ioctl problem with i2c driver on Epia board

Hi everyone,

We are trying to use the I2C bus (for custom application, not standard sensors) on a Via Epia M 10000 board (i2c chipset vt8235). We use a 2.4.27 Linux kernel (without i2c support), with i2c-2.9.1 and lm_sensors-2.9.1 (version 2.8.8 was tested too) compiled as modules, independently from kernel, with the uClibc toolchain we use in the target system (standard glibc was tested too). The development system has a 2.6 kernel, but we took care of choosing the right includes for the modules compilation.

We use the drivers exactly as showed in "i2c-2.9.1/doc/dev-interface" and have the following problems :

-> the ioctl (both I2C_FUNCS and I2C_SLAVE) return "Invalid argument".

-> when we try "cat /dev/i2c-0", the following message is written : i2c-core.o: I2C adapter 40002: I2C level transfers not supported /dev/i2c-0: Function not implemented

The first line of this error message is printed from the function "i2c_master_send" in i2c-core.c

-> but most things appear to work, as shown below :

- the modules compile correctly, are correctly inserted with insmod :

-the i2c-viapro module is correctly registered by the i2c-dev module

-as an adapter (address 0500, minor 0). The entry in /proc/bus/i2c

-shows :

i2c-0 smbus SMBus Via Pro adapter at 0500 Non-I2C SMBus adapter

By the way, we suppose that the "non-I2C adapter" means that i2c_send* functions are not available, which would explain the error message from the "cat /dev/i2c-0". But the ioctl error remains, and that even if we choose to use the i2c_smbus* functions.

- the "open" call on "/dev/i2c-0" apparently succeeds, and while the program is running, lsmod shows that i2c-dev and i2c-viapro are used by the program.

- the proc entry in /proc/bus/i2c-0 is empty, but this is normal since we use custom modules and not existing devices

- the command "cat /proc/ioports" shows the following entry, which appears to be right :

So, did any of you have a similar problem, and a solution, or at least ideas to investigate ? Thanks in advance (for you quick replies, since we are quite in a hurry !),