1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3 *
4 * Module Name: uthex -- Hex/ASCII support functions
5 *
6 * Copyright (C) 2000 - 2019, Intel Corp.
7 *
8 *****************************************************************************/
9
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12
13 #define _COMPONENT ACPI_COMPILER
14 ACPI_MODULE_NAME("uthex")
15
16 /* Hex to ASCII conversion table */
17 static const char acpi_gbl_hex_to_ascii[] = {
18 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
19 'E', 'F'
20 };
21
22 /*******************************************************************************
23 *
24 * FUNCTION: acpi_ut_hex_to_ascii_char
25 *
26 * PARAMETERS: integer - Contains the hex digit
27 * position - bit position of the digit within the
28 * integer (multiple of 4)
29 *
30 * RETURN: The converted Ascii character
31 *
32 * DESCRIPTION: Convert a hex digit to an Ascii character
33 *
34 ******************************************************************************/
35
36 char acpi_ut_hex_to_ascii_char(u64 integer, u32 position)
37 {
38 u64 index;
39
40 acpi_ut_short_shift_right(integer, position, &index);
41 return (acpi_gbl_hex_to_ascii[index & 0xF]);
42 }
43
44 /*******************************************************************************
45 *
46 * FUNCTION: acpi_ut_ascii_to_hex_byte
47 *
48 * PARAMETERS: two_ascii_chars - Pointer to two ASCII characters
49 * return_byte - Where converted byte is returned
50 *
51 * RETURN: Status and converted hex byte
52 *
53 * DESCRIPTION: Perform ascii-to-hex translation, exactly two ASCII characters
54 * to a single converted byte value.
55 *
56 ******************************************************************************/
57
58 acpi_status acpi_ut_ascii_to_hex_byte(char *two_ascii_chars, u8 *return_byte)
59 {
60
61 /* Both ASCII characters must be valid hex digits */
62
63 if (!isxdigit((int)two_ascii_chars[0]) ||
64 !isxdigit((int)two_ascii_chars[1])) {
65 return (AE_BAD_HEX_CONSTANT);
66 }
67
68 *return_byte =
69 acpi_ut_ascii_char_to_hex(two_ascii_chars[1]) |
70 (acpi_ut_ascii_char_to_hex(two_ascii_chars[0]) << 4);
71
72 return (AE_OK);
73 }
74
75 /*******************************************************************************
76 *
77 * FUNCTION: acpi_ut_ascii_char_to_hex
78 *
79 * PARAMETERS: hex_char - Hex character in Ascii. Must be:
80 * 0-9 or A-F or a-f
81 *
82 * RETURN: The binary value of the ascii/hex character
83 *
84 * DESCRIPTION: Perform ascii-to-hex translation
85 *
86 ******************************************************************************/
87
88 u8 acpi_ut_ascii_char_to_hex(int hex_char)
89 {
90
91 /* Values 0-9 */
92
93 if (hex_char <= '9') {
94 return ((u8)(hex_char - '0'));
95 }
96
97 /* Upper case A-F */
98
99 if (hex_char <= 'F') {
100 return ((u8)(hex_char - 0x37));
101 }
102
103 /* Lower case a-f */
104
105 return ((u8)(hex_char - 0x57));
106 }