lib: introduce common method to convert hex digits

[karo-tx-linux.git] / lib / hexdump.c

diff --git a/lib/hexdump.c b/lib/hexdump.c
index 1bd6a9779774455050d2df928104973565672f90..5d7a4802c5623c00056159735bf73d17165ba476 100644 (file)
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -15,6 +15,24 @@
 const char hex_asc[] = "0123456789abcdef";
 EXPORT_SYMBOL(hex_asc);
 
+/**
+ * hex_to_bin - convert a hex digit to its real value
+ * @ch: ascii character represents hex digit
+ *
+ * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad
+ * input.
+ */
+int hex_to_bin(char ch)
+{
+       if ((ch >= '0') && (ch <= '9'))
+               return ch - '0';
+       ch = tolower(ch);
+       if ((ch >= 'a') && (ch <= 'f'))
+               return ch - 'a' + 10;
+       return -1;
+}
+EXPORT_SYMBOL(hex_to_bin);
+
 /**
  * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
  * @buf: data blob to dump