diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 5413ffaf02e2..ae30c524a8ab 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -60,6 +60,8 @@ struct clk_core { struct clk_core *new_child; unsigned long flags; bool orphan; + bool need_sync; + bool boot_enabled; unsigned int enable_count; unsigned int prepare_count; unsigned int protect_count; @@ -1079,6 +1081,38 @@ static int 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) { @@ -1428,6 +1462,33 @@ static int clk_fetch_parent_index(struct clk_core *core, return -EINVAL; } +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. */ @@ -3058,6 +3119,8 @@ 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 @@ -3073,6 +3136,8 @@ static int __clk_core_init(struct clk_core *core) clk_enable_unlock(flags); } + clk_core_hold_state(core); + /* * walk the list of orphan clocks and reparent any that newly finds a * parent. @@ -3092,6 +3157,7 @@ static int __clk_core_init(struct clk_core *core) __clk_set_parent_after(orphan, parent, NULL); __clk_recalc_accuracies(orphan); __clk_recalc_rates(orphan, 0); + __clk_core_update_orphan_hold_state(orphan); } } diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index d1b6d2c3ada6..73aab8f9c59c 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -40,6 +40,7 @@ #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; @@ -769,6 +770,7 @@ void devm_clk_unregister(struct device *dev, struct clk *clk); void clk_hw_unregister(struct clk_hw *hw); void devm_clk_hw_unregister(struct device *dev, struct clk_hw *hw); +void clk_sync_state(struct device *dev); /* helper functions */ const char *__clk_get_name(const struct clk *clk);