libi2c device probing capability

Alexandru-Sever Horin alex.sever.h at
Wed Apr 1 14:31:56 UTC 2015


I am currently working on a project which uses I2C devices through libi2c

The problem that I am facing is that this function:
rtems_libi2c_register_drv actually registeres the device before
drvtbl->ops->initialization_entry returns success or failure. This means
that it is impossible to probe a device which might be at 2 different I2C
addreses on different PCB revisions.

For a device driver with no initialization function it should make no
difference, the function call being ignored, and the minor being returned.
If the device driver has a initialization function, it calls it and makes
sure that the return value is 0 before registering the name. If it returns
something different than RTEMS_SUCCESS, it makes sure the driver
registration returns negative error code (so it's not mistaken with minor
number), and does not register the device driver.

I have attached a patch to solve this problem, and bypass device
registration in the filesystem if the initialziation fails.
Please review the changes and merge if you agree.

Thank you,
Alex H.
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