74 lines
2.3 KiB
C
74 lines
2.3 KiB
C
/*
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* This file is part of the coreboot project.
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*
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* Copyright (C) 2011 Alexandru Gagniuc <mr.nuke.me@gmail.com>
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/**
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* @file device/early_smbus.h
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*
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* This file defines a common API for accessing the SMBus during early
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* initialization. It defines the prototypes for common SMBus functions. The
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* actual implementations are hardware-dependent.
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*
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* The first parameter of all SMBus functions take a u32 value smbus_dev which
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* represents some information on how to access the device, and is
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* implementation defined. Usually, it just contains the IO base for the smbus.
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* To get this argument @ref smbus_get_device() can be used.
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*
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* The header only defines the prototypes. Several steps are needed to use
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* these:
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*
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* 1. Include this header
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* @code{.c}
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* #include <device/early_smbus.h>
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* @endcode
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*
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* 2. Implement early_smbus.c for the hardware, or find a compatible
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* implementation.
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*
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* 3. Link against the file that implements these functions. In the Makefile.inc
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* of the chipset, add:
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* @code
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* romstage-y += ./path/to/early_smbus.c
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* @endcode
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*/
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#ifndef DEVICE_EARLY_SMBUS_H
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#define DEVICE_EARLY_SMBUS_H
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#include <stdint.h>
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/**
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* \brief printk macro for SMBus debugging
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*/
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#if IS_ENABLED(CONFIG_DEBUG_SMBUS)
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#define printsmbus(x, ...) printk(BIOS_DEBUG, x, ##__VA_ARGS__)
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#else
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#define printsmbus(x, ...)
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#endif
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u32 smbus_get_device(void);
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void smbus_reset(u32 smbus_dev);
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int smbus_print_error(u32 smbus_dev, u8 host_status, int loops);
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int smbus_is_busy(u32 smbus_dev);
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int smbus_wait_until_ready(u32 smbus_dev);
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u8 smbus_read_byte(u32 smbus_dev, u8 addr, u8 offset);
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void smbus_delay(void);
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#endif /* DEVICE_EARLY_SMBUS_H */
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