From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH] of: add helper for getting endpoint node with specific identifiers Date: Mon, 16 Feb 2015 11:47:24 -0600 Message-ID: References: <1424083050-7804-1-git-send-email-human.hwang@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <1424083050-7804-1-git-send-email-human.hwang-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Hyungwon Hwang Cc: "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Rob Herring , Grant Likely List-Id: devicetree@vger.kernel.org On Mon, Feb 16, 2015 at 4:37 AM, Hyungwon Hwang wrote: > When there are multiple ports or multiple endpoints in a port, they have to be > distinguished by the value of reg property. It is common. The drivers can get > the specific endpoint in the specific port via this function. Now the drivers > have to implement this code in themselves or have to force the order of dt nodes > to get the right node. > > Signed-off-by: Hyungwon Hwang > --- > drivers/of/base.c | 34 ++++++++++++++++++++++++++++++++++ > include/linux/of_graph.h | 2 ++ > 2 files changed, 36 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index 36536b6..95ffe1c 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -2155,6 +2155,40 @@ struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, > EXPORT_SYMBOL(of_graph_get_next_endpoint); > > /** > + * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers > + * @parent: pointer to the parent device node > + * @port_reg: identifier (value of reg property) of the parent port node > + * @reg: identifier (value of reg property) of the endpoint node > + * > + * Return: An 'endpoint' node pointer which is identified by reg and at the same > + * is the child of a port node identified by port_reg. reg and port_reg are > + * ignored when they are -1. > + */ > +struct device_node *of_graph_get_endpoint_by_regs( > + const struct device_node *parent, int port_reg, int reg) > +{ > + struct of_endpoint endpoint; > + struct device_node *node, *prev_node = NULL; > + > + while (1) { > + node = of_graph_get_next_endpoint(parent, prev_node); > + of_node_put(prev_node); > + if (!node) > + break; > + > + of_graph_parse_endpoint(node, &endpoint); Seems like this all could be in a "for_each_of_graph_child_endpoint" iterator. I've not looked, but I'd guess there are other similar loops? > + if (((port_reg == -1) || What if of_graph_parse_endpoint failed? > + (endpoint.port == (unsigned int) port_reg)) && > + ((reg == -1) || (endpoint.id == (unsigned int) reg))) Why the casts? > + return node; > + > + prev_node = node; > + } > + > + return NULL; > +} > + > +/** > * of_graph_get_remote_port_parent() - get remote port's parent node > * @node: pointer to a local endpoint device_node > * > diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h > index befef42..c119728 100644 > --- a/include/linux/of_graph.h > +++ b/include/linux/of_graph.h > @@ -31,6 +31,8 @@ int of_graph_parse_endpoint(const struct device_node *node, > struct of_endpoint *endpoint); > struct device_node *of_graph_get_next_endpoint(const struct device_node *parent, > struct device_node *previous); > +struct device_node *of_graph_get_endpoint_by_regs( > + const struct device_node *parent, int port_reg, int reg); Empty version is needed. > 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); > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html