--- zzzz-none-000/linux-3.10.107/drivers/clk/clk.c 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/drivers/clk/clk.c 2021-02-04 17:41:59.000000000 +0000 @@ -9,7 +9,9 @@ * Standard functionality for the common clock API. See Documentation/clk.txt */ -#include +#include +#include +#include #include #include #include @@ -20,6 +22,9 @@ #include #include #include +#include + +#include "clk.h" static DEFINE_SPINLOCK(enable_lock); static DEFINE_MUTEX(prepare_lock); @@ -34,6 +39,57 @@ static HLIST_HEAD(clk_orphan_list); static LIST_HEAD(clk_notifier_list); +/*** private data structures ***/ + +struct clk_core { + const char *name; + const struct clk_ops *ops; + struct clk_hw *hw; + struct module *owner; + struct clk_core *parent; + const char **parent_names; + struct clk_core **parents; + u8 num_parents; + u8 new_parent_index; + u8 safe_parent_index; + unsigned long rate; + unsigned long req_rate; + unsigned long old_rate; + unsigned long new_rate; + struct clk_core *safe_parent; + struct clk_core *new_parent; + struct clk_core *new_child; + unsigned long flags; + bool orphan; + unsigned int enable_count; + unsigned int prepare_count; + unsigned long min_rate; + unsigned long max_rate; + unsigned long accuracy; + int phase; + struct hlist_head children; + struct hlist_node child_node; + struct hlist_head clks; + unsigned int notifier_count; +#ifdef CONFIG_DEBUG_FS + struct dentry *dentry; + struct hlist_node debug_node; +#endif + struct kref ref; +}; + +#define CREATE_TRACE_POINTS +#include + +struct clk { + struct clk_core *core; + const char *dev_id; + const char *con_id; + unsigned long min_rate; + unsigned long max_rate; + struct hlist_node clks_node; +}; + /*** locking ***/ static void clk_prepare_lock(void) { @@ -62,12 +118,14 @@ } static unsigned long clk_enable_lock(void) + __acquires(enable_lock) { unsigned long flags; if (!spin_trylock_irqsave(&enable_lock, flags)) { if (enable_owner == current) { enable_refcnt++; + __acquire(enable_lock); return flags; } spin_lock_irqsave(&enable_lock, flags); @@ -80,404 +138,84 @@ } static void clk_enable_unlock(unsigned long flags) + __releases(enable_lock) { WARN_ON_ONCE(enable_owner != current); WARN_ON_ONCE(enable_refcnt == 0); - if (--enable_refcnt) + if (--enable_refcnt) { + __release(enable_lock); return; + } enable_owner = NULL; spin_unlock_irqrestore(&enable_lock, flags); } -/*** debugfs support ***/ - -#ifdef CONFIG_COMMON_CLK_DEBUG -#include - -static struct dentry *rootdir; -static struct dentry *orphandir; -static int inited = 0; - -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", - level * 3 + 1, "", - 30 - level * 3, c->name, - c->enable_count, c->prepare_count, c->rate); - seq_printf(s, "\n"); -} - -static void clk_summary_show_subtree(struct seq_file *s, struct clk *c, - int level) -{ - struct clk *child; - - if (!c) - return; - - clk_summary_show_one(s, c, level); - - hlist_for_each_entry(child, &c->children, child_node) - clk_summary_show_subtree(s, child, level + 1); -} - -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"); - - clk_prepare_lock(); - - hlist_for_each_entry(c, &clk_root_list, child_node) - clk_summary_show_subtree(s, c, 0); - - hlist_for_each_entry(c, &clk_orphan_list, child_node) - clk_summary_show_subtree(s, c, 0); - - clk_prepare_unlock(); - - return 0; -} - - -static int clk_summary_open(struct inode *inode, struct file *file) -{ - return single_open(file, clk_summary_show, inode->i_private); -} - -static const struct file_operations clk_summary_fops = { - .open = clk_summary_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - -static void clk_dump_one(struct seq_file *s, struct clk *c, int level) -{ - if (!c) - return; - - seq_printf(s, "\"%s\": { ", c->name); - seq_printf(s, "\"enable_count\": %d,", c->enable_count); - seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); - seq_printf(s, "\"rate\": %lu", c->rate); -} - -static void clk_dump_subtree(struct seq_file *s, struct clk *c, int level) -{ - struct clk *child; - - if (!c) - return; - - clk_dump_one(s, c, level); - - hlist_for_each_entry(child, &c->children, child_node) { - seq_printf(s, ","); - clk_dump_subtree(s, child, level + 1); - } - - seq_printf(s, "}"); -} - -static int clk_dump(struct seq_file *s, void *data) -{ - struct clk *c; - bool first_node = true; - - seq_printf(s, "{"); - - clk_prepare_lock(); - - hlist_for_each_entry(c, &clk_root_list, child_node) { - if (!first_node) - seq_printf(s, ","); - first_node = false; - clk_dump_subtree(s, c, 0); - } - - hlist_for_each_entry(c, &clk_orphan_list, child_node) { - seq_printf(s, ","); - clk_dump_subtree(s, c, 0); - } - - clk_prepare_unlock(); - - seq_printf(s, "}"); - return 0; -} - - -static int clk_dump_open(struct inode *inode, struct file *file) -{ - return single_open(file, clk_dump, inode->i_private); -} - -static const struct file_operations clk_dump_fops = { - .open = clk_dump_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - -/* caller must hold prepare_lock */ -static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) -{ - struct dentry *d; - int ret = -ENOMEM; - - if (!clk || !pdentry) { - ret = -EINVAL; - goto out; - } - - d = debugfs_create_dir(clk->name, pdentry); - if (!d) - goto out; - - clk->dentry = d; - - d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, - (u32 *)&clk->rate); - if (!d) - goto err_out; - - d = debugfs_create_x32("clk_flags", S_IRUGO, clk->dentry, - (u32 *)&clk->flags); - if (!d) - goto err_out; - - d = debugfs_create_u32("clk_prepare_count", S_IRUGO, clk->dentry, - (u32 *)&clk->prepare_count); - if (!d) - goto err_out; - - d = debugfs_create_u32("clk_enable_count", S_IRUGO, clk->dentry, - (u32 *)&clk->enable_count); - if (!d) - goto err_out; - - d = debugfs_create_u32("clk_notifier_count", S_IRUGO, clk->dentry, - (u32 *)&clk->notifier_count); - if (!d) - goto err_out; - - ret = 0; - goto out; - -err_out: - debugfs_remove(clk->dentry); -out: - return ret; -} - -/* caller must hold prepare_lock */ -static int clk_debug_create_subtree(struct clk *clk, struct dentry *pdentry) -{ - struct clk *child; - int ret = -EINVAL;; - - if (!clk || !pdentry) - goto out; - - ret = clk_debug_create_one(clk, pdentry); - - if (ret) - goto out; - - hlist_for_each_entry(child, &clk->children, child_node) - clk_debug_create_subtree(child, clk->dentry); - - ret = 0; -out: - return ret; -} - -/** - * clk_debug_register - add a clk node to the debugfs clk tree - * @clk: the clk being added to the debugfs clk tree - * - * Dynamically adds a clk to the debugfs clk tree if debugfs has been - * initialized. Otherwise it bails out early since the debugfs clk tree - * will be created lazily by clk_debug_init as part of a late_initcall. - * - * Caller must hold prepare_lock. Only clk_init calls this function (so - * far) so this is taken care. - */ -static int clk_debug_register(struct clk *clk) +static bool clk_core_is_prepared(struct clk_core *core) { - struct clk *parent; - struct dentry *pdentry; - int ret = 0; - - if (!inited) - goto out; - - parent = clk->parent; - /* - * Check to see if a clk is a root clk. Also check that it is - * safe to add this clk to debugfs + * .is_prepared is optional for clocks that can prepare + * fall back to software usage counter if it is missing */ - if (!parent) - if (clk->flags & CLK_IS_ROOT) - pdentry = rootdir; - else - pdentry = orphandir; - else - if (parent->dentry) - pdentry = parent->dentry; - else - goto out; - - ret = clk_debug_create_subtree(clk, pdentry); + if (!core->ops->is_prepared) + return core->prepare_count; -out: - return ret; + return core->ops->is_prepared(core->hw); } -/** - * clk_debug_reparent - reparent clk node in the debugfs clk tree - * @clk: the clk being reparented - * @new_parent: the new clk parent, may be NULL - * - * Rename clk entry in the debugfs clk tree if debugfs has been - * initialized. Otherwise it bails out early since the debugfs clk tree - * will be created lazily by clk_debug_init as part of a late_initcall. - * - * Caller must hold prepare_lock. - */ -static void clk_debug_reparent(struct clk *clk, struct clk *new_parent) +static bool clk_core_is_enabled(struct clk_core *core) { - struct dentry *d; - struct dentry *new_parent_d; - - if (!inited) - return; - - if (new_parent) - new_parent_d = new_parent->dentry; - else - new_parent_d = orphandir; + /* + * .is_enabled is only mandatory for clocks that gate + * fall back to software usage counter if .is_enabled is missing + */ + if (!core->ops->is_enabled) + return core->enable_count; - d = debugfs_rename(clk->dentry->d_parent, clk->dentry, - new_parent_d, clk->name); - if (d) - clk->dentry = d; - else - pr_debug("%s: failed to rename debugfs entry for %s\n", - __func__, clk->name); + return core->ops->is_enabled(core->hw); } -/** - * clk_debug_init - lazily create the debugfs clk tree visualization - * - * clks are often initialized very early during boot before memory can - * be dynamically allocated and well before debugfs is setup. - * clk_debug_init walks the clk tree hierarchy while holding - * prepare_lock and creates the topology as part of a late_initcall, - * thus insuring that clks initialized very early will still be - * represented in the debugfs clk tree. This function should only be - * called once at boot-time, and all other clks added dynamically will - * be done so with clk_debug_register. - */ -static int __init clk_debug_init(void) -{ - struct clk *clk; - struct dentry *d; - - rootdir = debugfs_create_dir("clk", NULL); - - if (!rootdir) - return -ENOMEM; - - d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, NULL, - &clk_summary_fops); - if (!d) - return -ENOMEM; - - d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, NULL, - &clk_dump_fops); - if (!d) - return -ENOMEM; - - orphandir = debugfs_create_dir("orphans", rootdir); - - if (!orphandir) - return -ENOMEM; - - clk_prepare_lock(); - - hlist_for_each_entry(clk, &clk_root_list, child_node) - clk_debug_create_subtree(clk, rootdir); - - hlist_for_each_entry(clk, &clk_orphan_list, child_node) - clk_debug_create_subtree(clk, orphandir); - - inited = 1; - - clk_prepare_unlock(); - - return 0; -} -late_initcall(clk_debug_init); -#else -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 void clk_unprepare_unused_subtree(struct clk_core *core) { -} -#endif + struct clk_core *child; -/* caller must hold prepare_lock */ -static void clk_unprepare_unused_subtree(struct clk *clk) -{ - struct clk *child; + lockdep_assert_held(&prepare_lock); - if (!clk) - return; - - hlist_for_each_entry(child, &clk->children, child_node) + hlist_for_each_entry(child, &core->children, child_node) clk_unprepare_unused_subtree(child); - if (clk->prepare_count) + if (core->prepare_count) return; - if (clk->flags & CLK_IGNORE_UNUSED) + if (core->flags & CLK_IGNORE_UNUSED) return; - if (__clk_is_prepared(clk)) { - if (clk->ops->unprepare_unused) - clk->ops->unprepare_unused(clk->hw); - else if (clk->ops->unprepare) - clk->ops->unprepare(clk->hw); + if (clk_core_is_prepared(core)) { + trace_clk_unprepare(core); + if (core->ops->unprepare_unused) + core->ops->unprepare_unused(core->hw); + else if (core->ops->unprepare) + core->ops->unprepare(core->hw); + trace_clk_unprepare_complete(core); } } -EXPORT_SYMBOL_GPL(__clk_get_flags); -/* caller must hold prepare_lock */ -static void clk_disable_unused_subtree(struct clk *clk) +static void clk_disable_unused_subtree(struct clk_core *core) { - struct clk *child; + struct clk_core *child; unsigned long flags; - if (!clk) - goto out; + lockdep_assert_held(&prepare_lock); - hlist_for_each_entry(child, &clk->children, child_node) + hlist_for_each_entry(child, &core->children, child_node) clk_disable_unused_subtree(child); flags = clk_enable_lock(); - if (clk->enable_count) + if (core->enable_count) goto unlock_out; - if (clk->flags & CLK_IGNORE_UNUSED) + if (core->flags & CLK_IGNORE_UNUSED) goto unlock_out; /* @@ -485,18 +223,17 @@ * sequence. call .disable_unused if available, otherwise fall * back to .disable */ - if (__clk_is_enabled(clk)) { - if (clk->ops->disable_unused) - clk->ops->disable_unused(clk->hw); - else if (clk->ops->disable) - clk->ops->disable(clk->hw); + if (clk_core_is_enabled(core)) { + trace_clk_disable(core); + if (core->ops->disable_unused) + core->ops->disable_unused(core->hw); + else if (core->ops->disable) + core->ops->disable(core->hw); + trace_clk_disable_complete(core); } unlock_out: clk_enable_unlock(flags); - -out: - return; } static bool clk_ignore_unused; @@ -509,7 +246,7 @@ static int clk_disable_unused(void) { - struct clk *clk; + struct clk_core *core; if (clk_ignore_unused) { pr_warn("clk: Not disabling unused clocks\n"); @@ -518,191 +255,349 @@ clk_prepare_lock(); - hlist_for_each_entry(clk, &clk_root_list, child_node) - clk_disable_unused_subtree(clk); + hlist_for_each_entry(core, &clk_root_list, child_node) + clk_disable_unused_subtree(core); - hlist_for_each_entry(clk, &clk_orphan_list, child_node) - clk_disable_unused_subtree(clk); + hlist_for_each_entry(core, &clk_orphan_list, child_node) + clk_disable_unused_subtree(core); - hlist_for_each_entry(clk, &clk_root_list, child_node) - clk_unprepare_unused_subtree(clk); + hlist_for_each_entry(core, &clk_root_list, child_node) + clk_unprepare_unused_subtree(core); - hlist_for_each_entry(clk, &clk_orphan_list, child_node) - clk_unprepare_unused_subtree(clk); + hlist_for_each_entry(core, &clk_orphan_list, child_node) + clk_unprepare_unused_subtree(core); clk_prepare_unlock(); return 0; } -late_initcall(clk_disable_unused); +late_initcall_sync(clk_disable_unused); /*** helper functions ***/ -const char *__clk_get_name(struct clk *clk) +const char *__clk_get_name(const struct clk *clk) { - return !clk ? NULL : clk->name; + return !clk ? NULL : clk->core->name; } EXPORT_SYMBOL_GPL(__clk_get_name); +const char *clk_hw_get_name(const struct clk_hw *hw) +{ + return hw->core->name; +} +EXPORT_SYMBOL_GPL(clk_hw_get_name); + struct clk_hw *__clk_get_hw(struct clk *clk) { - return !clk ? NULL : clk->hw; + return !clk ? NULL : clk->core->hw; } +EXPORT_SYMBOL_GPL(__clk_get_hw); -u8 __clk_get_num_parents(struct clk *clk) +unsigned int clk_hw_get_num_parents(const struct clk_hw *hw) { - return !clk ? 0 : clk->num_parents; + return hw->core->num_parents; } +EXPORT_SYMBOL_GPL(clk_hw_get_num_parents); -struct clk *__clk_get_parent(struct clk *clk) +struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw) { - return !clk ? NULL : clk->parent; + return hw->core->parent ? hw->core->parent->hw : NULL; } +EXPORT_SYMBOL_GPL(clk_hw_get_parent); -unsigned int __clk_get_enable_count(struct clk *clk) +static struct clk_core *__clk_lookup_subtree(const char *name, + struct clk_core *core) +{ + struct clk_core *child; + struct clk_core *ret; + + if (!strcmp(core->name, name)) + return core; + + hlist_for_each_entry(child, &core->children, child_node) { + ret = __clk_lookup_subtree(name, child); + if (ret) + return ret; + } + + return NULL; +} + +static struct clk_core *clk_core_lookup(const char *name) +{ + struct clk_core *root_clk; + struct clk_core *ret; + + if (!name) + return NULL; + + /* search the 'proper' clk tree first */ + hlist_for_each_entry(root_clk, &clk_root_list, child_node) { + ret = __clk_lookup_subtree(name, root_clk); + if (ret) + return ret; + } + + /* if not found, then search the orphan tree */ + hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { + ret = __clk_lookup_subtree(name, root_clk); + if (ret) + return ret; + } + + return NULL; +} + +static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core, + u8 index) +{ + if (!core || index >= core->num_parents) + return NULL; + else if (!core->parents) + return clk_core_lookup(core->parent_names[index]); + else if (!core->parents[index]) + return core->parents[index] = + clk_core_lookup(core->parent_names[index]); + else + return core->parents[index]; +} + +struct clk_hw * +clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index) { - return !clk ? 0 : clk->enable_count; + struct clk_core *parent; + + parent = clk_core_get_parent_by_index(hw->core, index); + + return !parent ? NULL : parent->hw; } +EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index); -unsigned int __clk_get_prepare_count(struct clk *clk) +unsigned int __clk_get_enable_count(struct clk *clk) { - return !clk ? 0 : clk->prepare_count; + return !clk ? 0 : clk->core->enable_count; } -unsigned long __clk_get_rate(struct clk *clk) +static unsigned long clk_core_get_rate_nolock(struct clk_core *core) { unsigned long ret; - if (!clk) { + if (!core) { ret = 0; goto out; } - ret = clk->rate; + ret = core->rate; - if (clk->flags & CLK_IS_ROOT) + if (core->flags & CLK_IS_ROOT) goto out; - if (!clk->parent) + if (!core->parent) ret = 0; out: return ret; } -unsigned long __clk_get_flags(struct clk *clk) +unsigned long clk_hw_get_rate(const struct clk_hw *hw) { - return !clk ? 0 : clk->flags; + return clk_core_get_rate_nolock(hw->core); } +EXPORT_SYMBOL_GPL(clk_hw_get_rate); -bool __clk_is_prepared(struct clk *clk) +static unsigned long __clk_get_accuracy(struct clk_core *core) { - int ret; + if (!core) + return 0; - if (!clk) - return false; + return core->accuracy; +} - /* - * .is_prepared is optional for clocks that can prepare - * fall back to software usage counter if it is missing - */ - if (!clk->ops->is_prepared) { - ret = clk->prepare_count ? 1 : 0; - goto out; - } +unsigned long __clk_get_flags(struct clk *clk) +{ + return !clk ? 0 : clk->core->flags; +} +EXPORT_SYMBOL_GPL(__clk_get_flags); - ret = clk->ops->is_prepared(clk->hw); -out: - return !!ret; +unsigned long clk_hw_get_flags(const struct clk_hw *hw) +{ + return hw->core->flags; } +EXPORT_SYMBOL_GPL(clk_hw_get_flags); -bool __clk_is_enabled(struct clk *clk) +bool clk_hw_is_prepared(const struct clk_hw *hw) { - int ret; + return clk_core_is_prepared(hw->core); +} + +bool clk_hw_is_enabled(const struct clk_hw *hw) +{ + return clk_core_is_enabled(hw->core); +} +bool __clk_is_enabled(struct clk *clk) +{ if (!clk) return false; - /* - * .is_enabled is only mandatory for clocks that gate - * fall back to software usage counter if .is_enabled is missing - */ - if (!clk->ops->is_enabled) { - ret = clk->enable_count ? 1 : 0; - goto out; - } + return clk_core_is_enabled(clk->core); +} +EXPORT_SYMBOL_GPL(__clk_is_enabled); - ret = clk->ops->is_enabled(clk->hw); -out: - return !!ret; +static bool mux_is_better_rate(unsigned long rate, unsigned long now, + unsigned long best, unsigned long flags) +{ + if (flags & CLK_MUX_ROUND_CLOSEST) + return abs(now - rate) < abs(best - rate); + + return now <= rate && now > best; } -static struct clk *__clk_lookup_subtree(const char *name, struct clk *clk) +static int +clk_mux_determine_rate_flags(struct clk_hw *hw, struct clk_rate_request *req, + unsigned long flags) { - struct clk *child; - struct clk *ret; + struct clk_core *core = hw->core, *parent, *best_parent = NULL; + int i, num_parents, ret; + unsigned long best = 0; + struct clk_rate_request parent_req = *req; - if (!strcmp(clk->name, name)) - return clk; + /* if NO_REPARENT flag set, pass through to current parent */ + if (core->flags & CLK_SET_RATE_NO_REPARENT) { + parent = core->parent; + if (core->flags & CLK_SET_RATE_PARENT) { + ret = __clk_determine_rate(parent ? parent->hw : NULL, + &parent_req); + if (ret) + return ret; - hlist_for_each_entry(child, &clk->children, child_node) { - ret = __clk_lookup_subtree(name, child); - if (ret) - return ret; + best = parent_req.rate; + } else if (parent) { + best = clk_core_get_rate_nolock(parent); + } else { + best = clk_core_get_rate_nolock(core); + } + + goto out; } - return NULL; + /* find the parent that can provide the fastest rate <= rate */ + num_parents = core->num_parents; + for (i = 0; i < num_parents; i++) { + parent = clk_core_get_parent_by_index(core, i); + if (!parent) + continue; + + if (core->flags & CLK_SET_RATE_PARENT) { + parent_req = *req; + ret = __clk_determine_rate(parent->hw, &parent_req); + if (ret) + continue; + } else { + parent_req.rate = clk_core_get_rate_nolock(parent); + } + + if (mux_is_better_rate(req->rate, parent_req.rate, + best, flags)) { + best_parent = parent; + best = parent_req.rate; + } + } + + if (!best_parent) + return -EINVAL; + +out: + if (best_parent) + req->best_parent_hw = best_parent->hw; + req->best_parent_rate = best; + req->rate = best; + + return 0; } struct clk *__clk_lookup(const char *name) { - struct clk *root_clk; - struct clk *ret; + struct clk_core *core = clk_core_lookup(name); - if (!name) - return NULL; + return !core ? NULL : core->hw->clk; +} - /* search the 'proper' clk tree first */ - hlist_for_each_entry(root_clk, &clk_root_list, child_node) { - ret = __clk_lookup_subtree(name, root_clk); - if (ret) - return ret; - } +static void clk_core_get_boundaries(struct clk_core *core, + unsigned long *min_rate, + unsigned long *max_rate) +{ + struct clk *clk_user; - /* if not found, then search the orphan tree */ - hlist_for_each_entry(root_clk, &clk_orphan_list, child_node) { - ret = __clk_lookup_subtree(name, root_clk); - if (ret) - return ret; - } + *min_rate = core->min_rate; + *max_rate = core->max_rate; - return NULL; + hlist_for_each_entry(clk_user, &core->clks, clks_node) + *min_rate = max(*min_rate, clk_user->min_rate); + + hlist_for_each_entry(clk_user, &core->clks, clks_node) + *max_rate = min(*max_rate, clk_user->max_rate); +} + +void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate, + unsigned long max_rate) +{ + hw->core->min_rate = min_rate; + hw->core->max_rate = max_rate; +} +EXPORT_SYMBOL_GPL(clk_hw_set_rate_range); + +/* + * Helper for finding best parent to provide a given frequency. This can be used + * directly as a determine_rate callback (e.g. for a mux), or from a more + * complex clock that may combine a mux with other operations. + */ +int __clk_mux_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + return clk_mux_determine_rate_flags(hw, req, 0); +} +EXPORT_SYMBOL_GPL(__clk_mux_determine_rate); + +int __clk_mux_determine_rate_closest(struct clk_hw *hw, + struct clk_rate_request *req) +{ + return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST); } +EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest); /*** clk api ***/ -void __clk_unprepare(struct clk *clk) +static void clk_core_unprepare(struct clk_core *core) { - if (!clk) + lockdep_assert_held(&prepare_lock); + + if (!core) + return; + + if (WARN_ON(core->prepare_count == 0)) return; - if (WARN_ON(clk->prepare_count == 0)) + if (WARN_ON(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL)) return; - if (--clk->prepare_count > 0) + if (--core->prepare_count > 0) return; - WARN_ON(clk->enable_count > 0); + WARN_ON(core->enable_count > 0); + + trace_clk_unprepare(core); - if (clk->ops->unprepare) - clk->ops->unprepare(clk->hw); + if (core->ops->unprepare) + core->ops->unprepare(core->hw); - __clk_unprepare(clk->parent); + trace_clk_unprepare_complete(core); + clk_core_unprepare(core->parent); } /** * clk_unprepare - undo preparation of a clock source - * @clk: the clk being unprepare + * @clk: the clk being unprepared * * clk_unprepare may sleep, which differentiates it from clk_disable. In a * simple case, clk_unprepare can be used instead of clk_disable to gate a clk @@ -713,34 +608,43 @@ */ void clk_unprepare(struct clk *clk) { + if (IS_ERR_OR_NULL(clk)) + return; + clk_prepare_lock(); - __clk_unprepare(clk); + clk_core_unprepare(clk->core); clk_prepare_unlock(); } EXPORT_SYMBOL_GPL(clk_unprepare); -int __clk_prepare(struct clk *clk) +static int clk_core_prepare(struct clk_core *core) { int ret = 0; - if (!clk) + lockdep_assert_held(&prepare_lock); + + if (!core) return 0; - if (clk->prepare_count == 0) { - ret = __clk_prepare(clk->parent); + if (core->prepare_count == 0) { + ret = clk_core_prepare(core->parent); if (ret) return ret; - if (clk->ops->prepare) { - ret = clk->ops->prepare(clk->hw); - if (ret) { - __clk_unprepare(clk->parent); - return ret; - } + trace_clk_prepare(core); + + if (core->ops->prepare) + ret = core->ops->prepare(core->hw); + + trace_clk_prepare_complete(core); + + if (ret) { + clk_core_unprepare(core->parent); + return ret; } } - clk->prepare_count++; + core->prepare_count++; return 0; } @@ -761,32 +665,43 @@ { int ret; + if (!clk) + return 0; + clk_prepare_lock(); - ret = __clk_prepare(clk); + ret = clk_core_prepare(clk->core); clk_prepare_unlock(); return ret; } EXPORT_SYMBOL_GPL(clk_prepare); -static void __clk_disable(struct clk *clk) +static void clk_core_disable(struct clk_core *core) { - if (!clk) + lockdep_assert_held(&enable_lock); + + if (!core) return; - if (WARN_ON(IS_ERR(clk))) + if (WARN_ON(core->enable_count == 0)) return; - if (WARN_ON(clk->enable_count == 0)) + if (WARN_ON(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL)) return; - if (--clk->enable_count > 0) + if (--core->enable_count > 0) return; - if (clk->ops->disable) - clk->ops->disable(clk->hw); + trace_clk_disable(core); + + pr_debug("%s: %s\n", __func__, core->name); + + if (core->ops->disable) + core->ops->disable(core->hw); - __clk_disable(clk->parent); + trace_clk_disable_complete(core); + + clk_core_disable(core->parent); } /** @@ -805,38 +720,49 @@ { unsigned long flags; + if (IS_ERR_OR_NULL(clk)) + return; + flags = clk_enable_lock(); - __clk_disable(clk); + clk_core_disable(clk->core); clk_enable_unlock(flags); } EXPORT_SYMBOL_GPL(clk_disable); -static int __clk_enable(struct clk *clk) +static int clk_core_enable(struct clk_core *core) { int ret = 0; - if (!clk) + lockdep_assert_held(&enable_lock); + + if (!core) return 0; - if (WARN_ON(clk->prepare_count == 0)) + if (WARN_ON(core->prepare_count == 0)) return -ESHUTDOWN; - if (clk->enable_count == 0) { - ret = __clk_enable(clk->parent); + if (core->enable_count == 0) { + ret = clk_core_enable(core->parent); if (ret) return ret; - if (clk->ops->enable) { - ret = clk->ops->enable(clk->hw); - if (ret) { - __clk_disable(clk->parent); - return ret; - } + trace_clk_enable(core); + + pr_debug("%s: %s\n", __func__, core->name); + + if (core->ops->enable) + ret = core->ops->enable(core->hw); + + trace_clk_enable_complete(core); + + if (ret) { + clk_core_disable(core->parent); + return ret; } } - clk->enable_count++; + core->enable_count++; return 0; } @@ -858,39 +784,90 @@ unsigned long flags; int ret; + if (!clk) + return 0; + flags = clk_enable_lock(); - ret = __clk_enable(clk); + ret = clk_core_enable(clk->core); clk_enable_unlock(flags); return ret; } EXPORT_SYMBOL_GPL(clk_enable); +static int clk_core_round_rate_nolock(struct clk_core *core, + struct clk_rate_request *req) +{ + struct clk_core *parent; + long rate; + + lockdep_assert_held(&prepare_lock); + + if (!core) + return 0; + + parent = core->parent; + if (parent) { + req->best_parent_hw = parent->hw; + req->best_parent_rate = parent->rate; + } else { + req->best_parent_hw = NULL; + req->best_parent_rate = 0; + } + + if (core->ops->determine_rate) { + return core->ops->determine_rate(core->hw, req); + } else if (core->ops->round_rate) { + rate = core->ops->round_rate(core->hw, req->rate, + &req->best_parent_rate); + if (rate < 0) + return rate; + + req->rate = rate; + } else if (core->flags & CLK_SET_RATE_PARENT) { + return clk_core_round_rate_nolock(parent, req); + } else { + req->rate = core->rate; + } + + return 0; +} + /** - * __clk_round_rate - round the given rate for a clk - * @clk: round the rate of this clock + * __clk_determine_rate - get the closest rate actually supported by a clock + * @hw: determine the rate of this clock + * @rate: target rate + * @min_rate: returned rate must be greater than this rate + * @max_rate: returned rate must be less than this rate * - * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate + * Useful for clk_ops such as .set_rate and .determine_rate. */ -unsigned long __clk_round_rate(struct clk *clk, unsigned long rate) +int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { - unsigned long parent_rate = 0; - - if (!clk) + if (!hw) { + req->rate = 0; return 0; - - if (!clk->ops->round_rate) { - if (clk->flags & CLK_SET_RATE_PARENT) - return __clk_round_rate(clk->parent, rate); - else - return clk->rate; } - if (clk->parent) - parent_rate = clk->parent->rate; + return clk_core_round_rate_nolock(hw->core, req); +} +EXPORT_SYMBOL_GPL(__clk_determine_rate); + +unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate) +{ + int ret; + struct clk_rate_request req; + + clk_core_get_boundaries(hw->core, &req.min_rate, &req.max_rate); + req.rate = rate; - return clk->ops->round_rate(clk->hw, rate, &parent_rate); + ret = clk_core_round_rate_nolock(hw->core, &req); + if (ret) + return 0; + + return req.rate; } +EXPORT_SYMBOL_GPL(clk_hw_round_rate); /** * clk_round_rate - round the given rate for a clk @@ -903,19 +880,30 @@ */ long clk_round_rate(struct clk *clk, unsigned long rate) { - unsigned long ret; + struct clk_rate_request req; + int ret; + + if (!clk) + return 0; clk_prepare_lock(); - ret = __clk_round_rate(clk, rate); + + clk_core_get_boundaries(clk->core, &req.min_rate, &req.max_rate); + req.rate = rate; + + ret = clk_core_round_rate_nolock(clk->core, &req); clk_prepare_unlock(); - return ret; + if (ret) + return ret; + + return req.rate; } EXPORT_SYMBOL_GPL(clk_round_rate); /** * __clk_notify - call clk notifier chain - * @clk: struct clk * that is changing rate + * @core: clk that is changing rate * @msg: clk notifier type (see include/linux/clk.h) * @old_rate: old clk rate * @new_rate: new clk rate @@ -927,22 +915,21 @@ * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if * a driver returns that. */ -static int __clk_notify(struct clk *clk, unsigned long msg, +static int __clk_notify(struct clk_core *core, unsigned long msg, unsigned long old_rate, unsigned long new_rate) { struct clk_notifier *cn; struct clk_notifier_data cnd; int ret = NOTIFY_DONE; - cnd.clk = clk; cnd.old_rate = old_rate; cnd.new_rate = new_rate; list_for_each_entry(cn, &clk_notifier_list, node) { - if (cn->clk == clk) { + if (cn->clk->core == core) { + cnd.clk = cn->clk; ret = srcu_notifier_call_chain(&cn->notifier_head, msg, &cnd); - break; } } @@ -950,46 +937,127 @@ } /** + * __clk_recalc_accuracies + * @core: 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 its + * parent. + */ +static void __clk_recalc_accuracies(struct clk_core *core) +{ + unsigned long parent_accuracy = 0; + struct clk_core *child; + + lockdep_assert_held(&prepare_lock); + + if (core->parent) + parent_accuracy = core->parent->accuracy; + + if (core->ops->recalc_accuracy) + core->accuracy = core->ops->recalc_accuracy(core->hw, + parent_accuracy); + else + core->accuracy = parent_accuracy; + + hlist_for_each_entry(child, &core->children, child_node) + __clk_recalc_accuracies(child); +} + +static long clk_core_get_accuracy(struct clk_core *core) +{ + unsigned long accuracy; + + clk_prepare_lock(); + if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE)) + __clk_recalc_accuracies(core); + + accuracy = __clk_get_accuracy(core); + clk_prepare_unlock(); + + return accuracy; +} + +/** + * 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) +{ + if (!clk) + return 0; + + return clk_core_get_accuracy(clk->core); +} +EXPORT_SYMBOL_GPL(clk_get_accuracy); + +static unsigned long clk_recalc(struct clk_core *core, + unsigned long parent_rate) +{ + if (core->ops->recalc_rate) + return core->ops->recalc_rate(core->hw, parent_rate); + return parent_rate; +} + +/** * __clk_recalc_rates - * @clk: first clk in the subtree + * @core: first clk in the subtree * @msg: notification type (see include/linux/clk.h) * * Walks the subtree of clks starting with clk and recalculates rates as it * goes. Note that if a clk does not implement the .recalc_rate callback then - * it is assumed that the clock will take on the rate of it's parent. + * it is assumed that the clock will take on the rate of its parent. * * clk_recalc_rates also propagates the POST_RATE_CHANGE notification, * if necessary. - * - * Caller must hold prepare_lock. */ -static void __clk_recalc_rates(struct clk *clk, unsigned long msg) +static void __clk_recalc_rates(struct clk_core *core, unsigned long msg) { unsigned long old_rate; unsigned long parent_rate = 0; - struct clk *child; + struct clk_core *child; - old_rate = clk->rate; + lockdep_assert_held(&prepare_lock); - if (clk->parent) - parent_rate = clk->parent->rate; + old_rate = core->rate; - if (clk->ops->recalc_rate) - clk->rate = clk->ops->recalc_rate(clk->hw, parent_rate); - else - clk->rate = parent_rate; + if (core->parent) + parent_rate = core->parent->rate; + + core->rate = clk_recalc(core, parent_rate); /* * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE * & ABORT_RATE_CHANGE notifiers */ - if (clk->notifier_count && msg) - __clk_notify(clk, msg, old_rate, clk->rate); + if (core->notifier_count && msg) + __clk_notify(core, msg, old_rate, core->rate); - hlist_for_each_entry(child, &clk->children, child_node) + hlist_for_each_entry(child, &core->children, child_node) __clk_recalc_rates(child, msg); } +static unsigned long clk_core_get_rate(struct clk_core *core) +{ + unsigned long rate; + + clk_prepare_lock(); + + if (core && (core->flags & CLK_GET_RATE_NOCACHE)) + __clk_recalc_rates(core, 0); + + rate = clk_core_get_rate_nolock(core); + clk_prepare_unlock(); + + return rate; +} + /** * clk_get_rate - return the rate of clk * @clk: the clk whose rate is being returned @@ -1000,23 +1068,180 @@ */ unsigned long clk_get_rate(struct clk *clk) { - unsigned long rate; + if (!clk) + return 0; - clk_prepare_lock(); + return clk_core_get_rate(clk->core); +} +EXPORT_SYMBOL_GPL(clk_get_rate); - if (clk && (clk->flags & CLK_GET_RATE_NOCACHE)) - __clk_recalc_rates(clk, 0); +static int clk_fetch_parent_index(struct clk_core *core, + struct clk_core *parent) +{ + int i; - rate = __clk_get_rate(clk); - clk_prepare_unlock(); + if (!core->parents) { + core->parents = kcalloc(core->num_parents, + sizeof(struct clk *), GFP_KERNEL); + if (!core->parents) + return -ENOMEM; + } - return rate; + /* + * find index of new parent clock using cached parent ptrs, + * or if not yet cached, use string name comparison and cache + * them now to avoid future calls to clk_core_lookup. + */ + for (i = 0; i < core->num_parents; i++) { + if (core->parents[i] == parent) + return i; + + if (core->parents[i]) + continue; + + if (!strcmp(core->parent_names[i], parent->name)) { + core->parents[i] = clk_core_lookup(parent->name); + return i; + } + } + + return -EINVAL; +} + +/* + * Update the orphan status of @core and all its children. + */ +static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan) +{ + struct clk_core *child; + + core->orphan = is_orphan; + + hlist_for_each_entry(child, &core->children, child_node) + clk_core_update_orphan_status(child, is_orphan); +} + +static void clk_reparent(struct clk_core *core, struct clk_core *new_parent) +{ + bool was_orphan = core->orphan; + + hlist_del(&core->child_node); + + if (new_parent) { + bool becomes_orphan = new_parent->orphan; + + /* avoid duplicate POST_RATE_CHANGE notifications */ + if (new_parent->new_child == core) + new_parent->new_child = NULL; + + hlist_add_head(&core->child_node, &new_parent->children); + + if (was_orphan != becomes_orphan) + clk_core_update_orphan_status(core, becomes_orphan); + } else { + hlist_add_head(&core->child_node, &clk_orphan_list); + if (!was_orphan) + clk_core_update_orphan_status(core, true); + } + + core->parent = new_parent; +} + +static struct clk_core *__clk_set_parent_before(struct clk_core *core, + struct clk_core *parent) +{ + unsigned long flags; + struct clk_core *old_parent = core->parent; + + /* + * Migrate prepare state between parents and prevent race with + * clk_enable(). + * + * If the clock is not prepared, then a race with + * clk_enable/disable() is impossible since we already have the + * prepare lock (future calls to clk_enable() need to be preceded by + * a clk_prepare()). + * + * If the clock is prepared, migrate the prepared state to the new + * parent and also protect against a race with clk_enable() by + * forcing the clock and the new parent on. This ensures that all + * future calls to clk_enable() are practically NOPs with respect to + * hardware and software states. + * + * See also: Comment for clk_set_parent() below. + */ + if (core->prepare_count) { + clk_core_prepare(parent); + flags = clk_enable_lock(); + clk_core_enable(parent); + clk_core_enable(core); + clk_enable_unlock(flags); + } + + /* update the clk tree topology */ + flags = clk_enable_lock(); + clk_reparent(core, parent); + clk_enable_unlock(flags); + + return old_parent; +} + +static void __clk_set_parent_after(struct clk_core *core, + struct clk_core *parent, + struct clk_core *old_parent) +{ + unsigned long flags; + + /* + * Finish the migration of prepare state and undo the changes done + * for preventing a race with clk_enable(). + */ + if (core->prepare_count) { + flags = clk_enable_lock(); + clk_core_disable(core); + clk_core_disable(old_parent); + clk_enable_unlock(flags); + clk_core_unprepare(old_parent); + } +} + +static int __clk_set_parent(struct clk_core *core, struct clk_core *parent, + u8 p_index) +{ + unsigned long flags; + int ret = 0; + struct clk_core *old_parent; + + old_parent = __clk_set_parent_before(core, parent); + + trace_clk_set_parent(core, parent); + + pr_debug("%s: clock %s reparented from %s to %s\n", + __func__, core->name, core->parent->name, parent->name); + + /* change clock input source */ + if (parent && core->ops->set_parent) + ret = core->ops->set_parent(core->hw, p_index); + + trace_clk_set_parent_complete(core, parent); + + if (ret) { + flags = clk_enable_lock(); + clk_reparent(core, old_parent); + clk_enable_unlock(flags); + __clk_set_parent_after(core, old_parent, parent); + + return ret; + } + + __clk_set_parent_after(core, parent, old_parent); + + return 0; } -EXPORT_SYMBOL_GPL(clk_get_rate); /** * __clk_speculate_rates - * @clk: first clk in the subtree + * @core: first clk in the subtree * @parent_rate: the "future" rate of clk's parent * * Walks the subtree of clks starting with clk, speculating rates as it @@ -1026,29 +1251,30 @@ * pre-rate change notifications and returns early if no clks in the * subtree have subscribed to the notifications. Note that if a clk does not * implement the .recalc_rate callback then it is assumed that the clock will - * take on the rate of it's parent. - * - * Caller must hold prepare_lock. + * take on the rate of its parent. */ -static int __clk_speculate_rates(struct clk *clk, unsigned long parent_rate) +static int __clk_speculate_rates(struct clk_core *core, + unsigned long parent_rate) { - struct clk *child; + struct clk_core *child; unsigned long new_rate; int ret = NOTIFY_DONE; - if (clk->ops->recalc_rate) - new_rate = clk->ops->recalc_rate(clk->hw, parent_rate); - else - new_rate = parent_rate; + lockdep_assert_held(&prepare_lock); + + new_rate = clk_recalc(core, parent_rate); /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */ - if (clk->notifier_count) - ret = __clk_notify(clk, PRE_RATE_CHANGE, clk->rate, new_rate); + if (core->notifier_count) + ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate); - if (ret & NOTIFY_STOP_MASK) + if (ret & NOTIFY_STOP_MASK) { + pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n", + __func__, core->name, ret); goto out; + } - hlist_for_each_entry(child, &clk->children, child_node) { + hlist_for_each_entry(child, &core->children, child_node) { ret = __clk_speculate_rates(child, new_rate); if (ret & NOTIFY_STOP_MASK) break; @@ -1058,18 +1284,36 @@ return ret; } -static void clk_calc_subtree(struct clk *clk, unsigned long new_rate) +static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate, + struct clk_core *new_parent, u8 p_index) { - struct clk *child; + struct clk_core *child, *parent; + struct clk_hw *parent_hw; + + core->new_rate = new_rate; + core->new_parent = new_parent; + core->new_parent_index = p_index; + /* include clk in new parent's PRE_RATE_CHANGE notifications */ + core->new_child = NULL; + if (new_parent && new_parent != core->parent) + new_parent->new_child = core; + + if (core->ops->get_safe_parent) { + parent_hw = core->ops->get_safe_parent(core->hw); + if (parent_hw) { + parent = parent_hw->core; + p_index = clk_fetch_parent_index(core, parent); + core->safe_parent_index = p_index; + core->safe_parent = parent; + } + } else { + core->safe_parent = NULL; + } - clk->new_rate = new_rate; - hlist_for_each_entry(child, &clk->children, child_node) { - if (child->ops->recalc_rate) - child->new_rate = child->ops->recalc_rate(child->hw, new_rate); - else - child->new_rate = new_rate; - clk_calc_subtree(child, child->new_rate); + hlist_for_each_entry(child, &core->children, child_node) { + child->new_rate = clk_recalc(child, new_rate); + clk_calc_subtree(child, child->new_rate, NULL, 0); } } @@ -1077,53 +1321,95 @@ * calculate the new rates returning the topmost clock that has to be * changed. */ -static struct clk *clk_calc_new_rates(struct clk *clk, unsigned long rate) +static struct clk_core *clk_calc_new_rates(struct clk_core *core, + unsigned long rate) { - struct clk *top = clk; + struct clk_core *top = core; + struct clk_core *old_parent, *parent; unsigned long best_parent_rate = 0; unsigned long new_rate; + unsigned long min_rate; + unsigned long max_rate; + int p_index = 0; + long ret; /* sanity */ - if (IS_ERR_OR_NULL(clk)) + if (IS_ERR_OR_NULL(core)) return NULL; /* save parent rate, if it exists */ - if (clk->parent) - best_parent_rate = clk->parent->rate; + parent = old_parent = core->parent; + if (parent) + best_parent_rate = parent->rate; + + clk_core_get_boundaries(core, &min_rate, &max_rate); + + /* find the closest rate and parent clk/rate */ + if (core->ops->determine_rate) { + struct clk_rate_request req; + + req.rate = rate; + req.min_rate = min_rate; + req.max_rate = max_rate; + if (parent) { + req.best_parent_hw = parent->hw; + req.best_parent_rate = parent->rate; + } else { + req.best_parent_hw = NULL; + req.best_parent_rate = 0; + } - /* never propagate up to the parent */ - if (!(clk->flags & CLK_SET_RATE_PARENT)) { - if (!clk->ops->round_rate) { - clk->new_rate = clk->rate; + ret = core->ops->determine_rate(core->hw, &req); + if (ret < 0) return NULL; - } - new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); + + best_parent_rate = req.best_parent_rate; + new_rate = req.rate; + parent = req.best_parent_hw ? req.best_parent_hw->core : NULL; + } else if (core->ops->round_rate) { + ret = core->ops->round_rate(core->hw, rate, + &best_parent_rate); + if (ret < 0) + return NULL; + + new_rate = ret; + if (new_rate < min_rate || new_rate > max_rate) + return NULL; + } else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) { + /* pass-through clock without adjustable parent */ + core->new_rate = core->rate; + return NULL; + } else { + /* pass-through clock with adjustable parent */ + top = clk_calc_new_rates(parent, rate); + new_rate = parent->new_rate; goto out; } - /* need clk->parent from here on out */ - if (!clk->parent) { - pr_debug("%s: %s has NULL parent\n", __func__, clk->name); + /* some clocks must be gated to change parent */ + if (parent != old_parent && + (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) { + pr_debug("%s: %s not gated but wants to reparent\n", + __func__, core->name); return NULL; } - if (!clk->ops->round_rate) { - top = clk_calc_new_rates(clk->parent, rate); - new_rate = clk->parent->new_rate; - - goto out; + /* try finding the new parent index */ + if (parent && core->num_parents > 1) { + p_index = clk_fetch_parent_index(core, parent); + if (p_index < 0) { + pr_debug("%s: clk %s can not be parent of clk %s\n", + __func__, parent->name, core->name); + return NULL; + } } - new_rate = clk->ops->round_rate(clk->hw, rate, &best_parent_rate); - - if (best_parent_rate != clk->parent->rate) { - top = clk_calc_new_rates(clk->parent, best_parent_rate); - - goto out; - } + if ((core->flags & CLK_SET_RATE_PARENT) && parent && + best_parent_rate != parent->rate) + top = clk_calc_new_rates(parent, best_parent_rate); out: - clk_calc_subtree(clk, new_rate); + clk_calc_subtree(core, new_rate, parent, p_index); return top; } @@ -1133,24 +1419,64 @@ * so that in case of an error we can walk down the whole tree again and * abort the change. */ -static struct clk *clk_propagate_rate_change(struct clk *clk, unsigned long event) +static struct clk_core *clk_propagate_rate_change(struct clk_core *core, + unsigned long event) { - struct clk *child, *fail_clk = NULL; + struct clk_core *child, *tmp_clk, *fail_clk = NULL; + struct clk_core *old_parent; int ret = NOTIFY_DONE; - if (clk->rate == clk->new_rate) + if (core->rate == core->new_rate && event != POST_RATE_CHANGE) return NULL; - if (clk->notifier_count) { - ret = __clk_notify(clk, event, clk->rate, clk->new_rate); - if (ret & NOTIFY_STOP_MASK) - fail_clk = clk; + switch (event) { + case PRE_RATE_CHANGE: + if (core->safe_parent) + core->ops->set_parent(core->hw, core->safe_parent_index); + core->old_rate = core->rate; + break; + case POST_RATE_CHANGE: + if (core->safe_parent) { + old_parent = __clk_set_parent_before(core, + core->new_parent); + if (core->ops->set_rate_and_parent) { + core->ops->set_rate_and_parent(core->hw, + core->new_rate, + core->new_parent ? + core->new_parent->rate : 0, + core->new_parent_index); + } else if (core->ops->set_parent) { + core->ops->set_parent(core->hw, + core->new_parent_index); + } + __clk_set_parent_after(core, core->new_parent, + old_parent); + } + break; + } + + if (core->notifier_count) { + if (event != POST_RATE_CHANGE || core->old_rate != core->rate) + ret = __clk_notify(core, event, core->old_rate, + core->new_rate); + if (ret & NOTIFY_STOP_MASK && event != POST_RATE_CHANGE) + fail_clk = core; } - hlist_for_each_entry(child, &clk->children, child_node) { - clk = clk_propagate_rate_change(child, event); - if (clk) - fail_clk = clk; + hlist_for_each_entry(child, &core->children, child_node) { + /* Skip children who will be reparented to another clock */ + if (child->new_parent && child->new_parent != core) + continue; + tmp_clk = clk_propagate_rate_change(child, event); + if (tmp_clk) + fail_clk = tmp_clk; + } + + /* handle the new child who might not be in core->children yet */ + if (core->new_child) { + tmp_clk = clk_propagate_rate_change(core->new_child, event); + if (tmp_clk) + fail_clk = tmp_clk; } return fail_clk; @@ -1160,30 +1486,110 @@ * walk down a subtree and set the new rates notifying the rate * change on the way */ -static void clk_change_rate(struct clk *clk) +static void clk_change_rate(struct clk_core *core) { - struct clk *child; + struct clk_core *child; + struct hlist_node *tmp; unsigned long old_rate; unsigned long best_parent_rate = 0; + bool skip_set_rate = false; + struct clk_core *old_parent; + + old_rate = core->rate; - old_rate = clk->rate; + if (core->new_parent) + best_parent_rate = core->new_parent->rate; + else if (core->parent) + best_parent_rate = core->parent->rate; + + if (core->new_parent && core->new_parent != core->parent && + !core->safe_parent) { + old_parent = __clk_set_parent_before(core, core->new_parent); + trace_clk_set_parent(core, core->new_parent); + + if (core->ops->set_rate_and_parent) { + skip_set_rate = true; + core->ops->set_rate_and_parent(core->hw, core->new_rate, + best_parent_rate, + core->new_parent_index); + } else if (core->ops->set_parent) { + core->ops->set_parent(core->hw, core->new_parent_index); + } - if (clk->parent) - best_parent_rate = clk->parent->rate; + trace_clk_set_parent_complete(core, core->new_parent); + __clk_set_parent_after(core, core->new_parent, old_parent); + } - if (clk->ops->set_rate) - clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate); + trace_clk_set_rate(core, core->new_rate); - if (clk->ops->recalc_rate) - clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate); - else - clk->rate = best_parent_rate; + pr_debug("%s: frequency for clock %s changed from %lu to %lu\n", + __func__, core->name, old_rate, core->new_rate); + + if (!skip_set_rate && core->ops->set_rate) + core->ops->set_rate(core->hw, core->new_rate, best_parent_rate); + + trace_clk_set_rate_complete(core, core->new_rate); - if (clk->notifier_count && old_rate != clk->rate) - __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate); + core->rate = clk_recalc(core, best_parent_rate); - hlist_for_each_entry(child, &clk->children, child_node) + if (core->flags & CLK_RECALC_NEW_RATES) + (void)clk_calc_new_rates(core, core->new_rate); + + /* + * Use safe iteration, as change_rate can actually swap parents + * for certain clock types. + */ + hlist_for_each_entry_safe(child, tmp, &core->children, child_node) { + /* Skip children who will be reparented to another clock */ + if (child->new_parent && child->new_parent != core) + continue; clk_change_rate(child); + } + + /* handle the new child who might not be in core->children yet */ + if (core->new_child) + clk_change_rate(core->new_child); +} + +static int clk_core_set_rate_nolock(struct clk_core *core, + unsigned long req_rate) +{ + struct clk_core *top, *fail_clk; + unsigned long rate = req_rate; + int ret = 0; + + if (!core) + return 0; + + /* bail early if nothing to do */ + if (rate == clk_core_get_rate_nolock(core)) + return 0; + + if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count) + return -EBUSY; + + /* calculate new rates and get the topmost changed clock */ + top = clk_calc_new_rates(core, rate); + if (!top) + return -EINVAL; + + /* notify that we are about to change rates */ + fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); + if (fail_clk) { + pr_debug("%s: failed to set %s rate\n", __func__, + fail_clk->name); + clk_propagate_rate_change(top, ABORT_RATE_CHANGE); + return -EBUSY; + } + + /* change the rates */ + clk_change_rate(top); + + core->req_rate = req_rate; + + clk_propagate_rate_change(top, POST_RATE_CHANGE); + + return ret; } /** @@ -1198,7 +1604,7 @@ * outcome of clk's .round_rate implementation. If *parent_rate is unchanged * after calling .round_rate then upstream parent propagation is ignored. If * *parent_rate comes back with a new rate for clk's parent then we propagate - * up to clk's parent and set it's rate. Upward propagation will continue + * up to clk's parent and set its rate. Upward propagation will continue * until either a clk does not support the CLK_SET_RATE_PARENT flag or * .round_rate stops requesting changes to clk's parent_rate. * @@ -1209,47 +1615,89 @@ */ int clk_set_rate(struct clk *clk, unsigned long rate) { - struct clk *top, *fail_clk; - int ret = 0; + int ret; + + if (!clk) + return 0; /* prevent racing with updates to the clock topology */ clk_prepare_lock(); - /* bail early if nothing to do */ - if (rate == clk->rate) - goto out; + ret = clk_core_set_rate_nolock(clk->core, rate); - if ((clk->flags & CLK_SET_RATE_GATE) && clk->prepare_count) { - ret = -EBUSY; - goto out; - } + clk_prepare_unlock(); - /* calculate new rates and get the topmost changed clock */ - top = clk_calc_new_rates(clk, rate); - if (!top) { - ret = -EINVAL; - goto out; - } + return ret; +} +EXPORT_SYMBOL_GPL(clk_set_rate); - /* notify that we are about to change rates */ - fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE); - if (fail_clk) { - pr_warn("%s: failed to set %s rate\n", __func__, - fail_clk->name); - clk_propagate_rate_change(top, ABORT_RATE_CHANGE); - ret = -EBUSY; - goto out; +/** + * clk_set_rate_range - set a rate range for a clock source + * @clk: clock source + * @min: desired minimum clock rate in Hz, inclusive + * @max: desired maximum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max) +{ + int ret = 0; + + if (!clk) + return 0; + + if (min > max) { + pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n", + __func__, clk->core->name, clk->dev_id, clk->con_id, + min, max); + return -EINVAL; } - /* change the rates */ - clk_change_rate(top); + clk_prepare_lock(); + + if (min != clk->min_rate || max != clk->max_rate) { + clk->min_rate = min; + clk->max_rate = max; + ret = clk_core_set_rate_nolock(clk->core, clk->core->req_rate); + } -out: clk_prepare_unlock(); return ret; } -EXPORT_SYMBOL_GPL(clk_set_rate); +EXPORT_SYMBOL_GPL(clk_set_rate_range); + +/** + * clk_set_min_rate - set a minimum clock rate for a clock source + * @clk: clock source + * @rate: desired minimum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_min_rate(struct clk *clk, unsigned long rate) +{ + if (!clk) + return 0; + + return clk_set_rate_range(clk, rate, clk->max_rate); +} +EXPORT_SYMBOL_GPL(clk_set_min_rate); + +/** + * clk_set_max_rate - set a maximum clock rate for a clock source + * @clk: clock source + * @rate: desired maximum clock rate in Hz, inclusive + * + * Returns success (0) or negative errno. + */ +int clk_set_max_rate(struct clk *clk, unsigned long rate) +{ + if (!clk) + return 0; + + return clk_set_rate_range(clk, clk->min_rate, rate); +} +EXPORT_SYMBOL_GPL(clk_set_max_rate); /** * clk_get_parent - return the parent of a clk @@ -1261,8 +1709,12 @@ { struct clk *parent; + if (!clk) + return NULL; + clk_prepare_lock(); - parent = __clk_get_parent(clk); + /* TODO: Create a per-user clk and change callers to call clk_put */ + parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk; clk_prepare_unlock(); return parent; @@ -1276,172 +1728,162 @@ * * For single-parent clocks without .get_parent, first check to see if the * .parents array exists, and if so use it to avoid an expensive tree - * traversal. If .parents does not exist then walk the tree with __clk_lookup. + * traversal. If .parents does not exist then walk the tree. */ -static struct clk *__clk_init_parent(struct clk *clk) +static struct clk_core *__clk_init_parent(struct clk_core *core) { - struct clk *ret = NULL; + struct clk_core *ret = NULL; u8 index; /* handle the trivial cases */ - if (!clk->num_parents) + if (!core->num_parents) goto out; - if (clk->num_parents == 1) { - if (IS_ERR_OR_NULL(clk->parent)) - ret = clk->parent = __clk_lookup(clk->parent_names[0]); - ret = clk->parent; + if (core->num_parents == 1) { + if (IS_ERR_OR_NULL(core->parent)) + core->parent = clk_core_lookup(core->parent_names[0]); + ret = core->parent; goto out; } - if (!clk->ops->get_parent) { - WARN(!clk->ops->get_parent, + if (!core->ops->get_parent) { + WARN(!core->ops->get_parent, "%s: multi-parent clocks must implement .get_parent\n", __func__); goto out; - }; + } /* - * Do our best to cache parent clocks in clk->parents. This prevents - * unnecessary and expensive calls to __clk_lookup. We don't set - * clk->parent here; that is done by the calling function + * Do our best to cache parent clocks in core->parents. This prevents + * unnecessary and expensive lookups. We don't set core->parent here; + * that is done by the calling function. */ - index = clk->ops->get_parent(clk->hw); + index = core->ops->get_parent(core->hw); - if (!clk->parents) - clk->parents = - kzalloc((sizeof(struct clk*) * clk->num_parents), + if (!core->parents) + core->parents = + kcalloc(core->num_parents, sizeof(struct clk *), GFP_KERNEL); - if (!clk->parents) - ret = __clk_lookup(clk->parent_names[index]); - else if (!clk->parents[index]) - ret = clk->parents[index] = - __clk_lookup(clk->parent_names[index]); - else - ret = clk->parents[index]; + ret = clk_core_get_parent_by_index(core, index); out: return ret; } -static void clk_reparent(struct clk *clk, struct clk *new_parent) +static void clk_core_reparent(struct clk_core *core, + struct clk_core *new_parent) { - hlist_del(&clk->child_node); - - if (new_parent) - hlist_add_head(&clk->child_node, &new_parent->children); - else - hlist_add_head(&clk->child_node, &clk_orphan_list); - - clk->parent = new_parent; + clk_reparent(core, new_parent); + __clk_recalc_accuracies(core); + __clk_recalc_rates(core, POST_RATE_CHANGE); } -void __clk_reparent(struct clk *clk, struct clk *new_parent) +void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent) { - clk_reparent(clk, new_parent); - clk_debug_reparent(clk, new_parent); - __clk_recalc_rates(clk, POST_RATE_CHANGE); + if (!hw) + return; + + clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core); } -static u8 clk_fetch_parent_index(struct clk *clk, struct clk *parent) +/** + * clk_has_parent - check if a clock is a possible parent for another + * @clk: clock source + * @parent: parent clock source + * + * This function can be used in drivers that need to check that a clock can be + * the parent of another without actually changing the parent. + * + * Returns true if @parent is a possible parent for @clk, false otherwise. + */ +bool clk_has_parent(struct clk *clk, struct clk *parent) { - u8 i; + struct clk_core *core, *parent_core; + unsigned int i; - if (!clk->parents) - clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), - GFP_KERNEL); + /* NULL clocks should be nops, so return success if either is NULL. */ + if (!clk || !parent) + return true; - /* - * find index of new parent clock using cached parent ptrs, - * or if not yet cached, use string name comparison and cache - * them now to avoid future calls to __clk_lookup. - */ - for (i = 0; i < clk->num_parents; i++) { - if (clk->parents && clk->parents[i] == parent) - break; - else if (!strcmp(clk->parent_names[i], parent->name)) { - if (clk->parents) - clk->parents[i] = __clk_lookup(parent->name); - break; - } - } + core = clk->core; + parent_core = parent->core; - return i; + /* Optimize for the case where the parent is already the parent. */ + if (core->parent == parent_core) + return true; + + for (i = 0; i < core->num_parents; i++) + if (strcmp(core->parent_names[i], parent_core->name) == 0) + return true; + + return false; } +EXPORT_SYMBOL_GPL(clk_has_parent); -static int __clk_set_parent(struct clk *clk, struct clk *parent, u8 p_index) +static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent) { - unsigned long flags; int ret = 0; - struct clk *old_parent = clk->parent; - bool migrated_enable = false; - - /* migrate prepare */ - if (clk->prepare_count) - __clk_prepare(parent); - - flags = clk_enable_lock(); - - /* migrate enable */ - if (clk->enable_count) { - __clk_enable(parent); - migrated_enable = true; - } + int p_index = 0; + unsigned long p_rate = 0; - /* update the clk tree topology */ - clk_reparent(clk, parent); + if (!core) + return 0; - clk_enable_unlock(flags); + /* prevent racing with updates to the clock topology */ + clk_prepare_lock(); - /* change clock input source */ - if (parent && clk->ops->set_parent) - ret = clk->ops->set_parent(clk->hw, p_index); + if (core->parent == parent) + goto out; - if (ret) { - /* - * The error handling is tricky due to that we need to release - * the spinlock while issuing the .set_parent callback. This - * means the new parent might have been enabled/disabled in - * between, which must be considered when doing rollback. - */ - flags = clk_enable_lock(); + /* verify ops for for multi-parent clks */ + if ((core->num_parents > 1) && (!core->ops->set_parent)) { + ret = -ENOSYS; + goto out; + } - clk_reparent(clk, old_parent); + /* check that we are allowed to re-parent if the clock is in use */ + if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) { + ret = -EBUSY; + goto out; + } - if (migrated_enable && clk->enable_count) { - __clk_disable(parent); - } else if (migrated_enable && (clk->enable_count == 0)) { - __clk_disable(old_parent); - } else if (!migrated_enable && clk->enable_count) { - __clk_disable(parent); - __clk_enable(old_parent); + /* try finding the new parent index */ + if (parent) { + p_index = clk_fetch_parent_index(core, parent); + p_rate = parent->rate; + if (p_index < 0) { + pr_debug("%s: clk %s can not be parent of clk %s\n", + __func__, parent->name, core->name); + ret = p_index; + goto out; } + } - clk_enable_unlock(flags); + /* propagate PRE_RATE_CHANGE notifications */ + ret = __clk_speculate_rates(core, p_rate); - if (clk->prepare_count) - __clk_unprepare(parent); + /* abort if a driver objects */ + if (ret & NOTIFY_STOP_MASK) + goto out; - return ret; - } + /* do the re-parent */ + ret = __clk_set_parent(core, parent, p_index); - /* clean up enable for old parent if migration was done */ - if (migrated_enable) { - flags = clk_enable_lock(); - __clk_disable(old_parent); - clk_enable_unlock(flags); + /* propagate rate an accuracy recalculation accordingly */ + if (ret) { + __clk_recalc_rates(core, ABORT_RATE_CHANGE); + } else { + __clk_recalc_rates(core, POST_RATE_CHANGE); + __clk_recalc_accuracies(core); } - /* clean up prepare for old parent if migration was done */ - if (clk->prepare_count) - __clk_unprepare(old_parent); +out: + clk_prepare_unlock(); - /* update debugfs with new clk tree topology */ - clk_debug_reparent(clk, parent); - return 0; + return ret; } /** @@ -1449,152 +1891,553 @@ * @clk: the mux clk whose input we are switching * @parent: the new input to clk * - * Re-parent clk to use parent as it's new input source. If clk has the - * CLK_SET_PARENT_GATE flag set then clk must be gated for this - * operation to succeed. After successfully changing clk's parent - * clk_set_parent will update the clk topology, sysfs topology and - * propagate rate recalculation via __clk_recalc_rates. Returns 0 on - * success, -EERROR otherwise. + * Re-parent clk to use parent as its new input source. If clk is in + * prepared state, the clk will get enabled for the duration of this call. If + * that's not acceptable for a specific clk (Eg: the consumer can't handle + * that, the reparenting is glitchy in hardware, etc), use the + * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared. + * + * After successfully changing clk's parent clk_set_parent will update the + * clk topology, sysfs topology and propagate rate recalculation via + * __clk_recalc_rates. + * + * Returns 0 on success, -EERROR otherwise. */ int clk_set_parent(struct clk *clk, struct clk *parent) { - int ret = 0; - u8 p_index = 0; - unsigned long p_rate = 0; + if (!clk) + return 0; - if (!clk || !clk->ops) - return -EINVAL; + return clk_core_set_parent(clk->core, parent ? parent->core : NULL); +} +EXPORT_SYMBOL_GPL(clk_set_parent); - /* verify ops for for multi-parent clks */ - if ((clk->num_parents > 1) && (!clk->ops->set_parent)) - return -ENOSYS; +/** + * clk_set_phase - adjust the phase shift of a clock signal + * @clk: clock signal source + * @degrees: number of degrees the signal is shifted + * + * Shifts the phase of a clock signal by the specified + * degrees. Returns 0 on success, -EERROR otherwise. + * + * This function makes no distinction about the input or reference + * signal that we adjust the clock signal phase against. For example + * phase locked-loop clock signal generators we may shift phase with + * respect to feedback clock signal input, but for other cases the + * clock phase may be shifted with respect to some other, unspecified + * signal. + * + * Additionally the concept of phase shift does not propagate through + * the clock tree hierarchy, which sets it apart from clock rates and + * clock accuracy. A parent clock phase attribute does not have an + * impact on the phase attribute of a child clock. + */ +int clk_set_phase(struct clk *clk, int degrees) +{ + int ret = -EINVAL; + + if (!clk) + return 0; + + /* sanity check degrees */ + degrees %= 360; + if (degrees < 0) + degrees += 360; - /* prevent racing with updates to the clock topology */ clk_prepare_lock(); - if (clk->parent == parent) - goto out; + trace_clk_set_phase(clk->core, degrees); - /* check that we are allowed to re-parent if the clock is in use */ - if ((clk->flags & CLK_SET_PARENT_GATE) && clk->prepare_count) { - ret = -EBUSY; - goto out; + if (clk->core->ops->set_phase) + ret = clk->core->ops->set_phase(clk->core->hw, degrees); + + trace_clk_set_phase_complete(clk->core, degrees); + + if (!ret) + clk->core->phase = degrees; + + clk_prepare_unlock(); + + return ret; +} +EXPORT_SYMBOL_GPL(clk_set_phase); + +static int clk_core_get_phase(struct clk_core *core) +{ + int ret; + + clk_prepare_lock(); + ret = core->phase; + clk_prepare_unlock(); + + return ret; +} + +/** + * clk_get_phase - return the phase shift of a clock signal + * @clk: clock signal source + * + * Returns the phase shift of a clock node in degrees, otherwise returns + * -EERROR. + */ +int clk_get_phase(struct clk *clk) +{ + if (!clk) + return 0; + + return clk_core_get_phase(clk->core); +} +EXPORT_SYMBOL_GPL(clk_get_phase); + +/** + * clk_is_match - check if two clk's point to the same hardware clock + * @p: clk compared against q + * @q: clk compared against p + * + * Returns true if the two struct clk pointers both point to the same hardware + * clock node. Put differently, returns true if struct clk *p and struct clk *q + * share the same struct clk_core object. + * + * Returns false otherwise. Note that two NULL clks are treated as matching. + */ +bool clk_is_match(const struct clk *p, const struct clk *q) +{ + /* trivial case: identical struct clk's or both NULL */ + if (p == q) + return true; + + /* true if clk->core pointers match. Avoid derefing garbage */ + if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q)) + if (p->core == q->core) + return true; + + return false; +} +EXPORT_SYMBOL_GPL(clk_is_match); + +/*** debugfs support ***/ + +#ifdef CONFIG_DEBUG_FS +#include + +static struct dentry *rootdir; +static int inited = 0; +static DEFINE_MUTEX(clk_debug_lock); +static HLIST_HEAD(clk_debug_list); + +static struct hlist_head *all_lists[] = { + &clk_root_list, + &clk_orphan_list, + NULL, +}; + +static struct hlist_head *orphan_list[] = { + &clk_orphan_list, + NULL, +}; + +static void clk_summary_show_one(struct seq_file *s, struct clk_core *c, + int level) +{ + if (!c) + return; + + seq_printf(s, "%*s%-*s %11d %12d %11lu %10lu %-3d\n", + level * 3 + 1, "", + 30 - level * 3, c->name, + c->enable_count, c->prepare_count, clk_core_get_rate(c), + clk_core_get_accuracy(c), clk_core_get_phase(c)); +} + +static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c, + int level) +{ + struct clk_core *child; + + if (!c) + return; + + clk_summary_show_one(s, c, level); + + hlist_for_each_entry(child, &c->children, child_node) + clk_summary_show_subtree(s, child, level + 1); +} + +static int clk_summary_show(struct seq_file *s, void *data) +{ + struct clk_core *c; + struct hlist_head **lists = (struct hlist_head **)s->private; + + seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n"); + seq_puts(s, "----------------------------------------------------------------------------------------\n"); + + clk_prepare_lock(); + + for (; *lists; lists++) + hlist_for_each_entry(c, *lists, child_node) + clk_summary_show_subtree(s, c, 0); + + clk_prepare_unlock(); + + return 0; +} + + +static int clk_summary_open(struct inode *inode, struct file *file) +{ + return single_open(file, clk_summary_show, inode->i_private); +} + +static const struct file_operations clk_summary_fops = { + .open = clk_summary_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level) +{ + if (!c) + return; + + /* This should be JSON format, i.e. elements separated with a comma */ + seq_printf(s, "\"%s\": { ", c->name); + seq_printf(s, "\"enable_count\": %d,", c->enable_count); + seq_printf(s, "\"prepare_count\": %d,", c->prepare_count); + seq_printf(s, "\"rate\": %lu,", clk_core_get_rate(c)); + seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy(c)); + seq_printf(s, "\"phase\": %d", clk_core_get_phase(c)); +} + +static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level) +{ + struct clk_core *child; + + if (!c) + return; + + clk_dump_one(s, c, level); + + hlist_for_each_entry(child, &c->children, child_node) { + seq_printf(s, ","); + clk_dump_subtree(s, child, level + 1); } - /* try finding the new parent index */ - if (parent) { - p_index = clk_fetch_parent_index(clk, parent); - p_rate = parent->rate; - if (p_index == clk->num_parents) { - pr_debug("%s: clk %s can not be parent of clk %s\n", - __func__, parent->name, clk->name); - ret = -EINVAL; - goto out; + seq_printf(s, "}"); +} + +static int clk_dump(struct seq_file *s, void *data) +{ + struct clk_core *c; + bool first_node = true; + struct hlist_head **lists = (struct hlist_head **)s->private; + + seq_printf(s, "{"); + + clk_prepare_lock(); + + for (; *lists; lists++) { + hlist_for_each_entry(c, *lists, child_node) { + if (!first_node) + seq_puts(s, ","); + first_node = false; + clk_dump_subtree(s, c, 0); } } - /* propagate PRE_RATE_CHANGE notifications */ - if (clk->notifier_count) - ret = __clk_speculate_rates(clk, p_rate); + clk_prepare_unlock(); - /* abort if a driver objects */ - if (ret & NOTIFY_STOP_MASK) + seq_puts(s, "}\n"); + return 0; +} + + +static int clk_dump_open(struct inode *inode, struct file *file) +{ + return single_open(file, clk_dump, inode->i_private); +} + +static const struct file_operations clk_dump_fops = { + .open = clk_dump_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry) +{ + struct dentry *d; + int ret = -ENOMEM; + + if (!core || !pdentry) { + ret = -EINVAL; goto out; + } - /* do the re-parent */ - ret = __clk_set_parent(clk, parent, p_index); + d = debugfs_create_dir(core->name, pdentry); + if (!d) + goto out; - /* propagate rate recalculation accordingly */ - if (ret) - __clk_recalc_rates(clk, ABORT_RATE_CHANGE); - else - __clk_recalc_rates(clk, POST_RATE_CHANGE); + core->dentry = d; + + d = debugfs_create_u32("clk_rate", S_IRUGO, core->dentry, + (u32 *)&core->rate); + if (!d) + goto err_out; + + d = debugfs_create_u32("clk_accuracy", S_IRUGO, core->dentry, + (u32 *)&core->accuracy); + if (!d) + goto err_out; + + d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry, + (u32 *)&core->phase); + if (!d) + goto err_out; + + d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry, + (u32 *)&core->flags); + if (!d) + goto err_out; + + d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry, + (u32 *)&core->prepare_count); + if (!d) + goto err_out; + + d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry, + (u32 *)&core->enable_count); + if (!d) + goto err_out; + + d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry, + (u32 *)&core->notifier_count); + if (!d) + goto err_out; + + if (core->ops->debug_init) { + ret = core->ops->debug_init(core->hw, core->dentry); + if (ret) + goto err_out; + } + + ret = 0; + goto out; +err_out: + debugfs_remove_recursive(core->dentry); + core->dentry = NULL; out: - clk_prepare_unlock(); + return ret; +} + +/** + * clk_debug_register - add a clk node to the debugfs clk directory + * @core: the clk being added to the debugfs clk directory + * + * Dynamically adds a clk to the debugfs clk directory if debugfs has been + * initialized. Otherwise it bails out early since the debugfs clk directory + * will be created lazily by clk_debug_init as part of a late_initcall. + */ +static int clk_debug_register(struct clk_core *core) +{ + int ret = 0; + + mutex_lock(&clk_debug_lock); + hlist_add_head(&core->debug_node, &clk_debug_list); + + if (!inited) + goto unlock; + + ret = clk_debug_create_one(core, rootdir); +unlock: + mutex_unlock(&clk_debug_lock); return ret; } -EXPORT_SYMBOL_GPL(clk_set_parent); + + /** + * clk_debug_unregister - remove a clk node from the debugfs clk directory + * @core: the clk being removed from the debugfs clk directory + * + * Dynamically removes a clk and all its child nodes from the + * debugfs clk directory if clk->dentry points to debugfs created by + * clk_debug_register in __clk_init. + */ +static void clk_debug_unregister(struct clk_core *core) +{ + mutex_lock(&clk_debug_lock); + hlist_del_init(&core->debug_node); + debugfs_remove_recursive(core->dentry); + core->dentry = NULL; + mutex_unlock(&clk_debug_lock); +} + +struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode, + void *data, const struct file_operations *fops) +{ + struct dentry *d = NULL; + + if (hw->core->dentry) + d = debugfs_create_file(name, mode, hw->core->dentry, data, + fops); + + return d; +} +EXPORT_SYMBOL_GPL(clk_debugfs_add_file); + +/** + * clk_debug_init - lazily populate the debugfs clk directory + * + * clks are often initialized very early during boot before memory can be + * dynamically allocated and well before debugfs is setup. This function + * populates the debugfs clk directory once at boot-time when we know that + * debugfs is setup. It should only be called once at boot-time, all other clks + * added dynamically will be done so with clk_debug_register. + */ +static int __init clk_debug_init(void) +{ + struct clk_core *core; + struct dentry *d; + + rootdir = debugfs_create_dir("clk", NULL); + + if (!rootdir) + return -ENOMEM; + + d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists, + &clk_summary_fops); + if (!d) + return -ENOMEM; + + d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists, + &clk_dump_fops); + if (!d) + return -ENOMEM; + + d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir, + &orphan_list, &clk_summary_fops); + if (!d) + return -ENOMEM; + + d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir, + &orphan_list, &clk_dump_fops); + if (!d) + return -ENOMEM; + + mutex_lock(&clk_debug_lock); + hlist_for_each_entry(core, &clk_debug_list, debug_node) + clk_debug_create_one(core, rootdir); + + inited = 1; + mutex_unlock(&clk_debug_lock); + + return 0; +} +late_initcall(clk_debug_init); +#else +static inline int clk_debug_register(struct clk_core *core) { return 0; } +static inline void clk_debug_reparent(struct clk_core *core, + struct clk_core *new_parent) +{ +} +static inline void clk_debug_unregister(struct clk_core *core) +{ +} +#endif /** * __clk_init - initialize the data structures in a struct clk * @dev: device initializing this clk, placeholder for now * @clk: clk being initialized * - * Initializes the lists in struct clk, queries the hardware for the + * Initializes the lists in struct clk_core, queries the hardware for the * parent and rate and sets them both. */ -int __clk_init(struct device *dev, struct clk *clk) +static int __clk_init(struct device *dev, struct clk *clk_user) { int i, ret = 0; - struct clk *orphan; + struct clk_core *orphan; struct hlist_node *tmp2; + struct clk_core *core; + unsigned long rate, enable_flags; - if (!clk) + if (!clk_user) return -EINVAL; + core = clk_user->core; + clk_prepare_lock(); + enable_flags = clk_enable_lock(); /* check to see if a clock with this name is already registered */ - if (__clk_lookup(clk->name)) { + if (clk_core_lookup(core->name)) { pr_debug("%s: clk %s already initialized\n", - __func__, clk->name); + __func__, core->name); ret = -EEXIST; goto out; } /* check that clk_ops are sane. See Documentation/clk.txt */ - if (clk->ops->set_rate && - !(clk->ops->round_rate && clk->ops->recalc_rate)) { - pr_warning("%s: %s must implement .round_rate & .recalc_rate\n", - __func__, clk->name); + if (core->ops->set_rate && + !((core->ops->round_rate || core->ops->determine_rate) && + core->ops->recalc_rate)) { + pr_warning("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n", + __func__, core->name); ret = -EINVAL; goto out; } - if (clk->ops->set_parent && !clk->ops->get_parent) { + if (core->ops->set_parent && !core->ops->get_parent) { pr_warning("%s: %s must implement .get_parent & .set_parent\n", - __func__, clk->name); + __func__, core->name); + ret = -EINVAL; + goto out; + } + + if (core->ops->set_rate_and_parent && + !(core->ops->set_parent && core->ops->set_rate)) { + pr_warn("%s: %s must implement .set_parent & .set_rate\n", + __func__, core->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], + for (i = 0; i < core->num_parents; i++) + WARN(!core->parent_names[i], "%s: invalid NULL in %s's .parent_names\n", - __func__, clk->name); + __func__, core->name); /* * Allocate an array of struct clk *'s to avoid unnecessary string * look-ups of clk's possible parents. This can fail for clocks passed - * in to clk_init during early boot; thus any access to clk->parents[] + * in to clk_init during early boot; thus any access to core->parents[] * must always check for a NULL pointer and try to populate it if * necessary. * - * If clk->parents is not NULL we skip this entire block. This allows - * for clock drivers to statically initialize clk->parents. + * If core->parents is not NULL we skip this entire block. This allows + * for clock drivers to statically initialize core->parents. */ - if (clk->num_parents > 1 && !clk->parents) { - clk->parents = kzalloc((sizeof(struct clk*) * clk->num_parents), - GFP_KERNEL); + if (core->num_parents > 1 && !core->parents) { + core->parents = kcalloc(core->num_parents, sizeof(struct clk *), + GFP_KERNEL); /* - * __clk_lookup returns NULL for parents that have not been + * clk_core_lookup returns NULL for parents that have not been * clk_init'd; thus any access to clk->parents[] must check * for a NULL pointer. We can always perform lazy lookups for * missing parents later on. */ - if (clk->parents) - for (i = 0; i < clk->num_parents; i++) - clk->parents[i] = - __clk_lookup(clk->parent_names[i]); + if (core->parents) + for (i = 0; i < core->num_parents; i++) + core->parents[i] = + clk_core_lookup(core->parent_names[i]); } - clk->parent = __clk_init_parent(clk); + core->parent = __clk_init_parent(core); /* - * Populate clk->parent if parent has already been __clk_init'd. If + * Populate core->parent if parent has already been __clk_init'd. If * parent has not yet been __clk_init'd then place clk in the orphan * list. If clk has set the CLK_IS_ROOT flag then place it in the root * clk list. @@ -1603,13 +2446,42 @@ * clocks and re-parent any that are children of the clock currently * being clk_init'd. */ - if (clk->parent) - hlist_add_head(&clk->child_node, - &clk->parent->children); - else if (clk->flags & CLK_IS_ROOT) - hlist_add_head(&clk->child_node, &clk_root_list); + if (core->parent) { + hlist_add_head(&core->child_node, + &core->parent->children); + core->orphan = core->parent->orphan; + } else if (core->flags & CLK_IS_ROOT) { + hlist_add_head(&core->child_node, &clk_root_list); + core->orphan = false; + } else { + hlist_add_head(&core->child_node, &clk_orphan_list); + core->orphan = true; + } + + /* + * 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 (core->ops->recalc_accuracy) + core->accuracy = core->ops->recalc_accuracy(core->hw, + __clk_get_accuracy(core->parent)); + else if (core->parent) + core->accuracy = core->parent->accuracy; + else + core->accuracy = 0; + + /* + * Set clk's phase. + * Since a phase is by definition relative to its parent, just + * query the current clock phase, or just assume it's in phase. + */ + if (core->ops->get_phase) + core->phase = core->ops->get_phase(core->hw); else - hlist_add_head(&clk->child_node, &clk_orphan_list); + core->phase = 0; /* * Set clk's rate. The preferred method is to use .recalc_rate. For @@ -1617,29 +2489,31 @@ * parent's rate. If a clock doesn't have a parent (or is orphaned) * then rate is set to zero. */ - if (clk->ops->recalc_rate) - clk->rate = clk->ops->recalc_rate(clk->hw, - __clk_get_rate(clk->parent)); - else if (clk->parent) - clk->rate = clk->parent->rate; + if (core->ops->recalc_rate) + rate = core->ops->recalc_rate(core->hw, + clk_core_get_rate_nolock(core->parent)); + else if (core->parent) + rate = core->parent->rate; else - clk->rate = 0; + rate = 0; + core->rate = core->req_rate = rate; /* * walk the list of orphan clocks and reparent any that are children of * this clock */ hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) { - if (orphan->ops->get_parent) { + if (orphan->num_parents && orphan->ops->get_parent) { i = orphan->ops->get_parent(orphan->hw); - if (!strcmp(clk->name, orphan->parent_names[i])) - __clk_reparent(orphan, clk); + if (i >= 0 && i < orphan->num_parents && + !strcmp(core->name, orphan->parent_names[i])) + clk_core_reparent(orphan, core); continue; } for (i = 0; i < orphan->num_parents; i++) - if (!strcmp(clk->name, orphan->parent_names[i])) { - __clk_reparent(orphan, clk); + if (!strcmp(core->name, orphan->parent_names[i])) { + clk_core_reparent(orphan, core); break; } } @@ -1650,154 +2524,250 @@ * The .init callback is not used by any of the basic clock types, but * exists for weird hardware that must perform initialization magic. * Please consider other ways of solving initialization problems before - * using this callback, as it's use is discouraged. + * using this callback, as its use is discouraged. */ - if (clk->ops->init) - clk->ops->init(clk->hw); + if (core->ops->init) + core->ops->init(core->hw); - clk_debug_register(clk); + if (core->flags & CLK_IS_CRITICAL) { + clk_core_prepare(core); + clk_core_enable(core); + } + kref_init(&core->ref); out: + clk_enable_unlock(enable_flags); clk_prepare_unlock(); + if (!ret) + clk_debug_register(core); + return ret; } -/** - * __clk_register - register a clock and return a cookie. - * - * Same as clk_register, except that the .clk field inside hw shall point to a - * preallocated (generally statically allocated) struct clk. None of the fields - * of the struct clk need to be initialized. - * - * The data pointed to by .init and .clk field shall NOT be marked as init - * data. - * - * __clk_register is only exposed via clk-private.h and is intended for use with - * very large numbers of clocks that need to be statically initialized. It is - * a layering violation to include clk-private.h from any code which implements - * a clock's .ops; as such any statically initialized clock data MUST be in a - * separate C file from the logic that implements it's operations. Returns 0 - * on success, otherwise an error code. - */ -struct clk *__clk_register(struct device *dev, struct clk_hw *hw) +struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id, + const char *con_id) { - int ret; struct clk *clk; - clk = hw->clk; - clk->name = hw->init->name; - clk->ops = hw->init->ops; - clk->hw = hw; - clk->flags = hw->init->flags; - clk->parent_names = hw->init->parent_names; - clk->num_parents = hw->init->num_parents; + /* This is to allow this function to be chained to others */ + if (!hw || IS_ERR(hw)) + return (struct clk *) hw; - ret = __clk_init(dev, clk); - if (ret) - return ERR_PTR(ret); + clk = kzalloc(sizeof(*clk), GFP_KERNEL); + if (!clk) + return ERR_PTR(-ENOMEM); + + clk->core = hw->core; + clk->dev_id = dev_id; + clk->con_id = con_id; + clk->max_rate = ULONG_MAX; + + clk_prepare_lock(); + hlist_add_head(&clk->clks_node, &hw->core->clks); + clk_prepare_unlock(); return clk; } -EXPORT_SYMBOL_GPL(__clk_register); -static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk) +void __clk_free_clk(struct clk *clk) +{ + clk_prepare_lock(); + hlist_del(&clk->clks_node); + clk_prepare_unlock(); + + kfree(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 + * + * clk_register is the primary interface for populating the clock tree with new + * clock nodes. It returns a pointer to the newly allocated struct clk which + * cannot be dereferenced by driver code but may be used in conjunction with the + * rest of the clock API. In the event of an error clk_register will return an + * error code; drivers must test for an error code after calling clk_register. + */ +struct clk *clk_register(struct device *dev, struct clk_hw *hw) { int i, ret; + struct clk_core *core; + + core = kzalloc(sizeof(*core), GFP_KERNEL); + if (!core) { + ret = -ENOMEM; + goto fail_out; + } - clk->name = kstrdup(hw->init->name, GFP_KERNEL); - if (!clk->name) { - pr_err("%s: could not allocate clk->name\n", __func__); + core->name = kstrdup_const(hw->init->name, GFP_KERNEL); + if (!core->name) { ret = -ENOMEM; goto fail_name; } - clk->ops = hw->init->ops; - clk->hw = hw; - clk->flags = hw->init->flags; - clk->num_parents = hw->init->num_parents; - hw->clk = clk; + core->ops = hw->init->ops; + if (dev && dev->driver) + core->owner = dev->driver->owner; + core->hw = hw; + core->flags = hw->init->flags; + core->num_parents = hw->init->num_parents; + core->min_rate = 0; + core->max_rate = ULONG_MAX; + hw->core = core; /* allocate local copy in case parent_names is __initdata */ - clk->parent_names = kzalloc((sizeof(char*) * clk->num_parents), - GFP_KERNEL); + core->parent_names = kcalloc(core->num_parents, sizeof(char *), + GFP_KERNEL); - if (!clk->parent_names) { - pr_err("%s: could not allocate clk->parent_names\n", __func__); + if (!core->parent_names) { ret = -ENOMEM; goto fail_parent_names; } /* copy each string name in case parent_names is __initdata */ - for (i = 0; i < clk->num_parents; i++) { - clk->parent_names[i] = kstrdup(hw->init->parent_names[i], + for (i = 0; i < core->num_parents; i++) { + core->parent_names[i] = kstrdup_const(hw->init->parent_names[i], GFP_KERNEL); - if (!clk->parent_names[i]) { - pr_err("%s: could not copy parent_names\n", __func__); + if (!core->parent_names[i]) { ret = -ENOMEM; goto fail_parent_names_copy; } } - ret = __clk_init(dev, clk); + INIT_HLIST_HEAD(&core->clks); + + hw->clk = __clk_create_clk(hw, NULL, NULL); + if (IS_ERR(hw->clk)) { + ret = PTR_ERR(hw->clk); + goto fail_parent_names_copy; + } + + ret = __clk_init(dev, hw->clk); if (!ret) - return 0; + return hw->clk; + + __clk_free_clk(hw->clk); + hw->clk = NULL; fail_parent_names_copy: while (--i >= 0) - kfree(clk->parent_names[i]); - kfree(clk->parent_names); + kfree_const(core->parent_names[i]); + kfree(core->parent_names); fail_parent_names: - kfree(clk->name); + kfree_const(core->name); fail_name: - return ret; + kfree(core); +fail_out: + return ERR_PTR(ret); } +EXPORT_SYMBOL_GPL(clk_register); -/** - * 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 - * - * clk_register is the primary interface for populating the clock tree with new - * clock nodes. It returns a pointer to the newly allocated struct clk which - * cannot be dereferenced by driver code but may be used in conjuction with the - * rest of the clock API. In the event of an error clk_register will return an - * error code; drivers must test for an error code after calling clk_register. +/* Free memory allocated for a clock. */ +static void __clk_release(struct kref *ref) +{ + struct clk_core *core = container_of(ref, struct clk_core, ref); + int i = core->num_parents; + + lockdep_assert_held(&prepare_lock); + + kfree(core->parents); + while (--i >= 0) + kfree_const(core->parent_names[i]); + + kfree(core->parent_names); + kfree_const(core->name); + kfree(core); +} + +/* + * 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. */ -struct clk *clk_register(struct device *dev, struct clk_hw *hw) +static int clk_nodrv_prepare_enable(struct clk_hw *hw) { - int ret; - struct clk *clk; + return -ENXIO; +} - clk = kzalloc(sizeof(*clk), GFP_KERNEL); - if (!clk) { - pr_err("%s: could not allocate clk\n", __func__); - ret = -ENOMEM; - goto fail_out; - } +static void clk_nodrv_disable_unprepare(struct clk_hw *hw) +{ + WARN_ON_ONCE(1); +} - ret = _clk_register(dev, hw, clk); - if (!ret) - return clk; +static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + return -ENXIO; +} - kfree(clk); -fail_out: - return ERR_PTR(ret); +static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index) +{ + return -ENXIO; } -EXPORT_SYMBOL_GPL(clk_register); + +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_debug_unregister(clk->core); + + clk_prepare_lock(); + + if (clk->core->ops == &clk_nodrv_ops) { + pr_err("%s: unregistered clock: %s\n", __func__, + clk->core->name); + return; + } + /* + * Assign empty clock ops for consumers that might still hold + * a reference to this clock. + */ + flags = clk_enable_lock(); + clk->core->ops = &clk_nodrv_ops; + clk_enable_unlock(flags); + + if (!hlist_empty(&clk->core->children)) { + struct clk_core *child; + struct hlist_node *t; + + /* Reparent all children to the orphan list. */ + hlist_for_each_entry_safe(child, t, &clk->core->children, + child_node) + clk_core_set_parent(child, NULL); + } + + hlist_del_init(&clk->core->child_node); + + if (clk->core->prepare_count) + pr_warn("%s: unregistering prepared clock: %s\n", + __func__, clk->core->name); + kref_put(&clk->core->ref, __clk_release); + + clk_prepare_unlock(); +} EXPORT_SYMBOL_GPL(clk_unregister); static void devm_clk_release(struct device *dev, void *res) { - clk_unregister(res); + clk_unregister(*(struct clk **)res); } /** @@ -1812,18 +2782,18 @@ struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw) { struct clk *clk; - int ret; + struct clk **clkp; - clk = devres_alloc(devm_clk_release, sizeof(*clk), GFP_KERNEL); - if (!clk) + clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL); + if (!clkp) return ERR_PTR(-ENOMEM); - ret = _clk_register(dev, hw, clk); - if (!ret) { - devres_add(dev, clk); + clk = clk_register(dev, hw); + if (!IS_ERR(clk)) { + *clkp = clk; + devres_add(dev, clkp); } else { - devres_free(clk); - clk = ERR_PTR(ret); + devres_free(clkp); } return clk; @@ -1852,6 +2822,46 @@ } EXPORT_SYMBOL_GPL(devm_clk_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; +} + +void __clk_put(struct clk *clk) +{ + struct module *owner; + + if (!clk || WARN_ON_ONCE(IS_ERR(clk))) + return; + + clk_prepare_lock(); + + hlist_del(&clk->clks_node); + if (clk->min_rate > clk->core->req_rate || + clk->max_rate < clk->core->req_rate) + clk_core_set_rate_nolock(clk->core, clk->core->req_rate); + + owner = clk->core->owner; + kref_put(&clk->core->ref, __clk_release); + + clk_prepare_unlock(); + + module_put(owner); + + kfree(clk); +} + /*** clk rate change notifiers ***/ /** @@ -1865,20 +2875,11 @@ * re-enter into the clk framework by calling any top-level clk APIs; * this will cause a nested prepare_lock mutex. * - * Pre-change notifier callbacks will be passed the current, pre-change - * rate of the clk via struct clk_notifier_data.old_rate. The new, - * post-change rate of the clk is passed via struct - * clk_notifier_data.new_rate. - * - * Post-change notifiers will pass the now-current, post-change rate of - * the clk in both struct clk_notifier_data.old_rate and struct + * In all notification cases cases (pre, post and abort rate change) the + * original clock rate is passed to the callback via struct + * clk_notifier_data.old_rate and the new frequency is passed via struct * clk_notifier_data.new_rate. * - * Abort-change notifiers are effectively the opposite of pre-change - * notifiers: the original pre-change clk rate is passed in via struct - * clk_notifier_data.new_rate and the failed post-change rate is passed - * in via struct clk_notifier_data.old_rate. - * * clk_notifier_register() must be called from non-atomic context. * Returns -EINVAL if called with null arguments, -ENOMEM upon * allocation failure; otherwise, passes along the return value of @@ -1913,7 +2914,7 @@ ret = srcu_notifier_chain_register(&cn->notifier_head, nb); - clk->notifier_count++; + clk->core->notifier_count++; out: clk_prepare_unlock(); @@ -1950,7 +2951,7 @@ if (cn->clk == clk) { ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb); - clk->notifier_count--; + clk->core->notifier_count--; /* XXX the notifier code should handle this better */ if (!cn->notifier_head.head) { @@ -1986,13 +2987,11 @@ void *data; }; -extern struct of_device_id __clk_of_table[]; - 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); struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec, void *data) @@ -2007,7 +3006,7 @@ unsigned int idx = clkspec->args[0]; if (idx >= clk_data->clk_num) { - pr_err("%s: invalid clock index %d\n", __func__, idx); + pr_err("%s: invalid clock index %u\n", __func__, idx); return ERR_PTR(-EINVAL); } @@ -2027,6 +3026,7 @@ void *data) { struct of_clk_provider *cp; + int ret; cp = kzalloc(sizeof(struct of_clk_provider), GFP_KERNEL); if (!cp) @@ -2036,12 +3036,16 @@ 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; + ret = of_clk_set_defaults(np, true); + if (ret < 0) + of_clk_del_provider(np); + + return ret; } EXPORT_SYMBOL_GPL(of_clk_add_provider); @@ -2053,7 +3057,7 @@ { 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); @@ -2062,33 +3066,70 @@ 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, + const char *dev_id, const char *con_id) { struct of_clk_provider *provider; - struct clk *clk = ERR_PTR(-ENOENT); + struct clk *clk = ERR_PTR(-EPROBE_DEFER); + + if (!clkspec) + return ERR_PTR(-EINVAL); /* Check if we have such a provider in our array */ - mutex_lock(&of_clk_lock); + mutex_lock(&of_clk_mutex); list_for_each_entry(provider, &of_clk_providers, link) { if (provider->node == clkspec->np) clk = provider->get(clkspec, provider->data); - if (!IS_ERR(clk)) + if (!IS_ERR(clk)) { + clk = __clk_create_clk(__clk_get_hw(clk), dev_id, + con_id); + + if (!IS_ERR(clk) && !__clk_get(clk)) { + __clk_free_clk(clk); + clk = ERR_PTR(-ENOENT); + } + break; + } } - mutex_unlock(&of_clk_lock); + mutex_unlock(&of_clk_mutex); return clk; } +/** + * of_clk_get_from_provider() - Lookup a clock from a clock provider + * @clkspec: pointer to a clock specifier data structure + * + * This function looks up a struct clk from the registered list of clock + * providers, an input is a clock specifier data structure as returned + * from the of_parse_phandle_with_args() function call. + */ +struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec) +{ + return __of_clk_get_from_provider(clkspec, NULL, __func__); +} + +int of_clk_get_parent_count(struct device_node *np) +{ + return of_count_phandle_with_args(np, "clocks", "#clock-cells"); +} +EXPORT_SYMBOL_GPL(of_clk_get_parent_count); + const char *of_clk_get_parent_name(struct device_node *np, int index) { struct of_phandle_args clkspec; + struct property *prop; const char *clk_name; + const __be32 *vp; + u32 pv; int rc; + int count; + struct clk *clk; if (index < 0) return NULL; @@ -2098,10 +3139,41 @@ if (rc) return NULL; + index = clkspec.args_count ? clkspec.args[0] : 0; + count = 0; + + /* if there is an indices property, use it to transfer the index + * specified into an array offset for the clock-output-names property. + */ + of_property_for_each_u32(clkspec.np, "clock-indices", prop, vp, pv) { + if (index == pv) { + index = count; + break; + } + count++; + } + if (of_property_read_string_index(clkspec.np, "clock-output-names", - clkspec.args_count ? clkspec.args[0] : 0, - &clk_name) < 0) - clk_name = clkspec.np->name; + index, + &clk_name) < 0) { + /* + * Best effort to get the name if the clock has been + * registered with the framework. If the clock isn't + * registered, we return the node name as the name of + * the clock as long as #clock-cells = 0. + */ + clk = of_clk_get_from_provider(&clkspec); + if (IS_ERR(clk)) { + if (clkspec.args_count == 0) + clk_name = clkspec.np->name; + else + clk_name = NULL; + } else { + clk_name = __clk_get_name(clk); + clk_put(clk); + } + } + of_node_put(clkspec.np); return clk_name; @@ -2109,23 +3181,132 @@ EXPORT_SYMBOL_GPL(of_clk_get_parent_name); /** + * of_clk_parent_fill() - Fill @parents with names of @np's parents and return + * number of parents + * @np: Device node pointer associated with clock provider + * @parents: pointer to char array that hold the parents' names + * @size: size of the @parents array + * + * Return: number of parents for the clock node. + */ +int of_clk_parent_fill(struct device_node *np, const char **parents, + unsigned int size) +{ + unsigned int i = 0; + + while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL) + i++; + + return i; +} +EXPORT_SYMBOL_GPL(of_clk_parent_fill); + +struct clock_provider { + of_clk_init_cb_t clk_init_cb; + struct device_node *np; + struct list_head node; +}; + +/* + * This function looks for a parent clock. If there is one, then it + * checks that the provider for this parent clock was initialized, in + * this case the parent clock will be ready. + */ +static int parent_ready(struct device_node *np) +{ + int i = 0; + + while (true) { + struct clk *clk = of_clk_get(np, i); + + /* this parent is ready we can check the next one */ + if (!IS_ERR(clk)) { + clk_put(clk); + i++; + continue; + } + + /* at least one parent is not ready, we exit now */ + if (PTR_ERR(clk) == -EPROBE_DEFER) + return 0; + + /* + * Here we make assumption that the device tree is + * written correctly. So an error means that there is + * no more parent. As we didn't exit yet, then the + * previous parent are ready. If there is no clock + * parent, no need to wait for them, then we can + * consider their absence as being ready + */ + return 1; + } +} + +/** * of_clk_init() - Scan and init clock providers from the DT * @matches: array of compatible values and init functions for providers. * - * This function scans the device tree for matching clock providers and - * calls their initialization functions + * This function scans the device tree for matching clock providers + * and calls their initialization functions. It also does it by trying + * to follow the dependencies. */ void __init of_clk_init(const struct of_device_id *matches) { + const struct of_device_id *match; struct device_node *np; + struct clock_provider *clk_provider, *next; + bool is_init_done; + bool force = false; + LIST_HEAD(clk_provider_list); if (!matches) - matches = __clk_of_table; + matches = &__clk_of_table; + + /* First prepare the list of the clocks providers */ + for_each_matching_node_and_match(np, matches, &match) { + struct clock_provider *parent; + + parent = kzalloc(sizeof(*parent), GFP_KERNEL); + if (!parent) { + list_for_each_entry_safe(clk_provider, next, + &clk_provider_list, node) { + list_del(&clk_provider->node); + of_node_put(clk_provider->np); + kfree(clk_provider); + } + of_node_put(np); + return; + } - for_each_matching_node(np, matches) { - const struct of_device_id *match = of_match_node(matches, np); - of_clk_init_cb_t clk_init_cb = match->data; - clk_init_cb(np); + parent->clk_init_cb = match->data; + parent->np = of_node_get(np); + list_add_tail(&parent->node, &clk_provider_list); + } + + while (!list_empty(&clk_provider_list)) { + is_init_done = false; + list_for_each_entry_safe(clk_provider, next, + &clk_provider_list, node) { + if (force || parent_ready(clk_provider->np)) { + + clk_provider->clk_init_cb(clk_provider->np); + of_clk_set_defaults(clk_provider->np, true); + + list_del(&clk_provider->node); + of_node_put(clk_provider->np); + kfree(clk_provider); + is_init_done = true; + } + } + + /* + * We didn't manage to initialize any of the + * remaining providers during the last loop, so now we + * initialize all the remaining ones unconditionally + * in case the clock parent was not mandatory + */ + if (!is_init_done) + force = true; } } #endif