diff options
Diffstat (limited to 'drivers/of/base.c')
| -rw-r--r-- | drivers/of/base.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index 13ebb16be64e..d023cf303d56 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -16,6 +16,7 @@ #define pr_fmt(fmt) "OF: " fmt +#include <linux/bitmap.h> #include <linux/console.h> #include <linux/ctype.h> #include <linux/cpu.h> @@ -1986,6 +1987,59 @@ int of_alias_get_id(struct device_node *np, const char *stem) EXPORT_SYMBOL_GPL(of_alias_get_id); /** + * of_alias_get_alias_list - Get alias list for the given device driver + * @matches: Array of OF device match structures to search in + * @stem: Alias stem of the given device_node + * @bitmap: Bitmap field pointer + * @nbits: Maximum number of alias IDs which can be recorded in bitmap + * + * The function travels the lookup table to record alias ids for the given + * device match structures and alias stem. + * + * Return: 0 or -ENOSYS when !CONFIG_OF or + * -EOVERFLOW if alias ID is greater then allocated nbits + */ +int of_alias_get_alias_list(const struct of_device_id *matches, + const char *stem, unsigned long *bitmap, + unsigned int nbits) +{ + struct alias_prop *app; + int ret = 0; + + /* Zero bitmap field to make sure that all the time it is clean */ + bitmap_zero(bitmap, nbits); + + mutex_lock(&of_mutex); + pr_debug("%s: Looking for stem: %s\n", __func__, stem); + list_for_each_entry(app, &aliases_lookup, link) { + pr_debug("%s: stem: %s, id: %d\n", + __func__, app->stem, app->id); + + if (strcmp(app->stem, stem) != 0) { + pr_debug("%s: stem comparison didn't pass %s\n", + __func__, app->stem); + continue; + } + + if (of_match_node(matches, app->np)) { + pr_debug("%s: Allocated ID %d\n", __func__, app->id); + + if (app->id >= nbits) { + pr_warn("%s: ID %d >= than bitmap field %d\n", + __func__, app->id, nbits); + ret = -EOVERFLOW; + } else { + set_bit(app->id, bitmap); + } + } + } + mutex_unlock(&of_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(of_alias_get_alias_list); + +/** * of_alias_get_highest_id - Get highest alias id for the given stem * @stem: Alias stem to be examined * |