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authorWolfram Sang <wsa+renesas@sang-engineering.com>2015-03-12 17:17:58 +0100
committerWolfram Sang <wsa@the-dreams.de>2015-03-18 13:36:46 +0100
commit351d224f64afc1b3b359a1738b7d4600c7e64061 (patch)
tree3cdb8debf2d255b55f0bddc54bafa721551faa89 /drivers/of
parentb20d386485e25934aef8aa24cbc8c2f51a2cb9cf (diff)
of: base: add function to get highest id of an alias stem
I2C supports adding adapters using either a dynamic or fixed id. The latter is provided by aliases in the DT case. To prevent id collisions of those two types, install this function which gives us the highest fixed id, so we can then let the dynamically created ones come after this highest number. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/of')
-rw-r--r--drivers/of/base.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 0a8aeb8523fe..63cba04aacf6 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1958,6 +1958,32 @@ int of_alias_get_id(struct device_node *np, const char *stem)
}
EXPORT_SYMBOL_GPL(of_alias_get_id);
+/**
+ * of_alias_get_highest_id - Get highest alias id for the given stem
+ * @stem: Alias stem to be examined
+ *
+ * The function travels the lookup table to get the highest alias id for the
+ * given alias stem. It returns the alias id if found.
+ */
+int of_alias_get_highest_id(const char *stem)
+{
+ struct alias_prop *app;
+ int id = -ENODEV;
+
+ mutex_lock(&of_mutex);
+ list_for_each_entry(app, &aliases_lookup, link) {
+ if (strcmp(app->stem, stem) != 0)
+ continue;
+
+ if (app->id > id)
+ id = app->id;
+ }
+ mutex_unlock(&of_mutex);
+
+ return id;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
+
const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
u32 *pu)
{