Files
Linux_Drivers/u-boot-2021.10/arch/x86/lib/early_cmos.c
sam.xiang f8fc109960 [uboot] create uboot from github:
repo: https://github.com/u-boot/u-boot
	commit: d80bb749fab53da72c4a0e09b8c2d2aaa3103c91

Change-Id: Ie6434426e1ec15bc08bb1832798e371f3fd5fb29
2023-03-10 20:30:57 +08:00

51 lines
915 B
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
*/
/*
* This library provides CMOS (inside RTC SRAM) access routines at a very
* early stage when driver model is not available yet. Only read access is
* provided. The 16-bit/32-bit read are compatible with driver model RTC
* uclass write ops, that data is stored in little-endian mode.
*/
#include <common.h>
#include <asm/early_cmos.h>
#include <asm/io.h>
u8 cmos_read8(u8 addr)
{
outb(addr, CMOS_IO_PORT);
return inb(CMOS_IO_PORT + 1);
}
u16 cmos_read16(u8 addr)
{
u16 value = 0;
u16 data;
int i;
for (i = 0; i < sizeof(value); i++) {
data = cmos_read8(addr + i);
value |= data << (i << 3);
}
return value;
}
u32 cmos_read32(u8 addr)
{
u32 value = 0;
u32 data;
int i;
for (i = 0; i < sizeof(value); i++) {
data = cmos_read8(addr + i);
value |= data << (i << 3);
}
return value;
}