287 lines
7.6 KiB
Groff
287 lines
7.6 KiB
Groff
.\" Copyright (c) 2004 Joerg Wunsch
|
|
.\" All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd May 16, 2004
|
|
.Dt SMBMSG 8
|
|
.Os
|
|
.Sh NAME
|
|
.Nm smbmsg
|
|
.Nd "send or receive messages over an SMBus"
|
|
.Sh SYNOPSIS
|
|
.Nm
|
|
.Op Fl f Ar dev
|
|
.Fl p
|
|
.Pp
|
|
.Nm
|
|
.Op Fl f Ar dev
|
|
.Fl s Ar slave
|
|
.Op Fl F Ar fmt
|
|
.Op Fl c Ar cmd
|
|
.Op Fl w
|
|
.Op Fl i Ar incnt
|
|
.Op Fl o Ar outcnt
|
|
.Op Ar outdata ...
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
utility can be used to send or receive messages over an
|
|
SMBus, see
|
|
.Xr smbus 4 .
|
|
.Pp
|
|
The
|
|
.Nm
|
|
utility has two different modi of operation.
|
|
The first form shown in the synopsis can be used to
|
|
.Dq probe
|
|
the devices on the SMBus.
|
|
This is done by sending each valid device address one
|
|
receive byte, and one quick read message, respectively.
|
|
Devices that respond to these requests will be displayed
|
|
by their device address, followed by the strings
|
|
.Ql r ,
|
|
.Ql w ,
|
|
or
|
|
.Ql rw ,
|
|
for devices that are readable, writeable, or both, readable
|
|
and writeable, respectively.
|
|
The only valid additional option for this modus of operation (besides
|
|
the
|
|
.Fl p
|
|
option that chooses the modus) is
|
|
.Fl f Ar dev .
|
|
See below for a description.
|
|
.Pp
|
|
Note that probing the bus is risky, since individual devices could
|
|
perform unwanted actions upon receiving one of the mentioned messages.
|
|
For example, if a particular SMBus device considers
|
|
.Em any
|
|
write operation issued to it as a request to power off the system,
|
|
the probing would trigger this action.
|
|
.Pp
|
|
The second form shown in the synopsis can be used to send or receive
|
|
arbitrary messages to or from individual devices.
|
|
This might be useful to explore individual devices on the SMBus, or
|
|
maybe even to write short shell scripts performing maintenance
|
|
operations on the bus.
|
|
.Pp
|
|
Any data values on the command-line are integer values in the
|
|
range 0 through 255 for byte values, or 0 through 65535 for
|
|
word values.
|
|
They can be specified using standard
|
|
.Ql C
|
|
notation (prefix 0 for octal interpretation, or 0x for
|
|
hexadecimal interpretation).
|
|
.Pp
|
|
Since the low-order bit of the device address of SMBus devices
|
|
selects between read and write operations, only even-numbered
|
|
slave addresses can exist on the bus.
|
|
.Pp
|
|
The options are as follows:
|
|
.Bl -tag -width ".Fl o Ar outcnt"
|
|
.It Fl F Ar fmt
|
|
Specify the
|
|
.Xr printf 3
|
|
format to be used for displaying input data.
|
|
This option is ignored in messages that do not read any input
|
|
from the SMBus device.
|
|
The format defaults to
|
|
.Ql 0x%02x
|
|
for byte input operations, and to
|
|
.Ql 0x%04x
|
|
for word input operations.
|
|
For multi-byte input (block read), the same format is used for
|
|
each individual byte read from the SMBus.
|
|
.It Fl c Ar cmd
|
|
This is the value of the
|
|
.Em command
|
|
byte to be issued as part of the SMBus message.
|
|
.It Fl f Ar dev
|
|
This specifies that
|
|
.Ar dev
|
|
should be used as the connection to the SMBus, rather than the
|
|
default of
|
|
.Pa /dev/smb0 .
|
|
.It Fl i Ar incnt
|
|
An SMBus message should be generated to read
|
|
.Ar incnt
|
|
bytes from the device.
|
|
.It Fl o Ar outcnt
|
|
An SMBus message should be generated to write
|
|
.Ar outcnt
|
|
bytes to the device.
|
|
The data values to write are expected to follow all of the options
|
|
(and their arguments) on the command-line, where the number of data
|
|
bytes must match the
|
|
.Ar outcnt
|
|
value.
|
|
.It Fl p
|
|
This selects the
|
|
.Em probe bus
|
|
modus of operation.
|
|
.It Fl s Ar slave
|
|
The
|
|
.Ar slave
|
|
parameter specifies which SMBus device to connect to.
|
|
This option also selects the
|
|
.Em transfer messages from/to device
|
|
modus of operation, where a slave address is mandatory.
|
|
.It Fl w
|
|
This option specifies that IO operations are word operations,
|
|
rather than byte operations.
|
|
Either
|
|
.Ar incnt ,
|
|
or
|
|
.Ar outcnt
|
|
(or both) must be equal 2 in this case.
|
|
Note that the SMBus byte order is defined to be little-endian
|
|
(low byte first, high byte follows).
|
|
.El
|
|
.Pp
|
|
Not all argument combinations make sense in order to form valid SMBus
|
|
messages.
|
|
If no
|
|
.Fl c Ar cmd
|
|
option has been provided, the following messages can be
|
|
issued:
|
|
.Bd -unfilled -offset indent
|
|
.TS
|
|
l r r.
|
|
\fBmessage incnt outcnt\fR
|
|
quick read 0 \&-
|
|
quick write \&- 0
|
|
receive byte 1 \&-
|
|
send byte \&- 1
|
|
.TE
|
|
.Ed
|
|
.Pp
|
|
Note in particular that specifying 0 as a count value
|
|
has a different meaning than omitting the respective
|
|
option entirely.
|
|
.Pp
|
|
If a command value has been given using the
|
|
.Fl c Ar cmd
|
|
option, the following messages can be generated:
|
|
.Bd -unfilled -offset indent
|
|
.TS
|
|
l l r r.
|
|
\fBmessage \&-w incnt outcnt\fR
|
|
read byte no 1 \&-
|
|
write byte no \&- 1
|
|
read word yes 2 \&-
|
|
write word yes \&- 2
|
|
process call yes 2 2
|
|
block read no \*(Ge 2 \&-
|
|
block write no \&- \*(Ge 2
|
|
.TE
|
|
.Ed
|
|
.Sh FILES
|
|
.Bl -tag -width ".Pa /dev/smb0" -compact
|
|
.It Pa /dev/smb0
|
|
The default device to connect to, unless
|
|
.Fl f Ar dev
|
|
has been provided.
|
|
.El
|
|
.Sh EXIT STATUS
|
|
Exit status is 0 on success, or according to
|
|
.Xr sysexits 3
|
|
in case of failure.
|
|
.Sh EXAMPLES
|
|
Typical usage examples of the
|
|
.Nm
|
|
command include:
|
|
.Pp
|
|
.Dl "smbmsg -f /dev/smb1 -p"
|
|
.Pp
|
|
Probe all devices on the SMBus attached to
|
|
.Pa /dev/smb1 .
|
|
.Pp
|
|
.Dl "smbmsg -s 0x70 -i 1"
|
|
.Pp
|
|
Issue a
|
|
.Em receive byte
|
|
message to the device at address 0x70, and display
|
|
the received byte using the default format.
|
|
.Pp
|
|
.Dl "smbmsg -s 0x70 -c 0xff -i 1 -F %d"
|
|
.Pp
|
|
Issue a
|
|
.Em read byte
|
|
message to the device at slave address 0x70, using
|
|
255 (0xff) as the command-byte to send to the device,
|
|
and display the result using the custom format
|
|
.Ql %d .
|
|
.Pp
|
|
.Dl "smbmsg -s 0xa0 -c 0 -o 1 0x80"
|
|
.Pp
|
|
Send a
|
|
.Em write byte
|
|
message to the slave device at address 0xa0, using
|
|
0 as the command-byte value, and 0x80 as the byte to
|
|
send (after the command).
|
|
Assuming this might be a Philips PCF8583 real-time clock,
|
|
this would stop the clock.
|
|
.Pp
|
|
.Dl "smbmsg -s 0xa0 -c 1 -i 6 -F %02x"
|
|
.Pp
|
|
Send a
|
|
.Em block read
|
|
command to device at address 0xa0, and read 6 bytes from
|
|
it, using hexadecimal display.
|
|
Again, assuming a PCF8583 RTC, this would display the
|
|
fractions of second, seconds, minutes, hours, year/date,
|
|
and weekday/month values.
|
|
Since this RTC uses BCD notation, the actual values displayed
|
|
were decimal then.
|
|
.Pp
|
|
.Dl "smbmsg -s 0xa0 -c 2 -o 5 0x00 0x07 0x22 0x16 0x05"
|
|
.Pp
|
|
Send a
|
|
.Em block write
|
|
command to device at address 0xa0.
|
|
For the PCF8583 RTC, this would set the clock to Sunday (2004%4)-05-16
|
|
22:07:00.
|
|
.Sh DIAGNOSTICS
|
|
Diagnostic messages issued are supposed to be self-explanatory.
|
|
.Sh SEE ALSO
|
|
.Xr printf 3 ,
|
|
.Xr sysexits 3 ,
|
|
.Xr smb 4 ,
|
|
.Xr smbus 4
|
|
.Rs
|
|
.%T "The SMBus specification"
|
|
.%U http://www.smbus.org/specs/
|
|
.Re
|
|
.Sh HISTORY
|
|
The
|
|
.Nm
|
|
utility first appeared in
|
|
.Fx 5.3 .
|
|
.Sh AUTHORS
|
|
The
|
|
.Nm
|
|
utility and this manual page were written by
|
|
.An J\(:org Wunsch .
|