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>
44 lines
1009 B
C
44 lines
1009 B
C
/*
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* Copyright (C) 2017, Bin Meng <bmeng.cn@gmail.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#ifndef __EARLY_CMOS_H
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#define __EARLY_CMOS_H
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/* CMOS actually resides in the RTC SRAM */
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#define CMOS_IO_PORT 0x70
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/**
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* cmos_read8() - Get 8-bit data stored at the given address
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*
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* This reads from CMOS for the 8-bit data stored at the given address.
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*
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* @addr: RTC SRAM address
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* @return: 8-bit data stored at the given address
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*/
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u8 cmos_read8(u8 addr);
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/**
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* cmos_read16() - Get 16-bit data stored at the given address
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*
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* This reads from CMOS for the 16-bit data stored at the given address.
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*
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* @addr: RTC SRAM address
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* @return: 16-bit data stored at the given address
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*/
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u16 cmos_read16(u8 addr);
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/**
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* cmos_read32() - Get 32-bit data stored at the given address
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*
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* This reads from CMOS for the 32-bit data stored at the given address.
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*
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* @addr: RTC SRAM address
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* @return: 32-bit data stored at the given address
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*/
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u32 cmos_read32(u8 addr);
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#endif /* __EARLY_CMOS_H */
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