Re: [PATCH V3 3/4] of: introduce of_parse_phandle_with_fixed_args

Re: [PATCH V3 3/4] of: introduce of_parse_phandle_with_fixed_args

[Grant Likely]

On Thu,  1 Aug 2013 11:38:46 -0600, Stephen Warren <swarren@wwwdotorg.org> wrote:
> From: Stephen Warren <swarren@nvidia.com>
> 
> This is identical to of_parse_phandle_with_args(), except that the
> number of argument cells is fixed, rather than being parsed out of the
> node referenced by each phandle.
> 
> Signed-off-by: Stephen Warren <swarren@nvidia.com>

Since you're pretty much enabling it anyway, of_parse_phandle() should
be rolled into the same core function.

g.

> ---
> v3: s/cells_count/cell_count, add missing braces per coding style
> 
> Grant, Rob, LinusW is looking for your ack here so he can take the series
> through the GPIO tree.
> ---
>  drivers/of/base.c  | 66 +++++++++++++++++++++++++++++++++++++++++++++++-------
>  include/linux/of.h | 10 +++++++++
>  2 files changed, 68 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 23e7073..2c9a808 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -1106,7 +1106,8 @@ EXPORT_SYMBOL(of_parse_phandle);
>  
>  static int __of_parse_phandle_with_args(const struct device_node *np,
>  					const char *list_name,
> -					const char *cells_name, int index,
> +					const char *cells_name,
> +					int cell_count, int index,
>  					struct of_phandle_args *out_args)
>  {
>  	const __be32 *list, *list_end;
> @@ -1142,11 +1143,17 @@ static int __of_parse_phandle_with_args(const struct device_node *np,
>  					 np->full_name);
>  				goto err;
>  			}
> -			if (of_property_read_u32(node, cells_name, &count)) {
> -				pr_err("%s: could not get %s for %s\n",
> -					 np->full_name, cells_name,
> -					 node->full_name);
> -				goto err;
> +
> +			if (cells_name) {
> +				if (of_property_read_u32(node, cells_name,
> +							 &count)) {
> +					pr_err("%s: could not get %s for %s\n",
> +						np->full_name, cells_name,
> +						node->full_name);
> +					goto err;
> +				}
> +			} else {
> +				count = cell_count;
>  			}
>  
>  			/*
> @@ -1244,11 +1251,53 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na
>  {
>  	if (index < 0)
>  		return -EINVAL;
> -	return __of_parse_phandle_with_args(np, list_name, cells_name, index, out_args);
> +	return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
> +					    index, out_args);
>  }
>  EXPORT_SYMBOL(of_parse_phandle_with_args);
>  
>  /**
> + * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
> + * @np:		pointer to a device tree node containing a list
> + * @list_name:	property name that contains a list
> + * @cell_count: number of argument cells following the phandle
> + * @index:	index of a phandle to parse out
> + * @out_args:	optional pointer to output arguments structure (will be filled)
> + *
> + * This function is useful to parse lists of phandles and their arguments.
> + * Returns 0 on success and fills out_args, on error returns appropriate
> + * errno value.
> + *
> + * Caller is responsible to call of_node_put() on the returned out_args->node
> + * pointer.
> + *
> + * Example:
> + *
> + * phandle1: node1 {
> + * }
> + *
> + * phandle2: node2 {
> + * }
> + *
> + * node3 {
> + * 	list = <&phandle1 0 2 &phandle2 2 3>;
> + * }
> + *
> + * To get a device_node of the `node2' node you may call this:
> + * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
> + */
> +int of_parse_phandle_with_fixed_args(const struct device_node *np,
> +				const char *list_name, int cell_count,
> +				int index, struct of_phandle_args *out_args)
> +{
> +	if (index < 0)
> +		return -EINVAL;
> +	return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
> +					   index, out_args);
> +}
> +EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
> +
> +/**
>   * of_count_phandle_with_args() - Find the number of phandles references in a property
>   * @np:		pointer to a device tree node containing a list
>   * @list_name:	property name that contains a list
> @@ -1266,7 +1315,8 @@ EXPORT_SYMBOL(of_parse_phandle_with_args);
>  int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
>  				const char *cells_name)
>  {
> -	return __of_parse_phandle_with_args(np, list_name, cells_name, -1, NULL);
> +	return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
> +					    NULL);
>  }
>  EXPORT_SYMBOL(of_count_phandle_with_args);
>  
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 90a8811..87d0830 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -280,6 +280,9 @@ extern struct device_node *of_parse_phandle(const struct device_node *np,
>  extern int of_parse_phandle_with_args(const struct device_node *np,
>  	const char *list_name, const char *cells_name, int index,
>  	struct of_phandle_args *out_args);
> +extern int of_parse_phandle_with_fixed_args(const struct device_node *np,
> +	const char *list_name, int cells_count, int index,
> +	struct of_phandle_args *out_args);
>  extern int of_count_phandle_with_args(const struct device_node *np,
>  	const char *list_name, const char *cells_name);
>  
> @@ -477,6 +480,13 @@ static inline int of_parse_phandle_with_args(struct device_node *np,
>  	return -ENOSYS;
>  }
>  
> +static inline int of_parse_phandle_with_fixed_args(const struct device_node *np,
> +	const char *list_name, int cells_count, int index,
> +	struct of_phandle_args *out_args)
> +{
> +	return -ENOSYS;
> +}
> +
>  static inline int of_count_phandle_with_args(struct device_node *np,
>  					     const char *list_name,
>  					     const char *cells_name)
> -- 
> 1.8.1.5
>