Trouble with libftdi on ARM

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Trouble with libftdi on ARM

Tyler Cordrey
Hello,

I'm trying to use libftdi as a replacement for ftdi_sio on an ARM9 with
linux. I'm using an older kernel that is provided with the board, it's
2.6.21. I've got two FT4232H chips plugged into it, and I can comm. fine
through them using the ftdi_sio module modified for this kernel version.

With libftdi, all of the functions return normally but nothing is read
or written on the ports. All of the initialization functions return zero
and write returns the number of bytes requested to be written. I've made
sure that ftdi_sio is not loaded, and I've even tried using
usb_detach_kernel_driver_np to make sure the module is not interfering.
The strange thing is that it behaves the same when the module is loaded
- no errors, same behavior.

Here is the code I am using to test: http://pastebin.com/FPz522k8. On my
386 box it works fine, and fails if the ftdi_sio module is loaded.

I've got libusb version 0.1.10a and libftdi version 0.18. Is there
anything about this configuration that might cause problems?

Thanks a lot for any suggestions.

Tyler


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RE: Trouble with libftdi on ARM

Spindler, Tyler L
Depending on the architecture of the of ARM processor you are running
on, it may not get initialized properly.  It sounds like you aren't
loading ftdi_sio, so I'm not sure if this will help.

There was a bug that was recently fixed to address an issue with this
chip in a new version of the kernel.  You would need to patch to fix.  I
was using OpenWRT running on an ARM processor when I ran into the
FT2232/4232 issue.  Patches are included as well as tickets submitted
into the kernel in the link.

https://dev.openwrt.org/ticket/7365

Tyler

-----Original Message-----
From: Tyler Cordrey [mailto:[hidden email]]
Sent: Thursday, December 16, 2010 1:43 PM
To: [hidden email]
Subject: Trouble with libftdi on ARM

Hello,

I'm trying to use libftdi as a replacement for ftdi_sio on an ARM9 with
linux. I'm using an older kernel that is provided with the board, it's
2.6.21. I've got two FT4232H chips plugged into it, and I can comm. fine

through them using the ftdi_sio module modified for this kernel version.

With libftdi, all of the functions return normally but nothing is read
or written on the ports. All of the initialization functions return zero

and write returns the number of bytes requested to be written. I've made

sure that ftdi_sio is not loaded, and I've even tried using
usb_detach_kernel_driver_np to make sure the module is not interfering.
The strange thing is that it behaves the same when the module is loaded
- no errors, same behavior.

Here is the code I am using to test: http://pastebin.com/FPz522k8. On my

386 box it works fine, and fails if the ftdi_sio module is loaded.

I've got libusb version 0.1.10a and libftdi version 0.18. Is there
anything about this configuration that might cause problems?

Thanks a lot for any suggestions.

Tyler


--
libftdi - see http://www.intra2net.com/en/developer/libftdi for details.
To unsubscribe send a mail to
[hidden email]  



--
libftdi - see http://www.intra2net.com/en/developer/libftdi for details.
To unsubscribe send a mail to [hidden email]