| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2011 Alexandru Gagniuc <mr.nuke.me@gmail.com> |
| * |
| * This program is free software: you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation, either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| |
| /** |
| * @file device/early_smbus.h |
| * |
| * This file defines a common API for accessing the SMBus during early |
| * initialization. It defines the prototypes for common SMBus functions. The |
| * actual implementations are hardware-dependent. |
| * |
| * The first parameter of all SMBus functions take a u32 value smbus_dev which |
| * represents some information on how to access the device, and is |
| * implementation defined. Usually, it just contains the IO base for the smbus. |
| * To get this argument @ref smbus_get_device() can be used. |
| * |
| * The header only defines the prototypes. Several steps are needed to use |
| * these: |
| * |
| * 1. Include this header |
| * @code{.c} |
| * #include <device/early_smbus.h> |
| * @endcode |
| * |
| * 2. Implement early_smbus.c for the hardware, or find a compatible |
| * implementation. |
| * |
| * 3. Link against the file that implements these functions. In the Makefile.inc |
| * of the chipset, add: |
| * @code |
| * romstage-y += ./path/to/early_smbus.c |
| * @endcode |
| */ |
| |
| #ifndef DEVICE_EARLY_SMBUS_H |
| #define DEVICE_EARLY_SMBUS_H |
| |
| #include <stdint.h> |
| |
| /** |
| * \brief printk macro for SMBus debugging |
| */ |
| #if IS_ENABLED(CONFIG_DEBUG_SMBUS) |
| #define printsmbus(x, ...) printk(BIOS_DEBUG, x, ##__VA_ARGS__) |
| #else |
| #define printsmbus(x, ...) |
| #endif |
| |
| u32 smbus_get_device(void); |
| void smbus_reset(u32 smbus_dev); |
| int smbus_print_error(u32 smbus_dev, u8 host_status, int loops); |
| int smbus_is_busy(u32 smbus_dev); |
| int smbus_wait_until_ready(u32 smbus_dev); |
| u8 smbus_read_byte(u32 smbus_dev, u8 addr, u8 offset); |
| |
| void smbus_delay(void); |
| |
| #endif /* DEVICE_EARLY_SMBUS_H */ |