Commit 26b36df7 authored by Abel Vesa's avatar Abel Vesa Committed by Bjorn Andersson
Browse files

clk: Add generic sync_state callback for disabling unused clocks 



There are unused clocks that need to remain untouched by clk_disable_unused,
and most likely could be disabled later on sync_state. So provide a generic
sync_state callback for the clock providers that register such clocks.
Then, use the same mechanism as clk_disable_unused from that generic
callback, but pass the device to make sure only the clocks belonging to
the current clock provider get disabled, if unused. Also, during the
default clk_disable_unused, if the driver that registered the clock has
the generic clk_sync_state_disable_unused callback set for sync_state,
skip disabling its clocks.

Signed-off-by: default avatarAbel Vesa <abel.vesa@linaro.org>
Reviewed-by: default avatarBjorn Andersson <andersson@kernel.org>
Reviewed-by: default avatarDmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: default avatarBjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221227204528.1899863-1-abel.vesa@linaro.org
parent ce273e69

drivers/clk/clk.c

+46 −11
Original line number Diff line number Diff line
@@ -1302,14 +1302,26 @@ static void clk_core_disable_unprepare(struct clk_core *core) 
	clk_core_unprepare_lock(core);

}



static void __init clk_unprepare_unused_subtree(struct clk_core *core)

static void clk_unprepare_unused_subtree(struct clk_core *core,

						struct device *dev)

{

	bool from_sync_state = !!dev;

	struct clk_core *child;



	lockdep_assert_held(&prepare_lock);



	hlist_for_each_entry(child, &core->children, child_node)

		clk_unprepare_unused_subtree(child);

		clk_unprepare_unused_subtree(child, dev);



	if (from_sync_state && core->dev != dev)

		return;



	/*

	 * clock will be unprepared on sync_state,

	 * so leave as is for now

	 */

	if (!from_sync_state && dev_has_sync_state(core->dev))

		return;



	if (core->prepare_count)

		return;
@@ -1332,15 +1344,27 @@ static void __init clk_unprepare_unused_subtree(struct clk_core *core) 
	clk_pm_runtime_put(core);

}



static void __init clk_disable_unused_subtree(struct clk_core *core)

static void clk_disable_unused_subtree(struct clk_core *core,

					struct device *dev)

{

	bool from_sync_state = !!dev;

	struct clk_core *child;

	unsigned long flags;



	lockdep_assert_held(&prepare_lock);



	hlist_for_each_entry(child, &core->children, child_node)

		clk_disable_unused_subtree(child);

		clk_disable_unused_subtree(child, dev);



	if (from_sync_state && core->dev != dev)

		return;



	/*

	 * clock will be disabled on sync_state,

	 * so leave as is for now

	 */

	if (!from_sync_state && dev_has_sync_state(core->dev))

		return;



	if (core->flags & CLK_OPS_PARENT_ENABLE)

		clk_core_prepare_enable(core->parent);
@@ -1378,7 +1402,7 @@ static void __init clk_disable_unused_subtree(struct clk_core *core) 
		clk_core_disable_unprepare(core->parent);

}



static bool clk_ignore_unused __initdata;

static bool clk_ignore_unused;

static int __init clk_ignore_unused_setup(char *__unused)

{

	clk_ignore_unused = true;
@@ -1386,35 +1410,46 @@ static int __init clk_ignore_unused_setup(char *__unused) 
}

__setup("clk_ignore_unused", clk_ignore_unused_setup);



static int __init clk_disable_unused(void)

static void __clk_disable_unused(struct device *dev)

{

	struct clk_core *core;



	if (clk_ignore_unused) {

		pr_warn("clk: Not disabling unused clocks\n");

		return 0;

		return;

	}



	clk_prepare_lock();



	hlist_for_each_entry(core, &clk_root_list, child_node)

		clk_disable_unused_subtree(core);

		clk_disable_unused_subtree(core, dev);



	hlist_for_each_entry(core, &clk_orphan_list, child_node)

		clk_disable_unused_subtree(core);

		clk_disable_unused_subtree(core, dev);



	hlist_for_each_entry(core, &clk_root_list, child_node)

		clk_unprepare_unused_subtree(core);

		clk_unprepare_unused_subtree(core, dev);



	hlist_for_each_entry(core, &clk_orphan_list, child_node)

		clk_unprepare_unused_subtree(core);

		clk_unprepare_unused_subtree(core, dev);



	clk_prepare_unlock();

}



static int __init clk_disable_unused(void)

{

	__clk_disable_unused(NULL);



	return 0;

}

late_initcall_sync(clk_disable_unused);



void clk_sync_state_disable_unused(struct device *dev)

{

	__clk_disable_unused(dev);

}

EXPORT_SYMBOL_GPL(clk_sync_state_disable_unused);



static int clk_core_determine_round_nolock(struct clk_core *core,

					   struct clk_rate_request *req)

{

include/linux/clk-provider.h

+1 −0
Original line number Diff line number Diff line
@@ -720,6 +720,7 @@ struct clk *clk_register_divider_table(struct device *dev, const char *name, 
		void __iomem *reg, u8 shift, u8 width,

		u8 clk_divider_flags, const struct clk_div_table *table,

		spinlock_t *lock);

void clk_sync_state_disable_unused(struct device *dev);

/**

 * clk_register_divider - register a divider clock with the clock framework

 * @dev: device registering this clock