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Message-Id: <20220706150411.708213-1-abel.vesa@linaro.org>
Date: Wed, 6 Jul 2022 18:04:10 +0300
From: Abel Vesa <abel.vesa@...aro.org>
To: Mike Turquette <mturquette@...libre.com>,
Stephen Boyd <sboyd@...nel.org>,
Bjorn Andersson <bjorn.andersson@...aro.org>,
Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
Konrad Dybcio <konrad.dybcio@...ainline.org>
Cc: linux-clk@...r.kernel.org,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
linux-arm-msm@...r.kernel.org, Abel Vesa <abel.vesa@...aro.org>
Subject: [RFC 1/2] clk: Add generic sync_state callback for disabling unused clocks
There are unused clocks that need to stay enabled on clk_disable_unused,
but rather should be disabled later on on sync_state. 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,
leave its clocks enabled.
Signed-off-by: Abel Vesa <abel.vesa@...aro.org>
---
drivers/clk/clk.c | 67 +++++++++++++++++++++++++++---------
include/linux/clk-provider.h | 1 +
2 files changed, 52 insertions(+), 16 deletions(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index 7fc191c15507..ea55806505c0 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -1218,19 +1218,31 @@ 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)
{
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 (dev && core->dev != dev)
+ return;
+
+ /*
+ * clock will be unprepared on sync_state,
+ * so leave as is on clk_disable_unused
+ */
+ if (!dev && dev_has_sync_state(core->dev) &&
+ core->dev->driver->sync_state == clk_sync_state_disable_unused)
+ return;
if (core->prepare_count)
return;
- if (core->flags & CLK_IGNORE_UNUSED)
+ if (!dev && core->flags & CLK_IGNORE_UNUSED)
return;
if (clk_pm_runtime_get(core))
@@ -1248,7 +1260,8 @@ 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)
{
struct clk_core *child;
unsigned long flags;
@@ -1256,7 +1269,18 @@ static void __init clk_disable_unused_subtree(struct clk_core *core)
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 (dev && core->dev != dev)
+ return;
+
+ /*
+ * clock will be disabled on sync_state,
+ * so leave as is on clk_disable_unused
+ */
+ if (!dev && dev_has_sync_state(core->dev) &&
+ core->dev->driver->sync_state == clk_sync_state_disable_unused)
+ return;
if (core->flags & CLK_OPS_PARENT_ENABLE)
clk_core_prepare_enable(core->parent);
@@ -1269,7 +1293,7 @@ static void __init clk_disable_unused_subtree(struct clk_core *core)
if (core->enable_count)
goto unlock_out;
- if (core->flags & CLK_IGNORE_UNUSED)
+ if (!dev && core->flags & CLK_IGNORE_UNUSED)
goto unlock_out;
/*
@@ -1302,35 +1326,46 @@ 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;
- }
-
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)
+{
+ if (clk_ignore_unused) {
+ pr_warn("clk: Not disabling unused clocks\n");
+ return 0;
+ }
+
+ __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)
{
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 72d937c03a3e..5d3ed2b14f2c 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -679,6 +679,7 @@ 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
--
2.34.3
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