linux/drivers/acpi/acpica/uthex.c

107 lines
2.9 KiB
C

// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: uthex -- Hex/ASCII support functions
*
* Copyright (C) 2000 - 2019, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#define _COMPONENT ACPI_COMPILER
ACPI_MODULE_NAME("uthex")
/* Hex to ASCII conversion table */
static const char acpi_gbl_hex_to_ascii[] = {
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
'E', 'F'
};
/*******************************************************************************
*
* FUNCTION: acpi_ut_hex_to_ascii_char
*
* PARAMETERS: integer - Contains the hex digit
* position - bit position of the digit within the
* integer (multiple of 4)
*
* RETURN: The converted Ascii character
*
* DESCRIPTION: Convert a hex digit to an Ascii character
*
******************************************************************************/
char acpi_ut_hex_to_ascii_char(u64 integer, u32 position)
{
u64 index;
acpi_ut_short_shift_right(integer, position, &index);
return (acpi_gbl_hex_to_ascii[index & 0xF]);
}
/*******************************************************************************
*
* 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. Must be:
* 0-9 or A-F or a-f
*
* RETURN: The binary value of the ascii/hex character
*
* DESCRIPTION: Perform ascii-to-hex translation
*
******************************************************************************/
u8 acpi_ut_ascii_char_to_hex(int hex_char)
{
/* Values 0-9 */
if (hex_char <= '9') {
return ((u8)(hex_char - '0'));
}
/* Upper case A-F */
if (hex_char <= 'F') {
return ((u8)(hex_char - 0x37));
}
/* Lower case a-f */
return ((u8)(hex_char - 0x57));
}