diff --git a/arch/arm/include/asm/clkdev.h b/arch/arm/include/asm/clkdev.h index 80751c15c300..4e8a4b27d7c7 100644 --- a/arch/arm/include/asm/clkdev.h +++ b/arch/arm/include/asm/clkdev.h @@ -14,12 +14,14 @@ #include +#ifndef CONFIG_COMMON_CLK #ifdef CONFIG_HAVE_MACH_CLKDEV #include #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 9053beda8c50..7ac2436856a5 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 262475414e5f..1b3ad7b09dc1 100644 --- a/arch/mips/include/asm/clkdev.h +++ b/arch/mips/include/asm/clkdev.h @@ -14,8 +14,10 @@ #include +#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 6ba91868201c..c41901465fb0 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 b7f6e99e61eb..e3e03270b95e 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -21,6 +21,8 @@ #include #include +#include "clk.h" + static DEFINE_SPINLOCK(enable_lock); static DEFINE_MUTEX(prepare_lock); @@ -350,6 +352,21 @@ 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 @@ -440,6 +457,9 @@ 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 */ @@ -1861,6 +1881,7 @@ int __clk_init(struct device *dev, struct clk *clk) if (clk->ops->init) clk->ops->init(clk->hw); + kref_init(&clk->ref); out: clk_prepare_unlock(); @@ -1896,6 +1917,10 @@ 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) @@ -1916,6 +1941,8 @@ 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; @@ -1990,13 +2017,104 @@ 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) @@ -2056,6 +2174,31 @@ 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; + + kref_get(&clk->ref); + return 1; +} + +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); +} + /*** clk rate change notifiers ***/ /** @@ -2196,7 +2339,18 @@ static const struct of_device_id __clk_of_table_sentinel __used __section(__clk_of_table_end); static LIST_HEAD(of_clk_providers); -static DEFINE_MUTEX(of_clk_lock); +static DEFINE_MUTEX(of_clk_mutex); + +/* of_clk_provider list locking helpers */ +void of_clk_lock(void) +{ + mutex_lock(&of_clk_mutex); +} + +void of_clk_unlock(void) +{ + mutex_unlock(&of_clk_mutex); +} struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, void *data) @@ -2240,9 +2394,9 @@ int of_clk_add_provider(struct device_node *np, cp->data = data; cp->get = clk_src_get; - mutex_lock(&of_clk_lock); + mutex_lock(&of_clk_mutex); list_add(&cp->link, &of_clk_providers); - mutex_unlock(&of_clk_lock); + mutex_unlock(&of_clk_mutex); pr_debug("Added clock from %s\n", np->full_name); return 0; @@ -2257,7 +2411,7 @@ void of_clk_del_provider(struct device_node *np) { struct of_clk_provider *cp; - mutex_lock(&of_clk_lock); + mutex_lock(&of_clk_mutex); list_for_each_entry(cp, &of_clk_providers, link) { if (cp->node == np) { list_del(&cp->link); @@ -2266,24 +2420,33 @@ void of_clk_del_provider(struct device_node *np) break; } } - mutex_unlock(&of_clk_lock); + mutex_unlock(&of_clk_mutex); } EXPORT_SYMBOL_GPL(of_clk_del_provider); -struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) +struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec) { struct of_clk_provider *provider; struct clk *clk = ERR_PTR(-ENOENT); /* Check if we have such a provider in our array */ - mutex_lock(&of_clk_lock); list_for_each_entry(provider, &of_clk_providers, link) { if (provider->node == clkspec->np) clk = provider->get(clkspec, provider->data); if (!IS_ERR(clk)) break; } - mutex_unlock(&of_clk_lock); + + return clk; +} + +struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) +{ + struct clk *clk; + + mutex_lock(&of_clk_mutex); + clk = __of_clk_get_from_provider(clkspec); + mutex_unlock(&of_clk_mutex); return clk; } diff --git a/drivers/clk/clk.h b/drivers/clk/clk.h new file mode 100644 index 000000000000..795cc9f0dac0 --- /dev/null +++ b/drivers/clk/clk.h @@ -0,0 +1,16 @@ +/* + * linux/drivers/clk/clk.h + * + * Copyright (C) 2013 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) +struct clk *__of_clk_get_from_provider(struct of_phandle_args *clkspec); +void of_clk_lock(void); +void of_clk_unlock(void); +#endif diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c index 442a31363873..48f67218247c 100644 --- a/drivers/clk/clkdev.c +++ b/drivers/clk/clkdev.c @@ -21,6 +21,8 @@ #include #include +#include "clk.h" + static LIST_HEAD(clocks); static DEFINE_MUTEX(clocks_mutex); @@ -39,7 +41,13 @@ struct clk *of_clk_get(struct device_node *np, int index) if (rc) return ERR_PTR(rc); - clk = of_clk_get_from_provider(&clkspec); + of_clk_lock(); + clk = __of_clk_get_from_provider(&clkspec); + + if (!IS_ERR(clk) && !__clk_get(clk)) + clk = ERR_PTR(-ENOENT); + + of_clk_unlock(); of_node_put(clkspec.np); return clk; } @@ -157,7 +165,7 @@ struct clk *clk_get(struct device *dev, const char *con_id) if (dev) { clk = of_clk_get_by_name(dev->of_node, con_id); - if (!IS_ERR(clk) && __clk_get(clk)) + if (!IS_ERR(clk)) return clk; } diff --git a/drivers/media/platform/omap3isp/isp.c b/drivers/media/platform/omap3isp/isp.c index 1c3608039663..59106623e71e 100644 --- a/drivers/media/platform/omap3isp/isp.c +++ b/drivers/media/platform/omap3isp/isp.c @@ -290,9 +290,11 @@ static int isp_xclk_init(struct isp_device *isp) struct clk_init_data init; unsigned int i; + for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i) + isp->xclks[i].clk = ERR_PTR(-EINVAL); + for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i) { struct isp_xclk *xclk = &isp->xclks[i]; - struct clk *clk; xclk->isp = isp; xclk->id = i == 0 ? ISP_XCLK_A : ISP_XCLK_B; @@ -305,10 +307,15 @@ static int isp_xclk_init(struct isp_device *isp) init.num_parents = 1; xclk->hw.init = &init; - - clk = devm_clk_register(isp->dev, &xclk->hw); - if (IS_ERR(clk)) - return PTR_ERR(clk); + /* + * The first argument is NULL in order to avoid circular + * reference, as this driver takes reference on the + * sensor subdevice modules and the sensors would take + * reference on this module through clk_get(). + */ + xclk->clk = clk_register(NULL, &xclk->hw); + if (IS_ERR(xclk->clk)) + return PTR_ERR(xclk->clk); if (pdata->xclks[i].con_id == NULL && pdata->xclks[i].dev_id == NULL) @@ -320,7 +327,7 @@ static int isp_xclk_init(struct isp_device *isp) xclk->lookup->con_id = pdata->xclks[i].con_id; xclk->lookup->dev_id = pdata->xclks[i].dev_id; - xclk->lookup->clk = clk; + xclk->lookup->clk = xclk->clk; clkdev_add(xclk->lookup); } @@ -335,6 +342,9 @@ static void isp_xclk_cleanup(struct isp_device *isp) for (i = 0; i < ARRAY_SIZE(isp->xclks); ++i) { struct isp_xclk *xclk = &isp->xclks[i]; + if (!IS_ERR(xclk->clk)) + clk_unregister(xclk->clk); + if (xclk->lookup) clkdev_drop(xclk->lookup); } diff --git a/drivers/media/platform/omap3isp/isp.h b/drivers/media/platform/omap3isp/isp.h index ce65d3ae1aa7..d1e857e41731 100644 --- a/drivers/media/platform/omap3isp/isp.h +++ b/drivers/media/platform/omap3isp/isp.h @@ -135,6 +135,7 @@ struct isp_xclk { struct isp_device *isp; struct clk_hw hw; struct clk_lookup *lookup; + struct clk *clk; enum isp_xclk_id id; spinlock_t lock; /* Protects enabled and divider */ diff --git a/include/linux/clk-private.h b/include/linux/clk-private.h index 5fb086b06c83..efbf70b9fd84 100644 --- a/include/linux/clk-private.h +++ b/include/linux/clk-private.h @@ -12,6 +12,7 @@ #define __LINUX_CLK_PRIVATE_H #include +#include #include /* @@ -25,10 +26,13 @@ #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; @@ -48,6 +52,7 @@ struct clk { #ifdef CONFIG_DEBUG_FS struct dentry *dentry; #endif + struct kref ref; }; /* diff --git a/include/linux/clkdev.h b/include/linux/clkdev.h index a6a6f603103b..94bad77eeb4a 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