From bd69f73f2c81eed9a398708b8c4bb3409ba1b0f9 Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Sun, 10 Feb 2013 22:57:21 +0000 Subject: of: Create function for counting number of phandles in a property This patch creates of_count_phandle_with_args(), a new function for counting the number of phandle+argument tuples in a given property. This is better than the existing method of parsing each phandle individually until parsing fails which is a horribly slow way to do the count. Tested on ARM using the selftest code. v3: - Rebased on top of selftest code cleanup patch v2: - fix bug where of_parse_phandle_with_args() could behave like _count_. - made of_gpio_named_count() into a static inline regardless of CONFIG_OF_GPIO Tested-by: Andreas Larsson Signed-off-by: Grant Likely Cc: Linus Walleij Cc: Rob Herring --- drivers/of/base.c | 41 +++++++++++++++++++++++++++++++++++++---- drivers/of/selftest.c | 15 +++++++++++++++ 2 files changed, 52 insertions(+), 4 deletions(-) (limited to 'drivers/of') diff --git a/drivers/of/base.c b/drivers/of/base.c index c5572cb87a88..321d3ef05006 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1091,9 +1091,10 @@ EXPORT_SYMBOL(of_parse_phandle); * 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_args(const struct device_node *np, const char *list_name, - const char *cells_name, int index, - struct of_phandle_args *out_args) +static 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) { const __be32 *list, *list_end; int rc = 0, size, cur_index = 0; @@ -1183,15 +1184,47 @@ int of_parse_phandle_with_args(const struct device_node *np, const char *list_na * Unlock node before returning result; will be one of: * -ENOENT : index is for empty phandle * -EINVAL : parsing error on data + * [1..n] : Number of phandle (count mode; when index = -1) */ - rc = -ENOENT; + rc = index < 0 ? cur_index : -ENOENT; err: if (node) of_node_put(node); return rc; } + +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) +{ + if (index < 0) + return -EINVAL; + return __of_parse_phandle_with_args(np, list_name, cells_name, index, out_args); +} EXPORT_SYMBOL(of_parse_phandle_with_args); +/** + * of_count_phandle_with_args() - Find the number of phandles references in a property + * @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 + * + * Returns the number of phandle + argument tuples within a property. It + * is a typical pattern to encode a list of phandle and variable + * arguments into a single property. The number of arguments is encoded + * by a property in the phandle-target node. For example, a gpios + * property would contain a list of GPIO specifies consisting of a + * phandle and 1 or more arguments. The number of arguments are + * determined by the #gpio-cells property in the node pointed to by the + * phandle. + */ +int of_count_phandle_with_args(const struct device_node *np, const char *list_name, + const char *cells_name) +{ + return __of_parse_phandle_with_args(np, list_name, cells_name, -1, NULL); +} +EXPORT_SYMBOL(of_count_phandle_with_args); + #if defined(CONFIG_OF_DYNAMIC) static int of_property_notify(int action, struct device_node *np, struct property *prop) diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c index 01b4174a3b46..0eb5c38b4e07 100644 --- a/drivers/of/selftest.c +++ b/drivers/of/selftest.c @@ -36,6 +36,9 @@ static void __init of_selftest_parse_phandle_with_args(void) return; } + rc = of_count_phandle_with_args(np, "phandle-list", "#phandle-cells"); + selftest(rc == 7, "of_count_phandle_with_args() returned %i, expected 7\n", rc); + for (i = 0; i < 8; i++) { bool passed = true; rc = of_parse_phandle_with_args(np, "phandle-list", @@ -94,21 +97,33 @@ static void __init of_selftest_parse_phandle_with_args(void) rc = of_parse_phandle_with_args(np, "phandle-list-missing", "#phandle-cells", 0, &args); selftest(rc == -ENOENT, "expected:%i got:%i\n", -ENOENT, rc); + rc = of_count_phandle_with_args(np, "phandle-list-missing", + "#phandle-cells"); + selftest(rc == -ENOENT, "expected:%i got:%i\n", -ENOENT, rc); /* Check for missing cells property */ rc = of_parse_phandle_with_args(np, "phandle-list", "#phandle-cells-missing", 0, &args); selftest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc); + rc = of_count_phandle_with_args(np, "phandle-list", + "#phandle-cells-missing"); + selftest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc); /* Check for bad phandle in list */ rc = of_parse_phandle_with_args(np, "phandle-list-bad-phandle", "#phandle-cells", 0, &args); selftest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc); + rc = of_count_phandle_with_args(np, "phandle-list-bad-phandle", + "#phandle-cells"); + selftest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc); /* Check for incorrectly formed argument list */ rc = of_parse_phandle_with_args(np, "phandle-list-bad-args", "#phandle-cells", 1, &args); selftest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc); + rc = of_count_phandle_with_args(np, "phandle-list-bad-args", + "#phandle-cells"); + selftest(rc == -EINVAL, "expected:%i got:%i\n", -EINVAL, rc); } static void __init of_selftest_property_match_string(void) -- cgit v1.2.3-59-g8ed1b