Subject: Re: SMBus implementation
To: Jason Thorpe <>
From: Jared D. McNeill <>
List: tech-kern
Date: 10/30/2005 18:24:37
On Wed, 2005-10-26 at 21:53 -0700, Jason Thorpe wrote:
> On Oct 25, 2005, at 4:07 PM, Jared D. McNeill wrote:
> > So I was bored, and decided to whip up some SMBus support code.  
> > Feedback
> > would be great.
> "Try again."  :-)
> This needs to be done within the context of sys/dev/i2c (which  
> already has support for doing smbus operations with "regular" I2C  
> interfaces).  If it doesn't integrate with the existing I2C  
> framework, it's a non-starter.

Here's an updated patch that attaches 'smbus' to 'iic', and 'iic' to the
host controller:

Boot messages:
  viapcib0 at pci0 dev 17 function 0
  viapcib0: VIA Technologies VT8235 (Apollo KT400) PCI-ISA Bridge (rev.
  viapcib0: SMBus found at 0xe800 (revision 0x0)
  iic0 at viapcib0: I2C bus
  smbus0 at iic0: SMBus controller

Not all smbus commands are implemented yet, but most are. There's still
no support for attaching devices to smbus; I'll be working on the direct
config goo over the next little bit (juggling between this, an audio
driver I'm working on, and real life).

> There should not be /dev/smb* device nodes, IMO.

Still there for now, but it will die eventually :)