diff options
author | Bin Meng <bmeng.cn@gmail.com> | 2017-04-21 07:24:38 -0700 |
---|---|---|
committer | Bin Meng <bmeng.cn@gmail.com> | 2017-05-17 17:11:46 +0800 |
commit | 9f1fad1e365f413e4f6f5a608a70be0e6ba95dc8 (patch) | |
tree | 385e28c34a46e6232048baf91996e85923674468 /arch/x86/lib | |
parent | 3a34cae01160d207d50db267585b963cf0a0018d (diff) |
x86: Add an early CMOS access library
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>
Diffstat (limited to 'arch/x86/lib')
-rw-r--r-- | arch/x86/lib/Makefile | 1 | ||||
-rw-r--r-- | arch/x86/lib/early_cmos.c | 51 |
2 files changed, 52 insertions, 0 deletions
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 21f59a0485..fe00d7573f 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -15,6 +15,7 @@ obj-$(CONFIG_CMD_BOOTM) += bootm.o endif obj-y += cmd_boot.o obj-$(CONFIG_SEABIOS) += coreboot_table.o +obj-y += early_cmos.o obj-$(CONFIG_EFI) += efi/ obj-y += e820.o obj-y += gcc.o diff --git a/arch/x86/lib/early_cmos.c b/arch/x86/lib/early_cmos.c new file mode 100644 index 0000000000..fa0b3273a8 --- /dev/null +++ b/arch/x86/lib/early_cmos.c @@ -0,0 +1,51 @@ +/* + * 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; +} |