Multi-serial USB Device

Multi-serial USB Device

[Paul Dugas]

First, please point me where I should be asking if this is not the
place.  Thanks.

I've got a number of USB devices I need to connect to a data-logging
machine.  Each device presents as 3 USB serial ports which are
properly recognized and setup as ttyUSB[0-2] once I added the right
vendor and product numbers to the module loader configs.  When I
connect the second device, I get ttyUSB[3-5].  I've been able to setup
udev rules that recognize the serial numbers for each of the devices
and can setup symlinks; i.e. ttyLogger1USB[0-2] -> ttyUSB?.
Something like so...

    KERNEL="ttyUSB*", SYSFS{serial}="111", SYMLINK+="ttyLogger1USB%n"
    KERNEL="ttyUSB*", SYSFS{serial}="222", SYMLINK+="ttyLogger2USB%n"
    KERNEL="ttyUSB*", SYSFS{serial}="333", SYMLINK+="ttyLogger3USB%n"

My hitch is that the %n values on the end of the SYMLINK setting
result in 0-2 for the first logger found, 3-5 for the second, etc.  I
really want them to be 0-2 for all of the loggers.  But, looking at
the udevinfo for the 3 ports on one logger, they're identical.

I tried adding a PROGRAM setting to run a little script that looked to
count the /dev/ttyLogger1USB* devices had already been created and it
always returned 0.  Are the device files and symlinks created in
parallel or in bulk at the end and thus this approach wouldn't work?

I tried another PROGRAM that opened the port and polled the logger to
see what port this was (that's supported by the device's protocol) but
the device file didn't exist yet.  Is there a way to trigger this
approach after the device file has been created? Is there a way to
temporarily create the device in the script instead?

Anyone got a suggestion on how to solve this?

Paul

Re: Multi-serial USB Device

[Paul Bender]

On 1/30/2010 10:05 AM, Paul Dugas wrote:
> First, please point me where I should be asking if this is not the
> place.  Thanks.
>
> I've got a number of USB devices I need to connect to a data-logging
> machine.  Each device presents as 3 USB serial ports which are
> properly recognized and setup as ttyUSB[0-2] once I added the right
> vendor and product numbers to the module loader configs.  When I
> connect the second device, I get ttyUSB[3-5].  I've been able to setup
> udev rules that recognize the serial numbers for each of the devices
> and can setup symlinks; i.e. ttyLogger1USB[0-2] ->  ttyUSB?.
> Something like so...
>
>      KERNEL="ttyUSB*", SYSFS{serial}="111", SYMLINK+="ttyLogger1USB%n"
>      KERNEL="ttyUSB*", SYSFS{serial}="222", SYMLINK+="ttyLogger2USB%n"
>      KERNEL="ttyUSB*", SYSFS{serial}="333", SYMLINK+="ttyLogger3USB%n"
>
> My hitch is that the %n values on the end of the SYMLINK setting
> result in 0-2 for the first logger found, 3-5 for the second, etc.  I
> really want them to be 0-2 for all of the loggers.  But, looking at
> the udevinfo for the 3 ports on one logger, they're identical.
>
> I tried adding a PROGRAM setting to run a little script that looked to
> count the /dev/ttyLogger1USB* devices had already been created and it
> always returned 0.  Are the device files and symlinks created in
> parallel or in bulk at the end and thus this approach wouldn't work?
>
> I tried another PROGRAM that opened the port and polled the logger to
> see what port this was (that's supported by the device's protocol) but
> the device file didn't exist yet.  Is there a way to trigger this
> approach after the device file has been created? Is there a way to
> temporarily create the device in the script instead?
>
> Anyone got a suggestion on how to solve this?

I suspect that the device presents itself as 3 USB serial interfaces on 
one USB device. If so, then you should be able to use bInterfaceNumber 
to set the USB serial device number. For example,

KERNEL="ttyUSB*", SYSFS{serial}="111", \
   SYMLINK+="ttyLogger1USB$attr{bInterfaceNumber}"
KERNEL="ttyUSB*", SYSFS{serial}="222", \
   SYMLINK+="ttyLogger2USB$attr{bInterfaceNumber}"
KERNEL="ttyUSB*", SYSFS{serial}="333", \
   SYMLINK+="ttyLogger3USB$attr{bInterfaceNumber}"

Re: Multi-serial USB Device

[David Zeuthen]

On Sat, 2010-01-30 at 13:05 -0500, Paul Dugas wrote:
> I tried adding a PROGRAM setting to run a little script that looked to
> count the /dev/ttyLogger1USB* devices had already been created and it
> always returned 0.  Are the device files and symlinks created in
> parallel or in bulk at the end and thus this approach wouldn't work?
> 
> I tried another PROGRAM that opened the port and polled the logger to
> see what port this was (that's supported by the device's protocol) but
> the device file didn't exist yet.  Is there a way to trigger this
> approach after the device file has been created? Is there a way to
> temporarily create the device in the script instead?
> 
> Anyone got a suggestion on how to solve this?

You should be able to use IMPORT and $tempnode - see the udev(7) man
page and, say, /lib/udev/rules.d/60-persistent-storage.rules for an
example of where this is used.

     David

Re: Multi-serial USB Device

[Greg KH]

On Sat, Jan 30, 2010 at 01:05:27PM -0500, Paul Dugas wrote:
> First, please point me where I should be asking if this is not the
> place.? Thanks.
> 
> I've got a number of USB devices I need to connect to a data-logging
> machine.? Each device presents as 3 USB serial ports which are
> properly recognized and setup as ttyUSB[0-2] once I added the right
> vendor and product numbers to the module loader configs.? When I
> connect the second device, I get ttyUSB[3-5].? I've been able to setup
> udev rules that recognize the serial numbers for each of the devices
> and can setup symlinks; i.e. ttyLogger1USB[0-2] -> ttyUSB?.
> Something like so...
> 
>     KERNEL="ttyUSB*", SYSFS{serial}="111", SYMLINK+="ttyLogger1USB%n"
>     KERNEL="ttyUSB*", SYSFS{serial}="222", SYMLINK+="ttyLogger2USB%n"
>     KERNEL="ttyUSB*", SYSFS{serial}="333", SYMLINK+="ttyLogger3USB%n"

Have you looked at the links in /dev/serial/?  that should work for what
you are trying to accomplish.

thanks,

greg k-h

Re: Multi-serial USB Device

[Paul Dugas]

On Sat, Jan 30, 2010 at 1:25 PM, Paul Bender <pebender@san.rr.com> wrote:
> I suspect that the device presents itself as 3 USB serial interfaces on one
> USB device. If so, then you should be able to use bInterfaceNumber to set
> the USB serial device number. For example,
>
> KERNEL="ttyUSB*", SYSFS{serial}="111", \
>  SYMLINK+="ttyLogger1USB$attr{bInterfaceNumber}"
> KERNEL="ttyUSB*", SYSFS{serial}="222", \
>  SYMLINK+="ttyLogger2USB$attr{bInterfaceNumber}"
> KERNEL="ttyUSB*", SYSFS{serial}="333", \
>  SYMLINK+="ttyLogger3USB$attr{bInterfaceNumber}"

Yeah, started down that road at the start but no joy.

# udevinfo -a -p /sys/class/tty/ttyUSB0 >/tmp/udevinfo.usb0
# udevinfo -a -p /sys/class/tty/ttyUSB1 >/tmp/udevinfo.usb1
# diff diff /tmp/udevinfo.usb0 /tmp/udevinfo.usb1
8,9c8,9
<   looking at device '/class/tty/ttyUSB0':
<     KERNEL="ttyUSB0"
---
>   looking at device '/class/tty/ttyUSB1':
>     KERNEL="ttyUSB1"
11c11
<     SYSFS{dev}="188:0"
---
>     SYSFS{dev}="188:1"
13,14c13,14
<   looking at parent device
'/devices/pci0000:00/0000:00:1d.7/usb1/1-1/1-1.1/1-1.1:1.0/ttyUSB0':
<     ID="ttyUSB0"
---
>   looking at parent device '/devices/pci0000:00/0000:00:1d.7/usb1/1-1/1-1.1/1-1.1:1.0/ttyUSB1':
>     ID="ttyUSB1"
#

There is a bInterfaceNumber in
/devices/pci0000:00/0000:00:1d.7/usb1/1-1/1-1.1/1-1.1:1.0 under which
I find ttyUSB0/, ttyUSB1/ and ttyUSB2/.  I think the USB
implementation on this logger just didn't take what I'm trying to do
into consideration.

Thanks,

Paul

Re: Multi-serial USB Device

[Paul Dugas]

On Sat, Jan 30, 2010 at 1:34 PM, Greg KH <greg@kroah.com> wrote:
> Have you looked at the links in /dev/serial/?  that should work for what
> you are trying to accomplish.

Alas, this is a RedHat machine at the moment so no /dev/serial :(

P

Re: Multi-serial USB Device

[Paul Dugas]

On Sat, Jan 30, 2010 at 1:27 PM, David Zeuthen <david@fubar.dk> wrote:
> You should be able to use IMPORT and $tempnode

And it seems the idea of getting IDs from the devices themselves is
not off-the-wall at all.  Sweet.  I completely missed the $tempnode
entry in the man page.

Is there a reason I should use IMPORT{program} instead of PROGRAM like so...

KERNEL="ttyUSB*", SYSFS{serial}="111", \
PROGRAM="logger_port $N", \
SYMLINK+="ttyLogger1USB%c"

I ask mainly because I'm not entirely sure what "environment key format" is.

Thanks much.

Paul

Re: Multi-serial USB Device

[David Zeuthen]

On Sat, 2010-01-30 at 13:59 -0500, Paul Dugas wrote:
> On Sat, Jan 30, 2010 at 1:27 PM, David Zeuthen <david@fubar.dk> wrote:
> > You should be able to use IMPORT and $tempnode
> 
> And it seems the idea of getting IDs from the devices themselves is
> not off-the-wall at all.  Sweet.  I completely missed the $tempnode
> entry in the man page.
> 
> Is there a reason I should use IMPORT{program} instead of PROGRAM like so...
> 
> KERNEL="ttyUSB*", SYSFS{serial}="111", \
> PROGRAM="logger_port $N", \
> SYMLINK+="ttyLogger1USB%c"
> 
> I ask mainly because I'm not entirely sure what "environment key format" is.

I'm not sure that the output of PROGRAM is parsed the same way it is for
IMPORT - in fact, I think it's just ignored for PROGRAM - Kay? Anyway,
the general idea is something like this

SUBSYSTEM="tty", SUBSYSTEMS="usb", IMPORT{program}="logger_import
$tempnode", SYMLINK+="ttyLogger$env{LOGGER_DEVICE_NUMBER}port
$env{LOGGER_PORT_NUMBER}"

where the logger_import program writes lines like this

LOGGER_PORT_NUMBERB
LOGGER_DEVICE_NUMBERC

on stdout which is then imported into the environment for the device
(and thus available for later rules and via libudev).

     David

Re: Multi-serial USB Device

[Paul Dugas]

On Sat, Jan 30, 2010 at 2:58 PM, David Zeuthen <david@fubar.dk> wrote:
> I'm not sure that the output of PROGRAM is parsed the same way it is for
> IMPORT - in fact, I think it's just ignored for PROGRAM - Kay? Anyway,
> the general idea is something like this

According to udev(7) on this RHEL5.4 machine (udev-095-14.21.el5),
RESULT can be matched against the output of the last PROGRAM call and
$result or %c can be use in substitutions.  Still, the idea of reading
both the serial number and the port number from the logger would allow
me to get by with a single udev rule along the lines of what you
wrote.

Thanks much for your input.  Looks like exactly what I needed.

Paul

Re: Multi-serial USB Device

[Greg KH]

On Sat, Jan 30, 2010 at 01:50:57PM -0500, Paul Dugas wrote:
> On Sat, Jan 30, 2010 at 1:34 PM, Greg KH <greg@kroah.com> wrote:
> > Have you looked at the links in /dev/serial/?  that should work for what
> > you are trying to accomplish.
> 
> Alas, this is a RedHat machine at the moment so no /dev/serial :(

That shouldn't matter, what version are you running?

thanks,

greg k-h

Re: Multi-serial USB Device

[Paul Dugas]

On Sat, Jan 30, 2010 at 7:47 PM, Greg KH <greg@kroah.com> wrote:
> On Sat, Jan 30, 2010 at 01:50:57PM -0500, Paul Dugas wrote:
>> On Sat, Jan 30, 2010 at 1:34 PM, Greg KH <greg@kroah.com> wrote:
>> > Have you looked at the links in /dev/serial/?  that should work for what
>> > you are trying to accomplish.
>>
>> Alas, this is a RedHat machine at the moment so no /dev/serial :(
>
> That shouldn't matter, what version are you running?

This is on an RHEL5.4 machine with a package named udev-095-14.21.el5.

Paul

Re: Multi-serial USB Device

[Greg KH]

On Sat, Jan 30, 2010 at 08:27:13PM -0500, Paul Dugas wrote:
> On Sat, Jan 30, 2010 at 7:47 PM, Greg KH <greg@kroah.com> wrote:
> > On Sat, Jan 30, 2010 at 01:50:57PM -0500, Paul Dugas wrote:
> >> On Sat, Jan 30, 2010 at 1:34 PM, Greg KH <greg@kroah.com> wrote:
> >> > Have you looked at the links in /dev/serial/?  that should work for what
> >> > you are trying to accomplish.
> >>
> >> Alas, this is a RedHat machine at the moment so no /dev/serial :(
> >
> > That shouldn't matter, what version are you running?
> 
> This is on an RHEL5.4 machine with a package named udev-095-14.21.el5.

Yes, you are right, that is too old :(