Re: [Qemu-devel] [PATCH 05/31] dt: add helper for phandle enumeration

[Peter Crosthwaite <peter.crosthwaite@petalogix.com>]

On Wed, 2012-06-06 at 01:52 +0200, Alexander Graf wrote:
> This patch adds a helper to search for a node's phandle by its path. This
> is especially useful when the phandle is part of an array, not just a single
> cell in which case qemu_devtree_setprop_phandle would be the easy choice.
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  device_tree.c |   16 +++++++++++++++-
>  device_tree.h |    1 +
>  2 files changed, 16 insertions(+), 1 deletions(-)
> 
> diff --git a/device_tree.c b/device_tree.c
> index 6cbc5af..6745d17 100644
> --- a/device_tree.c
> +++ b/device_tree.c
> @@ -162,10 +162,24 @@ int qemu_devtree_setprop_string(void *fdt, const char *node_path,
>      return r;
>  }
>  
> +uint32_t qemu_devtree_get_phandle(void *fdt, const char *path)
> +{
> +    uint32_t r;
> +
> +    r = fdt_get_phandle(fdt, findnode_nofail(fdt, path));
> +    if (r <= 0) {
> +        fprintf(stderr, "%s: Couldn't get phandle for %s: %s\n", __func__,
> +                path, fdt_strerror(r));
> +        exit(1);

Is it really this functions job to terminate qemu on fail?  There may be
scenarios where a node does not have a phandle where the client can
handle that. Perhaps return -1 on error and the client has to check?

> +    }
> +
> +    return r;
> +}
> +
>  int qemu_devtree_setprop_phandle(void *fdt, const char *node_path,
>                                   const char *property, const char *string)
>  {
> -    uint32_t phandle = fdt_get_phandle(fdt, findnode_nofail(fdt, string));
> +    uint32_t phandle = qemu_devtree_get_phandle(fdt, string);
>      return qemu_devtree_setprop_cell(fdt, node_path, property, phandle);
>  }
>  
> diff --git a/device_tree.h b/device_tree.h
> index 2e87c58..376287a 100644
> --- a/device_tree.h
> +++ b/device_tree.h
> @@ -33,6 +33,7 @@ int qemu_devtree_setprop_string(void *fdt, const char *node_path,
>                                  const char *property, const char *string);
>  int qemu_devtree_setprop_phandle(void *fdt, const char *node_path,
>                                   const char *property, const char *string);
> +uint32_t qemu_devtree_get_phandle(void *fdt, const char *path);
>  int qemu_devtree_nop_node(void *fdt, const char *node_path);
>  int qemu_devtree_add_subnode(void *fdt, const char *name);
>