[PATCH v6 06/15] of: add helper for getting endpoint node of specific identifiers

[Dave Airlie]

On 12 June 2015 at 22:59, Hyungwon Hwang <human.hwang at samsung.com> 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 <human.hwang at samsung.com>
> Acked-by: Rob Herring <robh+dt at kernel.org>

FYI, Since I'm merging this via exynos-next into my tree, it broke
module builds of exynos, because it doesn't export the symbol it adds,
I've added a patch to my -next tree to fix it up.

Inki, in future can you add a modular build to pre-pull testing.

Dave.

> ---
> Changes before:
> - Refer https://patchwork.kernel.org/patch/6191751/
> Changes for v6:
> - None
>  drivers/of/base.c        | 33 +++++++++++++++++++++++++++++++++
>  include/linux/of_graph.h |  8 ++++++++
>  2 files changed, 41 insertions(+)
>
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 99764db..f3b583b 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -2233,6 +2233,39 @@ 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);
> +               if (((port_reg == -1) || (endpoint.port == port_reg)) &&
> +                       ((reg == -1) || (endpoint.id == reg)))
> +                       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 7bc92e0..1c1d5b9 100644
> --- a/include/linux/of_graph.h
> +++ b/include/linux/of_graph.h
> @@ -45,6 +45,8 @@ int of_graph_parse_endpoint(const struct device_node *node,
>  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_endpoint_by_regs(
> +               const struct device_node *parent, int port_reg, int reg);
>  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);
> @@ -69,6 +71,12 @@ static inline struct device_node *of_graph_get_next_endpoint(
>         return NULL;
>  }
>
> +struct device_node *of_graph_get_endpoint_by_regs(
> +               const struct device_node *parent, int port_reg, int reg)
> +{
> +       return NULL;
> +}
> +
>  static inline struct device_node *of_graph_get_remote_port_parent(
>                                         const struct device_node *node)
>  {
> --
> 1.9.1
>
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