pcf8591 boot time parameters

pcf8591 boot time parameters

[Karel Kulhavy]

Is it possible to configure pcf8591 driver using boot time commandline
parameters? 

If yes, where are they described? I didn't find it. (<Help> doesn't say
anything).  also /linux-2.6.10/Documentation/i2c$ fgrep PCF * didn't reveal
anything related.

I only found documentation for module parameters by means of modinfo pcf8591

Cl<

Re: pcf8591 boot time parameters

[Randy.Dunlap]

Karel Kulhavy wrote:
> Is it possible to configure pcf8591 driver using boot time commandline
> parameters? 
> 
> If yes, where are they described? I didn't find it. (<Help> doesn't say
> anything).  also /linux-2.6.10/Documentation/i2c$ fgrep PCF * didn't reveal
> anything related.
> 
> I only found documentation for module parameters by means of modinfo pcf8591

and what did it tell you?  I see (when built as a loadable module,\
but they are still valid when built in-kernel):

parm:           force:List of adapter,address pairs to boldly assume 
to be present
parm:           force_pcf8591:List of adapter,address pairs which are 
unquestionably assumed to contain a `pcf8591' chip
parm:           probe:List of adapter,address pairs to scan additionally
parm:           ignore:List of adapter,address pairs not to scan
parm:           input_mode:Analog input mode:
  0 = four single ended inputs
  1 = three differential inputs
  2 = single ended and differential mixed
  3 = two differential inputs


It seems that there is a list of i2c client parameters in
Documentation/i2c/writing-clients .

I don't know i2c, but any driver that #includes
linux/i2c.h has defined for it these parameters:
   probe, probe_range
   ignore, ignore_range
   force

and any driver that #includes linux/i2c-sensor.h
has defined for it these parameters:
   force_<driver_basename>
   probe
   ignore
   force

but it would be better for someone who is familiar with those
twisted macros to document all of this.

-- 
~Randy