of_parse_phandle_with_args() is slightly inflexible as it doesn't allow the (unusual) case where the #*-cells property is not defined. In order to support this, introduce of_parse_phandle_with_opt_args() which assumes that #*-cells is zero when it is not defined, as required by the msi-parent binding
This is done by turning __of_parse_phandle_with_args into an even bigger monster, which is a bit frightening. Acked-by: Mark Rutland <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> --- drivers/of/base.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- include/linux/of.h | 3 +++ 2 files changed, 65 insertions(+), 2 deletions(-) diff --git a/drivers/of/base.c b/drivers/of/base.c index 8b5a187..1612342e 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1479,6 +1479,10 @@ static int __of_parse_phandle_with_args(const struct device_node *np, * (i.e. cells_name not set, but cell_count is set), * except when we're going to return the found node * below. + * + * If #*-cells is not found, but cell_count is set + * to a non-zero value, use (cell_count-1) as a + * fallback value. */ if (cells_name || cur_index == index) { node = of_find_node_by_phandle(phandle); @@ -1490,13 +1494,21 @@ static int __of_parse_phandle_with_args(const struct device_node *np, } if (cells_name) { - if (of_property_read_u32(node, cells_name, - &count)) { + int ret; + ret = of_property_read_u32(node, cells_name, + &count); + if (ret && !cell_count) { pr_err("%s: could not get %s for %s\n", np->full_name, cells_name, node->full_name); goto err; } + if (ret) { + count = cell_count - 1; + pr_debug("%s: could not get %s for %s, assuming %d\n", + np->full_name, cells_name, + node->full_name, count); + } } else { count = cell_count; } @@ -1628,6 +1640,54 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na EXPORT_SYMBOL(of_parse_phandle_with_args); /** + * of_parse_phandle_with_opt_args() - Find a node pointed by phandle in a list + * @np: pointer to a device tree node containing a list + * @list_name: property name that contains a list + * @cells_name: property name that specifies phandles' arguments count + * @index: index of a phandle to parse out + * @out_args: optional pointer to output arguments structure (will be filled) + * + * This function is useful to parse lists of phandles and their arguments. + * If cells_name is not found, then it is assumed to be zero. + * Returns 0 on success and fills out_args, on error returns appropriate + * errno value. + * + * Caller is responsible to call of_node_put() on the returned out_args->np + * pointer. + * + * Example: + * + * phandle1: node1 { + * #list-cells = <2>; + * } + * + * phandle2: node2 { + * } + * + * phandle3: node3 { + * #list-cells = <1>; + * } + * + * node3 { + * list = <&phandle1 1 2 &phandle2 &phandle 3>; + * } + * + * To get a device_node of the `node2' node you may call this: + * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args); + */ +int of_parse_phandle_with_opt_args(const struct device_node *np, + const char *list_name, + const char *cells_name, int index, + struct of_phandle_args *out_args) +{ + if (index < 0) + return -EINVAL; + return __of_parse_phandle_with_args(np, list_name, cells_name, 1, + index, out_args); +} +EXPORT_SYMBOL(of_parse_phandle_with_opt_args); + +/** * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list * @np: pointer to a device tree node containing a list * @list_name: property name that contains a list diff --git a/include/linux/of.h b/include/linux/of.h index 2194b8c..ae6cd03 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -328,6 +328,9 @@ extern struct device_node *of_parse_phandle(const struct device_node *np, extern int of_parse_phandle_with_args(const struct device_node *np, const char *list_name, const char *cells_name, int index, struct of_phandle_args *out_args); +extern int of_parse_phandle_with_opt_args(const struct device_node *np, + const char *list_name, const char *cells_name, int index, + struct of_phandle_args *out_args); extern int of_parse_phandle_with_fixed_args(const struct device_node *np, const char *list_name, int cells_count, int index, struct of_phandle_args *out_args); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
