diff options
| author | Sascha Hauer <s.hauer@pengutronix.de> | 2014-05-22 17:30:22 +0200 |
|---|---|---|
| committer | Nitin Garg <nitin.garg@freescale.com> | 2015-09-17 08:58:22 -0500 |
| commit | 2b94c0494a3e1cceeafd30f905107378938b8a8e (patch) | |
| tree | 0db611b81834962a3d9f1832f8d7f390abbfb468 /drivers/of | |
| parent | 7740576ff24fc5f842e0ed3c09e3c11e9d41a7d5 (diff) | |
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 <s.hauer@pengutronix.de>
(cherry picked from commit 5ce2ad39b36fd48b9f77249198655da7cbcc7ee5)
Diffstat (limited to 'drivers/of')
| -rw-r--r-- | drivers/of/base.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index e99f329c905e..974e3adcfebb 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -1756,6 +1756,35 @@ 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_aliases_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_aliases_mutex); + + return max; +} + /** * of_alias_scan - Scan all properties of 'aliases' node * |