xref: /OK3568_Linux_fs/u-boot/arch/x86/include/asm/early_cmos.h (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * SPDX-License-Identifier:	GPL-2.0+
5*4882a593Smuzhiyun  */
6*4882a593Smuzhiyun 
7*4882a593Smuzhiyun #ifndef __EARLY_CMOS_H
8*4882a593Smuzhiyun #define __EARLY_CMOS_H
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun /* CMOS actually resides in the RTC SRAM */
11*4882a593Smuzhiyun #define CMOS_IO_PORT	0x70
12*4882a593Smuzhiyun 
13*4882a593Smuzhiyun /**
14*4882a593Smuzhiyun  * cmos_read8() - Get 8-bit data stored at the given address
15*4882a593Smuzhiyun  *
16*4882a593Smuzhiyun  * This reads from CMOS for the 8-bit data stored at the given address.
17*4882a593Smuzhiyun  *
18*4882a593Smuzhiyun  * @addr:	RTC SRAM address
19*4882a593Smuzhiyun  * @return:	8-bit data stored at the given address
20*4882a593Smuzhiyun  */
21*4882a593Smuzhiyun u8 cmos_read8(u8 addr);
22*4882a593Smuzhiyun 
23*4882a593Smuzhiyun /**
24*4882a593Smuzhiyun  * cmos_read16() - Get 16-bit data stored at the given address
25*4882a593Smuzhiyun  *
26*4882a593Smuzhiyun  * This reads from CMOS for the 16-bit data stored at the given address.
27*4882a593Smuzhiyun  *
28*4882a593Smuzhiyun  * @addr:	RTC SRAM address
29*4882a593Smuzhiyun  * @return:	16-bit data stored at the given address
30*4882a593Smuzhiyun  */
31*4882a593Smuzhiyun u16 cmos_read16(u8 addr);
32*4882a593Smuzhiyun 
33*4882a593Smuzhiyun /**
34*4882a593Smuzhiyun  * cmos_read32() - Get 32-bit data stored at the given address
35*4882a593Smuzhiyun  *
36*4882a593Smuzhiyun  * This reads from CMOS for the 32-bit data stored at the given address.
37*4882a593Smuzhiyun  *
38*4882a593Smuzhiyun  * @addr:	RTC SRAM address
39*4882a593Smuzhiyun  * @return:	32-bit data stored at the given address
40*4882a593Smuzhiyun  */
41*4882a593Smuzhiyun u32 cmos_read32(u8 addr);
42*4882a593Smuzhiyun 
43*4882a593Smuzhiyun #endif /* __EARLY_CMOS_H */
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