static irqreturn_t s3c6410_i2c_xfer_irq(int irq, void *dev_id)
{
unsigned char byte;
unsigned long tmp;
unsigned int iicSt = readl(s3c6410_i2c_xfer_data.regs + S3C2410_IICSTAT);
//iicSt = s3c6410_i2c_regs->iicstat;
if(iicSt & S3C2410_IICSTAT_ARBITR)
printk("Bus arbitration failed\n\r");
switch (s3c6410_i2c_xfer_data.state) {
case STATE_START : /* 发出S和设备地址后,产生中断 */
{
AT24CXX_DBG("Start\n");
/* 如果没有ACK, 返回错误 */
if (iicSt & S3C2410_IICSTAT_LASTBIT) {
s3c6410_i2c_stop(-ENODEV);
break;
}
if (isLastMsg() && isEndData()) {
s3c6410_i2c_stop(0);
break;
}
/* 进入下一个状态 */
if (s3c6410_i2c_xfer_data.msgs->flags & I2C_M_RD) { /* 读 */
s3c6410_i2c_xfer_data.state = STATE_READ;
goto next_read;
}else {
s3c6410_i2c_xfer_data.state = STATE_WRITE;
}
}
case STATE_WRITE: {
AT24CXX_DBG("STATE_WRITE\n");
/* 如果没有ACK, 返回错误 */
if (iicSt & S3C2410_IICSTAT_LASTBIT) {
s3c6410_i2c_stop(-ENODEV);
break;
}
if (!isEndData()) { /* 如果当前msg还有数据要发送 */
byte = s3c6410_i2c_xfer_data.msgs->buf[s3c6410_i2c_xfer_data.cur_ptr];
writeb(byte, s3c6410_i2c_xfer_data.regs + S3C2410_IICDS);
//s3c6410_i2c_regs->iicds = s3c6410_i2c_xfer_data.msgs->buf[s3c6410_i2c_xfer_data.cur_ptr];
s3c6410_i2c_xfer_data.cur_ptr++;
// 将数据写入IICDS后，需要一段时间才能出现在SDA线上
ndelay(50);
tmp = readl(s3c6410_i2c_xfer_data.regs + S3C2410_IICCON);
/* tmp = 0xaf */
tmp = S3C2410_IICCON_ACKEN | S3C2410_IICCON_TXDIV_16 | S3C2410_IICCON_IRQEN | S3C2410_IICCON_SCALEMASK;
writel(tmp, s3c6410_i2c_xfer_data.regs + S3C2410_IICCON);
//s3c6410_i2c_regs->iiccon = 0xaf; // 恢复I2C传输
break;
}else if (!isLastMsg()) {
/* 开始处理下一个消息 */
s3c6410_i2c_xfer_data.msgs++;
s3c6410_i2c_xfer_data.cur_msg++;
s3c6410_i2c_xfer_data.cur_ptr = 0;
s3c6410_i2c_xfer_data.state = STATE_START;
/* 发出START信号和发出设备地址 */
s3c6410_i2c_start();
break;
}else {
/* 是最后一个消息的最后一个数据 */
s3c6410_i2c_stop(0);
break;
}
break;
}
case STATE_READ: {
AT24CXX_DBG("STATE_READ\n");
/* 读出数据 */
//s3c6410_i2c_xfer_data.msgs->buf[s3c6410_i2c_xfer_data.cur_ptr] = s3c6410_i2c_regs->iicds;
byte = readb(s3c6410_i2c_xfer_data.regs + S3C2410_IICDS);
s3c6410_i2c_xfer_data.msgs->buf[s3c6410_i2c_xfer_data.cur_ptr] = byte;
s3c6410_i2c_xfer_data.cur_ptr++;
next_read:
if (!isEndData()) { /* 如果数据没读写, 继续发起读操作 */
if (isLastData()) { /* 如果即将读的数据是最后一个, 不发ack */
tmp = readl(s3c6410_i2c_xfer_data.regs + S3C2410_IICCON);
/* tmp = 0x2f */
tmp = S3C2410_IICCON_IRQEN | S3C2410_IICCON_SCALEMASK;
writel(tmp, s3c6410_i2c_xfer_data.regs + S3C2410_IICCON);
//s3c6410_i2c_regs->iiccon = 0x2f; // 恢复I2C传输，接收到下一数据时无ACK
}else {
tmp = readl(s3c6410_i2c_xfer_data.regs + S3C2410_IICCON);
/* tmp = 0xaf */
tmp = S3C2410_IICCON_ACKEN | S3C2410_IICCON_TXDIV_16 | S3C2410_IICCON_IRQEN | S3C2410_IICCON_SCALEMASK;
writel(tmp, s3c6410_i2c_xfer_data.regs + S3C2410_IICCON);
//s3c6410_i2c_regs->iiccon = 0xaf; // 恢复I2C传输，接收到下一数据时发出ACK
}
break;
}else if (!isLastMsg()) {
/* 开始处理下一个消息 */
s3c6410_i2c_xfer_data.msgs++;
s3c6410_i2c_xfer_data.cur_msg++;
s3c6410_i2c_xfer_data.cur_ptr = 0;
s3c6410_i2c_xfer_data.state = STATE_START;
/* 发出START信号和发出设备地址 */
s3c6410_i2c_start();
break;
}else {
/* 是最后一个消息的最后一个数据 */
s3c6410_i2c_stop(0);
break;
}
break;
}
default: break;
}
/* 清中断 */
tmp = readl(s3c6410_i2c_xfer_data.regs + S3C2410_IICCON);
writel(tmp & ~(S3C2410_IICCON_IRQPEND), s3c6410_i2c_xfer_data.regs + S3C2410_IICCON);
//s3c6410_i2c_regs->iiccon &= ~(S3C2410_IICCON_IRQPEND);
return IRQ_HANDLED;
}
static irqreturn_t s3c2440_i2c_xfer_irq(int irq, void *dev_id)
{
unsigned int iicst;
iicst = s3c2440_i2c_regs->iicstat;
if(iicst & 0x08){printk("s3c2440 i2c Bus arbitration failed\n\r");}
switch(s3c2440_i2c_xfer_data.state)
{
case STATE_START: //发出START和设备地址后产生中断
{
//如果没有ACK，返回错误
if (iicst & S3C2410_IICSTAT_LASTBIT)
{
s3c2440_i2c_stop(-ENODEV);
break;
}
if(isLastMsg() && isEndData())
{
s3c2440_i2c_stop(0);
break;
}
//进入下一个状态
if(s3c2440_i2c_xfer_data.msgs->flags & I2C_M_RD) //read
{
s3c2440_i2c_xfer_data.state = STATE_READ;
goto next_read;
}
else
{
s3c2440_i2c_xfer_data.state = STATE_WRITE;
}
}
case STATE_WRITE:
{
//如果没有ACK，返回错误
if (iicst & S3C2410_IICSTAT_LASTBIT)
{
s3c2440_i2c_stop(-ENODEV);
break;
}
if(!isEndData()) //如果当前msg还有数据要发送
{
s3c2440_i2c_regs->iicds = s3c2440_i2c_xfer_data.msgs->buf[s3c2440_i2c_xfer_data.cur_ptr];
s3c2440_i2c_xfer_data.cur_ptr++;
ndelay(50);
s3c2440_i2c_regs->iiccon = 0xaf; //恢复I2C传输
break;
}
else if(!isLastMsg())
{
//开始处理下一个消息
s3c2440_i2c_xfer_data.msgs++;
s3c2440_i2c_xfer_data.cur_msg++;
s3c2440_i2c_xfer_data.cur_ptr=0;
s3c2440_i2c_xfer_data.state = STATE_START;
//发出START信号和发出设备地址
s3c2440_i2c_start();
break;
}
else
{
//如果是最后一个消息的最后一个数据
s3c2440_i2c_stop(0);
break;
}
break;
}
case STATE_READ:
{
//读出数据
s3c2440_i2c_xfer_data.msgs->buf[s3c2440_i2c_xfer_data.cur_ptr] = s3c2440_i2c_regs->iicds;
s3c2440_i2c_xfer_data.cur_ptr++;
next_read:
if(!isEndData())
{
//如果数据没读完，继续发起读操作
if(isLastData()) //如果即将读的数据是最后一个，那么不发ACK
{
s3c2440_i2c_regs->iiccon = 0x2f;
}
else
{
s3c2440_i2c_regs->iiccon = 0xaf;
}
break;
}
else if(!isLastMsg())
{
//开始处理下一个消息
s3c2440_i2c_xfer_data.msgs++;
s3c2440_i2c_xfer_data.cur_msg++;
s3c2440_i2c_xfer_data.cur_ptr=0;
s3c2440_i2c_xfer_data.state = STATE_START;
//发出START信号和发出设备地址
s3c2440_i2c_start();
break;
}
else
{
//如果是最后一个消息的最后一个数据
s3c2440_i2c_stop(0);
break;
}
break;
}
default: break;
}
//清中断
s3c2440_i2c_regs->iiccon &= ~(S3C2410_IICCON_IRQPEND);
return IRQ_HANDLED;
}