LXR linux/drivers/acpi/acpica/uthex.c

   1/******************************************************************************
   2 *
   3 * Module Name: uthex -- Hex/ASCII support functions
   4 *
   5 *****************************************************************************/
   6
   7/*
   8 * Copyright (C) 2000 - 2017, 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        u64 index;
  73
  74        acpi_ut_short_shift_right(integer, position, &index);
  75        return (acpi_gbl_hex_to_ascii[index & 0xF]);
  76}
  77
  78/*******************************************************************************
  79 *
  80 * FUNCTION:    acpi_ut_ascii_to_hex_byte
  81 *
  82 * PARAMETERS:  two_ascii_chars             - Pointer to two ASCII characters
  83 *              return_byte                 - Where converted byte is returned
  84 *
  85 * RETURN:      Status and converted hex byte
  86 *
  87 * DESCRIPTION: Perform ascii-to-hex translation, exactly two ASCII characters
  88 *              to a single converted byte value.
  89 *
  90 ******************************************************************************/
  91
  92acpi_status acpi_ut_ascii_to_hex_byte(char *two_ascii_chars, u8 *return_byte)
  93{
  94
  95        /* Both ASCII characters must be valid hex digits */
  96
  97        if (!isxdigit((int)two_ascii_chars[0]) ||
  98            !isxdigit((int)two_ascii_chars[1])) {
  99                return (AE_BAD_HEX_CONSTANT);
 100        }
 101
 102        *return_byte =
 103            acpi_ut_ascii_char_to_hex(two_ascii_chars[1]) |
 104            (acpi_ut_ascii_char_to_hex(two_ascii_chars[0]) << 4);
 105
 106        return (AE_OK);
 107}
 108
 109/*******************************************************************************
 110 *
 111 * FUNCTION:    acpi_ut_ascii_char_to_hex
 112 *
 113 * PARAMETERS:  hex_char                - Hex character in Ascii. Must be:
 114 *                                        0-9 or A-F or a-f
 115 *
 116 * RETURN:      The binary value of the ascii/hex character
 117 *
 118 * DESCRIPTION: Perform ascii-to-hex translation
 119 *
 120 ******************************************************************************/
 121
 122u8 acpi_ut_ascii_char_to_hex(int hex_char)
 123{
 124
 125        /* Values 0-9 */
 126
 127        if (hex_char <= '9') {
 128                return ((u8)(hex_char - '0'));
 129        }
 130
 131        /* Upper case A-F */
 132
 133        if (hex_char <= 'F') {
 134                return ((u8)(hex_char - 0x37));
 135        }
 136
 137        /* Lower case a-f */
 138
 139        return ((u8)(hex_char - 0x57));
 140}
 141