ioctl problem with i2c driver on Epia board

Apr 21, 2005 0 Replies

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 :



0500-0507 : viapro-smbus

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 !),


| -°) We are MicroSoft. You will be assimilated. (°- | | /\\ Resistance is futile. (Attributed to B.G., Gill //\ | | _\_v Bates) v_/_ |

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