| /* SPDX-License-Identifier: BSD-3-Clause |
| * Copyright (c) 2016-2018, NXP Semiconductors |
| * Copyright (c) 2018-2019, Vladimir Oltean <olteanv@gmail.com> |
| */ |
| #ifndef _LINUX_PACKING_H |
| #define _LINUX_PACKING_H |
| |
| #include <linux/types.h> |
| #include <linux/bitops.h> |
| |
| #define QUIRK_MSB_ON_THE_RIGHT BIT(0) |
| #define QUIRK_LITTLE_ENDIAN BIT(1) |
| #define QUIRK_LSW32_IS_FIRST BIT(2) |
| |
| enum packing_op { |
| PACK, |
| UNPACK, |
| }; |
| |
| /** |
| * packing - Convert numbers (currently u64) between a packed and an unpacked |
| * format. Unpacked means laid out in memory in the CPU's native |
| * understanding of integers, while packed means anything else that |
| * requires translation. |
| * |
| * @pbuf: Pointer to a buffer holding the packed value. |
| * @uval: Pointer to an u64 holding the unpacked value. |
| * @startbit: The index (in logical notation, compensated for quirks) where |
| * the packed value starts within pbuf. Must be larger than, or |
| * equal to, endbit. |
| * @endbit: The index (in logical notation, compensated for quirks) where |
| * the packed value ends within pbuf. Must be smaller than, or equal |
| * to, startbit. |
| * @op: If PACK, then uval will be treated as const pointer and copied (packed) |
| * into pbuf, between startbit and endbit. |
| * If UNPACK, then pbuf will be treated as const pointer and the logical |
| * value between startbit and endbit will be copied (unpacked) to uval. |
| * @quirks: A bit mask of QUIRK_LITTLE_ENDIAN, QUIRK_LSW32_IS_FIRST and |
| * QUIRK_MSB_ON_THE_RIGHT. |
| * |
| * Return: 0 on success, EINVAL or ERANGE if called incorrectly. Assuming |
| * correct usage, return code may be discarded. |
| * If op is PACK, pbuf is modified. |
| * If op is UNPACK, uval is modified. |
| */ |
| int packing(void *pbuf, u64 *uval, int startbit, int endbit, size_t pbuflen, |
| enum packing_op op, u8 quirks); |
| |
| #endif |