diff options
Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r-- | drivers/clk/clk.c | 371 |
1 files changed, 330 insertions, 41 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2cf2ea6..2b38dc9 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -21,6 +21,8 @@ #include <linux/init.h> #include <linux/sched.h> +#include "clk.h" + static DEFINE_SPINLOCK(enable_lock); static DEFINE_MUTEX(prepare_lock); @@ -92,7 +94,7 @@ static void clk_enable_unlock(unsigned long flags) /*** debugfs support ***/ -#ifdef CONFIG_COMMON_CLK_DEBUG +#ifdef CONFIG_DEBUG_FS #include <linux/debugfs.h> static struct dentry *rootdir; @@ -104,10 +106,11 @@ static void clk_summary_show_one(struct seq_file *s, struct clk *c, int level) if (!c) return; - seq_printf(s, "%*s%-*s %-11d %-12d %-10lu", + seq_printf(s, "%*s%-*s %-11d %-12d %-10lu %-11lu", level * 3 + 1, "", 30 - level * 3, c->name, - c->enable_count, c->prepare_count, clk_get_rate(c)); + c->enable_count, c->prepare_count, clk_get_rate(c), + clk_get_accuracy(c)); seq_printf(s, "\n"); } @@ -129,8 +132,8 @@ static int clk_summary_show(struct seq_file *s, void *data) { struct clk *c; - seq_printf(s, " clock enable_cnt prepare_cnt rate\n"); - seq_printf(s, "---------------------------------------------------------------------\n"); + seq_printf(s, " clock enable_cnt prepare_cnt rate accuracy\n"); + seq_printf(s, "---------------------------------------------------------------------------------\n"); clk_prepare_lock(); @@ -167,6 +170,7 @@ static void clk_dump_one(struct seq_file *s, struct clk *c, int level) seq_printf(s, "\"enable_count\": %d,", c->enable_count); seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); seq_printf(s, "\"rate\": %lu", clk_get_rate(c)); + seq_printf(s, "\"accuracy\": %lu", clk_get_accuracy(c)); } static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) @@ -248,6 +252,11 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) if (!d) goto err_out; + d = debugfs_create_u32("clk_accuracy", S_IRUGO, clk->dentry, + (u32 *)&clk->accuracy); + if (!d) + goto err_out; + d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, (u32 *)&clk->flags); if (!d) @@ -272,7 +281,8 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) goto out; err_out: - debugfs_remove(clk->dentry); + debugfs_remove_recursive(clk->dentry); + clk->dentry = NULL; out: return ret; } @@ -342,6 +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 @@ -432,6 +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 */ @@ -602,6 +630,14 @@ out: return ret; } +unsigned long __clk_get_accuracy(struct clk *clk) +{ + if (!clk) + return 0; + + return clk->accuracy; +} + unsigned long __clk_get_flags(struct clk *clk) { return !clk ? 0 : clk->flags; @@ -1016,6 +1052,59 @@ static int __clk_notify(struct clk *clk, unsigned long msg, } /** + * __clk_recalc_accuracies + * @clk: first clk in the subtree + * + * Walks the subtree of clks starting with clk and recalculates accuracies as + * it goes. Note that if a clk does not implement the .recalc_accuracy + * callback then it is assumed that the clock will take on the accuracy of it's + * parent. + * + * Caller must hold prepare_lock. + */ +static void __clk_recalc_accuracies(struct clk *clk) +{ + unsigned long parent_accuracy = 0; + struct clk *child; + + if (clk->parent) + parent_accuracy = clk->parent->accuracy; + + if (clk->ops->recalc_accuracy) + clk->accuracy = clk->ops->recalc_accuracy(clk->hw, + parent_accuracy); + else + clk->accuracy = parent_accuracy; + + hlist_for_each_entry(child, &clk->children, child_node) + __clk_recalc_accuracies(child); +} + +/** + * clk_get_accuracy - return the accuracy of clk + * @clk: the clk whose accuracy is being returned + * + * Simply returns the cached accuracy of the clk, unless + * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be + * issued. + * If clk is NULL then returns 0. + */ +long clk_get_accuracy(struct clk *clk) +{ + unsigned long accuracy; + + clk_prepare_lock(); + if (clk && (clk->flags & CLK_GET_ACCURACY_NOCACHE)) + __clk_recalc_accuracies(clk); + + accuracy = __clk_get_accuracy(clk); + clk_prepare_unlock(); + + return accuracy; +} +EXPORT_SYMBOL_GPL(clk_get_accuracy); + +/** * __clk_recalc_rates * @clk: first clk in the subtree * @msg: notification type (see include/linux/clk.h) @@ -1129,10 +1218,9 @@ static void clk_reparent(struct clk *clk, struct clk *new_parent) clk->parent = new_parent; } -static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) +static struct clk *__clk_set_parent_before(struct clk *clk, struct clk *parent) { unsigned long flags; - int ret = 0; struct clk *old_parent = clk->parent; /* @@ -1163,6 +1251,34 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) clk_reparent(clk, parent); clk_enable_unlock(flags); + return old_parent; +} + +static void __clk_set_parent_after(struct clk *clk, struct clk *parent, + struct clk *old_parent) +{ + /* + * Finish the migration of prepare state and undo the changes done + * for preventing a race with clk_enable(). + */ + if (clk->prepare_count) { + clk_disable(clk); + clk_disable(old_parent); + __clk_unprepare(old_parent); + } + + /* update debugfs with new clk tree topology */ + clk_debug_reparent(clk, parent); +} + +static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) +{ + unsigned long flags; + int ret = 0; + struct clk *old_parent; + + old_parent = __clk_set_parent_before(clk, parent); + /* change clock input source */ if (parent && clk->ops->set_parent) ret = clk->ops->set_parent(clk->hw, p_index); @@ -1180,18 +1296,8 @@ static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) return ret; } - /* - * Finish the migration of prepare state and undo the changes done - * for preventing a race with clk_enable(). - */ - if (clk->prepare_count) { - clk_disable(clk); - clk_disable(old_parent); - __clk_unprepare(old_parent); - } + __clk_set_parent_after(clk, parent, old_parent); - /* update debugfs with new clk tree topology */ - clk_debug_reparent(clk, parent); return 0; } @@ -1376,17 +1482,32 @@ static void clk_change_rate(struct clk *clk) struct clk *child; unsigned long old_rate; unsigned long best_parent_rate = 0; + bool skip_set_rate = false; + struct clk *old_parent; old_rate = clk->rate; - /* set parent */ - if (clk->new_parent && clk->new_parent != clk->parent) - __clk_set_parent(clk, clk->new_parent, clk->new_parent_index); - - if (clk->parent) + if (clk->new_parent) + best_parent_rate = clk->new_parent->rate; + else if (clk->parent) best_parent_rate = clk->parent->rate; - if (clk->ops->set_rate) + if (clk->new_parent && clk->new_parent != clk->parent) { + old_parent = __clk_set_parent_before(clk, clk->new_parent); + + if (clk->ops->set_rate_and_parent) { + skip_set_rate = true; + clk->ops->set_rate_and_parent(clk->hw, clk->new_rate, + best_parent_rate, + clk->new_parent_index); + } else if (clk->ops->set_parent) { + clk->ops->set_parent(clk->hw, clk->new_parent_index); + } + + __clk_set_parent_after(clk, clk->new_parent, old_parent); + } + + if (!skip_set_rate && clk->ops->set_rate) clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); if (clk->ops->recalc_rate) @@ -1551,6 +1672,7 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent) { clk_reparent(clk, new_parent); clk_debug_reparent(clk, new_parent); + __clk_recalc_accuracies(clk); __clk_recalc_rates(clk, POST_RATE_CHANGE); } @@ -1621,11 +1743,13 @@ int clk_set_parent(struct clk *clk, struct clk *parent) /* do the re-parent */ ret = __clk_set_parent(clk, parent, p_index); - /* propagate rate recalculation accordingly */ - if (ret) + /* propagate rate an accuracy recalculation accordingly */ + if (ret) { __clk_recalc_rates(clk, ABORT_RATE_CHANGE); - else + } else { __clk_recalc_rates(clk, POST_RATE_CHANGE); + __clk_recalc_accuracies(clk); + } out: clk_prepare_unlock(); @@ -1678,6 +1802,14 @@ int __clk_init(struct device *dev, struct clk *clk) goto out; } + if (clk->ops->set_rate_and_parent && + !(clk->ops->set_parent && clk->ops->set_rate)) { + pr_warn("%s: %s must implement .set_parent & .set_rate\n", + __func__, clk->name); + ret = -EINVAL; + goto out; + } + /* throw a WARN if any entries in parent_names are NULL */ for (i = 0; i < clk->num_parents; i++) WARN(!clk->parent_names[i], @@ -1730,6 +1862,21 @@ int __clk_init(struct device *dev, struct clk *clk) hlist_add_head(&clk->child_node, &clk_orphan_list); /* + * Set clk's accuracy. The preferred method is to use + * .recalc_accuracy. For simple clocks and lazy developers the default + * fallback is to use the parent's accuracy. If a clock doesn't have a + * parent (or is orphaned) then accuracy is set to zero (perfect + * clock). + */ + if (clk->ops->recalc_accuracy) + clk->accuracy = clk->ops->recalc_accuracy(clk->hw, + __clk_get_accuracy(clk->parent)); + else if (clk->parent) + clk->accuracy = clk->parent->accuracy; + else + clk->accuracy = 0; + + /* * Set clk's rate. The preferred method is to use .recalc_rate. For * simple clocks and lazy developers the default fallback is to use the * parent's rate. If a clock doesn't have a parent (or is orphaned) @@ -1743,6 +1890,7 @@ int __clk_init(struct device *dev, struct clk *clk) else clk->rate = 0; + clk_debug_register(clk); /* * walk the list of orphan clocks and reparent any that are children of * this clock @@ -1773,8 +1921,7 @@ int __clk_init(struct device *dev, struct clk *clk) if (clk->ops->init) clk->ops->init(clk->hw); - clk_debug_register(clk); - + kref_init(&clk->ref); out: clk_prepare_unlock(); @@ -1810,6 +1957,10 @@ 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) @@ -1830,6 +1981,8 @@ 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; @@ -1904,13 +2057,104 @@ 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) @@ -1970,6 +2214,31 @@ 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 ***/ /** @@ -2110,7 +2379,18 @@ 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) @@ -2154,9 +2434,9 @@ 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; @@ -2171,7 +2451,7 @@ 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); @@ -2180,24 +2460,33 @@ 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; } |