Revert "ANDROID: GKI: clk: Add support for clock providers with sync state"

This reverts commit 44ee1179cb.

Upstream reverted the equivalent patch in commit c1855dd0a6 ("clk: qcom:
Revert sync_state based clk_disable_unused") after finding some issues
with this approach [1]. Also, keeping this patch creates build issues
with further upstream patches, so let's just drop it. If this is really
needed please work on landing this functionality upstream.

Bug: 535619959
Cc: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Id9f47b9225b14dc8dce29394f4b55534c6c7df34
Signed-off-by: Carlos Llamas <cmllamas@google.com>

drivers/clk/clk.c

@@ -83,8 +83,6 @@ 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;
@@ -1559,38 +1557,6 @@ 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)
 {
@@ -2087,33 +2053,6 @@ 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.
  */
@@ -3903,7 +3842,6 @@ static void clk_core_reparent_orphans_nolock(void)
 			__clk_set_parent_after(orphan, parent, NULL);
 			__clk_recalc_accuracies(orphan);
 			__clk_recalc_rates(orphan, true, 0);
-			__clk_core_update_orphan_hold_state(orphan);
 
 			/*
 			 * __clk_init_parent() will set the initial req_rate to
@@ -4088,8 +4026,6 @@ 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
@@ -4112,7 +4048,6 @@ static int __clk_core_init(struct clk_core *core)
 		}
 	}
 
-	clk_core_hold_state(core);
 	clk_core_reparent_orphans_nolock();
 out:
 	clk_pm_runtime_put(core);

include/linux/clk-provider.h

@@ -32,7 +32,6 @@
 #define CLK_OPS_PARENT_ENABLE	BIT(12)
 /* duty cycle call may be forwarded to the parent clock */
 #define CLK_DUTY_CYCLE_PARENT	BIT(13)
-#define CLK_DONT_HOLD_STATE	BIT(14) /* Don't hold state */
 
 struct clk;
 struct clk_hw;
@@ -1376,7 +1375,6 @@ int __must_check of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
 void clk_unregister(struct clk *clk);
 
 void clk_hw_unregister(struct clk_hw *hw);
-void clk_sync_state(struct device *dev);
 
 /* helper functions */
 const char *__clk_get_name(const struct clk *clk);