gumstix

I don't actually know of an easy way of accessing GPIOs in userspace -- 
which is why I wrote the /proc/gpio driver.  You can quite easily write 
a kernel driver to do your GPIO stuff, and then expose that to 
userspace through /proc or /sys if you want to, or tie the GPIOs to 
some ioctl functionality on a /dev device -- but I don't think there's 
a stock thing in the linux kernel which does that for all GPIOs 
generically.  You'll almost certainly want to write a driver for your 
device if you need decent performance in dealing with the GPIOs -- ie 
if you have low latency requirements, or high bandwidth requirements.  
If not, then the /proc/gpio interface is probably pretty decent.

C

On Oct 5, 2004, at 5:52 PM, Brendan Simon wrote:

> I see GPIO can easily be read/written using /proc/gpio/* but how can I 
> access the GPIO from a user space C/C++ program??
>
> I guess I could fread/fwrite /proc/gpio/* but that seems a little 
> cumbersome.
> Is there a way to do it through a device driver, eg. IOCTL ??

On Wed, 2004-10-06 at 09:30, Emmanuel Seignez wrote:
>         Thank you for yor help.
>         
>         I have done what you said but the function "i2c_master_send"
>         (referenced in i2c.h) which is in i2c-core.c is still not
>         available.... Have my progam compiled with some object file ?
>         

Check out dec/developers/applications and kernel/include/i2c-dev.h in
the lm-sensors package.

HTH,
-Jonathan

Hi,

maybe I can help:
http://www.heise.de/ct/ftp/projekte/com2lan/
The stuff is in German.

Robert
>-- Original-Nachricht --
>From: Suprenant Joseph Civ AFRL/IFGC <Joseph.Suprenant@...>
>To: "'gumstix-users@...'"
>	 <gumstix-users@...>
>Subject: RE: [Gumstix-users] Serial to Ethernet
>Reply-To: gumstix-users@...
>Date: Wed, 6 Oct 2004 11:43:44 -0000
>
>
>I mean RS232 to Ethernet, not USB.  I am aware of the USB limitations. 
I
>have seen some devices that have rs232 at one end and RJ45 at the other.
>
>-----Original Message-----
>From: gumstix-users-admin@...
>[mailto:gumstix-users-admin@...] On Behalf Of David
>Farrell
>Sent: Tuesday, October 05, 2004 7:58 PM
>To: gumstix-users@...
>Subject: Re: [Gumstix-users] Serial to Ethernet
>
>
>I am not quite sure what you are asking. Do you
>mean a USB to ethernet? If so, can't do it. The
>gumstix port is a device port, not a host port.
>What do you mean by serial?
>David.
>
>--- Suprenant Joseph Civ AFRL/IFGC
><Joseph.Suprenant@...> wrote:
>
>> Has anyone used a serial to USB Ethernet
>> adapter on the gumstix?  If so any
>> suggestions?
>> 
>> Joseph Suprenant
>> Computer Scientist
>> Air Force Research Lab/IFGC
>> 525 Brooks Rd.
>> Rome, NY 13441
>> Phone: (315)330-2179 DSN: 587-2179
>> Fax: (315)330-7137 DSN: 587-7137
>> 
>> 
>> 
>>
>-------------------------------------------------------
>> This SF.net email is sponsored by: IT Product
>> Guide on ITManagersJournal
>> Use IT products in your business? Tell us what
>> you think of them. Give us
>> Your Opinions, Get Free ThinkGeek Gift
>> Certificates! Click to find out more
>>
>http://productguide.itmanagersjournal.com/guidepromo.tmpl
>> _______________________________________________
>> gumstix-users mailing list gumstix-users@...
>>
>https://lists.sourceforge.net/lists/listinfo/gumstix-users
>> 
>
>
>
>-------------------------------------------------------
>This SF.net email is sponsored by: IT Product Guide on ITManagersJournal
>Use
>IT products in your business? Tell us what you think of them. Give us Your
>Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more
>http://productguide.itmanagersjournal.com/guidepromo.tmpl
>_______________________________________________
>gumstix-users mailing list
>gumstix-users@...
>https://lists.sourceforge.net/lists/listinfo/gumstix-users
>
>
>-------------------------------------------------------
>This SF.net email is sponsored by: IT Product Guide on ITManagersJournal
>Use IT products in your business? Tell us what you think of them. Give us
>Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more
>http://productguide.itmanagersjournal.com/guidepromo.tmpl
>_______________________________________________
>gumstix-users mailing list
>gumstix-users@...
>https://lists.sourceforge.net/lists/listinfo/gumstix-users

Ok,
I have used these devices.  They are basically
serial port servers for ethernet.  They do not
provide ethernet to serially equipped computers.
The device I have used is also a power hog.  If
you really need ethernet, for now the gumstix is
not the board to use.  I do have the gumstix
connected via bluetooth to a belkin bluetooth
ethernet bridge.  This bridge works pretty well
for my ipaq pda and the gumstix. The bluetooth
linux code is still buggy at this point but good
progress is begin made.

David.

--- Suprenant Joseph Civ AFRL/IFGC
<Joseph.Suprenant@...> wrote:

> I mean RS232 to Ethernet, not USB.  I am aware
> of the USB limitations.  I
> have seen some devices that have rs232 at one
> end and RJ45 at the other.
> 
> -----Original Message-----
> From: gumstix-users-admin@...
>
[mailto:gumstix-users-admin@...]
> On Behalf Of David
> Farrell
> Sent: Tuesday, October 05, 2004 7:58 PM
> To: gumstix-users@...
> Subject: Re: [Gumstix-users] Serial to Ethernet
> 
> 
> I am not quite sure what you are asking. Do you
> mean a USB to ethernet? If so, can't do it. The
> gumstix port is a device port, not a host port.
> What do you mean by serial?
> David.
> 
> --- Suprenant Joseph Civ AFRL/IFGC
> <Joseph.Suprenant@...> wrote:
> 
> > Has anyone used a serial to USB Ethernet
> > adapter on the gumstix?  If so any
> > suggestions?
> > 
> > Joseph Suprenant
> > Computer Scientist
> > Air Force Research Lab/IFGC
> > 525 Brooks Rd.
> > Rome, NY 13441
> > Phone: (315)330-2179 DSN: 587-2179
> > Fax: (315)330-7137 DSN: 587-7137
> > 
> > 
> > 
> >
>
-------------------------------------------------------
> > This SF.net email is sponsored by: IT Product
> > Guide on ITManagersJournal
> > Use IT products in your business? Tell us
> what
> > you think of them. Give us
> > Your Opinions, Get Free ThinkGeek Gift
> > Certificates! Click to find out more
> >
>
http://productguide.itmanagersjournal.com/guidepromo.tmpl
> >
> _______________________________________________
> > gumstix-users mailing list
> gumstix-users@...
> >
>
https://lists.sourceforge.net/lists/listinfo/gumstix-users
> > 
> 
> 
> 
>
-------------------------------------------------------
> This SF.net email is sponsored by: IT Product
> Guide on ITManagersJournal Use
> IT products in your business? Tell us what you
> think of them. Give us Your
> Opinions, Get Free ThinkGeek Gift Certificates!
> Click to find out more
>
http://productguide.itmanagersjournal.com/guidepromo.tmpl
> _______________________________________________
> gumstix-users mailing list
> gumstix-users@...
>
https://lists.sourceforge.net/lists/listinfo/gumstix-users
> 
> 
>
-------------------------------------------------------
> This SF.net email is sponsored by: IT Product
> Guide on ITManagersJournal
> Use IT products in your business? Tell us what
> you think of them. Give us
> Your Opinions, Get Free ThinkGeek Gift
> Certificates! Click to find out more
>
http://productguide.itmanagersjournal.com/guidepromo.tmpl
> _______________________________________________
> gumstix-users mailing list
> gumstix-users@...
>
https://lists.sourceforge.net/lists/listinfo/gumstix-users
>

Yes, sorry, I'm working on fixing that which is why I overlooked it.

C

On Oct 5, 2004, at 6:10 PM, David Farrell wrote:

> It seems you also need:
>
> # echo 398131 >
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
>
> David.
>
> --- Craig Hughes <craig@...> wrote:
>
>> CPUFREQ is now included in the standard gumstix
>> kernel.  This allows
>> dynamic changing of the CPU frequency using the
>> sysfs filesystem.
>>
>> To change frequencies (simply), write the new
>> CPU clock frequency to
>>
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed,
>> eg:
>>
>> # echo 398131 >
>>
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
>> # echo 99533 >
>>
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed
>>
>> etc.  The valid values for cpu frequency are:
>>
>> 99533,132710,199066,265421,331776,398131,530842
>>
>> Note that strictly speaking, you're not
>> supposed to clock a 200MHz CPU
>> over 200MHz, nor a 400MHz CPU over 400MHz.  It
>> no doubt breaks some
>> kind of warranty agreement.
>>
>> You can also read up on the cpufreq governors
>> and policies in the linux
>> kernel source tree under Documentation/cpu-freq
>> -- but it's not the 
>> best written of linux docs.
>>
>> Benchmarks for some of these frequencies are on
>> the Wiki -- please feel
>> free to add more datapoints if they're
>> relevant; please don't add more
>> numbers for the same frequencies where your
>> results are just off ours
>> by 0.01%.  Also, we've got some basic
>> power-draw numbers for the
>> various frequencies, but I don't think we've
>> posted them yet on the
>> Wiki.  Basically though, slower = less power.
>>
>> C
>>
>>
>>
>>
> -------------------------------------------------------
>> This SF.net email is sponsored by: IT Product
>> Guide on ITManagersJournal
>> Use IT products in your business? Tell us what
>> you think of them. Give us
>> Your Opinions, Get Free ThinkGeek Gift
>> Certificates! Click to find out more
>>
> http://productguide.itmanagersjournal.com/guidepromo.tmpl
>> _______________________________________________
>> gumstix-users mailing list
>> gumstix-users@...
>>
> https://lists.sourceforge.net/lists/listinfo/gumstix-users
>>
>
>
>
> -------------------------------------------------------
> This SF.net email is sponsored by: IT Product Guide on 
> ITManagersJournal
> Use IT products in your business? Tell us what you think of them. Give 
> us
> Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out 
> more
> http://productguide.itmanagersjournal.com/guidepromo.tmpl
> _______________________________________________
> gumstix-users mailing list
> gumstix-users@...
> https://lists.sourceforge.net/lists/listinfo/gumstix-users