Re: [RFC PATCH v3 2/6] of: Make of_find_node_by_path() traverse /aliases for relative paths.

[Sergei Shtylyov <sshtylyov@mvista.com>]

Hello.

On 05-05-2011 21:02, David Daney wrote:

> Currently all paths passed to of_find_node_by_path() must begin with a
> '/', indicating a full path to the desired node.

> Augment the look-up code so that if a path does *not* begin with '/',
> the path is used as the name of an /aliases property.  The value of
> this alias is then used as the full node path to be found.

> Signed-off-by: David Daney<ddaney@caviumnetworks.com>
> ---
>   drivers/of/base.c |   41 ++++++++++++++++++++++++++++++++++++++++-
>   1 files changed, 40 insertions(+), 1 deletions(-)

> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 632ebae..1a0a83e 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
[...]
> @@ -348,14 +351,50 @@ EXPORT_SYMBOL(of_get_next_child);
>   struct device_node *of_find_node_by_path(const char *path)
>   {
>   	struct device_node *np = allnodes;
> +	struct device_node *aliases = NULL;
> +	char *alias = NULL;
> +	char *new_path = NULL;
>
>   	read_lock(&devtree_lock);
> +
> +	if (path[0] != '/') {
> +		const char *ps;
> +		aliases = of_find_node_by_path("/aliases");
> +		if (!aliases)
> +			goto out;
> +
> +		ps = strchr(path, '/');
> +		if (ps) {
> +			size_t len = ps - path;
> +			alias = kmalloc(len + 1, GFP_KERNEL);
> +			strncpy(alias, path, len);
> +			alias[len] = 0;

    BTW, you could use kstrndup() (from mm/util.c) instead of the above 3 lines.

WBR, Sergei