lib/string: add sysfs_match_string helper

Make a simple helper for matching strings with sysfs
attribute files. In most parts the same as match_string(),
except sysfs_match_string() uses sysfs_streq() instead of
strcmp() for matching. This is more convenient when used
with sysfs attributes.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/string.h b/include/linux/string.h
index 26b6f6a66f83..c4011b28f3d8 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -135,6 +135,16 @@ static inline int strtobool(const char *s, bool *res)
 }
 
 int match_string(const char * const *array, size_t n, const char *string);
+int __sysfs_match_string(const char * const *array, size_t n, const char *s);
+
+/**
+ * sysfs_match_string - matches given string in an array
+ * @_a: array of strings
+ * @_s: string to match with
+ *
+ * Helper for __sysfs_match_string(). Calculates the size of @a automatically.
+ */
+#define sysfs_match_string(_a, _s) __sysfs_match_string(_a, ARRAY_SIZE(_a), _s)
 
 #ifdef CONFIG_BINARY_PRINTF
 int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);