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Bin Meng39f8b082017-04-21 07:24:38 -07001/*
2 * Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 */
6
7#ifndef __EARLY_CMOS_H
8#define __EARLY_CMOS_H
9
10/* CMOS actually resides in the RTC SRAM */
11#define CMOS_IO_PORT 0x70
12
13/**
14 * cmos_read8() - Get 8-bit data stored at the given address
15 *
16 * This reads from CMOS for the 8-bit data stored at the given address.
17 *
18 * @addr: RTC SRAM address
19 * @return: 8-bit data stored at the given address
20 */
21u8 cmos_read8(u8 addr);
22
23/**
24 * cmos_read16() - Get 16-bit data stored at the given address
25 *
26 * This reads from CMOS for the 16-bit data stored at the given address.
27 *
28 * @addr: RTC SRAM address
29 * @return: 16-bit data stored at the given address
30 */
31u16 cmos_read16(u8 addr);
32
33/**
34 * cmos_read32() - Get 32-bit data stored at the given address
35 *
36 * This reads from CMOS for the 32-bit data stored at the given address.
37 *
38 * @addr: RTC SRAM address
39 * @return: 32-bit data stored at the given address
40 */
41u32 cmos_read32(u8 addr);
42
43#endif /* __EARLY_CMOS_H */