1/******************************************************************************
  2 *
  3 * Module Name: uthex -- Hex/ASCII support functions
  4 *
  5 *****************************************************************************/
  6
  7/*
  8 * Copyright (C) 2000 - 2016, Intel Corp.
  9 * All rights reserved.
 10 *
 11 * Redistribution and use in source and binary forms, with or without
 12 * modification, are permitted provided that the following conditions
 13 * are met:
 14 * 1. Redistributions of source code must retain the above copyright
 15 *    notice, this list of conditions, and the following disclaimer,
 16 *    without modification.
 17 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 18 *    substantially similar to the "NO WARRANTY" disclaimer below
 19 *    ("Disclaimer") and any redistribution must be conditioned upon
 20 *    including a substantially similar Disclaimer requirement for further
 21 *    binary redistribution.
 22 * 3. Neither the names of the above-listed copyright holders nor the names
 23 *    of any contributors may be used to endorse or promote products derived
 24 *    from this software without specific prior written permission.
 25 *
 26 * Alternatively, this software may be distributed under the terms of the
 27 * GNU General Public License ("GPL") version 2 as published by the Free
 28 * Software Foundation.
 29 *
 30 * NO WARRANTY
 31 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 32 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 33 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 34 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 35 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 36 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 37 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 40 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 41 * POSSIBILITY OF SUCH DAMAGES.
 42 */
 43
 44#include <acpi/acpi.h>
 45#include "accommon.h"
 46
 47#define _COMPONENT          ACPI_COMPILER
 48ACPI_MODULE_NAME("uthex")
 49
 50/* Hex to ASCII conversion table */
 51static const char acpi_gbl_hex_to_ascii[] = {
 52	'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
 53	    'E', 'F'
 54};
 55
 56/*******************************************************************************
 57 *
 58 * FUNCTION:    acpi_ut_hex_to_ascii_char
 59 *
 60 * PARAMETERS:  integer             - Contains the hex digit
 61 *              position            - bit position of the digit within the
 62 *                                    integer (multiple of 4)
 63 *
 64 * RETURN:      The converted Ascii character
 65 *
 66 * DESCRIPTION: Convert a hex digit to an Ascii character
 67 *
 68 ******************************************************************************/
 69
 70char acpi_ut_hex_to_ascii_char(u64 integer, u32 position)
 71{
 72
 73	return (acpi_gbl_hex_to_ascii[(integer >> position) & 0xF]);
 74}
 75
 76/*******************************************************************************
 77 *
 78 * FUNCTION:    acpi_ut_ascii_to_hex_byte
 79 *
 80 * PARAMETERS:  two_ascii_chars             - Pointer to two ASCII characters
 81 *              return_byte                 - Where converted byte is returned
 82 *
 83 * RETURN:      Status and converted hex byte
 84 *
 85 * DESCRIPTION: Perform ascii-to-hex translation, exactly two ASCII characters
 86 *              to a single converted byte value.
 87 *
 88 ******************************************************************************/
 89
 90acpi_status acpi_ut_ascii_to_hex_byte(char *two_ascii_chars, u8 *return_byte)
 91{
 92
 93	/* Both ASCII characters must be valid hex digits */
 94
 95	if (!isxdigit((int)two_ascii_chars[0]) ||
 96	    !isxdigit((int)two_ascii_chars[1])) {
 97		return (AE_BAD_HEX_CONSTANT);
 98	}
 99
100	*return_byte =
101	    acpi_ut_ascii_char_to_hex(two_ascii_chars[1]) |
102	    (acpi_ut_ascii_char_to_hex(two_ascii_chars[0]) << 4);
103
104	return (AE_OK);
105}
106
107/*******************************************************************************
108 *
109 * FUNCTION:    acpi_ut_ascii_char_to_hex
110 *
111 * PARAMETERS:  hex_char                - Hex character in Ascii. Must be:
112 *                                        0-9 or A-F or a-f
113 *
114 * RETURN:      The binary value of the ascii/hex character
115 *
116 * DESCRIPTION: Perform ascii-to-hex translation
117 *
118 ******************************************************************************/
119
120u8 acpi_ut_ascii_char_to_hex(int hex_char)
121{
122
123	/* Values 0-9 */
124
125	if (hex_char <= '9') {
126		return ((u8)(hex_char - '0'));
127	}
128
129	/* Upper case A-F */
130
131	if (hex_char <= 'F') {
132		return ((u8)(hex_char - 0x37));
133	}
134
135	/* Lower case a-f */
136
137	return ((u8)(hex_char - 0x57));
138}