communication with i2c client

Hi,
I've create an i2c client and my questions is how to access it from use=
rspace=2E This client is sitttng on adapter that  I was able to access =
via /dev interface=2E After the client were successfuly loaded and dete=
cted,
ioctl(fd,I2C_SLAVE,=2E=2E=2E) and read/write functions didn't work and =
 error messages like "device busy" or "ioctl error" have occured=2E Als=
o my debug messages from i2c client didn't arise when I am accessing=20
device only adapter's=2E
How to (standardly) access a an i2c client?=20
Do I need to create an ioctl interface or exports some helper function =
for access it from user space and also from kernel space? =20

regards,
Ladislav=2E