diff options
| -rw-r--r-- | drivers/clk/clk.c | 74 | ||||
| -rw-r--r-- | include/linux/clk-provider.h | 7 | ||||
| -rw-r--r-- | include/linux/clk.h | 25 |
3 files changed, 106 insertions, 0 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index d31055ae6ec6..8a0254a1c303 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -923,6 +923,80 @@ static int clk_core_enable_lock(struct clk_core *core) return ret; } +static int _clk_save_context(struct clk_core *clk) +{ + struct clk_core *child; + int ret = 0; + + hlist_for_each_entry(child, &clk->children, child_node) { + ret = _clk_save_context(child); + if (ret < 0) + return ret; + } + + if (clk->ops && clk->ops->save_context) + ret = clk->ops->save_context(clk->hw); + + return ret; +} + +static void _clk_restore_context(struct clk_core *clk) +{ + struct clk_core *child; + + if (clk->ops && clk->ops->restore_context) + clk->ops->restore_context(clk->hw); + + hlist_for_each_entry(child, &clk->children, child_node) + _clk_restore_context(child); +} + +/** + * clk_save_context - save clock context for poweroff + * + * Saves the context of the clock register for powerstates in which the + * contents of the registers will be lost. Occurs deep within the suspend + * code. Returns 0 on success. + */ +int clk_save_context(void) +{ + struct clk_core *clk; + int ret; + + hlist_for_each_entry(clk, &clk_root_list, child_node) { + ret = _clk_save_context(clk); + if (ret < 0) + return ret; + } + + hlist_for_each_entry(clk, &clk_orphan_list, child_node) { + ret = _clk_save_context(clk); + if (ret < 0) + return ret; + } + + return 0; +} +EXPORT_SYMBOL_GPL(clk_save_context); + +/** + * clk_restore_context - restore clock context after poweroff + * + * Restore the saved clock context upon resume. + * + */ +void clk_restore_context(void) +{ + struct clk_core *clk; + + hlist_for_each_entry(clk, &clk_root_list, child_node) + _clk_restore_context(clk); + + hlist_for_each_entry(clk, &clk_orphan_list, child_node) + _clk_restore_context(clk); +} +EXPORT_SYMBOL_GPL(clk_restore_context); + /** * clk_enable - ungate a clock * @clk: the clk being ungated diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 08b1aa70a38d..df7379da6269 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -119,6 +119,11 @@ struct clk_duty { * Called with enable_lock held. This function must not * sleep. * + * @save_context: Save the context of the clock in prepration for poweroff. + * + * @restore_context: Restore the context of the clock after a restoration + * of power. + * * @recalc_rate Recalculate the rate of this clock, by querying hardware. The * parent rate is an input parameter. It is up to the caller to * ensure that the prepare_mutex is held across this call. @@ -223,6 +228,8 @@ struct clk_ops { void (*disable)(struct clk_hw *hw); int (*is_enabled)(struct clk_hw *hw); void (*disable_unused)(struct clk_hw *hw); + int (*save_context)(struct clk_hw *hw); + void (*restore_context)(struct clk_hw *hw); unsigned long (*recalc_rate)(struct clk_hw *hw, unsigned long parent_rate); long (*round_rate)(struct clk_hw *hw, unsigned long rate, diff --git a/include/linux/clk.h b/include/linux/clk.h index 4f750c481b82..7da754d79f9d 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -629,6 +629,23 @@ struct clk *clk_get_parent(struct clk *clk); */ struct clk *clk_get_sys(const char *dev_id, const char *con_id); +/** + * clk_save_context - save clock context for poweroff + * + * Saves the context of the clock register for powerstates in which the + * contents of the registers will be lost. Occurs deep within the suspend + * code so locking is not necessary. + */ +int clk_save_context(void); + +/** + * clk_restore_context - restore clock context after poweroff + * + * This occurs with all clocks enabled. Occurs deep within the resume code + * so locking is not necessary. + */ +void clk_restore_context(void); + #else /* !CONFIG_HAVE_CLK */ static inline struct clk *clk_get(struct device *dev, const char *id) @@ -728,6 +745,14 @@ static inline struct clk *clk_get_sys(const char *dev_id, const char *con_id) { return NULL; } + +static inline int clk_save_context(void) +{ + return 0; +} + +static inline void clk_restore_context(void) {} + #endif /* clk_prepare_enable helps cases using clk_enable in non-atomic context. */ |