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path: root/drivers/clk/clk.c
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Diffstat (limited to 'drivers/clk/clk.c')
-rw-r--r--drivers/clk/clk.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 566ee2c78709..290b57977301 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -72,6 +72,8 @@ struct clk_core {
unsigned long flags;
bool orphan;
bool rpm_enabled;
+ bool need_sync;
+ bool boot_enabled;
unsigned int enable_count;
unsigned int prepare_count;
unsigned int protect_count;
@@ -1319,6 +1321,38 @@ static int __init clk_disable_unused(void)
}
late_initcall_sync(clk_disable_unused);
+static void clk_unprepare_disable_dev_subtree(struct clk_core *core,
+ struct device *dev)
+{
+ struct clk_core *child;
+
+ lockdep_assert_held(&prepare_lock);
+
+ hlist_for_each_entry(child, &core->children, child_node)
+ clk_unprepare_disable_dev_subtree(child, dev);
+
+ if (core->dev != dev || !core->need_sync)
+ return;
+
+ clk_core_disable_unprepare(core);
+}
+
+void clk_sync_state(struct device *dev)
+{
+ struct clk_core *core;
+
+ clk_prepare_lock();
+
+ hlist_for_each_entry(core, &clk_root_list, child_node)
+ clk_unprepare_disable_dev_subtree(core, dev);
+
+ hlist_for_each_entry(core, &clk_orphan_list, child_node)
+ clk_unprepare_disable_dev_subtree(core, dev);
+
+ clk_prepare_unlock();
+}
+EXPORT_SYMBOL_GPL(clk_sync_state);
+
static int clk_core_determine_round_nolock(struct clk_core *core,
struct clk_rate_request *req)
{
@@ -1725,6 +1759,33 @@ int clk_hw_get_parent_index(struct clk_hw *hw)
}
EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
+static void clk_core_hold_state(struct clk_core *core)
+{
+ if (core->need_sync || !core->boot_enabled)
+ return;
+
+ if (core->orphan || !dev_has_sync_state(core->dev))
+ return;
+
+ if (core->flags & CLK_DONT_HOLD_STATE)
+ return;
+
+ core->need_sync = !clk_core_prepare_enable(core);
+}
+
+static void __clk_core_update_orphan_hold_state(struct clk_core *core)
+{
+ struct clk_core *child;
+
+ if (core->orphan)
+ return;
+
+ clk_core_hold_state(core);
+
+ hlist_for_each_entry(child, &core->children, child_node)
+ __clk_core_update_orphan_hold_state(child);
+}
+
/*
* Update the orphan status of @core and all its children.
*/
@@ -3395,6 +3456,7 @@ static void clk_core_reparent_orphans_nolock(void)
__clk_set_parent_after(orphan, parent, NULL);
__clk_recalc_accuracies(orphan);
__clk_recalc_rates(orphan, 0);
+ __clk_core_update_orphan_hold_state(orphan);
}
}
}
@@ -3561,6 +3623,8 @@ static int __clk_core_init(struct clk_core *core)
rate = 0;
core->rate = core->req_rate = rate;
+ core->boot_enabled = clk_core_is_enabled(core);
+
/*
* Enable CLK_IS_CRITICAL clocks so newly added critical clocks
* don't get accidentally disabled when walking the orphan tree and
@@ -3583,6 +3647,7 @@ static int __clk_core_init(struct clk_core *core)
}
}
+ clk_core_hold_state(core);
clk_core_reparent_orphans_nolock();