diff options
| author | Sascha Hauer <s.hauer@pengutronix.de> | 2014-05-22 11:30:22 -0400 |
|---|---|---|
| committer | Dong Aisheng <b29396@freescale.com> | 2014-06-24 02:11:52 -0400 |
| commit | c819acf447205b1040d21606271899e19f9ade05 (patch) | |
| tree | 2b9b51ea327479defaec1c6c1887bdc18f26b4dc | |
| parent | 9f82045316a36af3a4ea9a666f367de416a2237a (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 18ae7362e9822993436c1a544e49cfd58fa175b2)
| -rw-r--r-- | drivers/of/base.c | 29 | ||||
| -rw-r--r-- | include/linux/of.h | 6 |
2 files changed, 35 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index c258df42b002..5e713b42621f 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c | |||
| @@ -1588,6 +1588,35 @@ static void of_alias_add(struct alias_prop *ap, struct device_node *np, | |||
| 1588 | ap->alias, ap->stem, ap->id, of_node_full_name(np)); | 1588 | ap->alias, ap->stem, ap->id, of_node_full_name(np)); |
| 1589 | } | 1589 | } |
| 1590 | 1590 | ||
| 1591 | /* | ||
| 1592 | * of_alias_max_index() - get the maximum index for a given alias stem | ||
| 1593 | * @stem: The alias stem for which the maximum index is searched for | ||
| 1594 | * | ||
| 1595 | * Given an alias stem (the alias without the number) this function | ||
| 1596 | * returns the maximum number for which an alias exists. | ||
| 1597 | * | ||
| 1598 | * Return: The maximum existing alias index or -ENODEV if no alias | ||
| 1599 | * exists for this stem. | ||
| 1600 | */ | ||
| 1601 | int of_alias_max_index(const char *stem) | ||
| 1602 | { | ||
| 1603 | struct alias_prop *app; | ||
| 1604 | int max = -ENODEV; | ||
| 1605 | |||
| 1606 | mutex_lock(&of_aliases_mutex); | ||
| 1607 | |||
| 1608 | list_for_each_entry(app, &aliases_lookup, link) { | ||
| 1609 | if (strcmp(app->stem, stem)) | ||
| 1610 | continue; | ||
| 1611 | if (app->id > max) | ||
| 1612 | max = app->id; | ||
| 1613 | } | ||
| 1614 | |||
| 1615 | mutex_unlock(&of_aliases_mutex); | ||
| 1616 | |||
| 1617 | return max; | ||
| 1618 | } | ||
| 1619 | |||
| 1591 | /** | 1620 | /** |
| 1592 | * of_alias_scan - Scan all properties of 'aliases' node | 1621 | * of_alias_scan - Scan all properties of 'aliases' node |
| 1593 | * | 1622 | * |
diff --git a/include/linux/of.h b/include/linux/of.h index 668e12322dd4..7a07fa495bc7 100644 --- a/include/linux/of.h +++ b/include/linux/of.h | |||
| @@ -286,6 +286,7 @@ extern int of_count_phandle_with_args(const struct device_node *np, | |||
| 286 | 286 | ||
| 287 | extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)); | 287 | extern void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)); |
| 288 | extern int of_alias_get_id(struct device_node *np, const char *stem); | 288 | extern int of_alias_get_id(struct device_node *np, const char *stem); |
| 289 | extern int of_alias_max_index(const char *stem); | ||
| 289 | 290 | ||
| 290 | extern int of_machine_is_compatible(const char *compat); | 291 | extern int of_machine_is_compatible(const char *compat); |
| 291 | 292 | ||
| @@ -503,6 +504,11 @@ static inline int of_alias_get_id(struct device_node *np, const char *stem) | |||
| 503 | return -ENOSYS; | 504 | return -ENOSYS; |
| 504 | } | 505 | } |
| 505 | 506 | ||
| 507 | static inline int of_alias_max_index(const char *stem) | ||
| 508 | { | ||
| 509 | return -ENODEV; | ||
| 510 | } | ||
| 511 | |||
| 506 | static inline int of_machine_is_compatible(const char *compat) | 512 | static inline int of_machine_is_compatible(const char *compat) |
| 507 | { | 513 | { |
| 508 | return 0; | 514 | return 0; |