CONTIKI下CC2538 i2c回环测试的问题

[zhou286]

各位前辈前天做了一个CC2538往Contiki-OS下的i2c驱动移植，有TI的例程，按说例程怎么配置寄存器我就怎么配置，只是换了一个编程风格写寄存器而已。但是运行起来收不到发出的数据。之后一行一行的对照着例程查错误，并没有查出错误，实属无奈，现在贴出来，请大家帮忙。
下面是我的代码

/**
 * \file
 *         A very simple Contiki application about i2c
 */

#include "contiki.h"
#include "shell.h"
#include <stdio.h>              /* For printf() */
#include <string.h>
#include "sys/clock.h"
#include "dev/i2c.h"
#include "dev/serial-line.h"
#include "dev/sys-ctrl.h"
#include "dev/gpio.h"
#include "dev/ioc.h"
/*---------------------------------------------------------------------------*/
PROCESS(shell_i2c_process, "i2c");
SHELL_COMMAND(i2c_command,
              "i2c",
              "i2c: will start i2c test",
              &shell_i2c_process);
/*---------------------------------------------------------------------------*/
#define END '\n'
#define BUFSIZE 128
#define SLAVE_ADDRESS 0x3C

#if (BUFSIZE & (BUFSIZE - 1) != 0)
#error UART_BUFSIZE must be a power of two
#error Chang UART_BUFSIZE
#endif

int my_i2c_input(unsigned char c);
void i2c_loop_init(void);
void i2c_init(void);
void echo_m_stat(void);
void echo_s_stat(void);
char *txbuf;

void master_slave_loopback_test(void *);
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(shell_i2c_process, ev, data)
{
  PROCESS_BEGIN();

  printf("Enter a string for I2C test \n");
  while (1) {
	PROCESS_WAIT_EVENT_UNTIL(ev == serial_line_event_message && data != NULL);
	master_slave_loopback_test(data);
	printf("end of transmission\n");
  }

  PROCESS_END();
}
/*---------------------------------------------------------------------------*/
void
shell_i2c_init(void)
{
  shell_register_command(&i2c_command);
}
/*---------------------------------------------------------------------------*/
void
i2c_loop_init(void)
{
  /* Enable clock for the I2C while Running */
  REG(SYS_CTRL_RCGCI2C) = 1;

  /* RESET of I2C module */
  REG(SYS_CTRL_SRI2C) = 1;

  GPIO_SET_INPUT(GPIO_PORT_TO_BASE(CC2538_I2C_SCL_PORT_NUM), GPIO_PIN_MASK(CC2538_I2C_SCL_PIN_NUM));
  GPIO_SET_INPUT(GPIO_PORT_TO_BASE(CC2538_I2C_SDA_PORT_NUM), GPIO_PIN_MASK(CC2538_I2C_SDA_PIN_NUM));
  /* Put all the I2C gpios into peripheral mode */
  GPIO_PERIPHERAL_CONTROL(GPIO_PORT_TO_BASE(CC2538_I2C_SCL_PORT_NUM), GPIO_PIN_MASK(CC2538_I2C_SCL_PIN_NUM));
  GPIO_PERIPHERAL_CONTROL(GPIO_PORT_TO_BASE(CC2538_I2C_SDA_PORT_NUM), GPIO_PIN_MASK(CC2538_I2C_SDA_PIN_NUM));
  /* Disable any pull ups or the like */
  ioc_set_over(CC2538_I2C_SCL_PORT_NUM, CC2538_I2C_SCL_PIN_NUM, IOC_OVERRIDE_DIS);
  ioc_set_over(CC2538_I2C_SDA_PORT_NUM, CC2538_I2C_SDA_PIN_NUM, IOC_OVERRIDE_DIS);
  
  /* Set the mux correctly to connect the I2C pins to the correct GPIO pins */
  /* input */
  REG(IOC_I2CMSSCL) = (CC2538_I2C_SCL_PORT_NUM << 3) + CC2538_I2C_SCL_PIN_NUM;
  REG(IOC_I2CMSSDA) = (CC2538_I2C_SDA_PORT_NUM << 3) + CC2538_I2C_SDA_PIN_NUM;
  /* output */
  ioc_set_sel(CC2538_I2C_SCL_PORT_NUM, CC2538_I2C_SCL_PIN_NUM, IOC_PXX_SEL_I2C_CMSSCL);
  ioc_set_sel(CC2538_I2C_SDA_PORT_NUM, CC2538_I2C_SDA_PIN_NUM, IOC_PXX_SEL_I2C_CMSSDA);
  
  /* enable LOOP */
  REG(I2CM_CR) |= I2CM_CR_LPBK;
  
  /* enable master mode */
  REG(I2CM_CR) |= I2CM_CR_MFE;    
  
  /* Configure the SCL 100Kbps */
  REG(I2CM_TPR) = 7;
  
  /* enable slave mode*/
  REG(I2CM_CR) |= I2CM_CR_SFE;
  REG(I2CS_CTRL) = I2CS_CTRL_DA;
  /* set slave own address */
  REG(I2CS_OAR) = SLAVE_ADDRESS;
  /* Tell the master module what address it will place on the bus */
  REG(I2CM_SA) = (SLAVE_ADDRESS << 1) | 0;
}
/*---------------------------------------------------------------------------*/
void
master_slave_loopback_test(void *data)
{
  static int i, j;
  static char *txbuf;
  static char rxbuf[128] = "";


  
  txbuf = (char *)data;
  i2c_loop_init();
  printf("\n\n\nI2C Loopback Example ->\n");
  printf("  Module = I2C\r\n");
  printf("  Mode = Single Send/Receive\n");
  printf("  Rate = 100kbps\n");
  printf("\nTranferring from: Master -> Slave\n");
  for (i = 0; i < strlen(txbuf); i++) {
	printf("  Sending: %c . . .", txbuf[i]);
	flush();
	/*send 1 byte*/
	REG(I2CM_DR) = txbuf[i];
	/* 发送命令让数据发出 */
	REG(I2CM_CTRL) = I2C_MASTER_CMD_SINGLE_SEND;
    /* 如果收到数据,从机拉低数据线拖延主机,如果没有收到,则等待 */
    while(!REG(I2CS_STAT) & I2C_SLAVE_ACT_RREQ)
      echo_s_stat();	
    rxbuf[i] = REG(I2CS_DR);
	printf("%c\n", rxbuf[i]);
  }
  printf("receive string: %s\n", rxbuf);
}
/*-------------------------------------------------------- */
void
echo_m_stat(void)
{
  static int stat;

  printf("master stat: \n");
  stat = REG(I2CM_STAT);
    if (stat & I2CM_STAT_BUSY) {
      printf("i2c_busy\n");
      return;
    }
  if (stat & I2CM_STAT_ERROR)
    printf("has error\n");
  if (stat & I2CM_STAT_BUSBSY)
    printf("i2c_bus_busy\n");
  if (stat & I2CM_STAT_IDLE)
    printf("i2c_idle\n");
  if (stat & I2CM_STAT_ARBLST)
    printf("lost arblst\n");
  if (stat & I2CM_STAT_DATACK)
    printf("send data not rev ack\n");
  if (stat & I2CM_STAT_ADRACK)
    printf("send address not rev ack\n");
}
/* ------------------------------------------------------- */
void
echo_s_stat(void)
{
  static int stat;

  printf("slave stat: \n");
  stat = REG(I2CS_STAT);
  if (stat & I2C_SLAVE_ACT_RREQ) {
    printf("master has sent data\n");
	if (stat & I2C_SLAVE_ACT_RREQ_FBR)
      printf("master has sent first byte\n");
}
  if (stat & I2C_SLAVE_ACT_TREQ)
    printf("mast has requested data\n");
}

[zhou286]

问题找到了，把重启I2C模块功能去掉就好了，但是不知道为什么不能重启。

  
  /* RESET of I2C module */
  REG(SYS_CTRL_SRI2C) = 1;