[v2,3/3] CLK: add more managed APIs

[linux@roeck-us.net (Guenter Roeck)]

On Wed, Nov 21, 2012 at 09:34:42PM -0800, Dmitry Torokhov wrote:
> When converting a driver to managed resources it is desirable to be able to
> manage all resources in the same fashion. This change allows managing clocks
> in the same way we manage all other resources.
> 
> This adds the following managed APIs:
> 
> - devm_clk_prepare()/devm_clk_unprepare();
> - devm_clk_enable()/devm_clk_disable();
> - devm_clk_preapre_enable()/devm_clk_diable_unprepare().

s/devm_clk_preapre_enable/devm_clk_prepare_enable/
s//devm_clk_diable_unprepare//devm_clk_disable_unprepare/
> 
> Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

What happened with this patch ? I find it highly inconventient having to add
devm_add_action_or_reset() for pretty much every call to clk_prepare_enable().

Another odd one is that there is a devm_clk_get(), but no devm_of_clk_get()
or devm_of_clk_get_by_name().

Thanks,
Guenter

> ---
>  drivers/clk/clk-devres.c |  90 +++++++++++++++++++++++++++++++---------
>  include/linux/clk.h      | 105 +++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 176 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/clk/clk-devres.c b/drivers/clk/clk-devres.c
> index 8f57154..3a2286b 100644
> --- a/drivers/clk/clk-devres.c
> +++ b/drivers/clk/clk-devres.c
> @@ -9,6 +9,32 @@
>  #include <linux/export.h>
>  #include <linux/gfp.h>
>  
> +static int devm_clk_match(struct device *dev, void *res, void *data)
> +{
> +	struct clk **c = res;
> +
> +	if (WARN_ON(!c || !*c))
> +		return 0;
> +
> +	return *c == data;
> +}
> +
> +
> +static int devm_clk_create_devres(struct device *dev, struct clk *clk,
> +				  void (*release)(struct device *, void *))
> +{
> +	struct clk **ptr;
> +
> +	ptr = devres_alloc(release, sizeof(*ptr), GFP_KERNEL);
> +	if (!ptr)
> +		return -ENOMEM;
> +
> +	*ptr = clk;
> +	devres_add(dev, ptr);
> +
> +	return 0;
> +}
> +
>  static void devm_clk_release(struct device *dev, void *res)
>  {
>  	clk_put(*(struct clk **)res);
> @@ -16,34 +42,22 @@ static void devm_clk_release(struct device *dev, void *res)
>  
>  struct clk *devm_clk_get(struct device *dev, const char *id)
>  {
> -	struct clk **ptr, *clk;
> -
> -	ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
> -	if (!ptr)
> -		return ERR_PTR(-ENOMEM);
> +	struct clk *clk;
> +	int error;
>  
>  	clk = clk_get(dev, id);
>  	if (!IS_ERR(clk)) {
> -		*ptr = clk;
> -		devres_add(dev, ptr);
> -	} else {
> -		devres_free(ptr);
> +		error = devm_clk_create_devres(dev, clk, devm_clk_release);
> +		if (error) {
> +			clk_put(clk);
> +			return ERR_PTR(error);
> +		}
>  	}
>  
>  	return clk;
>  }
>  EXPORT_SYMBOL(devm_clk_get);
>  
> -static int devm_clk_match(struct device *dev, void *res, void *data)
> -{
> -	struct clk **c = res;
> -	if (!c || !*c) {
> -		WARN_ON(!c || !*c);
> -		return 0;
> -	}
> -	return *c == data;
> -}
> -
>  void devm_clk_put(struct device *dev, struct clk *clk)
>  {
>  	int ret;
> @@ -53,3 +67,41 @@ void devm_clk_put(struct device *dev, struct clk *clk)
>  	WARN_ON(ret);
>  }
>  EXPORT_SYMBOL(devm_clk_put);
> +
> +#define DEFINE_DEVM_CLK_OP(create_op, destroy_op)			\
> +static void devm_##destroy_op##_release(struct device *devm, void *res)	\
> +{									\
> +	destroy_op(*(struct clk **)res);				\
> +}									\
> +									\
> +int devm_##create_op(struct device *dev, struct clk *clk)		\
> +{									\
> +	int error;							\
> +									\
> +	error = devm_clk_create_devres(dev, clk,			\
> +					devm_##destroy_op##_release);	\
> +	if (error)							\
> +		return error;						\
> +									\
> +	error = create_op(clk);						\
> +	if (error) {							\
> +		WARN_ON(devres_destroy(dev,				\
> +					devm_##destroy_op##_release,	\
> +					devm_clk_match, clk));		\
> +		return error;						\
> +	}								\
> +									\
> +	return 0;							\
> +}									\
> +EXPORT_SYMBOL(devm_##create_op);					\
> +									\
> +void devm_##destroy_op(struct device *dev, struct clk *clk)		\
> +{									\
> +	WARN_ON(devres_release(dev, devm_##destroy_op##_release,	\
> +				devm_clk_match, clk));			\
> +}									\
> +EXPORT_SYMBOL(devm_##destroy_op)
> +
> +DEFINE_DEVM_CLK_OP(clk_prepare, clk_unprepare);
> +DEFINE_DEVM_CLK_OP(clk_prepare_enable, clk_disable_unprepare);
> +DEFINE_DEVM_CLK_OP(clk_enable, clk_disable);
> diff --git a/include/linux/clk.h b/include/linux/clk.h
> index 8bf149e..04b6300 100644
> --- a/include/linux/clk.h
> +++ b/include/linux/clk.h
> @@ -133,6 +133,17 @@ struct clk *devm_clk_get(struct device *dev, const char *id);
>  int clk_prepare(struct clk *clk);
>  
>  /**
> + * devm_clk_prepare - prepare a clock source as managed resource
> + * @dev: device owning the resource
> + * @clk: clock source
> + *
> + * This prepares the clock source for use.
> + *
> + * Must not be called from within atomic context.
> + */
> +int devm_clk_prepare(struct device *dev, struct clk *clk);
> +
> +/**
>   * clk_unprepare - undo preparation of a clock source
>   * @clk: clock source
>   *
> @@ -144,6 +155,18 @@ int clk_prepare(struct clk *clk);
>  void clk_unprepare(struct clk *clk);
>  
>  /**
> + * devm_clk_unprepare - undo preparation of a managed clock source.
> + * @dev: device used to prepare the clock
> + * @clk: clock source
> + *
> + * This undoes preparation of a clock previously prepared with call
> + * to devm_clk_pepare().
> + *
> + * Must not be called from within atomic context.
> + */
> +void devm_clk_unprepare(struct device *dev, struct clk *clk);
> +
> +/**
>   * clk_enable - inform the system when the clock source should be running.
>   * @clk: clock source
>   *
> @@ -156,6 +179,19 @@ void clk_unprepare(struct clk *clk);
>  int clk_enable(struct clk *clk);
>  
>  /**
> + * devm_clk_enable - enable the clock source as managed resource
> + * @dev: device owning the resource
> + * @clk: clock source
> + *
> + * If the clock can not be enabled/disabled, this should return success.
> + *
> + * May be not called from atomic contexts.
> + *
> + * Returns success (0) or negative errno.
> + */
> +int devm_clk_enable(struct device *dev, struct clk *clk);
> +
> +/**
>   * clk_disable - inform the system when the clock source is no longer required.
>   * @clk: clock source
>   *
> @@ -172,6 +208,18 @@ int clk_enable(struct clk *clk);
>  void clk_disable(struct clk *clk);
>  
>  /**
> + * devm_clk_disable - disable managed clock source resource
> + * @dev: device used to enable the clock
> + * @clk: clock source
> + *
> + * Inform the system that a clock source is no longer required by
> + * a driver and may be shut down.
> + *
> + * Must not be called from atomic contexts.
> + */
> +void devm_clk_disable(struct device *dev, struct clk *clk);
> +
> +/**
>   * clk_prepare_enable - prepare and enable a clock source
>   * @clk: clock source
>   *
> @@ -182,6 +230,17 @@ void clk_disable(struct clk *clk);
>  int clk_prepare_enable(struct clk *clk);
>  
>  /**
> + * devm_clk_prepare_enable - prepare and enable a managed clock source
> + * @dev: device owning the clock source
> + * @clk: clock source
> + *
> + * This prepares the clock source for use and enables it.
> + *
> + * Must not be called from within atomic context.
> + */
> +int devm_clk_prepare_enable(struct device *dev, struct clk *clk);
> +
> +/**
>   * clk_disable_unprepare - disable and undo preparation of a clock source
>   * @clk: clock source
>   *
> @@ -192,6 +251,17 @@ int clk_prepare_enable(struct clk *clk);
>  void clk_disable_unprepare(struct clk *clk);
>  
>  /**
> + * clk_disable_unprepare - disable and undo preparation of a managed clock source
> + * @dev: device used to prepare and enable the clock
> + * @clk: clock source
> + *
> + * This disables and undoes a previously prepared clock.
> + *
> + * Must not be called from within atomic context.
> + */
> +void devm_clk_disable_unprepare(struct device *dev, struct clk *clk);
> +
> +/**
>   * clk_get_rate - obtain the current clock rate (in Hz) for a clock source.
>   *		  This is only valid once the clock source has been enabled.
>   * @clk: clock source
> @@ -303,29 +373,64 @@ static inline int clk_prepare(struct clk *clk)
>  	return 0;
>  }
>  
> +static inline int devm_clk_prepare(struct device *dev, struct clk *clk)
> +{
> +	might_sleep();
> +	return 0;
> +}
> +
>  static inline void clk_unprepare(struct clk *clk)
>  {
>  	might_sleep();
>  }
>  
> +static inline void devm_clk_unprepare(struct device *dev, struct clk *clk)
> +{
> +	might_sleep();
> +}
> +
>  static inline int clk_enable(struct clk *clk)
>  {
>  	return 0;
>  }
>  
> +static inline int devm_clk_enable(struct device *dev, struct clk *clk)
> +{
> +	might_sleep();
> +	return 0;
> +}
> +
>  static inline void clk_disable(struct clk *clk) {}
>  
> +static inline void devm_clk_disable(struct device *dev, struct clk *clk)
> +{
> +	might_sleep();
> +	return 0;
> +}
> +
>  static inline int clk_prepare_enable(struct clk *clk)
>  {
>  	might_sleep();
>  	return 0;
>  }
>  
> +static inline int devm_clk_prepare_enable(struct device *dev, struct clk *clk)
> +{
> +	might_sleep();
> +	return 0;
> +}
> +
>  static inline void clk_disable_unprepare(struct clk *clk)
>  {
>  	might_sleep();
>  }
>  
> +static inline void devm_clk_disable_unprepare(struct device *dev,
> +					      struct clk *clk)
> +{
> +	might_sleep();
> +}
> +
>  static inline unsigned long clk_get_rate(struct clk *clk)
>  {
>  	return 0;