New nfpm.c driver available for testing

Ruslan Ermilov ru at
Mon Dec 19 08:32:29 PST 2005

On Mon, Dec 19, 2005 at 10:59:43AM +1300, Philip Murray wrote:
> This is on a Dual Dual-Core Opteron 275 on a Tyan S2882-D motherboard  
> w/ 4GB of RAM running -amd64
I have the same motherboard.

> root at stratos# dmesg | grep nf
> nfpm0: <AMD-8111 SMBus 2.0 Controller> port 0xcc00-0xcc1f irq 19 at  
> device 7.2 on pci0
> smbus0: <System Management Bus> on nfpm0
I figured that AMD-8111 uses an EC-based SMBus register access, so
I've split the drivers into two: amdsmb(4) supports AMD-8111 SMBus
2.0 controller which uses EC to read/write SMBus registers, and
nfsmb(4) supports NVIDIA nForce-2/3/4 MCP twin SMBus 2.0 controller
that appears to use an I/O based access to SMBus registers.

Recompile everything in /sys/modules/i2c/ (create two directories,
controllers/amdsmb and controllers/nfsmb before applying a patch).

Check with smbtest:

  a) on nForce:
	smbtest /dev/smb0
	smbtest /dev/smb1
  b) on AMD-8111:

All smbtest commands should include "slave 8" device which is
the SMBus Host device.  If it didn't find any more devices, it
means that you now have a working SMBus bus, which it otherwise
useless on your system.  It if detects some other devices,
chances are that some of them are xmbmon recognizeable sensors.

Make sure you compile the latest sysutils/xmbmon port which has
smb(4) support ("mbmon" should have the -s option (lowercase ell)).

Substitute your PCI ID in xmbmon's pci_pm.h (see my original
post that explains this in more detail).

On nForce2/3/4, run mbmon -S -s0 -d and mbmon -S -s1 -d.
On AMD-8111, run mbmon -S -d.

You may also want to s/-d/-D/ to verify it finds devices
attached to SMBus, it's similar to smbtest.  If it finds any
known sensors (my systems don't have them), you can run
mbmon -S -s[01] -c8 1 to display eight probes with a one
second interval.

P.S.  I don't know how useful all of this is, since my systems
don't seem to have any sensors attached to SMBus 2.0 busses.

Ruslan Ermilov
ru at
FreeBSD committer
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