Re: [PATCH v6 6/8] of: Implement simplified graph binding for single port devices

Grant Likely
2014-03-08T05:36:45Z

On Wed, 5 Mar 2014 10:20:40 +0100, Philipp Zabel <p.zabel@pengutronix.de> wrote:
> For simple devices with only one port, it can be made implicit.
> The endpoint node can be a direct child of the device node.
>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Ergh... I think this is too loosely defined. The caller really should be
explicit about which behaviour it needs. I'll listen to arguments
though if you can make a strong argument.

g.

> --- > Changes since v5:
> - Unrolled for-loop in of_graph_get_remote_port_parent
> ---
> drivers/of/base.c | 42 +++++++++++++++++++++++++++++-------------
> 1 file changed, 29 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 715144af..ffd0217 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -2003,7 +2003,8 @@ int of_graph_parse_endpoint(const struct device_node *node,
> * It doesn't matter whether the two calls below succeed.
> * If they don't then the default value 0 is used.
> */
> - of_property_read_u32(port_node, "reg", &endpoint->port);
> + if (port_node && !of_node_cmp(port_node->name, "port"))
> + of_property_read_u32(port_node, "reg", &endpoint->port);
> of_property_read_u32(node, "reg", &endpoint->id);
>
> of_node_put(port_node);
> @@ -2034,8 +2035,13 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
> struct device_node *node;
> /*
> * It's the first call, we have to find a port subnode
> - * within this node or within an optional 'ports' node.
> + * within this node or within an optional 'ports' node,
> + * or at least a single endpoint.
> */
> + endpoint = of_get_child_by_name(parent, "endpoint");
> + if (endpoint)
> + return endpoint;
> +
> node = of_get_child_by_name(parent, "ports");
> if (node)
> parent = node;
> @@ -2046,8 +2052,6 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
> /* Found a port, get an endpoint. */
> endpoint = of_get_next_child(port, NULL);
> of_node_put(port);
> - } else {
> - endpoint = NULL;
> }
>
> if (!endpoint)
> @@ -2062,6 +2066,10 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
> if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
> __func__, prev->full_name))
> return NULL;
> + if (port == parent) {
> + of_node_put(port);
> + return NULL;
> + }
>
> /* Avoid dropping prev node refcount to 0. */
> of_node_get(prev);
> @@ -2097,18 +2105,21 @@ struct device_node *of_graph_get_remote_port_parent(
> const struct device_node *node)
> {
> struct device_node *np;
> - unsigned int depth;
>
> /* Get remote endpoint node. */
> np = of_parse_phandle(node, "remote-endpoint", 0);
> + if (!np)
> + return NULL;
>
> - /* Walk 3 levels up only if there is 'ports' node. */
> - for (depth = 3; depth && np; depth--) {
> - np = of_get_next_parent(np);
> - if (depth == 2 && of_node_cmp(np->name, "ports"))
> - break;
> - }
> - return np;
> + np = of_get_next_parent(np);
> + if (!np || of_node_cmp(np->name, "port") != 0)
> + return np;
> +
> + np = of_get_next_parent(np);
> + if (!np || of_node_cmp(np->name, "ports") != 0)
> + return np;
> +
> + return of_get_next_parent(np);
> }
> EXPORT_SYMBOL(of_graph_get_remote_port_parent);
>
> @@ -2127,6 +2138,11 @@ struct device_node *of_graph_get_remote_port(const struct device_node *node)
> np = of_parse_phandle(node, "remote-endpoint", 0);
> if (!np)
> return NULL;
> - return of_get_next_parent(np);
> + np = of_get_next_parent(np);
> + if (of_node_cmp(np->name, "port")) {
> + of_node_put(np);
> + return NULL;
> + }
> + return np;
> }
> EXPORT_SYMBOL(of_graph_get_remote_port);
> --
> 1.9.0.rc3
>