{ + unsigned long flags; + + if (!clk || WARN_ON_ONCE(IS_ERR(clk))) + return; + + clk_prepare_lock(); + + if (clk->ops == &clk_nodrv_ops) { + pr_err("%s: unregistered clock: %s\n", __func__, clk->name); + goto out; + } + /* + * Assign empty clock ops for consumers that might still hold + * a reference to this clock. + */ + flags = clk_enable_lock(); + clk->ops = &clk_nodrv_ops; + clk_enable_unlock(flags); + + if (!hlist_empty(&clk->children)) { + struct clk *child; + + /* Reparent all children to the orphan list. */ + hlist_for_each_entry(child, &clk->children, child_node) + clk_set_parent(child, NULL); + } + + clk_debug_unregister(clk); + + hlist_del_init(&clk->child_node); + + if (clk->prepare_count) + pr_warn("%s: unregistering prepared clock: %s\n", + __func__, clk->name); + + kref_put(&clk->ref, __clk_release); +out: + clk_prepare_unlock(); +} EXPORT_SYMBOL_GPL(clk_unregister); static void devm_clk_release(struct device *dev, void *res) @@ -1987,6 +2097,7 @@ int __clk_get(struct clk *clk) if (clk && !try_module_get(clk->owner)) return 0; + kref_get(&clk->ref); return 1; } @@ -1995,6 +2106,10 @@ void __clk_put(struct clk *clk) if (WARN_ON_ONCE(IS_ERR(clk))) return; + clk_prepare_lock(); + kref_put(&clk->ref, __clk_release); + clk_prepare_unlock(); + if (clk) module_put(clk->owner); } diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h index 8cb1865e7d9d..72c65e05450b 100644 --- a/include/linux/clk-private.h +++ b/include/linux/clk-private.h @@ -12,6 +12,7 @@ #define __LINUX_CLK_PRIVATE_H #include <linux/clk-provider.h> +#include <linux/kref.h> #include <linux/list.h> /* @@ -50,6 +51,7 @@ struct clk { #ifdef CONFIG_COMMON_CLK_DEBUG struct dentry *dentry; #endif + struct kref ref; }; /* |