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# 智融PD芯片I2C通信实战：从零实现高效可靠的模拟I2C驱动

news 2026/6/16 12:46:27

🔥 智融PD芯片I2C通信实战：从零实现高效可靠的模拟I2C驱动

📋 概述

本文详细介绍了一个用于与智融PD芯片进行通信的模拟I2C驱动程序实现。该驱动通过GPIO模拟I2C协议，实现了完整的I2C通信功能，包括起始信号、停止信号、数据传输和应答检测等核心功能。

🛠️ 驱动程序基础函数

1. GPIO引脚配置

/* SDA引脚输出模式设置 */staticinlinevoidpd_sda_set_out_mode(structpd_i2c_bus_typedef*bus){gpio_init(PD_SDA_GPIO_PORT,GPIO_MODE_OUT_OD,GPIO_OSPEED_50MHZ,PD_SDA_PIN);}/* SDA引脚输入模式设置 */staticinlinevoidpd_sda_set_in_mode(structpd_i2c_bus_typedef*bus){gpio_init(PD_SDA_GPIO_PORT,GPIO_MODE_IN_FLOATING,GPIO_OSPEED_50MHZ,PD_SDA_PIN);}/* 获取SDA引脚状态 */staticinlineuint8_tget_sda(structpd_i2c_bus_typedef*bus){returngpio_input_bit_get(bus->gpiox,bus->sda_gpio_pin);}/* SDA引脚电平控制 */staticinlinevoidPD_SDA_L(structpd_i2c_bus_typedef*bus){gpio_bit_reset(bus->gpiox,bus->sda_gpio_pin);}staticinlinevoidPD_SDA_H(structpd_i2c_bus_typedef*bus){gpio_bit_set(bus->gpiox,bus->sda_gpio_pin);}/* SCL引脚电平控制 */staticinlinevoidPD_SCL_L(structpd_i2c_bus_typedef*bus){gpio_bit_reset(bus->gpiox,bus->scl_gpio_pin);}staticinlinevoidPD_SCL_H(structpd_i2c_bus_typedef*bus){gpio_bit_set(bus->gpiox,bus->scl_gpio_pin);}

ＩＩＣ起始信号

staticinlinevoidpd_i2c_start(structpd_i2c_bus_typedef*bus){pd_sda_set_out_mode(bus);PD_SDA_H(bus);bus->udelay(10);PD_SCL_H(bus);bus->udelay(10);PD_SDA_L(bus);bus->udelay(10);PD_SCL_L(bus);bus->udelay(10);}

ＩＩＣ结束信号

staticinlinevoidpd_i2c_stop(structpd_i2c_bus_typedef*bus){bus->udelay(6);PD_SDA_L(bus);bus->udelay(6);PD_SCL_H(bus);bus->udelay(6);PD_SDA_H(bus);bus->udelay(6);PD_SDA_H(bus);pd_sda_set_out_mode(bus);}

ＩＩＣ重启信号

staticinlinevoidpd_i2c_restart(structpd_i2c_bus_typedef*bus){PD_SDA_H(bus);bus->udelay(6);PD_SCL_H(bus);bus->udelay(6);PD_SDA_L(bus);bus->udelay(6);PD_SCL_L(bus);bus->udelay(6);}

判断从机回复

/** * @brief pd_iic 检测响应，pd_iic * @param struct pd_i2c_bus_typedef *bus * @param NONE * @retval 返回 0 从机接收成功; 返回1，应答失败 */staticinlineuint8_tpd_i2c_check_ack(structpd_i2c_bus_typedef*bus){uint8_tack=0;uint16_tpd_chip_timeout=0;PD_SDA_H(bus);bus->udelay(5);PD_SCL_H(bus);bus->udelay(5);pd_sda_set_in_mode(bus);while(1==get_sda(bus)){pd_chip_timeout++;if(pd_chip_timeout>250){pd_i2c_stop(&pd_i2c_bus);ack=1;break;}}pd_sda_set_out_mode(bus);PD_SCL_L(bus);bus->udelay(5);returnack;}

发送检测响应

/** * @brief pd_iic 发送检测响应，iic 协议第9位为应答 * @param struct pd_i2c_bus_typedef *bus * @param ack 需要继续通信拉低0, 不需要继续通信拉高1 * @retval */staticinlinevoidpd_i2c_send_ack_Or_nack(structpd_i2c_bus_typedef*bus,intack){//int re_ack = 0;PD_SCL_L(bus);bus->udelay(10);if(ack){PD_SDA_L(bus);//继续通信}else{PD_SDA_H(bus);}bus->udelay(10);PD_SCL_H(bus);bus->udelay(10);PD_SCL_L(bus);bus->udelay(10);}

写单字节

//写单字节staticvoidpd_i2c_write_byte(structpd_i2c_bus_typedef*bus,uint8_tdata){uint8_ti=0;uint8_tdat=0;uint8_ttemps=0;dat=0x80;temps=data;for(i=0;i<8;i++){PD_SCL_L(bus);if(dat&temps)//对应位为一就发一{PD_SDA_H(bus);bus->udelay(WR_RD_DELAY_TIME);//延时一下PD_SCL_H(bus);bus->udelay(WR_RD_DELAY_TIME);//t(HIGH) Clock high period See Note 2 4.0~50 μs}else{PD_SDA_L(bus);bus->udelay(WR_RD_DELAY_TIME);//延时一下PD_SCL_H(bus);bus->udelay(WR_RD_DELAY_TIME);}dat=dat>>1;}PD_SCL_L(bus);bus->udelay(WR_RD_DELAY_TIME);PD_SDA_H(bus);//数据线拉高，为等待响应做准备bus->udelay(WR_RD_DELAY_TIME);}

读单字节

//读单字节staticuint8_tpd_i2c_read_byte(structpd_i2c_bus_typedef*bus){uint8_tmask;uint8_tdata=0;PD_SDA_H(bus);bus->udelay(10);pd_sda_set_in_mode(bus);for(mask=0x80;mask!=0;mask>>=1){PD_SCL_H(bus);bus->udelay(10);if(get_sda(bus)){data|=mask;}PD_SCL_L(bus);bus->udelay(10);}pd_sda_set_out_mode(bus);returndata;}

读寄存器

intpd_i2c_read_register(uint8_t*pd_data_buff,uint16_taddr,uint16_tlen){uint16_ti=0;// uint16_t data = 0;uint8_tsda_status=0;uint16_tstart_addr=0;// uint8_t start_temp = 0;start_addr=addr;pd_lock();//PD 读pd_i2c_start(&pd_i2c_bus);//开始pd_i2c_write_byte(&pd_i2c_bus,PD_I2C_WRITE_SLAVE_ADDR);//设备地址 0x3Cpd_i2c_bus.udelay(DLY_TIMER_1);sda_status=pd_i2c_check_ack(&pd_i2c_bus);//等待响应if(1==sda_status){pd_i2c_stop(&pd_i2c_bus);pd_i2c_stop(&pd_i2c_bus);pd_unlock();return(-1);}pd_i2c_bus.udelay(DLY_TIMER_1);pd_i2c_write_byte(&pd_i2c_bus,(uint8_t)start_addr);//数据地址pd_i2c_bus.udelay(DLY_TIMER_1);sda_status=pd_i2c_check_ack(&pd_i2c_bus);//等待响应if(1==sda_status){pd_i2c_stop(&pd_i2c_bus);pd_i2c_stop(&pd_i2c_bus);pd_unlock();return(-1);}pd_i2c_bus.udelay(DLY_TIMER_1);pd_i2c_restart(&pd_i2c_bus);//再次启动pd_i2c_write_byte(&pd_i2c_bus,PD_I2C_READ_SLAVE_ADDR);//设备地址 0x3Dsda_status=pd_i2c_check_ack(&pd_i2c_bus);//等待响应if(1==sda_status){pd_i2c_stop(&pd_i2c_bus);pd_i2c_stop(&pd_i2c_bus);pd_unlock();return(-1);}for(i=0;i<len;i++){pd_data_buff[i]=pd_i2c_read_byte(&pd_i2c_bus);//pd_i2c_bus.udelay(DLY_TIMER_2);pd_i2c_send_ack_Or_nack(&pd_i2c_bus,ACK_FLAG);}pd_i2c_bus.udelay(DLY_TIMER_1);pd_i2c_stop(&pd_i2c_bus);//停止pd_unlock();return0;}

写寄存器

/** * @brief PD 芯片写单字节 * @param register PD 芯片写寄存器 * @param p_data 数据指针 * @retval 异常返回 1,正常返回 0 * @note 软件模拟SMBUS协议 */uint8_tpd_i2c_write_register(uint8_t*pd_data_buff,uint16_taddr,uint16_tlen){uint16_ti=0;//uint16_t data = 0;uint8_tsda_status=0;uint16_tstart_addr=0;//uint8_t start_temp = 0;pd_lock();start_addr=addr;//PD 读pd_i2c_start(&pd_i2c_bus);//开始pd_i2c_write_byte(&pd_i2c_bus,PD_I2C_WRITE_SLAVE_ADDR);//设备地址 0x3Cpd_i2c_bus.udelay(DLY_TIMER_2);sda_status=pd_i2c_check_ack(&pd_i2c_bus);//等待响应if(1==sda_status){pd_unlock();returnsda_status;}pd_i2c_write_byte(&pd_i2c_bus,(uint8_t)start_addr);//数据地址pd_i2c_bus.udelay(DLY_TIMER_2);sda_status=pd_i2c_check_ack(&pd_i2c_bus);//等待响应if(1==sda_status){pd_unlock();returnsda_status;}pd_i2c_bus.udelay(DLY_TIMER_2);for(i=0;i<len;i++){pd_i2c_write_byte(&pd_i2c_bus,pd_data_buff[i]);pd_i2c_bus.udelay(DLY_TIMER_2);sda_status=pd_i2c_check_ack(&pd_i2c_bus);}pd_i2c_stop(&pd_i2c_bus);//停止pd_unlock();returnsda_status;}