DM642 I2C通用读写源代码

参考了各家的I2C源代码，均发现有不足之处，经过一周时间的学习，搞了个通用的I2C读写代码，抛砖引玉一下。

#include <csl_i2c.h>
#include <stdio.h>

I2C_Handle g_I2C_Handle; // I2C 全局句柄

Bool I2C_Initialize(void)
{
g_I2C_Handle = I2C_open(I2C_PORT0,I2C_OPEN_RESET);

if(g_I2C_Handle == INV)
{
return FALSE;
}
else
{
I2C_outOfReset(g_I2C_Handle); // 允许I2C总线

I2C_RSETH(g_I2C_Handle, I2CPSC, 0x0E); // I2C模块时钟设置为10M 150M/15
//I2C_RSETH(g_I2C_Handle, I2CCLKL, 0x2D); // 设置I2C外部时钟为100K
//I2C_RSETH(g_I2C_Handle, I2CCLKH, 0x2D); // 设置I2C外部时钟为100K
//I2C_RSETH(g_I2C_Handle, I2CCLKL, 0x500); // 设置I2C外部时钟为100K
//I2C_RSETH(g_I2C_Handle, I2CCLKH, 0x500); // 设置I2C外部时钟为100K
I2C_RSETH(g_I2C_Handle, I2CCLKL, 0x300); // 设置I2C外部时钟为100K
I2C_RSETH(g_I2C_Handle, I2CCLKH, 0x300); // 设置I2C外部时钟为100K

return TRUE;
}
}

Uint8 I2C_Write(Uint8 dev_addr, Uint8 *sub_addr, Uint8 sub_addr_len, Uint8 *write_buffer, Uint8 write_len)
{
Uint8 bResult = 0;
Uint32 I2CState;

I2C_Config prevI2CCfg;

if(write_len == 0)
{
return 0;
}

while (I2C_bb(g_I2C_Handle));

I2C_getConfig(g_I2C_Handle, &prevI2CCfg);

// clear all interrupt state
I2C_FSETH(g_I2C_Handle, I2CSTR, AL, 1);
I2C_FSETH(g_I2C_Handle, I2CSTR, NACK, 1);
I2C_FSETH(g_I2C_Handle, I2CSTR, ARDY, 1);
I2C_FSETH(g_I2C_Handle, I2CSTR, ICRRDY, 1);
I2C_FSETH(g_I2C_Handle, I2CSTR, ICXRDY, 1);

I2C_RSETH(g_I2C_Handle, I2COAR, 0);
I2C_RSETH(g_I2C_Handle, I2CIER, 0);
I2C_RSETH(g_I2C_Handle, I2CCNT, 0);
I2C_RSETH(g_I2C_Handle, I2CSAR, dev_addr);

I2C_RSETH(g_I2C_Handle, I2CMDR, 0x26A0);

// wait send start condition
while(I2C_FGETH(g_I2C_Handle, I2CMDR, STT));

while(1)
{
I2CState = I2C_RGETH(g_I2C_Handle, I2CSTR);

if(I2CState & 0x01)
{
// Arbitration lost
// clear AL state in I2C Status Register
I2C_FSETH(g_I2C_Handle, I2CSTR, AL, 1);
break;
}

if(I2CState & 0x04)
{ // ARDY == 1
if(I2CState & 0x02)
{ // NACK == 1
// clear NACK state in I2C Status Register
I2C_FSETH(g_I2C_Handle, I2CSTR, NACK, 1);
break;
}
else
{
if(I2CState & 0x10)
{ // ICXRDY == 1
if(bResult < sub_addr_len)
{
I2C_RSETH(g_I2C_Handle, I2CDXR, sub_addr[bResult]);
bResult ++;
}
else if(bResult < sub_addr_len + write_len)
{
I2C_RSETH(g_I2C_Handle, I2CDXR, write_buffer[bResult - sub_addr_len]);
bResult ++;
}
else
{
break;
}
}
}
}
}

I2C_sendStop(g_I2C_Handle);
//I2C_FSETSH(g_I2C_Handle,I2CMDR,STP,STOP);

while (I2C_bb(g_I2C_Handle));

I2C_config(g_I2C_Handle, &prevI2CCfg);
return (bResult < sub_addr_len) ? 0 : (bResult - sub_addr_len);
}

Uint8 I2C_Read(Uint8 dev_addr, Uint8 *sub_addr, Uint8 sub_addr_len, Uint8 *read_buffer, Uint8 read_len)
{
Uint8 bResult = 0;
Uint32 I2CState;

I2C_Config prevI2CCfg;

if(read_len == 0)
{
return 0;
}

while (I2C_bb(g_I2C_Handle));

I2C_getConfig(g_I2C_Handle, &prevI2CCfg);

// clear all interrupt state
I2C_FSETH(g_I2C_Handle, I2CSTR, AL, 1);
I2C_FSETH(g_I2C_Handle, I2CSTR, NACK, 1);
I2C_FSETH(g_I2C_Handle, I2CSTR, ARDY, 1);
I2C_FSETH(g_I2C_Handle, I2CSTR, ICRRDY, 1);
I2C_FSETH(g_I2C_Handle, I2CSTR, ICXRDY, 1);

// 写子地址
if(sub_addr_len)
{
I2C_RSETH(g_I2C_Handle, I2COAR, 0);
I2C_RSETH(g_I2C_Handle, I2CIER, 0);
I2C_RSETH(g_I2C_Handle, I2CCNT, 0);
I2C_RSETH(g_I2C_Handle, I2CSAR, dev_addr);

I2C_RSETH(g_I2C_Handle, I2CMDR, 0x26A0);

// wait send start condition
while(I2C_FGETH(g_I2C_Handle, I2CMDR, STT));

while(1)
{
I2CState = I2C_RGETH(g_I2C_Handle, I2CSTR);

if(I2CState & 0x01)
{ // Arbitration lost
I2C_FSETH(g_I2C_Handle, I2CSTR, AL, 1);

I2C_sendStop(g_I2C_Handle);
//I2C_FSETSH(g_I2C_Handle,I2CMDR,STP,STOP);

while (I2C_bb(g_I2C_Handle));

I2C_config(g_I2C_Handle, &prevI2CCfg);
return 0;
}

if(I2CState & 0x04)
{ // ARDY == 1
if(I2CState & 0x02)
{ // NACK == 1
I2C_FSETH(g_I2C_Handle, I2CSTR, NACK, 1);

I2C_sendStop(g_I2C_Handle);
//I2C_FSETSH(g_I2C_Handle,I2CMDR,STP,STOP);

while (I2C_bb(g_I2C_Handle));

I2C_config(g_I2C_Handle, &prevI2CCfg);
return 0;
}
else
{
if(I2CState & 0x10)
{ // ICXRDY == 1
if(bResult < sub_addr_len)
{
I2C_RSETH(g_I2C_Handle, I2CDXR, sub_addr[bResult]);
bResult ++;
}
else
{
break;
}
}
}
}
}
}

// 是否需要等待由发送转换为接收重复起始条件

bResult = 0;

I2C_RSETH(g_I2C_Handle, I2COAR, 0);
I2C_RSETH(g_I2C_Handle, I2CIER, 0);
I2C_RSETH(g_I2C_Handle, I2CCNT, 0);
I2C_RSETH(g_I2C_Handle, I2CSAR, dev_addr);

I2C_RSETH(g_I2C_Handle, I2CMDR, 0x24A0);

// wait send start condition
while(I2C_FGETH(g_I2C_Handle, I2CMDR, STT));

while(1)
{
I2CState = I2C_RGETH(g_I2C_Handle, I2CSTR);

if(I2CState & 0x01)
{ // Arbitration lost
I2C_FSETH(g_I2C_Handle, I2CSTR, AL, 1);
break;
}

if(I2CState & 0x04)
{ // ARDY == 1
if(I2CState & 0x02)
{ // NACK == 1
I2C_FSETH(g_I2C_Handle, I2CSTR, NACK, 1);
break;
}
else if(I2CState & 0x2000)
{ // NACKSNT == 1
I2C_FSETH(g_I2C_Handle, I2CSTR, NACKSNT, 1);
break;
}
else
{
if(I2CState & 0x08)
{ // ICRRDY == 1
if(bResult < read_len)
{
read_buffer[bResult] = I2C_RGETH(g_I2C_Handle, I2CDRR);
bResult ++;

if(bResult >= read_len)
{ // 如果收完所有字节则发送NACK
I2C_FSETSH(g_I2C_Handle,I2CMDR,NACKMOD,NACK);
}
}
else
{
I2C_FSETSH(g_I2C_Handle,I2CMDR,NACKMOD,NACK);
I2C_RGETH(g_I2C_Handle, I2CDRR);
}
}
}
}
}

I2C_sendStop(g_I2C_Handle);
//I2C_FSETSH(g_I2C_Handle,I2CMDR,STP,STOP);

while (I2C_bb(g_I2C_Handle));

I2C_config(g_I2C_Handle, &prevI2CCfg);
return bResult;
}

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