drivers/acpi/acpica/uthex.c

   1 /******************************************************************************
   2  *
   3  * Module Name: uthex -- Hex/ASCII support functions
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2018, 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
  48 ACPI_MODULE_NAME("uthex")
  49
  50 /* Hex to ASCII conversion table */
  51 static 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
  70 char 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
  92 acpi_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
 122 u8 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 }