One Wire

Evgeniy Polyakov johnpol at 2ka.mipt.ru
Mon Jan 31 18:40:05 CET 2005


On Mon, 31 Jan 2005 11:06:56 -0600
Frank Beesley <frank.beesley at aeroflex.com> wrote:

> Evgeniy Polyakov wrote:
> 
> >On Mon, 31 Jan 2005 17:11:06 +0100 (CET)
> >"Jean Delvare" <khali at linux-fr.org> wrote:
> >
> >  
> >
> >>Hi Frank,
> >>
> >>    
> >>
> >>>I am now looking at the one-wire drivers and see some issues coming up
> >>>already. Our one-wire devices (DS2401s and DS18B20s) are connected
> >>>through a CPLD at ISA port 0x304. I am looking at the matrox driver
> >>>since it has a port to access through. Under the linux documentation
> >>>(Linux 2.6.9) I can't find anything on one-wire devices. Is there some
> >>>docs somewhere that discusses how to use these w1 modules. I believe I
> >>>need w1 and w1_therm to start with but I don't see how everything needs
> >>>to tie together.
> >>>      
> >>>
> >>I as said, Evgeniy Polyakov (CC'd) is the right person for that kind of
> >>questions. My personal knowledge about one-wire is void.
> >>    
> >>
> >
> >Hello, Frank, Jean.
> >
> >ds2401 and ds18*20 are supported by w1_smem and w1_therm drivers.
> >So you need to create so called w1 bus master device - it is a driver
> >that drives the actual physicall bus and reports to the w1 core
> >about this process. Actually it is w1 core that drives the bus using
> >callbaks provided by w1 bus master driver.
> >
> >Since you use ISA port based access then the easiest way is to implement
> >only bit operations and register bus master with the w1 core.
> >
> >You can use matrox_w1 driver and recently included sc_w1 driver(w1 over SuperIO GPIO)
> >driver as examples.
> >
> >Documenting all created cruft has a very high priority for me, bits of
> >generic information about w1 already exist in Documentation/w1.
> >
> >I wish you success in this implementation.
> >
> >  
> >
> Ok, now I feel stupid or blind but I can't find a directory under 
> Documentation called w1 and a "find" does not find sc_w1.c or sw_gpio.c. 
> I currently have kernel 2.6.9 but also looked at the standard 2.6.10 
> download. Is the superio and documentation in an individuals patch set 
> or am I missing something.

superio has appeared in the latest -mm patchset.
w1 documentation a bit earlier - it exists in the 2.6.11-rc2 patchset.

> Thanks again.


	Evgeniy Polyakov

Only failure makes us experts. -- Theo de Raadt



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