[RFC PATCH v3 1/5] dt: add of_get_child_count helper function

[Marek Vasut]

> From: Dong Aisheng <dong.aisheng at linaro.org>
> 
> Currently most code to get child count in kernel are almost same,
> add a helper to implement this function for dt to use.
> 
> ---
> Changes v1->v2:
>  * change the name from of_get_child_number to of_get_child_count
> 
> Signed-off-by: Dong Aisheng <dong.aisheng at linaro.org>
> Cc: Grant Likely <grant.likely at secretlab.ca>
> Cc: Rob Herring <rob.herring at calxeda.com>
> ---
>  include/linux/of.h |   16 ++++++++++++++++
>  1 files changed, 16 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 4948552..d0d91a1 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -189,6 +189,17 @@ extern struct device_node *of_get_next_child(const
> struct device_node *node, for (child = of_get_next_child(parent, NULL);
> child != NULL; \
>  	     child = of_get_next_child(parent, child))
> 
> +static inline int of_get_child_count(const struct device_node *np)
> +{
> +	struct device_node *child = NULL;
> +	int num = 0;
> +
> +	while ((child = of_get_next_child(np, child)))

The assignment in this condition really looks eerie, maybe just rewrite it to do  
{ } while () ? Also, aren't the parenthesis unnecessary?

M
> +		num++;
> +
> +	return num;
> +}
> +
>  extern struct device_node *of_find_node_with_property(
>  	struct device_node *from, const char *prop_name);
>  #define for_each_node_with_property(dn, prop_name) \
> @@ -262,6 +273,11 @@ static inline bool of_have_populated_dt(void)
>  #define for_each_child_of_node(parent, child) \
>  	while (0)
> 
> +static inline int of_get_child_count(const struct device_node *np)
> +{
> +	return -ENOSYS;
> +}
> +
>  static inline int of_device_is_compatible(const struct device_node
> *device, const char *name)
>  {