mpc8xx usb controller on linux 2.6

[Josef Angermeier]

Hello,

I am using linux 2.6.18 on a MPC875, which runs on a custom board. Some changes 
to the official kernel allow me to get the mpc8xx internal usb host controller 
working and access an usb stick successfully. I just used Brad Parkers 2.4 
patch, ported it to linux 2.6 and merged
it with the cpm2usb project. Until now it just worked for my board. Maybe any 
skilled programmer would like to test the patch also on his own board, fix some 
bugs and give me some confidence that the patch is somehow stable so that it 
once can be added to official linux source tree. I would appreciate that and 
try to help to get it working.

You can find the patch at

http://wwwcip.informatik.uni-erlangen.de/~sijoange/

Because of a bug in the m8xx USB CPM (read m8xx errata) you must feed a 1khz 
signal out and feed it at the DREQ pin in again on your board. Then you have to 
patch the kernel, configure linux to use the m8xx usb sof patch and the m8xx 
usb host controller, startup the compiled linux, fix some bugs, give me some 
feedback. 

Regards,
Josef

Linux controlling Hardware-Tasks on FPGA

[Josef Angermeier]

Hello,

anyone else out there using or wanting to use Linux to control the
reconfiguration of a FPGA ? - Do you use dynamic partial reconfiguration
too ? - If so how did you design the relevant software coarsely ?

thanks in advance,
Josef

undefined symbols of modules

[Josef Angermeier]

Hello,

when i try to compile my kernel extension as modul, i get some undefined 
references. But a look in System.map shows, that the relevant symbols 
are defined in the main kernel. Why then those undefined references ?

Any hint is appreciated!
bye

Josef

make ARCH=ppc -C linux modules
make[1]: Entering directory `/scratch-local/esm/linux'
  CHK include/linux/version.h
  Building modules, stage 2.
  MODPOST
*** Warning: cpm_load_patch [drivers/usb/host/m82xx-hcd.ko] undefined!
*** Warning: cpmp [drivers/usb/host/m82xx-hcd.ko] undefined!

MPC8xx Debugging: function call vs. no function call

[Josef Angermeier]

Hello,

I am not yet pretty familiar with 8xx system programming, so maybe you 
could give me some debugging hint. My C code which programs the the CPM 
(USB) has to execute the following commands:

eieio();
usbregs-usb_uscom = 0x80 | 0;
mb();


If i put those instructions in an new function, the CPM behaves as 
wished, elsewise it depends on the remaining code. E.g. the number of 
NOP machine code instructions before make a difference:

1.)
   ... remaining C function code
   __asm__(nop\n\t);
eieio();
usbregs-usb_uscom = 0x80 | 0;
mb();
   ... other code

2.)
   ... remaining C function code
   __asm__(nop\n\t);
   __asm__(nop\n\t);
eieio();
usbregs-usb_uscom = 0x80 | 0;
mb();
   ... other code

Every hint howto find my mistake is appreciated! Thanks
Josef

MPC8xx USB SOF microcode patch

[Josef Angermeier]

Hello,

I am using linux 2.6.15 and try to get the MPC875 USB controller 
working. I just checked if the microcode patch in 
arch/ppc/8xx_io/micropatch.c for CONFIG_USB_SOF_UCODE_PATCH set 
corresponds with the newest microcode patch for mpc8xx, downloadable 
from freescale: They differ slighly, is it an older (working) version or 
where is it from ?

ciao
josef

linux 2.4.25: loading usbcore.o gives segmentation fault

[Josef Angermeier]

Hello,

I am using linux 2.4.25 for a custom MPC875 based board. When adding 
general usb support as module (- usbcore.o), loading usbcore.o gives a 
segmentation fault.,  while compiling it builtin seems to work. How can 
i find out what could be the reasons for that ?

thanks in advance, best regards
Josef

USB-Hostcontroller-Support for MPC875

[Josef Angermeier]

Hello,

I'd like to make use of the MP875 internal USB-Hostcontroller on my 
custome board. Such support is not included in official kernel releases, 
but theres exists a usbhost-for-mpc8xx patch from brad parker for the 
2.4 kernel series. Did ever someone use that one with an MPC875 ?

thanks for every help,
best regards,
Josef

lseek/write char driver versus usermode iomem access

[Josef Angermeier]

Hello,

besides adapting linux to my custom board, i now have to write a driver 
for a special device. This device mainly consists of an up to 512 bytes 
big IO memory. Because performance matters alot, i wonder if i shall 
write a simple char driver offering a write/lseek-interface to access 
this memory or if i shall do something new to me, mapping the IO-memory 
to the userspace, so that the user-program can directly access the 
device memory. Can anyone tell me how performance probably differs 
between those two design.

Thanks, you probably save me alot of time to tryout!

Josef

freescale 8xx: which architecture to use ? ppc - powerpc ?

[Josef Angermeier]

Hello,

i want to run linux (2.6.15) on my MPC875 board. I wonder which 
architecture to choose:  powerpc or ppc ? - menuconfig shows a 
freescale 8xx option when used with powerpc, and a 8xx option when 
used with ARCH=ppc. Because i use a embedded freescale 8xx i wanted to 
use the powerpc architecture. BUT: i seems to be unstable, i got some 
undefined referencies. Or am i wrong ?

thanks
Josef

Freescale MPC8xx USB support

[Josef Angermeier]

Hello,

in the last linux stable release 2.6.15 i couldn't find any driver for 
the USB-hostcontroller embedded in Freescale MPC875. Is there some work 
ongoing or must i start writing my own driver ?

thanks in advance
Josef