Re: [Xenomai-help] Problem accesing I2C without using Linux kernel

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

On 06/19/2011 04:21 PM, Andrey Nechypurenko wrote:
>>> The module works. I think kernel configured it properly because I can
>>> use user space utility for example i2cdetect and see my sensors
>>> detected on the bus. At the moment where I was trying to read the
>>> status I did not made any reconfiguration before. So my assumption was
>>> that the module is already configured properly and at least an attempt
>>> to read the status should succede.
>>
>> To be sure of that, you would have to be sure that the clocks are not
>> disabled when the device is not opened. To check this, either check the
>> kernel sources, or try and open the i2c device, and keep it open before
>> you mmap /dev/mem
> 
> Just tried your suggestion but unfortunately it does not change enything.
> 

There may be (at least) two possible reasons:
- the clocks are disabled, you need to check the kernel source to know
if that is the case;
- or the compiler generated a byte access to the 32 bits register, not
knowing the alignment of mmap return value, you need to send the
disassembly as I requested to know if that is the case.

-- 
                                                                Gilles.