From da248c0308078f63386c8606e64c9eb96c124416 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Thu, 22 May 2014 17:30:22 +0200 Subject: [PATCH] of: Add helper for getting the maximum alias index for a stem of_alias_max_index will return the maximum number for which an alias of a given stem exists. This is useful for frameworks whishing to reserve a number of device slots from dynamic allocation. Signed-off-by: Sascha Hauer (cherry picked from commit 5ce2ad39b36fd48b9f77249198655da7cbcc7ee5) Conflicts: include/linux/of.h --- drivers/of/base.c | 29 +++++++++++++++++++++++++++++ include/linux/of.h | 6 ++++++ 2 files changed, 35 insertions(+) diff --git a/drivers/of/base.c b/drivers/of/base.c index a0bccb54a9bd..5fbd49290175 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -2049,6 +2049,35 @@ static void of_alias_add(struct alias_prop *ap, struct device_node *np, ap->alias, ap->stem, ap->id, of_node_full_name(np)); } +/* + * of_alias_max_index() - get the maximum index for a given alias stem + * @stem: The alias stem for which the maximum index is searched for + * + * Given an alias stem (the alias without the number) this function + * returns the maximum number for which an alias exists. + * + * Return: The maximum existing alias index or -ENODEV if no alias + * exists for this stem. + */ +int of_alias_max_index(const char *stem) +{ + struct alias_prop *app; + int max = -ENODEV; + + mutex_lock(&of_mutex); + + list_for_each_entry(app, &aliases_lookup, link) { + if (strcmp(app->stem, stem)) + continue; + if (app->id > max) + max = app->id; + } + + mutex_unlock(&of_mutex); + + return max; +} + /** * of_alias_scan - Scan all properties of the 'aliases' node * diff --git a/include/linux/of.h b/include/linux/of.h index 299aeb192727..fc12b433c54f 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -365,6 +365,7 @@ extern int of_phandle_iterator_args(struct of_phandle_iterator *it, 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); extern int of_alias_get_highest_id(const char *stem); +extern int of_alias_max_index(const char *stem); extern int of_machine_is_compatible(const char *compat); @@ -783,6 +784,11 @@ static inline int of_alias_get_highest_id(const char *stem) return -ENOSYS; } +static inline int of_alias_max_index(const char *stem) +{ + return -ENODEV; +} + static inline int of_machine_is_compatible(const char *compat) { return 0; -- 2.17.1