nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

clk: Add generic sync_state callback for disabling unused clocks

Browse source 
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: Abel Vesa <abel.vesa@linaro.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221227204528.1899863-1-abel.vesa@linaro.org
This commit is contained in:
Abel Vesa 2022-12-27 22:45:27 +02:00 committed by Bjorn Andersson
parent ce273e690d
commit 26b36df751
2 changed files with 47 additions and 11 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

57
drivers/clk/clk.c
View file

@ -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)
{

1
include/linux/clk-provider.h
View file

@ -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