mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-11-14 17:07:38 +00:00
9f1fad1e36
This adds a library that provides CMOS (inside RTC SRAM) access at a very early stage when driver model is not available yet. Signed-off-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org> Tested-by: Stefan Roese <sr@denx.de>
51 lines
918 B
C
51 lines
918 B
C
/*
|
|
* Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*/
|
|
|
|
/*
|
|
* 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;
|
|
}
|