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/*
* This file is part of the coreboot project.
*
* Copyright 2017 Intel Corporation.
*
* 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; version 2 of the License.
*
* 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.
*/
#ifndef __DRIVERS_I2C_DESIGNWARE_I2C_H__
#define __DRIVERS_I2C_DESIGNWARE_I2C_H__
#include <compiler.h>
#include <device/device.h>
#include <device/i2c.h>
#include <stdint.h>
#if IS_ENABLED(CONFIG_DRIVERS_I2C_DESIGNWARE_DEBUG)
#define DW_I2C_DEBUG BIOS_DEBUG
#else
#define DW_I2C_DEBUG BIOS_NEVER
#endif // CONFIG_DRIVERS_I2C_DESIGNWARE_DEBUG
/*
* Timing values are in units of clock period, with the clock speed
* provided by the SOC in CONFIG_DRIVERS_I2C_DESIGNWARE_I2C_CLOCK_MHZ
* Automatic configuration is done based on requested speed, but the
* values may need tuned depending on the board and the number of
* devices present on the bus.
*/
struct dw_i2c_speed_config {
enum i2c_speed speed;
/* SCL high and low period count */
uint16_t scl_lcnt;
uint16_t scl_hcnt;
/*
* SDA hold time should be 300ns in standard and fast modes
* and long enough for deterministic logic level change in
* fast-plus and high speed modes.
*
* [15:0] SDA TX Hold Time
* [23:16] SDA RX Hold Time
*/
uint32_t sda_hold;
};
/*
* This I2C controller has support for 3 independent speed configs but can
* support both FAST_PLUS and HIGH speeds through the same set of speed
* config registers. These are treated separately so the speed config values
* can be provided via ACPI to the OS.
*/
#define DW_I2C_SPEED_CONFIG_COUNT 4
struct dw_i2c_bus_config {
/* Bus should be enabled prior to ramstage with temporary base */
int early_init;
/* Bus speed in Hz, default is I2C_SPEED_FAST (400 KHz) */
enum i2c_speed speed;
/* If rise_time_ns is non-zero the calculations for lcnt and hcnt
* registers take into account the times of the bus. However, if
* there is a match in speed_config those register values take
* precedence. */
int rise_time_ns;
int fall_time_ns;
int data_hold_time_ns;
/* Specific bus speed configuration */
struct dw_i2c_speed_config speed_config[DW_I2C_SPEED_CONFIG_COUNT];
};
/* Functions to be implemented by SoC code */
/* Get base address for early init of I2C controllers. */
uintptr_t dw_i2c_get_soc_early_base(unsigned int bus);
/*
* Map given I2C bus number to devfn.
* Return value:
* -1 = error
* otherwise, devfn(>=0) corresponding to I2C bus number.
*/
int dw_i2c_soc_devfn_to_bus(unsigned int devfn);
/*
* Map given bus number to a I2C Controller.
* Return value:
* -1 = error
* otherwise, devfn(>=0) corresponding to I2C bus number.
*/
int dw_i2c_soc_bus_to_devfn(unsigned int bus);
/*
* SoC implemented callback for getting I2C bus configuration.
*
* Returns NULL if i2c config is not found
*/
const struct dw_i2c_bus_config *dw_i2c_get_soc_cfg(unsigned int bus);
/* Get I2C controller base address */
uintptr_t dw_i2c_base_address(unsigned int bus);
/*
* Initialize this bus controller and set the speed
* Return value:
* -1 = failure
* 0 = success
*/
int dw_i2c_init(unsigned int bus, const struct dw_i2c_bus_config *bcfg);
/*
* Generate speed config based on clock
* Return value:
* -1 = failure
* 0 = success
*/
int dw_i2c_gen_speed_config(uintptr_t dw_i2c_addr,
enum i2c_speed speed,
const struct dw_i2c_bus_config *bcfg,
struct dw_i2c_speed_config *config);
/*
* Process given I2C segments in a single transfer
* Return value:
* -1 = failure
* 0 = success
*/
int dw_i2c_transfer(unsigned int bus,
const struct i2c_msg *segments,
size_t count);
/*
* Map an i2c host controller device to a logical bus number.
* Return value:
* -1 = failure
* >=0 = logical bus number
*/
int dw_i2c_soc_dev_to_bus(struct device *dev);
/*
* Common device_operations implementation to initialize the i2c host
* controller.
*/
void dw_i2c_dev_init(struct device *dev);
/*
* Common device_operations implementation to fill ACPI SSDT table for i2c
* host controller.
*/
void dw_i2c_acpi_fill_ssdt(struct device *dev);
/*
* Common device_operations implementation for i2c host controller ops.
*/
extern const struct i2c_bus_operations dw_i2c_bus_ops;
#endif /* __DRIVERS_I2C_DESIGNWARE_I2C_H__ */
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