From 26b36df7516692292312063ca6fd19e73c06d4e7 Mon Sep 17 00:00:00 2001 From: Abel Vesa Date: Tue, 27 Dec 2022 22:45:27 +0200 Subject: [PATCH] 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: Abel Vesa Reviewed-by: Bjorn Andersson Reviewed-by: Dmitry Baryshkov Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20221227204528.1899863-1-abel.vesa@linaro.org --- drivers/clk/clk.c | 57 +++++++++++++++++++++++++++++++++++--------- include/linux/clk-provider.h | 1 + 2 files changed, 47 insertions(+), 11 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index e62552a..ac71829 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -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 @@ unprepare_out: 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) { diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 842e72a..cf1adfe 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -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 -- 2.7.4