From: Grant Likely Date: Sun, 10 Feb 2013 22:57:21 +0000 (+0000) Subject: of: Create function for counting number of phandles in a property X-Git-Tag: firefly_0821_release~3680^2~1100^2~3 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bd69f73;p=firefly-linux-kernel-4.4.55.git 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 --- 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) diff --git a/include/linux/of.h b/include/linux/of.h index b9e1b911f0eb..a0f129284948 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -277,6 +277,8 @@ 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_count_phandle_with_args(const struct device_node *np, + const char *list_name, const char *cells_name); extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)); extern int of_alias_get_id(struct device_node *np, const char *stem); @@ -467,6 +469,13 @@ static inline int of_parse_phandle_with_args(struct device_node *np, return -ENOSYS; } +static inline int of_count_phandle_with_args(struct device_node *np, + const char *list_name, + const char *cells_name) +{ + return -ENOSYS; +} + static inline int of_alias_get_id(struct device_node *np, const char *stem) { return -ENOSYS;