[PATCH RFC v3 1/2] clk: Add function parsing arbitrary clock list DT property

[Bartlomiej Zolnierkiewicz]

Hi Sylwester,

On Thursday, March 27, 2014 01:16:18 PM Sylwester Nawrocki wrote:
> The of_clk_get_by_property() function added by this patch is similar to
> of_clk_get(), except it allows to pass name of a DT property containing
> list of phandles and clock specifiers. For of_clk_get() this has been
> hard coded to "clocks".
> 
> Signed-off-by: Sylwester Nawrocki <s.nawrocki at samsung.com>
> ---
> Changes since v2:
>  - moved the function declaration from drivers/clk/clk.h to
>    include/linux/clk.h
> 
> Changes since v1:
>  - s/of_clk_get_list_entry/of_clk_get_by_property.
> ---
>  drivers/clk/clkdev.c |   25 +++++++++++++++++++++----
>  include/linux/clk.h  |    7 +++++++
>  2 files changed, 28 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
> index a360b2e..1d41540 100644
> --- a/drivers/clk/clkdev.c
> +++ b/drivers/clk/clkdev.c
> @@ -27,17 +27,28 @@ static LIST_HEAD(clocks);
>  static DEFINE_MUTEX(clocks_mutex);
>  
>  #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
> -struct clk *of_clk_get(struct device_node *np, int index)
> +/**
> + * of_clk_get_by_property() - Parse and lookup a clock referenced by a device node
> + * @np: pointer to clock consumer node
> + * @list_name: name of the clock list property
> + * @index: index to the clock list
> + *
> + * This function parses the @list_name property and together with @index
> + * value indicating an entry of the list uses it to look up the struct clk
> + * from the registered list of clock providers.
> + */
> +struct clk *of_clk_get_by_property(struct device_node *np,
> +				   const char *list_name, int index)
>  {
>  	struct of_phandle_args clkspec;
>  	struct clk *clk;
>  	int rc;
>  
> -	if (index < 0)
> +	if (index < 0 || !list_name)
>  		return ERR_PTR(-EINVAL);
>  
> -	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
> -					&clkspec);
> +	rc = of_parse_phandle_with_args(np, list_name, "#clock-cells",
> +					index, &clkspec);
>  	if (rc)
>  		return ERR_PTR(rc);
>  
> @@ -51,6 +62,12 @@ struct clk *of_clk_get(struct device_node *np, int index)
>  	of_node_put(clkspec.np);
>  	return clk;
>  }
> +EXPORT_SYMBOL(of_clk_get_by_property);
> +
> +struct clk *of_clk_get(struct device_node *np, int index)
> +{
> +	return of_clk_get_by_property(np, "clocks", index);
> +}
>  EXPORT_SYMBOL(of_clk_get);
>  
>  /**
> diff --git a/include/linux/clk.h b/include/linux/clk.h
> index 0dd9114..f71235b 100644
> --- a/include/linux/clk.h
> +++ b/include/linux/clk.h
> @@ -383,6 +383,8 @@ struct of_phandle_args;
>  
>  #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
>  struct clk *of_clk_get(struct device_node *np, int index);
> +struct clk *of_clk_get_by_property(struct device_node *np,
> +				   const char *list_name, int index);
>  struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
>  struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
>  #else
> @@ -395,6 +397,11 @@ static inline struct clk *of_clk_get_by_name(struct device_node *np,
>  {
>  	return ERR_PTR(-ENOENT);
>  }
> +struct clk *of_clk_get_by_property(struct device_node *np,

This causes build brake with s3c6400_defconfig
(it should be 'static inline').

> +				   const char *list_name, int index)
> +{
> +	return ERR_PTR(-ENOENT);
> +}
>  #endif
>  
>  #endif

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics