/**********************************************************************
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* Copyright: (C)2024 LingYun IoT System Studio
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* Author: GuoWenxue<guowenxue@gmail.com>
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*
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* Description: The purpose of this code is to provide a simple C library,
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* which providing software bit-bang of the I2C protocol on
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* any GPIO pins for ISKBoard.
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*
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* ChangeLog:
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* Version Date Author Description
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* V1.0.0 2024.08.29 GuoWenxue Release initial version
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*
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***********************************************************************/
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#ifndef __I2C_BITBANG_H
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#define __I2C_BITBANG_H
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#include "stm32l4xx_hal.h"
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#include <stdint.h>
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#include <stdatomic.h>
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#define I2C_DELAY_US 5 /* I2C timing delay in microseconds */
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#define I2C_TIMEOUT_COUNT 100 /* Timeout counter for waiting ACK */
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/* GPIO port for I2C typedef */
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typedef struct i2c_gpio_s
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{
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GPIO_TypeDef *group; /* GPIO group */
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uint16_t pin; /* GPIO pin */
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} i2c_gpio_t;
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/* I2C bus typedef */
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typedef struct i2c_bus_s
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{
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volatile atomic_bool lock; /* Bus lock flag */
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uint8_t addr; /* 7-bits slave address */
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i2c_gpio_t scl; /* SCL GPIO pin */
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i2c_gpio_t sda; /* SDA GPIO pin */
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} i2c_bus_t;
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/* GPIO level enum */
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enum
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{
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LOW = 0,
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HIGH = 1,
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};
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/* I2C ACK/NACK enum */
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typedef enum
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{
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I2C_ACK = 0,
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I2C_NACK = 1
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} i2c_ack_t;
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/* I2C status enum */
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typedef enum
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{
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I2C_OK = 0,
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I2C_ERROR = 1,
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I2C_TIMEOUT = 2,
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I2C_BUSY = 3
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} i2c_status_t;
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/*
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*+---------------------------------+
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*| I2C bus control function |
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*+---------------------------------+
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*/
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/* I2C1 bus instance for SHT20, RTC, OLED on board */
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extern i2c_bus_t i2c1_bus;
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/* I2C2 bus instance on MikroBUS */
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extern i2c_bus_t i2c2_bus;
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/**
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* @brief Initialize I2C GPIO pins
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* @param bus: pointer to I2C bus structure
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* @retval None
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*/
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extern void i2c_init(i2c_bus_t *bus);
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/**
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* @brief Deinitialize I2C GPIO pins
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* @param bus: pointer to I2C bus structure
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* @retval None
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*/
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extern void i2c_deinit(i2c_bus_t *bus);
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/**
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* @brief 通用 I2C 设备属性结构体
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*/
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typedef struct {
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i2c_bus_t *bus; /* 绑定的 I2C 物理总线实例 */
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uint8_t dev_addr; /* 7位设备物理从机地址 */
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} i2c_dev_t;
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/**
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* @brief 绑定设备及地址到 I2C 总线上
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* @param dev: I2C 设备结构体指针
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* @param bus: 物理总线指针
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* @param dev_addr: 7位从机地址
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* @retval 0: 成功; -1: 失败
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*/
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extern int i2c_bind_dev(i2c_dev_t *dev, i2c_bus_t *bus, uint8_t dev_addr);
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/**
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* @brief 将I2C总线加锁让设备独占总线
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* @param dev: I2C 设备结构体指针
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* @retval 0: 成功; -1: 失败
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*/
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extern int i2c_lock_dev(i2c_dev_t *dev);
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/**
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* @brief 释放设备的 I2C 总线锁
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* @param dev: I2C 设备结构体指针
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* @retval 无
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*/
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extern void i2c_free_dev(i2c_dev_t *dev);
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/**
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* @brief Lock I2C bus for exclusive access (bare metal mutex)
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* @param bus: pointer to I2C bus structure
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* @retval I2C_OK if success, I2C_BUSY if bus is locked
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*/
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extern i2c_status_t i2c_lock(i2c_bus_t *bus);
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/**
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* @brief Unlock I2C bus
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* @param bus: pointer to I2C bus structure
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* @retval None
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*/
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extern void i2c_unlock(i2c_bus_t *bus);
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/**
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* @brief Scan I2C bus for connected devices
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* @param bus: pointer to I2C bus structure
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* @retval none
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*/
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extern void i2c_scan(i2c_bus_t *bus);
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/*
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*+---------------------------------+
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*| I2C timing sequence function |
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*+---------------------------------+
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*/
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/**
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* @brief Generate I2C start condition
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* @param bus: pointer to I2C bus structure
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* @retval None
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*/
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extern void i2c_start(i2c_bus_t *bus);
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/**
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* @brief Generate I2C stop condition
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* @param bus: pointer to I2C bus structure
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* @retval None
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*/
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extern void i2c_stop(i2c_bus_t *bus);
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/**
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* @brief Wait for ACK from slave
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* @param bus: pointer to I2C bus structure
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* @retval I2C_ACK or I2C_NACK
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*/
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extern i2c_ack_t i2c_wait_ack(i2c_bus_t *bus);
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/**
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* @brief Send ACK to slave
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* @param bus: pointer to I2C bus structure
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* @retval None
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*/
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extern void i2c_send_ack(i2c_bus_t *bus);
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/**
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* @brief Send NACK to slave
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* @param bus: pointer to I2C bus structure
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* @retval None
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*/
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extern void i2c_send_nack(i2c_bus_t *bus);
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/**
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* @brief Write one byte to I2C bus
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* @param bus: pointer to I2C bus structure
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* @param byte: byte to write
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* @retval None
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*/
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extern void i2c_write_byte(i2c_bus_t *bus, uint8_t byte);
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/**
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* @brief Read one byte from I2C bus
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* @param bus: pointer to I2C bus structure
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* @retval received byte
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*/
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extern uint8_t i2c_read_byte(i2c_bus_t *bus);
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/*
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*+-----------------------------------+
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*| I2C read/write function |
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*+-----------------------------------+
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*/
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/**
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* @brief Write data to I2C slave device
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* @param bus: pointer to I2C bus structure
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* @param addr: 7-bit slave address
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* @param reg: register address
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* @param data: pointer to data buffer
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* @param len: data length
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* @retval I2C status
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*/
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extern i2c_status_t i2c_write(i2c_bus_t *bus, uint8_t addr, uint8_t reg, uint8_t *data, uint16_t len);
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/**
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* @brief Read data from I2C slave device
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* @param bus: pointer to I2C bus structure
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* @param addr: 7-bit slave address
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* @param reg: register address
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* @param data: pointer to data buffer
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* @param len: data length
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* @retval I2C status
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*/
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extern i2c_status_t i2c_read(i2c_bus_t *bus, uint8_t addr, uint8_t reg, uint8_t *data, uint16_t len);
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/**
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* @brief Write data to I2C slave device without register address
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* @param bus: pointer to I2C bus structure
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* @param addr: 7-bit slave address
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* @param data: pointer to data buffer
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* @param len: data length
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* @retval I2C status
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*/
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extern i2c_status_t i2c_write_no_reg(i2c_bus_t *bus, uint8_t addr, uint8_t *data, uint16_t len);
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/**
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* @brief Read data from I2C slave device without register address
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* @param bus: pointer to I2C bus structure
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* @param addr: 7-bit slave address
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* @param data: pointer to data buffer
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* @param len: data length
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* @retval I2C status
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*/
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extern i2c_status_t i2c_read_no_reg(i2c_bus_t *bus, uint8_t addr, uint8_t *data, uint16_t len);
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/*
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*+-----------------------------------+
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*| Linux I2C API–compatible function |
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*+-----------------------------------+
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*/
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#define I2C_M_WR 0x0000 /* 写控制标志 */
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#define I2C_M_RD 0x0001 /* 读控制标志 */
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typedef struct {
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uint8_t addr; /* 7位从机地址 */
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uint16_t flags; /* I2C_M_WR 或 I2C_M_RD */
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uint16_t len; /* 数据长度 */
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uint8_t *buf; /* 数据指针 */
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} i2c_msg_t;
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/* Functions compatible with the Linux I2C adapter API */
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extern i2c_status_t i2c_transfer(i2c_bus_t *bus, i2c_msg_t *msgs, int num);
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#endif /* __I2C_BITBANG_H */
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