static HLIST_HEAD(clk_orphan_list);
static LIST_HEAD(clk_notifier_list);
-static long clk_core_get_accuracy(struct clk_core *core);
-static unsigned long clk_core_get_rate(struct clk_core *core);
-static int clk_core_get_phase(struct clk_core *core);
-static bool clk_core_is_prepared(struct clk_core *core);
-static bool clk_core_is_enabled(struct clk_core *core);
-static struct clk_core *clk_core_lookup(const char *name);
-
/*** private data structures ***/
struct clk_core {
spin_unlock_irqrestore(&enable_lock, flags);
}
-/*** debugfs support ***/
-
-#ifdef CONFIG_DEBUG_FS
-#include <linux/debugfs.h>
+static bool clk_core_is_prepared(struct clk_core *core)
+{
+ /*
+ * .is_prepared is optional for clocks that can prepare
+ * fall back to software usage counter if it is missing
+ */
+ if (!core->ops->is_prepared)
+ return core->prepare_count;
-static struct dentry *rootdir;
-static int inited = 0;
-static DEFINE_MUTEX(clk_debug_lock);
-static HLIST_HEAD(clk_debug_list);
+ return core->ops->is_prepared(core->hw);
+}
-static struct hlist_head *all_lists[] = {
- &clk_root_list,
- &clk_orphan_list,
- NULL,
-};
+static bool clk_core_is_enabled(struct clk_core *core)
+{
+ /*
+ * .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;
-static struct hlist_head *orphan_list[] = {
- &clk_orphan_list,
- NULL,
-};
+ return core->ops->is_enabled(core->hw);
+}
-static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
- int level)
+/* caller must hold prepare_lock */
+static void clk_unprepare_unused_subtree(struct clk_core *core)
{
- if (!c)
+ struct clk_core *child;
+
+ lockdep_assert_held(&prepare_lock);
+
+ hlist_for_each_entry(child, &core->children, child_node)
+ clk_unprepare_unused_subtree(child);
+
+ if (core->prepare_count)
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));
+ if (core->flags & CLK_IGNORE_UNUSED)
+ return;
+
+ 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);
+ }
}
-static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
- int level)
+/* caller must hold prepare_lock */
+static void clk_disable_unused_subtree(struct clk_core *core)
{
struct clk_core *child;
+ unsigned long flags;
- if (!c)
- return;
+ lockdep_assert_held(&prepare_lock);
- clk_summary_show_one(s, c, level);
+ hlist_for_each_entry(child, &core->children, child_node)
+ clk_disable_unused_subtree(child);
- hlist_for_each_entry(child, &c->children, child_node)
- clk_summary_show_subtree(s, child, level + 1);
+ flags = clk_enable_lock();
+
+ if (core->enable_count)
+ goto unlock_out;
+
+ if (core->flags & CLK_IGNORE_UNUSED)
+ goto unlock_out;
+
+ /*
+ * some gate clocks have special needs during the disable-unused
+ * sequence. call .disable_unused if available, otherwise fall
+ * back to .disable
+ */
+ 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);
}
-static int clk_summary_show(struct seq_file *s, void *data)
+static bool clk_ignore_unused;
+static int __init clk_ignore_unused_setup(char *__unused)
{
- struct clk_core *c;
- struct hlist_head **lists = (struct hlist_head **)s->private;
+ clk_ignore_unused = true;
+ return 1;
+}
+__setup("clk_ignore_unused", clk_ignore_unused_setup);
- seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
- seq_puts(s, "----------------------------------------------------------------------------------------\n");
+static int clk_disable_unused(void)
+{
+ struct clk_core *core;
+
+ if (clk_ignore_unused) {
+ pr_warn("clk: Not disabling unused clocks\n");
+ return 0;
+ }
clk_prepare_lock();
- for (; *lists; lists++)
- hlist_for_each_entry(c, *lists, child_node)
- clk_summary_show_subtree(s, c, 0);
+ hlist_for_each_entry(core, &clk_root_list, child_node)
+ clk_disable_unused_subtree(core);
+
+ hlist_for_each_entry(core, &clk_orphan_list, child_node)
+ clk_disable_unused_subtree(core);
+
+ hlist_for_each_entry(core, &clk_root_list, child_node)
+ clk_unprepare_unused_subtree(core);
+
+ hlist_for_each_entry(core, &clk_orphan_list, child_node)
+ clk_unprepare_unused_subtree(core);
clk_prepare_unlock();
return 0;
}
+late_initcall_sync(clk_disable_unused);
+/*** helper functions ***/
-static int clk_summary_open(struct inode *inode, struct file *file)
+const char *__clk_get_name(struct clk *clk)
{
- return single_open(file, clk_summary_show, inode->i_private);
+ return !clk ? NULL : clk->core->name;
}
+EXPORT_SYMBOL_GPL(__clk_get_name);
-static const struct file_operations clk_summary_fops = {
- .open = clk_summary_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
+struct clk_hw *__clk_get_hw(struct clk *clk)
+{
+ return !clk ? NULL : clk->core->hw;
+}
+EXPORT_SYMBOL_GPL(__clk_get_hw);
-static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
+u8 __clk_get_num_parents(struct clk *clk)
{
- if (!c)
- return;
+ return !clk ? 0 : clk->core->num_parents;
+}
+EXPORT_SYMBOL_GPL(__clk_get_num_parents);
- 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));
+struct clk *__clk_get_parent(struct clk *clk)
+{
+ if (!clk)
+ return NULL;
+
+ /* TODO: Create a per-user clk and change callers to call clk_put */
+ return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
}
+EXPORT_SYMBOL_GPL(__clk_get_parent);
-static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
+static struct clk_core *__clk_lookup_subtree(const char *name,
+ struct clk_core *core)
{
struct clk_core *child;
+ struct clk_core *ret;
- if (!c)
- return;
-
- clk_dump_one(s, c, level);
+ if (!strcmp(core->name, name))
+ return core;
- hlist_for_each_entry(child, &c->children, child_node) {
- seq_printf(s, ",");
- clk_dump_subtree(s, child, level + 1);
+ hlist_for_each_entry(child, &core->children, child_node) {
+ ret = __clk_lookup_subtree(name, child);
+ if (ret)
+ return ret;
}
- seq_printf(s, "}");
+ return NULL;
}
-static int clk_dump(struct seq_file *s, void *data)
+static struct clk_core *clk_core_lookup(const char *name)
{
- struct clk_core *c;
- bool first_node = true;
- struct hlist_head **lists = (struct hlist_head **)s->private;
-
- seq_printf(s, "{");
+ struct clk_core *root_clk;
+ struct clk_core *ret;
- clk_prepare_lock();
+ if (!name)
+ return NULL;
- 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);
- }
+ /* 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;
}
- clk_prepare_unlock();
+ /* 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;
+ }
- seq_printf(s, "}");
- return 0;
+ return NULL;
}
-
-static int clk_dump_open(struct inode *inode, struct file *file)
+static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
+ u8 index)
{
- return single_open(file, clk_dump, inode->i_private);
+ 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];
}
-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 clk *clk_get_parent_by_index(struct clk *clk, u8 index)
{
- struct dentry *d;
- int ret = -ENOMEM;
+ struct clk_core *parent;
- if (!core || !pdentry) {
- ret = -EINVAL;
- goto out;
- }
+ if (!clk)
+ return NULL;
- d = debugfs_create_dir(core->name, pdentry);
- if (!d)
- goto out;
-
- 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;
+ parent = clk_core_get_parent_by_index(clk->core, index);
- d = debugfs_create_u32("clk_phase", S_IRUGO, core->dentry,
- (u32 *)&core->phase);
- if (!d)
- goto err_out;
+ return !parent ? NULL : parent->hw->clk;
+}
+EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
- d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
- (u32 *)&core->flags);
- if (!d)
- goto err_out;
+unsigned int __clk_get_enable_count(struct clk *clk)
+{
+ return !clk ? 0 : clk->core->enable_count;
+}
- d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
- (u32 *)&core->prepare_count);
- if (!d)
- goto err_out;
+static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
+{
+ unsigned long ret;
- d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
- (u32 *)&core->enable_count);
- if (!d)
- goto err_out;
+ if (!core) {
+ ret = 0;
+ goto out;
+ }
- d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
- (u32 *)&core->notifier_count);
- if (!d)
- goto err_out;
+ ret = core->rate;
- if (core->ops->debug_init) {
- ret = core->ops->debug_init(core->hw, core->dentry);
- if (ret)
- goto err_out;
- }
+ if (core->flags & CLK_IS_ROOT)
+ goto out;
- ret = 0;
- goto out;
+ if (!core->parent)
+ ret = 0;
-err_out:
- debugfs_remove_recursive(core->dentry);
- core->dentry = NULL;
out:
return ret;
}
-/**
- * clk_debug_register - add a clk node to the debugfs clk tree
- * @core: 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.
- */
-static int clk_debug_register(struct clk_core *core)
+unsigned long __clk_get_rate(struct clk *clk)
{
- int ret = 0;
-
- mutex_lock(&clk_debug_lock);
- hlist_add_head(&core->debug_node, &clk_debug_list);
+ if (!clk)
+ return 0;
- if (!inited)
- goto unlock;
+ return clk_core_get_rate_nolock(clk->core);
+}
+EXPORT_SYMBOL_GPL(__clk_get_rate);
- ret = clk_debug_create_one(core, rootdir);
-unlock:
- mutex_unlock(&clk_debug_lock);
+static unsigned long __clk_get_accuracy(struct clk_core *core)
+{
+ if (!core)
+ return 0;
- return ret;
+ return core->accuracy;
}
- /**
- * clk_debug_unregister - remove a clk node from the debugfs clk tree
- * @core: the clk being removed from the debugfs clk tree
- *
- * Dynamically removes a clk and all it's children clk nodes from the
- * debugfs clk tree if clk->dentry points to debugfs created by
- * clk_debug_register in __clk_init.
- */
-static void clk_debug_unregister(struct clk_core *core)
+unsigned long __clk_get_flags(struct clk *clk)
{
- mutex_lock(&clk_debug_lock);
- hlist_del_init(&core->debug_node);
- debugfs_remove_recursive(core->dentry);
- core->dentry = NULL;
- mutex_unlock(&clk_debug_lock);
+ return !clk ? 0 : clk->core->flags;
}
+EXPORT_SYMBOL_GPL(__clk_get_flags);
-struct dentry *clk_debugfs_add_file(struct clk_hw *hw, char *name, umode_t mode,
- void *data, const struct file_operations *fops)
+bool __clk_is_prepared(struct clk *clk)
{
- struct dentry *d = NULL;
-
- if (hw->core->dentry)
- d = debugfs_create_file(name, mode, hw->core->dentry, data,
- fops);
+ if (!clk)
+ return false;
- return d;
+ return clk_core_is_prepared(clk->core);
}
-EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
-/**
- * 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)
+bool __clk_is_enabled(struct clk *clk)
{
- struct clk_core *core;
- struct dentry *d;
-
- rootdir = debugfs_create_dir("clk", NULL);
+ if (!clk)
+ return false;
- if (!rootdir)
- return -ENOMEM;
+ return clk_core_is_enabled(clk->core);
+}
+EXPORT_SYMBOL_GPL(__clk_is_enabled);
- d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
- &clk_summary_fops);
- if (!d)
- return -ENOMEM;
+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);
- d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
- &clk_dump_fops);
- if (!d)
- return -ENOMEM;
+ return now <= rate && now > best;
+}
- d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
- &orphan_list, &clk_summary_fops);
- if (!d)
- return -ENOMEM;
+static long
+clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
+ unsigned long min_rate,
+ unsigned long max_rate,
+ unsigned long *best_parent_rate,
+ struct clk_hw **best_parent_p,
+ unsigned long flags)
+{
+ struct clk_core *core = hw->core, *parent, *best_parent = NULL;
+ int i, num_parents;
+ unsigned long parent_rate, best = 0;
- d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
- &orphan_list, &clk_dump_fops);
- if (!d)
- return -ENOMEM;
+ /* 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)
+ best = __clk_determine_rate(parent ? parent->hw : NULL,
+ rate, min_rate, max_rate);
+ else if (parent)
+ best = clk_core_get_rate_nolock(parent);
+ else
+ best = clk_core_get_rate_nolock(core);
+ goto out;
+ }
- mutex_lock(&clk_debug_lock);
- hlist_for_each_entry(core, &clk_debug_list, debug_node)
- clk_debug_create_one(core, rootdir);
+ /* 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_rate = __clk_determine_rate(parent->hw, rate,
+ min_rate,
+ max_rate);
+ else
+ parent_rate = clk_core_get_rate_nolock(parent);
+ if (mux_is_better_rate(rate, parent_rate, best, flags)) {
+ best_parent = parent;
+ best = parent_rate;
+ }
+ }
- inited = 1;
- mutex_unlock(&clk_debug_lock);
+out:
+ if (best_parent)
+ *best_parent_p = best_parent->hw;
+ *best_parent_rate = best;
- 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)
-{
+ return best;
}
-static inline void clk_debug_unregister(struct clk_core *core)
+
+struct clk *__clk_lookup(const char *name)
{
+ struct clk_core *core = clk_core_lookup(name);
+
+ return !core ? NULL : core->hw->clk;
}
-#endif
-/* caller must hold prepare_lock */
-static void clk_unprepare_unused_subtree(struct clk_core *core)
+static void clk_core_get_boundaries(struct clk_core *core,
+ unsigned long *min_rate,
+ unsigned long *max_rate)
{
- struct clk_core *child;
+ struct clk *clk_user;
- lockdep_assert_held(&prepare_lock);
+ *min_rate = 0;
+ *max_rate = ULONG_MAX;
- hlist_for_each_entry(child, &core->children, child_node)
- clk_unprepare_unused_subtree(child);
+ hlist_for_each_entry(clk_user, &core->clks, clks_node)
+ *min_rate = max(*min_rate, clk_user->min_rate);
- if (core->prepare_count)
- return;
+ hlist_for_each_entry(clk_user, &core->clks, clks_node)
+ *max_rate = min(*max_rate, clk_user->max_rate);
+}
- if (core->flags & CLK_IGNORE_UNUSED)
- return;
-
- 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);
- }
+/*
+ * 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.
+ */
+long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long min_rate,
+ unsigned long max_rate,
+ unsigned long *best_parent_rate,
+ struct clk_hw **best_parent_p)
+{
+ return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
+ best_parent_rate,
+ best_parent_p, 0);
}
+EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
-/* caller must hold prepare_lock */
-static void clk_disable_unused_subtree(struct clk_core *core)
+long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
+ unsigned long min_rate,
+ unsigned long max_rate,
+ unsigned long *best_parent_rate,
+ struct clk_hw **best_parent_p)
{
- struct clk_core *child;
- unsigned long flags;
+ return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
+ best_parent_rate,
+ best_parent_p,
+ CLK_MUX_ROUND_CLOSEST);
+}
+EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
- lockdep_assert_held(&prepare_lock);
+/*** clk api ***/
- hlist_for_each_entry(child, &core->children, child_node)
- clk_disable_unused_subtree(child);
+static void clk_core_unprepare(struct clk_core *core)
+{
+ if (!core)
+ return;
- flags = clk_enable_lock();
+ if (WARN_ON(core->prepare_count == 0))
+ return;
- if (core->enable_count)
- goto unlock_out;
+ if (--core->prepare_count > 0)
+ return;
- if (core->flags & CLK_IGNORE_UNUSED)
- goto unlock_out;
+ WARN_ON(core->enable_count > 0);
- /*
- * some gate clocks have special needs during the disable-unused
- * sequence. call .disable_unused if available, otherwise fall
- * back to .disable
- */
- 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);
- }
+ trace_clk_unprepare(core);
-unlock_out:
- clk_enable_unlock(flags);
+ if (core->ops->unprepare)
+ core->ops->unprepare(core->hw);
+
+ trace_clk_unprepare_complete(core);
+ clk_core_unprepare(core->parent);
}
-static bool clk_ignore_unused;
-static int __init clk_ignore_unused_setup(char *__unused)
+/**
+ * clk_unprepare - undo preparation of a clock source
+ * @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
+ * if the operation may sleep. One example is a clk which is accessed over
+ * I2c. In the complex case a clk gate operation may require a fast and a slow
+ * part. It is this reason that clk_unprepare and clk_disable are not mutually
+ * exclusive. In fact clk_disable must be called before clk_unprepare.
+ */
+void clk_unprepare(struct clk *clk)
{
- clk_ignore_unused = true;
- return 1;
+ if (IS_ERR_OR_NULL(clk))
+ return;
+
+ clk_prepare_lock();
+ clk_core_unprepare(clk->core);
+ clk_prepare_unlock();
}
-__setup("clk_ignore_unused", clk_ignore_unused_setup);
+EXPORT_SYMBOL_GPL(clk_unprepare);
-static int clk_disable_unused(void)
+static int clk_core_prepare(struct clk_core *core)
{
- struct clk_core *core;
+ int ret = 0;
- if (clk_ignore_unused) {
- pr_warn("clk: Not disabling unused clocks\n");
+ if (!core)
return 0;
- }
- clk_prepare_lock();
+ if (core->prepare_count == 0) {
+ ret = clk_core_prepare(core->parent);
+ if (ret)
+ return ret;
- hlist_for_each_entry(core, &clk_root_list, child_node)
- clk_disable_unused_subtree(core);
+ trace_clk_prepare(core);
- hlist_for_each_entry(core, &clk_orphan_list, child_node)
- clk_disable_unused_subtree(core);
+ if (core->ops->prepare)
+ ret = core->ops->prepare(core->hw);
- hlist_for_each_entry(core, &clk_root_list, child_node)
- clk_unprepare_unused_subtree(core);
+ trace_clk_prepare_complete(core);
- hlist_for_each_entry(core, &clk_orphan_list, child_node)
- clk_unprepare_unused_subtree(core);
+ if (ret) {
+ clk_core_unprepare(core->parent);
+ return ret;
+ }
+ }
- clk_prepare_unlock();
+ core->prepare_count++;
return 0;
}
-late_initcall_sync(clk_disable_unused);
-
-/*** helper functions ***/
-const char *__clk_get_name(struct clk *clk)
+/**
+ * clk_prepare - prepare a clock source
+ * @clk: the clk being prepared
+ *
+ * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
+ * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
+ * operation may sleep. One example is a clk which is accessed over I2c. In
+ * the complex case a clk ungate operation may require a fast and a slow part.
+ * It is this reason that clk_prepare and clk_enable are not mutually
+ * exclusive. In fact clk_prepare must be called before clk_enable.
+ * Returns 0 on success, -EERROR otherwise.
+ */
+int clk_prepare(struct clk *clk)
{
- return !clk ? NULL : clk->core->name;
-}
-EXPORT_SYMBOL_GPL(__clk_get_name);
+ int ret;
-struct clk_hw *__clk_get_hw(struct clk *clk)
-{
- return !clk ? NULL : clk->core->hw;
-}
-EXPORT_SYMBOL_GPL(__clk_get_hw);
+ if (!clk)
+ return 0;
-u8 __clk_get_num_parents(struct clk *clk)
-{
- return !clk ? 0 : clk->core->num_parents;
+ clk_prepare_lock();
+ ret = clk_core_prepare(clk->core);
+ clk_prepare_unlock();
+
+ return ret;
}
-EXPORT_SYMBOL_GPL(__clk_get_num_parents);
+EXPORT_SYMBOL_GPL(clk_prepare);
-struct clk *__clk_get_parent(struct clk *clk)
+static void clk_core_disable(struct clk_core *core)
{
- if (!clk)
- return NULL;
+ if (!core)
+ return;
- /* TODO: Create a per-user clk and change callers to call clk_put */
- return !clk->core->parent ? NULL : clk->core->parent->hw->clk;
-}
-EXPORT_SYMBOL_GPL(__clk_get_parent);
+ if (WARN_ON(core->enable_count == 0))
+ return;
-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];
-}
+ if (--core->enable_count > 0)
+ return;
-struct clk *clk_get_parent_by_index(struct clk *clk, u8 index)
-{
- struct clk_core *parent;
+ trace_clk_disable(core);
- if (!clk)
- return NULL;
+ if (core->ops->disable)
+ core->ops->disable(core->hw);
- parent = clk_core_get_parent_by_index(clk->core, index);
+ trace_clk_disable_complete(core);
- return !parent ? NULL : parent->hw->clk;
+ clk_core_disable(core->parent);
}
-EXPORT_SYMBOL_GPL(clk_get_parent_by_index);
-unsigned int __clk_get_enable_count(struct clk *clk)
+/**
+ * clk_disable - gate a clock
+ * @clk: the clk being gated
+ *
+ * clk_disable must not sleep, which differentiates it from clk_unprepare. In
+ * a simple case, clk_disable can be used instead of clk_unprepare to gate a
+ * clk if the operation is fast and will never sleep. One example is a
+ * SoC-internal clk which is controlled via simple register writes. In the
+ * complex case a clk gate operation may require a fast and a slow part. It is
+ * this reason that clk_unprepare and clk_disable are not mutually exclusive.
+ * In fact clk_disable must be called before clk_unprepare.
+ */
+void clk_disable(struct clk *clk)
{
- return !clk ? 0 : clk->core->enable_count;
+ unsigned long flags;
+
+ if (IS_ERR_OR_NULL(clk))
+ return;
+
+ flags = clk_enable_lock();
+ clk_core_disable(clk->core);
+ clk_enable_unlock(flags);
}
+EXPORT_SYMBOL_GPL(clk_disable);
-static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
+static int clk_core_enable(struct clk_core *core)
{
- unsigned long ret;
+ int ret = 0;
- if (!core) {
- ret = 0;
- goto out;
- }
+ if (!core)
+ return 0;
- ret = core->rate;
+ if (WARN_ON(core->prepare_count == 0))
+ return -ESHUTDOWN;
- if (core->flags & CLK_IS_ROOT)
- goto out;
+ if (core->enable_count == 0) {
+ ret = clk_core_enable(core->parent);
- if (!core->parent)
- ret = 0;
+ if (ret)
+ return ret;
-out:
- return ret;
-}
+ trace_clk_enable(core);
-unsigned long __clk_get_rate(struct clk *clk)
-{
- if (!clk)
- return 0;
+ if (core->ops->enable)
+ ret = core->ops->enable(core->hw);
- return clk_core_get_rate_nolock(clk->core);
+ trace_clk_enable_complete(core);
+
+ if (ret) {
+ clk_core_disable(core->parent);
+ return ret;
+ }
+ }
+
+ core->enable_count++;
+ return 0;
}
-EXPORT_SYMBOL_GPL(__clk_get_rate);
-static unsigned long __clk_get_accuracy(struct clk_core *core)
+/**
+ * clk_enable - ungate a clock
+ * @clk: the clk being ungated
+ *
+ * clk_enable must not sleep, which differentiates it from clk_prepare. In a
+ * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
+ * if the operation will never sleep. One example is a SoC-internal clk which
+ * is controlled via simple register writes. In the complex case a clk ungate
+ * operation may require a fast and a slow part. It is this reason that
+ * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
+ * must be called before clk_enable. Returns 0 on success, -EERROR
+ * otherwise.
+ */
+int clk_enable(struct clk *clk)
{
- if (!core)
+ unsigned long flags;
+ int ret;
+
+ if (!clk)
return 0;
- return core->accuracy;
-}
+ flags = clk_enable_lock();
+ ret = clk_core_enable(clk->core);
+ clk_enable_unlock(flags);
-unsigned long __clk_get_flags(struct clk *clk)
-{
- return !clk ? 0 : clk->core->flags;
+ return ret;
}
-EXPORT_SYMBOL_GPL(__clk_get_flags);
+EXPORT_SYMBOL_GPL(clk_enable);
-static bool clk_core_is_prepared(struct clk_core *core)
+static unsigned long clk_core_round_rate_nolock(struct clk_core *core,
+ unsigned long rate,
+ unsigned long min_rate,
+ unsigned long max_rate)
{
- int ret;
+ unsigned long parent_rate = 0;
+ struct clk_core *parent;
+ struct clk_hw *parent_hw;
+
+ lockdep_assert_held(&prepare_lock);
if (!core)
- return false;
+ return 0;
- /*
- * .is_prepared is optional for clocks that can prepare
- * fall back to software usage counter if it is missing
- */
- if (!core->ops->is_prepared) {
- ret = core->prepare_count ? 1 : 0;
- goto out;
- }
+ parent = core->parent;
+ if (parent)
+ parent_rate = parent->rate;
- ret = core->ops->is_prepared(core->hw);
-out:
- return !!ret;
+ if (core->ops->determine_rate) {
+ parent_hw = parent ? parent->hw : NULL;
+ return core->ops->determine_rate(core->hw, rate,
+ min_rate, max_rate,
+ &parent_rate, &parent_hw);
+ } else if (core->ops->round_rate)
+ return core->ops->round_rate(core->hw, rate, &parent_rate);
+ else if (core->flags & CLK_SET_RATE_PARENT)
+ return clk_core_round_rate_nolock(core->parent, rate, min_rate,
+ max_rate);
+ else
+ return core->rate;
}
-bool __clk_is_prepared(struct clk *clk)
+/**
+ * __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 and
+ * .determine_rate.
+ */
+unsigned long __clk_determine_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long min_rate,
+ unsigned long max_rate)
{
- if (!clk)
- return false;
+ if (!hw)
+ return 0;
- return clk_core_is_prepared(clk->core);
+ return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate);
}
+EXPORT_SYMBOL_GPL(__clk_determine_rate);
-static bool clk_core_is_enabled(struct clk_core *core)
+/**
+ * __clk_round_rate - round the given rate for a clk
+ * @clk: round the rate of this clock
+ * @rate: the rate which is to be rounded
+ *
+ * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
+ */
+unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
{
- int ret;
+ unsigned long min_rate;
+ unsigned long max_rate;
- if (!core)
- return false;
+ if (!clk)
+ return 0;
- /*
- * .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) {
- ret = core->enable_count ? 1 : 0;
- goto out;
- }
+ clk_core_get_boundaries(clk->core, &min_rate, &max_rate);
- ret = core->ops->is_enabled(core->hw);
-out:
- return !!ret;
+ return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate);
}
+EXPORT_SYMBOL_GPL(__clk_round_rate);
-bool __clk_is_enabled(struct clk *clk)
+/**
+ * clk_round_rate - round the given rate for a clk
+ * @clk: the clk for which we are rounding a rate
+ * @rate: the rate which is to be rounded
+ *
+ * Takes in a rate as input and rounds it to a rate that the clk can actually
+ * use which is then returned. If clk doesn't support round_rate operation
+ * then the parent rate is returned.
+ */
+long clk_round_rate(struct clk *clk, unsigned long rate)
{
+ unsigned long ret;
+
if (!clk)
- return false;
+ return 0;
- return clk_core_is_enabled(clk->core);
+ clk_prepare_lock();
+ ret = __clk_round_rate(clk, rate);
+ clk_prepare_unlock();
+
+ return ret;
}
-EXPORT_SYMBOL_GPL(__clk_is_enabled);
+EXPORT_SYMBOL_GPL(clk_round_rate);
-static struct clk_core *__clk_lookup_subtree(const char *name,
- struct clk_core *core)
+/**
+ * __clk_notify - call clk notifier chain
+ * @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
+ *
+ * Triggers a notifier call chain on the clk rate-change notification
+ * for 'clk'. Passes a pointer to the struct clk and the previous
+ * and current rates to the notifier callback. Intended to be called by
+ * internal clock code only. Returns NOTIFY_DONE from the last driver
+ * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
+ * a driver returns that.
+ */
+static int __clk_notify(struct clk_core *core, unsigned long msg,
+ unsigned long old_rate, unsigned long new_rate)
{
- struct clk_core *child;
- struct clk_core *ret;
+ struct clk_notifier *cn;
+ struct clk_notifier_data cnd;
+ int ret = NOTIFY_DONE;
- if (!strcmp(core->name, name))
- return core;
+ cnd.old_rate = old_rate;
+ cnd.new_rate = new_rate;
- hlist_for_each_entry(child, &core->children, child_node) {
- ret = __clk_lookup_subtree(name, child);
- if (ret)
- return ret;
+ list_for_each_entry(cn, &clk_notifier_list, node) {
+ if (cn->clk->core == core) {
+ cnd.clk = cn->clk;
+ ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
+ &cnd);
+ }
}
- return NULL;
+ return ret;
}
-static struct clk_core *clk_core_lookup(const char *name)
+/**
+ * __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 it's
+ * parent.
+ *
+ * Caller must hold prepare_lock.
+ */
+static void __clk_recalc_accuracies(struct clk_core *core)
{
- struct clk_core *root_clk;
- struct clk_core *ret;
+ unsigned long parent_accuracy = 0;
+ struct clk_core *child;
- if (!name)
- return NULL;
+ lockdep_assert_held(&prepare_lock);
- /* 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 (core->parent)
+ parent_accuracy = core->parent->accuracy;
- /* 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;
- }
+ if (core->ops->recalc_accuracy)
+ core->accuracy = core->ops->recalc_accuracy(core->hw,
+ parent_accuracy);
+ else
+ core->accuracy = parent_accuracy;
- return NULL;
+ hlist_for_each_entry(child, &core->children, child_node)
+ __clk_recalc_accuracies(child);
}
-static bool mux_is_better_rate(unsigned long rate, unsigned long now,
- unsigned long best, unsigned long flags)
+static long clk_core_get_accuracy(struct clk_core *core)
{
- if (flags & CLK_MUX_ROUND_CLOSEST)
- return abs(now - rate) < abs(best - rate);
+ unsigned long accuracy;
- return now <= rate && now > best;
-}
+ clk_prepare_lock();
+ if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
+ __clk_recalc_accuracies(core);
-static long
-clk_mux_determine_rate_flags(struct clk_hw *hw, unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate,
- unsigned long *best_parent_rate,
- struct clk_hw **best_parent_p,
- unsigned long flags)
-{
- struct clk_core *core = hw->core, *parent, *best_parent = NULL;
- int i, num_parents;
- unsigned long parent_rate, best = 0;
-
- /* 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)
- best = __clk_determine_rate(parent ? parent->hw : NULL,
- rate, min_rate, max_rate);
- else if (parent)
- best = clk_core_get_rate_nolock(parent);
- else
- best = clk_core_get_rate_nolock(core);
- goto out;
- }
-
- /* 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_rate = __clk_determine_rate(parent->hw, rate,
- min_rate,
- max_rate);
- else
- parent_rate = clk_core_get_rate_nolock(parent);
- if (mux_is_better_rate(rate, parent_rate, best, flags)) {
- best_parent = parent;
- best = parent_rate;
- }
- }
-
-out:
- if (best_parent)
- *best_parent_p = best_parent->hw;
- *best_parent_rate = best;
+ accuracy = __clk_get_accuracy(core);
+ clk_prepare_unlock();
- return best;
+ return accuracy;
}
-struct clk *__clk_lookup(const char *name)
+/**
+ * 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)
{
- struct clk_core *core = clk_core_lookup(name);
+ if (!clk)
+ return 0;
- return !core ? NULL : core->hw->clk;
+ return clk_core_get_accuracy(clk->core);
}
+EXPORT_SYMBOL_GPL(clk_get_accuracy);
-static void clk_core_get_boundaries(struct clk_core *core,
- unsigned long *min_rate,
- unsigned long *max_rate)
+static unsigned long clk_recalc(struct clk_core *core,
+ unsigned long parent_rate)
{
- struct clk *clk_user;
-
- *min_rate = 0;
- *max_rate = ULONG_MAX;
-
- 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);
+ if (core->ops->recalc_rate)
+ return core->ops->recalc_rate(core->hw, parent_rate);
+ return parent_rate;
}
-/*
- * 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.
+/**
+ * __clk_recalc_rates
+ * @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 its parent.
+ *
+ * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
+ * if necessary.
+ *
+ * Caller must hold prepare_lock.
*/
-long __clk_mux_determine_rate(struct clk_hw *hw, unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate,
- unsigned long *best_parent_rate,
- struct clk_hw **best_parent_p)
+static void __clk_recalc_rates(struct clk_core *core, unsigned long msg)
{
- return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
- best_parent_rate,
- best_parent_p, 0);
-}
-EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
+ unsigned long old_rate;
+ unsigned long parent_rate = 0;
+ struct clk_core *child;
-long __clk_mux_determine_rate_closest(struct clk_hw *hw, unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate,
- unsigned long *best_parent_rate,
- struct clk_hw **best_parent_p)
-{
- return clk_mux_determine_rate_flags(hw, rate, min_rate, max_rate,
- best_parent_rate,
- best_parent_p,
- CLK_MUX_ROUND_CLOSEST);
-}
-EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
+ lockdep_assert_held(&prepare_lock);
-/*** clk api ***/
+ old_rate = core->rate;
-static void clk_core_unprepare(struct clk_core *core)
-{
- if (!core)
- return;
+ if (core->parent)
+ parent_rate = core->parent->rate;
- if (WARN_ON(core->prepare_count == 0))
- return;
+ core->rate = clk_recalc(core, parent_rate);
- if (--core->prepare_count > 0)
- return;
+ /*
+ * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
+ * & ABORT_RATE_CHANGE notifiers
+ */
+ if (core->notifier_count && msg)
+ __clk_notify(core, msg, old_rate, core->rate);
- WARN_ON(core->enable_count > 0);
+ hlist_for_each_entry(child, &core->children, child_node)
+ __clk_recalc_rates(child, msg);
+}
- trace_clk_unprepare(core);
+static unsigned long clk_core_get_rate(struct clk_core *core)
+{
+ unsigned long rate;
- if (core->ops->unprepare)
- core->ops->unprepare(core->hw);
+ clk_prepare_lock();
- trace_clk_unprepare_complete(core);
- clk_core_unprepare(core->parent);
+ 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_unprepare - undo preparation of a clock source
- * @clk: the clk being unprepared
+ * clk_get_rate - return the rate of clk
+ * @clk: the clk whose rate is being returned
*
- * 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
- * if the operation may sleep. One example is a clk which is accessed over
- * I2c. In the complex case a clk gate operation may require a fast and a slow
- * part. It is this reason that clk_unprepare and clk_disable are not mutually
- * exclusive. In fact clk_disable must be called before clk_unprepare.
+ * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
+ * is set, which means a recalc_rate will be issued.
+ * If clk is NULL then returns 0.
*/
-void clk_unprepare(struct clk *clk)
+unsigned long clk_get_rate(struct clk *clk)
{
- if (IS_ERR_OR_NULL(clk))
- return;
+ if (!clk)
+ return 0;
- clk_prepare_lock();
- clk_core_unprepare(clk->core);
- clk_prepare_unlock();
+ return clk_core_get_rate(clk->core);
}
-EXPORT_SYMBOL_GPL(clk_unprepare);
+EXPORT_SYMBOL_GPL(clk_get_rate);
-static int clk_core_prepare(struct clk_core *core)
+static int clk_fetch_parent_index(struct clk_core *core,
+ struct clk_core *parent)
{
- int ret = 0;
-
- if (!core)
- return 0;
-
- if (core->prepare_count == 0) {
- ret = clk_core_prepare(core->parent);
- if (ret)
- return ret;
+ int i;
- trace_clk_prepare(core);
+ if (!core->parents) {
+ core->parents = kcalloc(core->num_parents,
+ sizeof(struct clk *), GFP_KERNEL);
+ if (!core->parents)
+ return -ENOMEM;
+ }
- if (core->ops->prepare)
- ret = core->ops->prepare(core->hw);
+ /*
+ * 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;
- trace_clk_prepare_complete(core);
+ if (core->parents[i])
+ continue;
- if (ret) {
- clk_core_unprepare(core->parent);
- return ret;
+ if (!strcmp(core->parent_names[i], parent->name)) {
+ core->parents[i] = clk_core_lookup(parent->name);
+ return i;
}
}
- core->prepare_count++;
-
- return 0;
+ return -EINVAL;
}
-/**
- * clk_prepare - prepare a clock source
- * @clk: the clk being prepared
- *
- * clk_prepare may sleep, which differentiates it from clk_enable. In a simple
- * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
- * operation may sleep. One example is a clk which is accessed over I2c. In
- * the complex case a clk ungate operation may require a fast and a slow part.
- * It is this reason that clk_prepare and clk_enable are not mutually
- * exclusive. In fact clk_prepare must be called before clk_enable.
- * Returns 0 on success, -EERROR otherwise.
- */
-int clk_prepare(struct clk *clk)
+static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
{
- int ret;
-
- if (!clk)
- return 0;
+ hlist_del(&core->child_node);
- clk_prepare_lock();
- ret = clk_core_prepare(clk->core);
- clk_prepare_unlock();
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(clk_prepare);
-
-static void clk_core_disable(struct clk_core *core)
-{
- if (!core)
- return;
-
- if (WARN_ON(core->enable_count == 0))
- return;
-
- if (--core->enable_count > 0)
- return;
-
- trace_clk_disable(core);
-
- if (core->ops->disable)
- core->ops->disable(core->hw);
+ if (new_parent) {
+ /* avoid duplicate POST_RATE_CHANGE notifications */
+ if (new_parent->new_child == core)
+ new_parent->new_child = NULL;
- trace_clk_disable_complete(core);
+ hlist_add_head(&core->child_node, &new_parent->children);
+ } else {
+ hlist_add_head(&core->child_node, &clk_orphan_list);
+ }
- clk_core_disable(core->parent);
+ core->parent = new_parent;
}
-/**
- * clk_disable - gate a clock
- * @clk: the clk being gated
- *
- * clk_disable must not sleep, which differentiates it from clk_unprepare. In
- * a simple case, clk_disable can be used instead of clk_unprepare to gate a
- * clk if the operation is fast and will never sleep. One example is a
- * SoC-internal clk which is controlled via simple register writes. In the
- * complex case a clk gate operation may require a fast and a slow part. It is
- * this reason that clk_unprepare and clk_disable are not mutually exclusive.
- * In fact clk_disable must be called before clk_unprepare.
- */
-void clk_disable(struct clk *clk)
+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;
- if (IS_ERR_OR_NULL(clk))
- return;
+ /*
+ * 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);
+ clk_core_enable(parent);
+ clk_core_enable(core);
+ }
+ /* update the clk tree topology */
flags = clk_enable_lock();
- clk_core_disable(clk->core);
+ clk_reparent(core, parent);
clk_enable_unlock(flags);
+
+ return old_parent;
}
-EXPORT_SYMBOL_GPL(clk_disable);
-static int clk_core_enable(struct clk_core *core)
+static void __clk_set_parent_after(struct clk_core *core,
+ struct clk_core *parent,
+ struct clk_core *old_parent)
{
- int ret = 0;
-
- if (!core)
- return 0;
+ /*
+ * Finish the migration of prepare state and undo the changes done
+ * for preventing a race with clk_enable().
+ */
+ if (core->prepare_count) {
+ clk_core_disable(core);
+ clk_core_disable(old_parent);
+ clk_core_unprepare(old_parent);
+ }
+}
- if (WARN_ON(core->prepare_count == 0))
- return -ESHUTDOWN;
+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;
- if (core->enable_count == 0) {
- ret = clk_core_enable(core->parent);
+ old_parent = __clk_set_parent_before(core, parent);
- if (ret)
- return ret;
+ trace_clk_set_parent(core, parent);
- trace_clk_enable(core);
+ /* change clock input source */
+ if (parent && core->ops->set_parent)
+ ret = core->ops->set_parent(core->hw, p_index);
- if (core->ops->enable)
- ret = core->ops->enable(core->hw);
+ trace_clk_set_parent_complete(core, parent);
- trace_clk_enable_complete(core);
+ if (ret) {
+ flags = clk_enable_lock();
+ clk_reparent(core, old_parent);
+ clk_enable_unlock(flags);
- if (ret) {
- clk_core_disable(core->parent);
- return ret;
+ if (core->prepare_count) {
+ clk_core_disable(core);
+ clk_core_disable(parent);
+ clk_core_unprepare(parent);
}
+ return ret;
}
- core->enable_count++;
+ __clk_set_parent_after(core, parent, old_parent);
+
return 0;
}
/**
- * clk_enable - ungate a clock
- * @clk: the clk being ungated
+ * __clk_speculate_rates
+ * @core: first clk in the subtree
+ * @parent_rate: the "future" rate of clk's parent
*
- * clk_enable must not sleep, which differentiates it from clk_prepare. In a
- * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
- * if the operation will never sleep. One example is a SoC-internal clk which
- * is controlled via simple register writes. In the complex case a clk ungate
- * operation may require a fast and a slow part. It is this reason that
- * clk_enable and clk_prepare are not mutually exclusive. In fact clk_prepare
- * must be called before clk_enable. Returns 0 on success, -EERROR
- * otherwise.
+ * Walks the subtree of clks starting with clk, speculating rates as it
+ * goes and firing off PRE_RATE_CHANGE notifications as necessary.
+ *
+ * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
+ * 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 its parent.
+ *
+ * Caller must hold prepare_lock.
*/
-int clk_enable(struct clk *clk)
+static int __clk_speculate_rates(struct clk_core *core,
+ unsigned long parent_rate)
{
- unsigned long flags;
- int ret;
+ struct clk_core *child;
+ unsigned long new_rate;
+ int ret = NOTIFY_DONE;
- if (!clk)
- return 0;
+ lockdep_assert_held(&prepare_lock);
- flags = clk_enable_lock();
- ret = clk_core_enable(clk->core);
- clk_enable_unlock(flags);
+ new_rate = clk_recalc(core, parent_rate);
+
+ /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
+ if (core->notifier_count)
+ ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
+
+ 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, &core->children, child_node) {
+ ret = __clk_speculate_rates(child, new_rate);
+ if (ret & NOTIFY_STOP_MASK)
+ break;
+ }
+out:
return ret;
}
-EXPORT_SYMBOL_GPL(clk_enable);
-static unsigned long clk_core_round_rate_nolock(struct clk_core *core,
- unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate)
+static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
+ struct clk_core *new_parent, u8 p_index)
{
- unsigned long parent_rate = 0;
- struct clk_core *parent;
- struct clk_hw *parent_hw;
+ struct clk_core *child;
- lockdep_assert_held(&prepare_lock);
+ 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)
- return 0;
+ 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);
+ }
+}
- parent = core->parent;
+/*
+ * calculate the new rates returning the topmost clock that has to be
+ * changed.
+ */
+static struct clk_core *clk_calc_new_rates(struct clk_core *core,
+ unsigned long rate)
+{
+ struct clk_core *top = core;
+ struct clk_core *old_parent, *parent;
+ struct clk_hw *parent_hw;
+ 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(core))
+ return NULL;
+
+ /* save parent rate, if it exists */
+ parent = old_parent = core->parent;
if (parent)
- parent_rate = parent->rate;
+ 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) {
parent_hw = parent ? parent->hw : NULL;
- return core->ops->determine_rate(core->hw, rate,
- min_rate, max_rate,
- &parent_rate, &parent_hw);
- } else if (core->ops->round_rate)
- return core->ops->round_rate(core->hw, rate, &parent_rate);
- else if (core->flags & CLK_SET_RATE_PARENT)
- return clk_core_round_rate_nolock(core->parent, rate, min_rate,
- max_rate);
- else
- return core->rate;
-}
-
-/**
- * __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 and
- * .determine_rate.
- */
-unsigned long __clk_determine_rate(struct clk_hw *hw,
- unsigned long rate,
- unsigned long min_rate,
- unsigned long max_rate)
-{
- if (!hw)
- return 0;
-
- return clk_core_round_rate_nolock(hw->core, rate, min_rate, max_rate);
-}
-EXPORT_SYMBOL_GPL(__clk_determine_rate);
-
-/**
- * __clk_round_rate - round the given rate for a clk
- * @clk: round the rate of this clock
- * @rate: the rate which is to be rounded
- *
- * Caller must hold prepare_lock. Useful for clk_ops such as .set_rate
- */
-unsigned long __clk_round_rate(struct clk *clk, unsigned long rate)
-{
- unsigned long min_rate;
- unsigned long max_rate;
+ ret = core->ops->determine_rate(core->hw, rate,
+ min_rate,
+ max_rate,
+ &best_parent_rate,
+ &parent_hw);
+ if (ret < 0)
+ return NULL;
- if (!clk)
- return 0;
+ new_rate = ret;
+ parent = parent_hw ? 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;
- clk_core_get_boundaries(clk->core, &min_rate, &max_rate);
+ 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;
+ }
- return clk_core_round_rate_nolock(clk->core, rate, min_rate, max_rate);
-}
-EXPORT_SYMBOL_GPL(__clk_round_rate);
+ /* 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;
+ }
-/**
- * clk_round_rate - round the given rate for a clk
- * @clk: the clk for which we are rounding a rate
- * @rate: the rate which is to be rounded
- *
- * Takes in a rate as input and rounds it to a rate that the clk can actually
- * use which is then returned. If clk doesn't support round_rate operation
- * then the parent rate is returned.
- */
-long clk_round_rate(struct clk *clk, unsigned long rate)
-{
- unsigned long ret;
+ /* 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;
+ }
+ }
- if (!clk)
- return 0;
+ if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
+ best_parent_rate != parent->rate)
+ top = clk_calc_new_rates(parent, best_parent_rate);
- clk_prepare_lock();
- ret = __clk_round_rate(clk, rate);
- clk_prepare_unlock();
+out:
+ clk_calc_subtree(core, new_rate, parent, p_index);
- return ret;
+ return top;
}
-EXPORT_SYMBOL_GPL(clk_round_rate);
-/**
- * __clk_notify - call clk notifier chain
- * @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
- *
- * Triggers a notifier call chain on the clk rate-change notification
- * for 'clk'. Passes a pointer to the struct clk and the previous
- * and current rates to the notifier callback. Intended to be called by
- * internal clock code only. Returns NOTIFY_DONE from the last driver
- * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
- * a driver returns that.
+/*
+ * Notify about rate changes in a subtree. Always walk down the whole tree
+ * so that in case of an error we can walk down the whole tree again and
+ * abort the change.
*/
-static int __clk_notify(struct clk_core *core, unsigned long msg,
- unsigned long old_rate, unsigned long new_rate)
+static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
+ unsigned long event)
{
- struct clk_notifier *cn;
- struct clk_notifier_data cnd;
+ struct clk_core *child, *tmp_clk, *fail_clk = NULL;
int ret = NOTIFY_DONE;
- cnd.old_rate = old_rate;
- cnd.new_rate = new_rate;
+ if (core->rate == core->new_rate)
+ return NULL;
- list_for_each_entry(cn, &clk_notifier_list, node) {
- if (cn->clk->core == core) {
- cnd.clk = cn->clk;
- ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
- &cnd);
- }
+ if (core->notifier_count) {
+ ret = __clk_notify(core, event, core->rate, core->new_rate);
+ if (ret & NOTIFY_STOP_MASK)
+ fail_clk = core;
}
- return ret;
-}
-
-/**
- * __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 it's
- * parent.
- *
- * Caller must hold prepare_lock.
- */
-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;
+ 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;
+ }
- if (core->ops->recalc_accuracy)
- core->accuracy = core->ops->recalc_accuracy(core->hw,
- parent_accuracy);
- else
- core->accuracy = parent_accuracy;
+ /* 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;
+ }
- hlist_for_each_entry(child, &core->children, child_node)
- __clk_recalc_accuracies(child);
+ return fail_clk;
}
-static long clk_core_get_accuracy(struct clk_core *core)
+/*
+ * walk down a subtree and set the new rates notifying the rate
+ * change on the way
+ */
+static void clk_change_rate(struct clk_core *core)
{
- unsigned long accuracy;
-
- clk_prepare_lock();
- if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
- __clk_recalc_accuracies(core);
+ 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;
- accuracy = __clk_get_accuracy(core);
- clk_prepare_unlock();
+ old_rate = core->rate;
- return accuracy;
-}
+ if (core->new_parent)
+ best_parent_rate = core->new_parent->rate;
+ else if (core->parent)
+ best_parent_rate = core->parent->rate;
-/**
- * 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;
+ if (core->new_parent && core->new_parent != core->parent) {
+ old_parent = __clk_set_parent_before(core, core->new_parent);
+ trace_clk_set_parent(core, core->new_parent);
- return clk_core_get_accuracy(clk->core);
-}
-EXPORT_SYMBOL_GPL(clk_get_accuracy);
+ 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);
+ }
-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;
-}
+ trace_clk_set_parent_complete(core, core->new_parent);
+ __clk_set_parent_after(core, core->new_parent, old_parent);
+ }
-/**
- * __clk_recalc_rates
- * @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 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_core *core, unsigned long msg)
-{
- unsigned long old_rate;
- unsigned long parent_rate = 0;
- struct clk_core *child;
+ trace_clk_set_rate(core, core->new_rate);
- lockdep_assert_held(&prepare_lock);
+ if (!skip_set_rate && core->ops->set_rate)
+ core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
- old_rate = core->rate;
+ trace_clk_set_rate_complete(core, core->new_rate);
- if (core->parent)
- parent_rate = core->parent->rate;
+ core->rate = clk_recalc(core, best_parent_rate);
- core->rate = clk_recalc(core, parent_rate);
+ if (core->notifier_count && old_rate != core->rate)
+ __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
/*
- * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
- * & ABORT_RATE_CHANGE notifiers
+ * Use safe iteration, as change_rate can actually swap parents
+ * for certain clock types.
*/
- if (core->notifier_count && msg)
- __clk_notify(core, msg, old_rate, core->rate);
+ 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);
+ }
- hlist_for_each_entry(child, &core->children, child_node)
- __clk_recalc_rates(child, msg);
+ /* handle the new child who might not be in core->children yet */
+ if (core->new_child)
+ clk_change_rate(core->new_child);
}
-static unsigned long clk_core_get_rate(struct clk_core *core)
+static int clk_core_set_rate_nolock(struct clk_core *core,
+ unsigned long req_rate)
{
- unsigned long rate;
+ struct clk_core *top, *fail_clk;
+ unsigned long rate = req_rate;
+ int ret = 0;
- clk_prepare_lock();
+ if (!core)
+ return 0;
- if (core && (core->flags & CLK_GET_RATE_NOCACHE))
- __clk_recalc_rates(core, 0);
+ /* bail early if nothing to do */
+ if (rate == clk_core_get_rate_nolock(core))
+ return 0;
- rate = clk_core_get_rate_nolock(core);
- clk_prepare_unlock();
+ if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
+ return -EBUSY;
- return rate;
+ /* 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;
+
+ return ret;
}
/**
- * clk_get_rate - return the rate of clk
- * @clk: the clk whose rate is being returned
+ * clk_set_rate - specify a new rate for clk
+ * @clk: the clk whose rate is being changed
+ * @rate: the new rate for clk
*
- * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
- * is set, which means a recalc_rate will be issued.
- * If clk is NULL then returns 0.
+ * In the simplest case clk_set_rate will only adjust the rate of clk.
+ *
+ * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
+ * propagate up to clk's parent; whether or not this happens depends on the
+ * 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 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.
+ *
+ * Rate changes are accomplished via tree traversal that also recalculates the
+ * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
+ *
+ * Returns 0 on success, -EERROR otherwise.
*/
-unsigned long clk_get_rate(struct clk *clk)
+int clk_set_rate(struct clk *clk, unsigned long rate)
{
+ int ret;
+
if (!clk)
return 0;
- return clk_core_get_rate(clk->core);
-}
-EXPORT_SYMBOL_GPL(clk_get_rate);
-
-static int clk_fetch_parent_index(struct clk_core *core,
- struct clk_core *parent)
-{
- int i;
-
- if (!core->parents) {
- core->parents = kcalloc(core->num_parents,
- sizeof(struct clk *), GFP_KERNEL);
- if (!core->parents)
- return -ENOMEM;
- }
-
- /*
- * 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;
+ /* prevent racing with updates to the clock topology */
+ clk_prepare_lock();
- if (core->parents[i])
- continue;
+ ret = clk_core_set_rate_nolock(clk->core, rate);
- if (!strcmp(core->parent_names[i], parent->name)) {
- core->parents[i] = clk_core_lookup(parent->name);
- return i;
- }
- }
+ clk_prepare_unlock();
- return -EINVAL;
+ return ret;
}
+EXPORT_SYMBOL_GPL(clk_set_rate);
-static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
+/**
+ * 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)
{
- hlist_del(&core->child_node);
+ int ret = 0;
- if (new_parent) {
- /* avoid duplicate POST_RATE_CHANGE notifications */
- if (new_parent->new_child == core)
- new_parent->new_child = NULL;
+ if (!clk)
+ return 0;
- hlist_add_head(&core->child_node, &new_parent->children);
- } else {
- hlist_add_head(&core->child_node, &clk_orphan_list);
+ 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;
}
- 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;
+ clk_prepare_lock();
- /*
- * 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);
- clk_core_enable(parent);
- clk_core_enable(core);
+ 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);
}
- /* update the clk tree topology */
- flags = clk_enable_lock();
- clk_reparent(core, parent);
- clk_enable_unlock(flags);
+ clk_prepare_unlock();
- return old_parent;
+ return ret;
}
+EXPORT_SYMBOL_GPL(clk_set_rate_range);
-static void __clk_set_parent_after(struct clk_core *core,
- struct clk_core *parent,
- struct clk_core *old_parent)
+/**
+ * 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)
{
- /*
- * Finish the migration of prepare state and undo the changes done
- * for preventing a race with clk_enable().
- */
- if (core->prepare_count) {
- clk_core_disable(core);
- clk_core_disable(old_parent);
- clk_core_unprepare(old_parent);
- }
+ if (!clk)
+ return 0;
+
+ return clk_set_rate_range(clk, rate, clk->max_rate);
}
+EXPORT_SYMBOL_GPL(clk_set_min_rate);
-static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
- u8 p_index)
+/**
+ * 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)
{
- 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);
-
- /* 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);
-
- if (core->prepare_count) {
- clk_core_disable(core);
- clk_core_disable(parent);
- clk_core_unprepare(parent);
- }
- return ret;
- }
-
- __clk_set_parent_after(core, parent, old_parent);
+ if (!clk)
+ return 0;
- return 0;
+ return clk_set_rate_range(clk, clk->min_rate, rate);
}
+EXPORT_SYMBOL_GPL(clk_set_max_rate);
/**
- * __clk_speculate_rates
- * @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
- * goes and firing off PRE_RATE_CHANGE notifications as necessary.
- *
- * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
- * 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 its parent.
+ * clk_get_parent - return the parent of a clk
+ * @clk: the clk whose parent gets returned
*
- * Caller must hold prepare_lock.
+ * Simply returns clk->parent. Returns NULL if clk is NULL.
*/
-static int __clk_speculate_rates(struct clk_core *core,
- unsigned long parent_rate)
+struct clk *clk_get_parent(struct clk *clk)
{
- struct clk_core *child;
- unsigned long new_rate;
- int ret = NOTIFY_DONE;
+ struct clk *parent;
- lockdep_assert_held(&prepare_lock);
+ clk_prepare_lock();
+ parent = __clk_get_parent(clk);
+ clk_prepare_unlock();
- new_rate = clk_recalc(core, parent_rate);
+ return parent;
+}
+EXPORT_SYMBOL_GPL(clk_get_parent);
- /* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
- if (core->notifier_count)
- ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
+/*
+ * .get_parent is mandatory for clocks with multiple possible parents. It is
+ * optional for single-parent clocks. Always call .get_parent if it is
+ * available and WARN if it is missing for multi-parent clocks.
+ *
+ * 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.
+ */
+static struct clk_core *__clk_init_parent(struct clk_core *core)
+{
+ struct clk_core *ret = NULL;
+ u8 index;
- if (ret & NOTIFY_STOP_MASK) {
- pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
- __func__, core->name, ret);
+ /* handle the trivial cases */
+
+ if (!core->num_parents)
goto out;
- }
- hlist_for_each_entry(child, &core->children, child_node) {
- ret = __clk_speculate_rates(child, new_rate);
- if (ret & NOTIFY_STOP_MASK)
- break;
+ 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 (!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 core->parents. This prevents
+ * unnecessary and expensive lookups. We don't set core->parent here;
+ * that is done by the calling function.
+ */
+
+ index = core->ops->get_parent(core->hw);
+
+ if (!core->parents)
+ core->parents =
+ kcalloc(core->num_parents, sizeof(struct clk *),
+ GFP_KERNEL);
+
+ ret = clk_core_get_parent_by_index(core, index);
+
out:
return ret;
}
-static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
- struct clk_core *new_parent, u8 p_index)
+static void clk_core_reparent(struct clk_core *core,
+ struct clk_core *new_parent)
{
- struct clk_core *child;
-
- 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;
-
- 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);
- }
+ clk_reparent(core, new_parent);
+ __clk_recalc_accuracies(core);
+ __clk_recalc_rates(core, POST_RATE_CHANGE);
}
-/*
- * calculate the new rates returning the topmost clock that has to be
- * changed.
+/**
+ * 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.
*/
-static struct clk_core *clk_calc_new_rates(struct clk_core *core,
- unsigned long rate)
+bool clk_has_parent(struct clk *clk, struct clk *parent)
{
- struct clk_core *top = core;
- struct clk_core *old_parent, *parent;
- struct clk_hw *parent_hw;
- unsigned long best_parent_rate = 0;
- unsigned long new_rate;
- unsigned long min_rate;
- unsigned long max_rate;
- int p_index = 0;
- long ret;
+ struct clk_core *core, *parent_core;
+ unsigned int i;
- /* sanity */
- if (IS_ERR_OR_NULL(core))
- return NULL;
+ /* NULL clocks should be nops, so return success if either is NULL. */
+ if (!clk || !parent)
+ return true;
- /* save parent rate, if it exists */
- parent = old_parent = core->parent;
- if (parent)
- best_parent_rate = parent->rate;
+ core = clk->core;
+ parent_core = parent->core;
- clk_core_get_boundaries(core, &min_rate, &max_rate);
+ /* Optimize for the case where the parent is already the parent. */
+ if (core->parent == parent_core)
+ return true;
- /* find the closest rate and parent clk/rate */
- if (core->ops->determine_rate) {
- parent_hw = parent ? parent->hw : NULL;
- ret = core->ops->determine_rate(core->hw, rate,
- min_rate,
- max_rate,
- &best_parent_rate,
- &parent_hw);
- if (ret < 0)
- return NULL;
+ for (i = 0; i < core->num_parents; i++)
+ if (strcmp(core->parent_names[i], parent_core->name) == 0)
+ return true;
- new_rate = ret;
- parent = parent_hw ? 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;
+ return false;
+}
+EXPORT_SYMBOL_GPL(clk_has_parent);
- 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;
+static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
+{
+ int ret = 0;
+ int p_index = 0;
+ unsigned long p_rate = 0;
+
+ if (!core)
+ return 0;
+
+ /* prevent racing with updates to the clock topology */
+ clk_prepare_lock();
+
+ if (core->parent == parent)
+ goto out;
+
+ /* verify ops for for multi-parent clks */
+ if ((core->num_parents > 1) && (!core->ops->set_parent)) {
+ ret = -ENOSYS;
goto out;
}
- /* 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;
+ /* 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;
}
/* try finding the new parent index */
- if (parent && core->num_parents > 1) {
+ 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);
- return NULL;
+ __func__, parent->name, core->name);
+ ret = p_index;
+ 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(core, new_rate, parent, p_index);
-
- return top;
-}
+ /* propagate PRE_RATE_CHANGE notifications */
+ ret = __clk_speculate_rates(core, p_rate);
-/*
- * Notify about rate changes in a subtree. Always walk down the whole tree
- * so that in case of an error we can walk down the whole tree again and
- * abort the change.
- */
-static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
- unsigned long event)
-{
- struct clk_core *child, *tmp_clk, *fail_clk = NULL;
- int ret = NOTIFY_DONE;
+ /* abort if a driver objects */
+ if (ret & NOTIFY_STOP_MASK)
+ goto out;
- if (core->rate == core->new_rate)
- return NULL;
+ /* do the re-parent */
+ ret = __clk_set_parent(core, parent, p_index);
- if (core->notifier_count) {
- ret = __clk_notify(core, event, core->rate, core->new_rate);
- if (ret & NOTIFY_STOP_MASK)
- fail_clk = core;
+ /* 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);
}
- 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;
- }
+out:
+ clk_prepare_unlock();
- /* 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 ret;
+}
- return fail_clk;
+/**
+ * clk_set_parent - switch the parent of a mux clk
+ * @clk: the mux clk whose input we are switching
+ * @parent: the new input to clk
+ *
+ * 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)
+{
+ if (!clk)
+ return 0;
+
+ return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
}
+EXPORT_SYMBOL_GPL(clk_set_parent);
-/*
- * walk down a subtree and set the new rates notifying the rate
- * change on the way
+/**
+ * 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.
*/
-static void clk_change_rate(struct clk_core *core)
+int clk_set_phase(struct clk *clk, int degrees)
{
- 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;
+ int ret = -EINVAL;
- old_rate = core->rate;
+ if (!clk)
+ return 0;
- if (core->new_parent)
- best_parent_rate = core->new_parent->rate;
- else if (core->parent)
- best_parent_rate = core->parent->rate;
+ /* sanity check degrees */
+ degrees %= 360;
+ if (degrees < 0)
+ degrees += 360;
- if (core->new_parent && core->new_parent != core->parent) {
- old_parent = __clk_set_parent_before(core, core->new_parent);
- trace_clk_set_parent(core, core->new_parent);
+ clk_prepare_lock();
- 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);
- }
+ trace_clk_set_phase(clk->core, degrees);
- trace_clk_set_parent_complete(core, core->new_parent);
- __clk_set_parent_after(core, core->new_parent, old_parent);
- }
+ if (clk->core->ops->set_phase)
+ ret = clk->core->ops->set_phase(clk->core->hw, degrees);
- trace_clk_set_rate(core, core->new_rate);
+ trace_clk_set_phase_complete(clk->core, degrees);
- if (!skip_set_rate && core->ops->set_rate)
- core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
+ if (!ret)
+ clk->core->phase = degrees;
- trace_clk_set_rate_complete(core, core->new_rate);
+ clk_prepare_unlock();
- core->rate = clk_recalc(core, best_parent_rate);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(clk_set_phase);
- if (core->notifier_count && old_rate != core->rate)
- __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
+static int clk_core_get_phase(struct clk_core *core)
+{
+ int ret;
- /*
- * 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);
- }
+ clk_prepare_lock();
+ ret = core->phase;
+ clk_prepare_unlock();
- /* handle the new child who might not be in core->children yet */
- if (core->new_child)
- clk_change_rate(core->new_child);
+ return ret;
}
-static int clk_core_set_rate_nolock(struct clk_core *core,
- unsigned long req_rate)
+/**
+ * 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)
{
- struct clk_core *top, *fail_clk;
- unsigned long rate = req_rate;
- int ret = 0;
-
- if (!core)
+ if (!clk)
return 0;
- /* bail early if nothing to do */
- if (rate == clk_core_get_rate_nolock(core))
- return 0;
+ return clk_core_get_phase(clk->core);
+}
+EXPORT_SYMBOL_GPL(clk_get_phase);
- if ((core->flags & CLK_SET_RATE_GATE) && core->prepare_count)
- return -EBUSY;
+/**
+ * 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;
- /* calculate new rates and get the topmost changed clock */
- top = clk_calc_new_rates(core, rate);
- if (!top)
- return -EINVAL;
+ /* 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;
- /* 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;
- }
+ return false;
+}
+EXPORT_SYMBOL_GPL(clk_is_match);
- /* change the rates */
- clk_change_rate(top);
+/*** debugfs support ***/
- core->req_rate = req_rate;
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
- return ret;
-}
+static struct dentry *rootdir;
+static int inited = 0;
+static DEFINE_MUTEX(clk_debug_lock);
+static HLIST_HEAD(clk_debug_list);
-/**
- * clk_set_rate - specify a new rate for clk
- * @clk: the clk whose rate is being changed
- * @rate: the new rate for clk
- *
- * In the simplest case clk_set_rate will only adjust the rate of clk.
- *
- * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
- * propagate up to clk's parent; whether or not this happens depends on the
- * 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 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.
- *
- * Rate changes are accomplished via tree traversal that also recalculates the
- * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
- *
- * Returns 0 on success, -EERROR otherwise.
- */
-int clk_set_rate(struct clk *clk, unsigned long rate)
+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)
{
- int ret;
+ if (!c)
+ return;
- if (!clk)
- return 0;
+ 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));
+}
- /* prevent racing with updates to the clock topology */
- clk_prepare_lock();
+static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
+ int level)
+{
+ struct clk_core *child;
- ret = clk_core_set_rate_nolock(clk->core, rate);
+ if (!c)
+ return;
- clk_prepare_unlock();
+ clk_summary_show_one(s, c, level);
- return ret;
+ hlist_for_each_entry(child, &c->children, child_node)
+ clk_summary_show_subtree(s, child, level + 1);
}
-EXPORT_SYMBOL_GPL(clk_set_rate);
-/**
- * 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)
+static int clk_summary_show(struct seq_file *s, void *data)
{
- int ret = 0;
-
- if (!clk)
- return 0;
+ struct clk_core *c;
+ struct hlist_head **lists = (struct hlist_head **)s->private;
- 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;
- }
+ seq_puts(s, " clock enable_cnt prepare_cnt rate accuracy phase\n");
+ seq_puts(s, "----------------------------------------------------------------------------------------\n");
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);
- }
+ for (; *lists; lists++)
+ hlist_for_each_entry(c, *lists, child_node)
+ clk_summary_show_subtree(s, c, 0);
clk_prepare_unlock();
- return ret;
+ return 0;
}
-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)
+static int clk_summary_open(struct inode *inode, struct file *file)
{
- if (!clk)
- return 0;
-
- return clk_set_rate_range(clk, clk->min_rate, rate);
+ return single_open(file, clk_summary_show, inode->i_private);
}
-EXPORT_SYMBOL_GPL(clk_set_max_rate);
-/**
- * clk_get_parent - return the parent of a clk
- * @clk: the clk whose parent gets returned
- *
- * Simply returns clk->parent. Returns NULL if clk is NULL.
- */
-struct clk *clk_get_parent(struct clk *clk)
-{
- struct clk *parent;
+static const struct file_operations clk_summary_fops = {
+ .open = clk_summary_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
- clk_prepare_lock();
- parent = __clk_get_parent(clk);
- clk_prepare_unlock();
+static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
+{
+ if (!c)
+ return;
- return parent;
+ 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));
}
-EXPORT_SYMBOL_GPL(clk_get_parent);
-/*
- * .get_parent is mandatory for clocks with multiple possible parents. It is
- * optional for single-parent clocks. Always call .get_parent if it is
- * available and WARN if it is missing for multi-parent clocks.
- *
- * 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.
- */
-static struct clk_core *__clk_init_parent(struct clk_core *core)
+static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
{
- struct clk_core *ret = NULL;
- u8 index;
+ struct clk_core *child;
- /* handle the trivial cases */
+ if (!c)
+ return;
- if (!core->num_parents)
- goto out;
+ clk_dump_one(s, c, level);
- 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;
+ hlist_for_each_entry(child, &c->children, child_node) {
+ seq_printf(s, ",");
+ clk_dump_subtree(s, child, level + 1);
}
- 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 core->parents. This prevents
- * unnecessary and expensive lookups. We don't set core->parent here;
- * that is done by the calling function.
- */
-
- index = core->ops->get_parent(core->hw);
-
- if (!core->parents)
- core->parents =
- kcalloc(core->num_parents, sizeof(struct clk *),
- GFP_KERNEL);
-
- ret = clk_core_get_parent_by_index(core, index);
-
-out:
- return ret;
-}
-
-static void clk_core_reparent(struct clk_core *core,
- struct clk_core *new_parent)
-{
- clk_reparent(core, new_parent);
- __clk_recalc_accuracies(core);
- __clk_recalc_rates(core, POST_RATE_CHANGE);
+ seq_printf(s, "}");
}
-/**
- * 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)
+static int clk_dump(struct seq_file *s, void *data)
{
- struct clk_core *core, *parent_core;
- unsigned int i;
+ struct clk_core *c;
+ bool first_node = true;
+ struct hlist_head **lists = (struct hlist_head **)s->private;
- /* NULL clocks should be nops, so return success if either is NULL. */
- if (!clk || !parent)
- return true;
+ seq_printf(s, "{");
- core = clk->core;
- parent_core = parent->core;
+ clk_prepare_lock();
- /* Optimize for the case where the parent is already the parent. */
- if (core->parent == parent_core)
- return true;
+ 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);
+ }
+ }
- for (i = 0; i < core->num_parents; i++)
- if (strcmp(core->parent_names[i], parent_core->name) == 0)
- return true;
+ clk_prepare_unlock();
- return false;
+ seq_printf(s, "}");
+ return 0;
}
-EXPORT_SYMBOL_GPL(clk_has_parent);
-static int clk_core_set_parent(struct clk_core *core, struct clk_core *parent)
+
+static int clk_dump_open(struct inode *inode, struct file *file)
{
- int ret = 0;
- int p_index = 0;
- unsigned long p_rate = 0;
+ return single_open(file, clk_dump, inode->i_private);
+}
- if (!core)
- return 0;
+static const struct file_operations clk_dump_fops = {
+ .open = clk_dump_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
- /* prevent racing with updates to the clock topology */
- clk_prepare_lock();
+static int clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
+{
+ struct dentry *d;
+ int ret = -ENOMEM;
- if (core->parent == parent)
+ if (!core || !pdentry) {
+ ret = -EINVAL;
goto out;
+ }
- /* verify ops for for multi-parent clks */
- if ((core->num_parents > 1) && (!core->ops->set_parent)) {
- ret = -ENOSYS;
+ d = debugfs_create_dir(core->name, pdentry);
+ if (!d)
goto out;
- }
- /* 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;
- }
+ 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;
- /* 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;
- }
- }
+ d = debugfs_create_x32("clk_flags", S_IRUGO, core->dentry,
+ (u32 *)&core->flags);
+ if (!d)
+ goto err_out;
- /* propagate PRE_RATE_CHANGE notifications */
- ret = __clk_speculate_rates(core, p_rate);
+ d = debugfs_create_u32("clk_prepare_count", S_IRUGO, core->dentry,
+ (u32 *)&core->prepare_count);
+ if (!d)
+ goto err_out;
- /* abort if a driver objects */
- if (ret & NOTIFY_STOP_MASK)
- goto out;
+ d = debugfs_create_u32("clk_enable_count", S_IRUGO, core->dentry,
+ (u32 *)&core->enable_count);
+ if (!d)
+ goto err_out;
- /* do the re-parent */
- ret = __clk_set_parent(core, parent, p_index);
+ d = debugfs_create_u32("clk_notifier_count", S_IRUGO, core->dentry,
+ (u32 *)&core->notifier_count);
+ if (!d)
+ goto err_out;
- /* 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);
+ if (core->ops->debug_init) {
+ ret = core->ops->debug_init(core->hw, core->dentry);
+ if (ret)
+ goto err_out;
}
-out:
- clk_prepare_unlock();
+ ret = 0;
+ goto out;
+err_out:
+ debugfs_remove_recursive(core->dentry);
+ core->dentry = NULL;
+out:
return ret;
}
/**
- * clk_set_parent - switch the parent of a mux clk
- * @clk: the mux clk whose input we are switching
- * @parent: the new input to clk
- *
- * 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.
+ * clk_debug_register - add a clk node to the debugfs clk tree
+ * @core: the clk being added to the debugfs clk tree
*
- * Returns 0 on success, -EERROR otherwise.
+ * 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.
*/
-int clk_set_parent(struct clk *clk, struct clk *parent)
+static int clk_debug_register(struct clk_core *core)
{
- if (!clk)
- return 0;
+ int ret = 0;
- return clk_core_set_parent(clk->core, parent ? parent->core : NULL);
+ 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_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.
+ /**
+ * clk_debug_unregister - remove a clk node from the debugfs clk tree
+ * @core: the clk being removed from the debugfs clk tree
*
- * 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.
+ * Dynamically removes a clk and all it's children clk nodes from the
+ * debugfs clk tree if clk->dentry points to debugfs created by
+ * clk_debug_register in __clk_init.
*/
-int clk_set_phase(struct clk *clk, int degrees)
+static void clk_debug_unregister(struct clk_core *core)
{
- int ret = -EINVAL;
+ mutex_lock(&clk_debug_lock);
+ hlist_del_init(&core->debug_node);
+ debugfs_remove_recursive(core->dentry);
+ core->dentry = NULL;
+ mutex_unlock(&clk_debug_lock);
+}
- if (!clk)
- return 0;
+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;
- /* sanity check degrees */
- degrees %= 360;
- if (degrees < 0)
- degrees += 360;
+ if (hw->core->dentry)
+ d = debugfs_create_file(name, mode, hw->core->dentry, data,
+ fops);
- clk_prepare_lock();
+ return d;
+}
+EXPORT_SYMBOL_GPL(clk_debugfs_add_file);
- trace_clk_set_phase(clk->core, degrees);
+/**
+ * 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_core *core;
+ struct dentry *d;
- if (clk->core->ops->set_phase)
- ret = clk->core->ops->set_phase(clk->core->hw, degrees);
+ rootdir = debugfs_create_dir("clk", NULL);
- trace_clk_set_phase_complete(clk->core, degrees);
+ if (!rootdir)
+ return -ENOMEM;
- if (!ret)
- clk->core->phase = degrees;
+ d = debugfs_create_file("clk_summary", S_IRUGO, rootdir, &all_lists,
+ &clk_summary_fops);
+ if (!d)
+ return -ENOMEM;
- clk_prepare_unlock();
+ d = debugfs_create_file("clk_dump", S_IRUGO, rootdir, &all_lists,
+ &clk_dump_fops);
+ if (!d)
+ return -ENOMEM;
- return ret;
-}
-EXPORT_SYMBOL_GPL(clk_set_phase);
+ d = debugfs_create_file("clk_orphan_summary", S_IRUGO, rootdir,
+ &orphan_list, &clk_summary_fops);
+ if (!d)
+ return -ENOMEM;
-static int clk_core_get_phase(struct clk_core *core)
-{
- int ret;
+ d = debugfs_create_file("clk_orphan_dump", S_IRUGO, rootdir,
+ &orphan_list, &clk_dump_fops);
+ if (!d)
+ return -ENOMEM;
- clk_prepare_lock();
- ret = core->phase;
- clk_prepare_unlock();
+ mutex_lock(&clk_debug_lock);
+ hlist_for_each_entry(core, &clk_debug_list, debug_node)
+ clk_debug_create_one(core, rootdir);
- return ret;
-}
-EXPORT_SYMBOL_GPL(clk_get_phase);
+ inited = 1;
+ mutex_unlock(&clk_debug_lock);
-/**
- * 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)
+ 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)
{
- if (!clk)
- return 0;
-
- return clk_core_get_phase(clk->core);
}
-
-/**
- * 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)
+static inline void clk_debug_unregister(struct clk_core *core)
{
- /* 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);
+#endif
/**
* __clk_init - initialize the data structures in a struct clk
projects / mirror_ubuntu-artful-kernel.git / commitdiff