esp-open-rtos/extras/i2c/i2c.h
Our Air Quality afa834a805 i2c: remove wip 400k define
Looks like this was test wip code that should not have been included.
Want to be able to set the i2c per-project rather than having to patch
the driver.
2017-08-02 10:36:06 +10:00

135 lines
4 KiB
C

/*
* The MIT License (MIT)
*
* Copyright (c) 2015 Johan Kanflo (github.com/kanflo)
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef __I2C_H__
#define __I2C_H__
#include <stdint.h>
#include <stdbool.h>
#include <errno.h>
#include <FreeRTOS.h>
#include <task.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* Some bit can be transmit slower.
* Selected frequency fix the speed of a bit transmission
* I2C lib take the maximum frequency defined
* Don't change frequency when I2C transaction had begin
*/
#ifdef I2C_FREQUENCY_500K
#define I2C_CUSTOM_DELAY_160MHZ 6
#define I2C_CUSTOM_DELAY_80MHZ 1 //Sry, maximum is 320kHz at 80MHz
#elif defined(I2C_FREQUENCY_400K)
#define I2C_CUSTOM_DELAY_160MHZ 10
#define I2C_CUSTOM_DELAY_80MHZ 1 //Sry, maximum is 320kHz at 80MHz
#else
#define I2C_CUSTOM_DELAY_160MHZ 100
#define I2C_CUSTOM_DELAY_80MHZ 20
#endif
// I2C driver for ESP8266 written for use with esp-open-rtos
// Based on https://en.wikipedia.org/wiki/I²C#Example_of_bit-banging_the_I.C2.B2C_Master_protocol
// With calling overhead, we end up at ~320kbit/s
//Level 0 API
/**
* Init bitbanging I2C driver on given pins
* @param scl_pin SCL pin for I2C
* @param sda_pin SDA pin for I2C
*/
void i2c_init(uint8_t scl_pin, uint8_t sda_pin);
/**
* Write a byte to I2C bus.
* @param byte Pointer to device descriptor
* @return true if slave acked
*/
bool i2c_write(uint8_t byte);
/**
* Read a byte from I2C bus.
* @param ack Set Ack for slave (false: Ack // true: NoAck)
* @return byte read from slave.
*/
uint8_t i2c_read(bool ack);
/**
* Send start or restart condition
*/
void i2c_start(void);
/**
* Send stop condition
* @return false if link was broken
*/
bool i2c_stop(void);
/**
* get status from I2C bus.
* @return true if busy.
*/
bool i2c_status(void);
//Level 1 API (Don't need functions above)
/**
* This function will allow you to force a transmission I2C, cancel current transmission.
* Warning: Use with precaution. Don't use it if you can avoid it. Usefull for priority transmission.
* @param state Force the next I2C transmission if true (Use with precaution)
*/
void i2c_force_bus(bool state);
/**
* Write 'len' bytes from 'buf' to slave at 'data' register adress .
* @param slave_addr slave device address
* @param data Pointer to register address to send if non-null
* @param buf Pointer to data buffer
* @param len Number of byte to send
* @return Non-Zero if error occured
*/
int i2c_slave_write(uint8_t slave_addr, const uint8_t *data, const uint8_t *buf, uint32_t len);
/**
* Issue a send operation of 'data' register adress, followed by reading 'len' bytes
* from slave into 'buf'.
* @param slave_addr slave device address
* @param data Pointer to register address to send if non-null
* @param buf Pointer to data buffer
* @param len Number of byte to read
* @return Non-Zero if error occured
*/
int i2c_slave_read(uint8_t slave_addr, const uint8_t *data, uint8_t *buf, uint32_t len);
#ifdef __cplusplus
}
#endif
#endif /* __I2C_H__ */