Zynq-Linux移植学习笔记之67- 国产ZYNQ上通过GPIO模拟MDC/MDIO协议

1、背景介绍

模块上有9个PHY，其中两个PHY通过ZYNQ PS端的MDIO总线连接，其余7个PHY单独通过GPIO进行控制，需要实现GPIO模拟MDC/MDIO协议。

2、vivado工程设计

vivado工程内为每个PHY建立两个GPIO IP核，分别用来代表MDC和MDIO（虽然有点浪费）

MDC配置为默认输出

MDIO配置为双向

MDIO管脚默认上拉

3、MDIO时序介绍

MDIO接口包括两条线，MDIO和MDC，其中MDIO是双向数据线，而MDC是由STA驱动的时钟线。MDC时钟的最高速率一般为2.5MHz，MDC也可以是非固定频率，甚至可以是非周期的。MDIO接口只是会在MDC时钟的上升沿进行采样，而并不在意MDC时钟的频率（类似于I2C接口）。MDIO是一个PHY的管理接口，用来读/写PHY的寄存器，以控制PHY的行为或获取PHY的状态，MDC为MDIO提供时钟。

Preamble+Start：32bits的前导码以及2bit的开始位。

OP Code：2bits的操作码，10表示读，01表示写。

PHYAD：5bits的PHY地址，一般PHY地址，从0开始顺序编号，例如6口switch中PHY地址为0-5。

REGAD：5bits的寄存器地址，即要读或写的寄存器。

Turn Around：2bits的TA，在读命令中，MDIO在此时由MAC驱动改为PHY驱动，并等待一个时钟周期准备发送数据。在写命令中，不需要MDIO方向发生变化，则只是等待两个时钟周期准备写入数据。

Data：16bits数据，在读命令中，PHY芯片将读到的对应PHYAD的REGAD寄存器的数据写到Data中，在写命令中，MAC将要写入对应PHYAD的REGAD寄存器的值写入Data中。

Idle：空闲状态，此时MDIO无源驱动，处高阻状态，但一般用上拉电阻使其处在高电平，上拉电阻一般为1.5K。（空闲电平是低电平）

逻辑分析上抓到的示意图如下：

4、应用程序设计

参考上面的时序，采用GPIO翻转实现，注意AXI GPIO IP核0x4写0为输出，写1为输入，主要是用来操作MDIO方向

代码如下：

/** Copyright (c) 2012 Xilinx, Inc.  All rights reserved.** Xilinx, Inc.* XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A* COURTESY TO YOU.  BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS* ONE POSSIBLE   IMPLEMENTATION OF THIS FEATURE, APPLICATION OR* STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION* IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE* FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION.* XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO* THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO* ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE* FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY* AND FITNESS FOR A PARTICULAR PURPOSE.**/#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <linux/mii.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/sockios.h>
#include <linux/types.h>
#include <netinet/in.h>
#include <unistd.h>
#include "xil_io.h"#define  PHY2_YT8521_ADDR                             0x01
#define  PHY3_YT8521_ADDR                             0x02
#define  PHY5_YT8521_ADDR                             0x04
#define  PHY6_YT8521_ADDR                             0x05
#define  PHY7_YT8521_ADDR                             0x06
#define  PHY8_YT8521_ADDR                             0x07
#define  PHY9_YT8521_ADDR                             0x00#define  PHY_YT8521_ID_REG_ADDR                      0x03
#define  PHY_YT8521_REG_DEBUG_ADDR_OFFSET            0x1E
#define  PHY_YT8521_REG_DEBUG_DATA                   0x1F
#define  PHY_YT8521_EXT_REG_ADDR                     0xa00d#define MDC2_GPIO_ADDR 0x412B0000
#define MDC3_GPIO_ADDR 0x412D0000
#define MDC5_GPIO_ADDR 0x412F0000
#define MDC6_GPIO_ADDR 0x41310000
#define MDC7_GPIO_ADDR 0x41330000
#define MDC8_GPIO_ADDR 0x41350000
#define MDC9_GPIO_ADDR 0x41370000#define MDIO2_GPIO_ADDR 0x412C0000
#define MDIO3_GPIO_ADDR 0x412E0000
#define MDIO5_GPIO_ADDR 0x41300000
#define MDIO6_GPIO_ADDR 0x41320000
#define MDIO7_GPIO_ADDR 0x41340000
#define MDIO8_GPIO_ADDR 0x41360000
#define MDIO9_GPIO_ADDR 0x41380000#define PHY2_SOFT_SMI_MDIO_READ Xil_In32(MDIO2_GPIO_ADDR)
#define PHY3_SOFT_SMI_MDIO_READ Xil_In32(MDIO3_GPIO_ADDR)
#define PHY5_SOFT_SMI_MDIO_READ Xil_In32(MDIO5_GPIO_ADDR)
#define PHY6_SOFT_SMI_MDIO_READ Xil_In32(MDIO6_GPIO_ADDR)
#define PHY7_SOFT_SMI_MDIO_READ Xil_In32(MDIO7_GPIO_ADDR)
#define PHY8_SOFT_SMI_MDIO_READ Xil_In32(MDIO8_GPIO_ADDR)
#define PHY9_SOFT_SMI_MDIO_READ Xil_In32(MDIO9_GPIO_ADDR)typedef unsigned char u8;
typedef unsigned short u16;void mdio_out(int index)
{switch(index){case 2:Xil_Out32(MDIO2_GPIO_ADDR+0x4,0x0);break;case 3:Xil_Out32(MDIO3_GPIO_ADDR+0x4,0x0);break;case 5:Xil_Out32(MDIO5_GPIO_ADDR+0x4,0x0);break;case 6:Xil_Out32(MDIO6_GPIO_ADDR+0x4,0x0);break;case 7:Xil_Out32(MDIO7_GPIO_ADDR+0x4,0x0);break;case 8:Xil_Out32(MDIO8_GPIO_ADDR+0x4,0x0);break;case 9:Xil_Out32(MDIO9_GPIO_ADDR+0x4,0x0);break;default:break;}}void mdio_in(int index)
{switch(index){case 2:Xil_Out32(MDIO2_GPIO_ADDR+0x4,0x1);break;case 3:Xil_Out32(MDIO3_GPIO_ADDR+0x4,0x1);break;case 5:Xil_Out32(MDIO5_GPIO_ADDR+0x4,0x1);break;case 6:Xil_Out32(MDIO6_GPIO_ADDR+0x4,0x1);break;case 7:Xil_Out32(MDIO7_GPIO_ADDR+0x4,0x1);break;case 8:Xil_Out32(MDIO8_GPIO_ADDR+0x4,0x1);break;case 9:Xil_Out32(MDIO9_GPIO_ADDR+0x4,0x1);break;default:break;}}void mdc_low(int index)
{switch(index){case 2:Xil_Out32(MDC2_GPIO_ADDR,0x0);break;case 3:Xil_Out32(MDC3_GPIO_ADDR,0x0);break;case 5:Xil_Out32(MDC5_GPIO_ADDR,0x0);break;case 6:Xil_Out32(MDC6_GPIO_ADDR,0x0);break;case 7:Xil_Out32(MDC7_GPIO_ADDR,0x0);break;case 8:Xil_Out32(MDC8_GPIO_ADDR,0x0);break;case 9:Xil_Out32(MDC9_GPIO_ADDR,0x0);break;default:break;}}void mdc_high(int index)
{switch(index){case 2:Xil_Out32(MDC2_GPIO_ADDR,0xffffffff);break;case 3:Xil_Out32(MDC3_GPIO_ADDR,0xffffffff);break;case 5:Xil_Out32(MDC5_GPIO_ADDR,0xffffffff);break;case 6:Xil_Out32(MDC6_GPIO_ADDR,0xffffffff);break;case 7:Xil_Out32(MDC7_GPIO_ADDR,0xffffffff);break;case 8:Xil_Out32(MDC8_GPIO_ADDR,0xffffffff);break;case 9:Xil_Out32(MDC9_GPIO_ADDR,0xffffffff);break;default:break;}}void mdio_low(int index)
{switch(index){case 2:Xil_Out32(MDIO2_GPIO_ADDR,0x0);break;case 3:Xil_Out32(MDIO3_GPIO_ADDR,0x0);break;case 5:Xil_Out32(MDIO5_GPIO_ADDR,0x0);break;case 6:Xil_Out32(MDIO6_GPIO_ADDR,0x0);break;case 7:Xil_Out32(MDIO7_GPIO_ADDR,0x0);break;case 8:Xil_Out32(MDIO8_GPIO_ADDR,0x0);break;case 9:Xil_Out32(MDIO9_GPIO_ADDR,0x0);break;default:break;}}void mdio_high(int index)
{switch(index){case 2:Xil_Out32(MDIO2_GPIO_ADDR,0xffffffff);break;case 3:Xil_Out32(MDIO3_GPIO_ADDR,0xffffffff);break;case 5:Xil_Out32(MDIO5_GPIO_ADDR,0xffffffff);break;case 6:Xil_Out32(MDIO6_GPIO_ADDR,0xffffffff);break;case 7:Xil_Out32(MDIO7_GPIO_ADDR,0xffffffff);break;case 8:Xil_Out32(MDIO8_GPIO_ADDR,0xffffffff);break;case 9:Xil_Out32(MDIO9_GPIO_ADDR,0xffffffff);break;default:break;}}void Mcu_Yt8521_Soft_Smi_Bit_Set(int index,u8 bit)
{// set mdio dir out// set mdiomdio_out(index);if(bit) mdio_high(index);else mdio_low(index);// set clk.mdc_low(index);mdc_high(index);
}void Mcu_Yt8521_Soft_Smi_Bit_Get(int index,u8 *bit)
{// set mdio dir in// get mdiomdio_in(index);      //MDIO线设置为输入switch(index){case 2:*bit = !!PHY2_SOFT_SMI_MDIO_READ;break;case 3:*bit = !!PHY3_SOFT_SMI_MDIO_READ;break;case 5:*bit = !!PHY5_SOFT_SMI_MDIO_READ;break;case 6:*bit = !!PHY6_SOFT_SMI_MDIO_READ;break;case 7:*bit = !!PHY7_SOFT_SMI_MDIO_READ;break;case 8:*bit = !!PHY8_SOFT_SMI_MDIO_READ;break;case 9:*bit = !!PHY9_SOFT_SMI_MDIO_READ;break;default:break;}// set clk.mdc_low(index);mdc_high(index);}u16 Srv_Yt8521_Soft_I2c_Device_Write(int index,u8 phy_addr, u8 reg_addr, u16 data)
{u16 i = 0;//idelfor(i = 0; i < 32; i++){Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);}//startMcu_Yt8521_Soft_Smi_Bit_Set(index,0);Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);//op codeMcu_Yt8521_Soft_Smi_Bit_Set(index,0);Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);//phy addressfor(i = 0; i < 5; i++){if( phy_addr & (0x10 >> i) ){Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);}else{Mcu_Yt8521_Soft_Smi_Bit_Set(index,0);}}//register addressfor(i = 0; i < 5; i++){if( reg_addr & (0x10 >> i) ){Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);}else{Mcu_Yt8521_Soft_Smi_Bit_Set(index,0);}}//TA翻转状态（ack）Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);Mcu_Yt8521_Soft_Smi_Bit_Set(index,0);//register datafor(i = 0; i < 16; i++){if( data & (0x8000 >> i) ){Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);}else{Mcu_Yt8521_Soft_Smi_Bit_Set(index,0);}}return 0;
}u16 Srv_Yt8521_Soft_I2c_Device_Read(int index,u8 phy_addr, u8 reg_addr)
{u16 i = 0;u16 data = 0;     //待获取的数据u8  bit  = 0;//idelfor(i = 0; i < 32; i++){Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);}//startMcu_Yt8521_Soft_Smi_Bit_Set(index,0);Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);//op codeMcu_Yt8521_Soft_Smi_Bit_Set(index,1);Mcu_Yt8521_Soft_Smi_Bit_Set(index,0);//phy addressfor(i = 0; i < 5; i++){if( phy_addr & (0x10 >> i) ){Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);}else{Mcu_Yt8521_Soft_Smi_Bit_Set(index,0);}}//register addressfor(i = 0; i < 5; i++){if( reg_addr & (0x10 >> i) ){Mcu_Yt8521_Soft_Smi_Bit_Set(index,1);}else{Mcu_Yt8521_Soft_Smi_Bit_Set(index,0);}}//TA翻转状态（ack）Mcu_Yt8521_Soft_Smi_Bit_Get(index,&bit);Mcu_Yt8521_Soft_Smi_Bit_Get(index,&bit);//register datafor(i = 0; i < 16; i++){data<<=1;Mcu_Yt8521_Soft_Smi_Bit_Get(index,&bit);if(bit){data |= 0x1;}}return data;
}int main(int argc, char *argv[])
{int phy_index=0;int reg_addr=0;int value=0;u16 Reg_Value;if(argc<4){printf("Usage mdio_test w/r phy_index[2,3,5,6,7,8,9] reg_addr [value]\n ");return 0;}if(argc==4){phy_index=(uint16_t) strtoul(argv[2], NULL, 0);reg_addr=(uint16_t) strtoul(argv[3], NULL, 0);switch(phy_index){case 2:Reg_Value=Srv_Yt8521_Soft_I2c_Device_Read(2,PHY2_YT8521_ADDR, reg_addr);printf("[READ]phy_index %d reg_addr 0x%x value is 0x%x\n",phy_index,reg_addr,Reg_Value);break;case 3:Reg_Value=Srv_Yt8521_Soft_I2c_Device_Read(3,PHY3_YT8521_ADDR, reg_addr);printf("[READ]phy_index %d reg_addr 0x%x value is 0x%x\n",phy_index,reg_addr,Reg_Value);break;case 5:Reg_Value=Srv_Yt8521_Soft_I2c_Device_Read(5,PHY5_YT8521_ADDR, reg_addr);printf("[READ]phy_index %d reg_addr 0x%x value is 0x%x\n",phy_index,reg_addr,Reg_Value);break;case 6:Reg_Value=Srv_Yt8521_Soft_I2c_Device_Read(6,PHY6_YT8521_ADDR, reg_addr);printf("[READ]phy_index %d reg_addr 0x%x value is 0x%x\n",phy_index,reg_addr,Reg_Value);break;case 7:Reg_Value=Srv_Yt8521_Soft_I2c_Device_Read(7,PHY7_YT8521_ADDR, reg_addr);printf("[READ]phy_index %d reg_addr 0x%x value is 0x%x\n",phy_index,reg_addr,Reg_Value);break;case 8:Reg_Value=Srv_Yt8521_Soft_I2c_Device_Read(8,PHY8_YT8521_ADDR, reg_addr);printf("[READ]phy_index %d reg_addr 0x%x value is 0x%x\n",phy_index,reg_addr,Reg_Value);break;case 9:Reg_Value=Srv_Yt8521_Soft_I2c_Device_Read(9,PHY9_YT8521_ADDR, reg_addr);printf("[READ]phy_index %d reg_addr 0x%x value is 0x%x\n",phy_index,reg_addr,Reg_Value);break;default:break;}}else if(argc==5){phy_index=(uint16_t) strtoul(argv[2], NULL, 0);reg_addr=(uint16_t) strtoul(argv[3], NULL, 0);value=(uint16_t) strtoul(argv[4], NULL, 0);printf("[WRITE] phy_index is %d reg_addr is 0x%x value is 0x%x\n",phy_index,reg_addr,value);switch(phy_index){case 2:Srv_Yt8521_Soft_I2c_Device_Write(2,PHY2_YT8521_ADDR, reg_addr,value);break;case 3:Srv_Yt8521_Soft_I2c_Device_Write(3,PHY3_YT8521_ADDR, reg_addr,value);break;case 5:Srv_Yt8521_Soft_I2c_Device_Write(5,PHY5_YT8521_ADDR, reg_addr,value);break;case 6:Srv_Yt8521_Soft_I2c_Device_Write(6,PHY6_YT8521_ADDR, reg_addr,value);break;case 7:Srv_Yt8521_Soft_I2c_Device_Write(7,PHY7_YT8521_ADDR, reg_addr,value);break;case 8:Srv_Yt8521_Soft_I2c_Device_Write(8,PHY8_YT8521_ADDR, reg_addr,value);break;case 9:Srv_Yt8521_Soft_I2c_Device_Write(9,PHY9_YT8521_ADDR, reg_addr,value);break;default:break;}}#if 0u16 id = 0;printf("//***************** Read SMI Reg of YT8521 ******************//\r\n");printf("------ PHY Identification Registers ------\r\n");id = Srv_Yt8521_Soft_I2c_Device_Read(2,PHY2_YT8521_ADDR, PHY_YT8521_ID_REG_ADDR);   //reg_addr:0x03  读取的值应为0x11aprintf("PHY2_YT8521 id = 0x%x\n", id);id = Srv_Yt8521_Soft_I2c_Device_Read(3,PHY3_YT8521_ADDR, PHY_YT8521_ID_REG_ADDR);   //reg_addr:0x03  读取的值应为0x11aprintf("PHY3_YT8521 id = 0x%x\n", id);id = Srv_Yt8521_Soft_I2c_Device_Read(5,PHY5_YT8521_ADDR, PHY_YT8521_ID_REG_ADDR);   //reg_addr:0x03  读取的值应为0x11aprintf("PHY5_YT8521 id = 0x%x\n", id);id = Srv_Yt8521_Soft_I2c_Device_Read(6,PHY6_YT8521_ADDR, PHY_YT8521_ID_REG_ADDR);   //reg_addr:0x03  读取的值应为0x11aprintf("PHY6_YT8521 id = 0x%x\n", id);id = Srv_Yt8521_Soft_I2c_Device_Read(7,PHY7_YT8521_ADDR, PHY_YT8521_ID_REG_ADDR);   //reg_addr:0x03  读取的值应为0x11aprintf("PHY7_YT8521 id = 0x%x\n", id);id = Srv_Yt8521_Soft_I2c_Device_Read(8,PHY8_YT8521_ADDR, PHY_YT8521_ID_REG_ADDR);   //reg_addr:0x03  读取的值应为0x11aprintf("PHY8_YT8521 id = 0x%x\n", id);id = Srv_Yt8521_Soft_I2c_Device_Read(9,PHY9_YT8521_ADDR, PHY_YT8521_ID_REG_ADDR);   //reg_addr:0x03  读取的值应为0x11aprintf("PHY9_YT8521 id = 0x%x\n", id);printf("Setting PHY2\n");Srv_Yt8521_Soft_I2c_Device_Write(2,PHY2_YT8521_ADDR, PHY_YT8521_REG_DEBUG_ADDR_OFFSET, PHY_YT8521_EXT_REG_ADDR);Srv_Yt8521_Soft_I2c_Device_Write(2,PHY2_YT8521_ADDR, PHY_YT8521_REG_DEBUG_DATA,0x604);printf("Setting PHY3\n");Srv_Yt8521_Soft_I2c_Device_Write(3,PHY3_YT8521_ADDR, PHY_YT8521_REG_DEBUG_ADDR_OFFSET, PHY_YT8521_EXT_REG_ADDR);Srv_Yt8521_Soft_I2c_Device_Write(3,PHY3_YT8521_ADDR, PHY_YT8521_REG_DEBUG_DATA,0x604);printf("Setting PHY5\n");Srv_Yt8521_Soft_I2c_Device_Write(5,PHY5_YT8521_ADDR, PHY_YT8521_REG_DEBUG_ADDR_OFFSET, PHY_YT8521_EXT_REG_ADDR);Srv_Yt8521_Soft_I2c_Device_Write(5,PHY5_YT8521_ADDR, PHY_YT8521_REG_DEBUG_DATA,0x604);printf("Setting PHY6\n");Srv_Yt8521_Soft_I2c_Device_Write(6,PHY6_YT8521_ADDR, PHY_YT8521_REG_DEBUG_ADDR_OFFSET, PHY_YT8521_EXT_REG_ADDR);Srv_Yt8521_Soft_I2c_Device_Write(6,PHY6_YT8521_ADDR, PHY_YT8521_REG_DEBUG_DATA,0x604);printf("Setting PHY7\n");Srv_Yt8521_Soft_I2c_Device_Write(7,PHY7_YT8521_ADDR, PHY_YT8521_REG_DEBUG_ADDR_OFFSET, PHY_YT8521_EXT_REG_ADDR);Srv_Yt8521_Soft_I2c_Device_Write(7,PHY7_YT8521_ADDR, PHY_YT8521_REG_DEBUG_DATA,0x604);printf("Setting PHY8\n");Srv_Yt8521_Soft_I2c_Device_Write(8,PHY8_YT8521_ADDR, PHY_YT8521_REG_DEBUG_ADDR_OFFSET, PHY_YT8521_EXT_REG_ADDR);Srv_Yt8521_Soft_I2c_Device_Write(8,PHY8_YT8521_ADDR, PHY_YT8521_REG_DEBUG_DATA,0x604);printf("Setting PHY9\n");Srv_Yt8521_Soft_I2c_Device_Write(9,PHY9_YT8521_ADDR, PHY_YT8521_REG_DEBUG_ADDR_OFFSET, PHY_YT8521_EXT_REG_ADDR);Srv_Yt8521_Soft_I2c_Device_Write(9,PHY9_YT8521_ADDR, PHY_YT8521_REG_DEBUG_DATA,0x604);
#endifreturn 0;
}

5、测试验证

读取裕太8521的PHY ID