diff --git a/drivers/of/base.c b/drivers/of/base.c index 08ef1a1..b3718e7 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -2043,3 +2044,169 @@ return of_device_disable(node); } + +/** + * of_graph_parse_endpoint() - parse common endpoint node properties + * @node: pointer to endpoint device_node + * @endpoint: pointer to the OF endpoint data structure + * + * The caller should hold a reference to @node. + */ +int of_graph_parse_endpoint(const struct device_node *node, + struct of_endpoint *endpoint) +{ + struct device_node *port_node = of_get_parent(node); + + if (!port_node) + pr_warn("%s(): endpoint %s has no parent node\n", + __func__, node->full_name); + + memset(endpoint, 0, sizeof(*endpoint)); + + endpoint->local_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); + of_property_read_u32(node, "reg", &endpoint->id); + + return 0; +} +EXPORT_SYMBOL(of_graph_parse_endpoint); + +/** + * of_graph_get_port_by_id() - get the port matching a given id + * @parent: pointer to the parent device node + * @id: id of the port + * + * Return: A 'port' node pointer with refcount incremented. + */ +struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id) +{ + struct device_node *port; + + for_each_child_of_node(node, port) { + u32 port_id = 0; + + if (strncmp(port->name, "port", 4) != 0) + continue; + of_property_read_u32(port, "reg", &port_id); + if (id == port_id) + return port; + } + + return NULL; +} +EXPORT_SYMBOL(of_graph_get_port_by_id); + +/** + * of_graph_get_next_endpoint() - get next endpoint node + * @parent: pointer to the parent device node + * @prev: previous endpoint node, or NULL to get first + * + * Return: An 'endpoint' node pointer with refcount incremented. Refcount + * of the passed @prev node is decremented. + */ +struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, + struct device_node *prev) +{ + struct device_node *endpoint; + struct device_node *port; + + if (!parent) + return NULL; + + /* + * Start by locating the port node. If no previous endpoint is specified + * search for the first port node, otherwise get the previous endpoint + * parent port node. + */ + if (!prev) { + struct device_node *node; + + node = of_get_child_by_name(parent, "ports"); + if (node) + parent = node; + + port = of_get_child_by_name(parent, "port"); + if (!port) { + pr_err("%s(): no port node found in %s\n", + __func__, parent->full_name); + return NULL; + } + } else { + port = of_get_parent(prev); + if (!port) { + pr_warn("%s(): endpoint %s has no parent node\n", + __func__, prev->full_name); + return NULL; + } + } + + while (1) { + /* + * Now that we have a port node, get the next endpoint by + * getting the next child. If the previous endpoint is NULL this + * will return the first child. + */ + endpoint = of_get_next_child(port, prev); + if (endpoint) + return endpoint; + + /* No more endpoints under this port, try the next one. */ + prev = NULL; + + do { + port = of_get_next_child(parent, port); + if (!port) + return NULL; + } while (of_node_cmp(port->name, "port")); + } +} +EXPORT_SYMBOL(of_graph_get_next_endpoint); + +/** + * of_graph_get_remote_port_parent() - get remote port's parent node + * @node: pointer to a local endpoint device_node + * + * Return: Remote device node associated with remote endpoint node linked + * to @node. + */ +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); + + /* Walk 3 levels up only if there is 'ports' node. */ + for (depth = 3; depth && np; depth--) { + np = np->parent; + if (depth == 2 && of_node_cmp(np->name, "ports")) + break; + } + return np; +} +EXPORT_SYMBOL(of_graph_get_remote_port_parent); + +/** + * of_graph_get_remote_port() - get remote port node + * @node: pointer to a local endpoint device_node + * + * Return: Remote port node associated with remote endpoint node linked + * to @node. + */ +struct device_node *of_graph_get_remote_port(const struct device_node *node) +{ + struct device_node *np; + + /* Get remote endpoint node. */ + np = of_parse_phandle(node, "remote-endpoint", 0); + if (!np) + return NULL; + return np->parent; +} +EXPORT_SYMBOL(of_graph_get_remote_port); diff --git a/include/of_graph.h b/include/of_graph.h new file mode 100644 index 0000000..fa037db --- /dev/null +++ b/include/of_graph.h @@ -0,0 +1,49 @@ +/* + * OF graph binding parsing helpers + * + * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd. + * Author: Sylwester Nawrocki + * + * Copyright (C) 2012 Renesas Electronics Corp. + * Author: Guennadi Liakhovetski + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + */ +#ifndef __LINUX_OF_GRAPH_H +#define __LINUX_OF_GRAPH_H + +/** + * struct of_endpoint - the OF graph endpoint data structure + * @port: identifier (value of reg property) of a port this endpoint belongs to + * @id: identifier (value of reg property) of this endpoint + * @local_node: pointer to device_node of this endpoint + */ +struct of_endpoint { + unsigned int port; + unsigned int id; + const struct device_node *local_node; +}; + +/** + * for_each_endpoint_of_node - iterate over every endpoint in a device node + * @parent: parent device node containing ports and endpoints + * @child: loop variable pointing to the current endpoint node + * + * When breaking out of the loop, of_node_put(child) has to be called manually. + */ +#define for_each_endpoint_of_node(parent, child) \ + for (child = of_graph_get_next_endpoint(parent, NULL); child != NULL; \ + child = of_graph_get_next_endpoint(parent, child)) + +int of_graph_parse_endpoint(const struct device_node *node, + struct of_endpoint *endpoint); +struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id); +struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, + struct device_node *previous); +struct device_node *of_graph_get_remote_port_parent( + const struct device_node *node); +struct device_node *of_graph_get_remote_port(const struct device_node *node); + +#endif /* __LINUX_OF_GRAPH_H */