From e42ee61017f58cd91cb9e30001450be3981e0e83 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Sat, 24 Aug 2019 15:28:46 +0200 Subject: [PATCH] of: Let of_for_each_phandle fallback to non-negative cell_count MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Referencing device tree nodes from a property allows to pass arguments. This is for example used for referencing gpios. This looks as follows: gpio_ctrl: gpio-controller { #gpio-cells = <2> ... } someothernode { gpios = <&gpio_ctrl 5 0 &gpio_ctrl 3 0>; ... } To know the number of arguments this must be either fixed, or the referenced node is checked for a $cells_name (here: "#gpio-cells") property and with this information the start of the second reference can be determined. Currently regulators are referenced with no additional arguments. To allow some optional arguments without having to change all referenced nodes this change introduces a way to specify a default cell_count. So when a phandle is parsed we check for the $cells_name property and use it as before if present. If it is not present we fall back to cells_count if non-negative and only fail if cells_count is smaller than zero. Signed-off-by: Uwe Kleine-König Signed-off-by: Rob Herring --- drivers/of/base.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff --git a/drivers/of/base.c b/drivers/of/base.c index 55e7f5bb0549..2f25d2dfecfa 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1335,11 +1335,20 @@ int of_phandle_iterator_next(struct of_phandle_iterator *it) if (of_property_read_u32(it->node, it->cells_name, &count)) { - pr_err("%pOF: could not get %s for %pOF\n", - it->parent, - it->cells_name, - it->node); - goto err; + /* + * If both cell_count and cells_name is given, + * fall back to cell_count in absence + * of the cells_name property + */ + if (it->cell_count >= 0) { + count = it->cell_count; + } else { + pr_err("%pOF: could not get %s for %pOF\n", + it->parent, + it->cells_name, + it->node); + goto err; + } } } else { count = it->cell_count; @@ -1505,7 +1514,7 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na { if (index < 0) return -EINVAL; - return __of_parse_phandle_with_args(np, list_name, cells_name, 0, + return __of_parse_phandle_with_args(np, list_name, cells_name, -1, index, out_args); } EXPORT_SYMBOL(of_parse_phandle_with_args); @@ -1588,7 +1597,7 @@ int of_parse_phandle_with_args_map(const struct device_node *np, if (!pass_name) goto free; - ret = __of_parse_phandle_with_args(np, list_name, cells_name, 0, index, + ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index, out_args); if (ret) goto free; @@ -1756,7 +1765,7 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na struct of_phandle_iterator it; int rc, cur_index = 0; - rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0); + rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1); if (rc) return rc; -- 2.30.2