omap3 i2c speed / method

I do have a question regarding I2C. I am using Omap3530 and access several I2C devices.

It is working but terrible slow. For a write and read back it will take around 0.5ms. Kernel is configured for 400kHz

I build a kernel driver and did there

    i2cdev3=i2c_get_adapter(3); // aquire interface

and uses this routines:

.int i2cw8(struct i2c_adapter *dev,unsigned char i2cadr,unsigned char addr,unsigned char dat)
{
    int ret_val;
    if (down_interruptible(&mutex))
        ;

    msg->addr=i2cadr;
    msg->flags=0;
    msg->len=2;                //number of bytes + 1
    msg->buf=data;
    data[0]=addr;
    data[1]=dat;
    ret_val=i2c_transfer(dev,msg,1);
     up(&mutex);
     return 0;
}

unsigned char i2cr8(struct i2c_adapter *dev,unsigned char i2cadr,unsigned char addr)
{
    unsigned char ret_val;
    if (down_interruptible(&mutex))
        ;

    msg[0].addr=i2cadr;
    msg[0].flags=0;
    msg[0].len=1;                //just the address
    msg[0].buf=data;
    data[0]=addr;

    msg[1].addr=i2cadr;
    msg[1].flags=I2C_M_RD;
    msg[1].len=1;                //number of bytes
    msg[1].buf=data;
   
    i2c_transfer(dev,msg,2);
    ret_val = data[0];
    up(&mutex);
    return ret_val;
}

Is there a better/faster way ?

Best regards

Arno