diff options
Diffstat (limited to 'drivers/acpi/acpica/uthex.c')
| -rw-r--r-- | drivers/acpi/acpica/uthex.c | 46 |
1 files changed, 42 insertions, 4 deletions
diff --git a/drivers/acpi/acpica/uthex.c b/drivers/acpi/acpica/uthex.c index 4354fb800fe4..36d2fc789088 100644 --- a/drivers/acpi/acpica/uthex.c +++ b/drivers/acpi/acpica/uthex.c @@ -75,9 +75,41 @@ char acpi_ut_hex_to_ascii_char(u64 integer, u32 position) /******************************************************************************* * + * FUNCTION: acpi_ut_ascii_to_hex_byte + * + * PARAMETERS: two_ascii_chars - Pointer to two ASCII characters + * return_byte - Where converted byte is returned + * + * RETURN: Status and converted hex byte + * + * DESCRIPTION: Perform ascii-to-hex translation, exactly two ASCII characters + * to a single converted byte value. + * + ******************************************************************************/ + +acpi_status acpi_ut_ascii_to_hex_byte(char *two_ascii_chars, u8 *return_byte) +{ + + /* Both ASCII characters must be valid hex digits */ + + if (!isxdigit((int)two_ascii_chars[0]) || + !isxdigit((int)two_ascii_chars[1])) { + return (AE_BAD_HEX_CONSTANT); + } + + *return_byte = + acpi_ut_ascii_char_to_hex(two_ascii_chars[1]) | + (acpi_ut_ascii_char_to_hex(two_ascii_chars[0]) << 4); + + return (AE_OK); +} + +/******************************************************************************* + * * FUNCTION: acpi_ut_ascii_char_to_hex * - * PARAMETERS: hex_char - Hex character in Ascii + * PARAMETERS: hex_char - Hex character in Ascii. Must be: + * 0-9 or A-F or a-f * * RETURN: The binary value of the ascii/hex character * @@ -88,13 +120,19 @@ char acpi_ut_hex_to_ascii_char(u64 integer, u32 position) u8 acpi_ut_ascii_char_to_hex(int hex_char) { - if (hex_char <= 0x39) { - return ((u8)(hex_char - 0x30)); + /* Values 0-9 */ + + if (hex_char <= '9') { + return ((u8)(hex_char - '0')); } - if (hex_char <= 0x46) { + /* Upper case A-F */ + + if (hex_char <= 'F') { return ((u8)(hex_char - 0x37)); } + /* Lower case a-f */ + return ((u8)(hex_char - 0x57)); } |