Re: [Xenomai-help] [Socketcan-users] RT - Socketcan

[Wolfgang Grandegger <wg@domain.hid>]

Breno wrote:
> Wolfgang Grandegger wrote:
>> Breno wrote:
>>  
>>> Wolfgang Grandegger wrote:
>>>    
>>>> Wolfgang Grandegger wrote:
>>>>        
>>>>> breno@domain.hid wrote:
>>>>>            
>>>>>>> Breno wrote:
>>>>>>>                    
>>>>>>>> Wolfgang Grandegger wrote:
>>>>>>>>                        
>>>>>>>>> Breno wrote:
>>>>>>>>>
>>>>>>>>>                            
>>>>>>>>>> Wolfgang Grandegger wrote:
>>>>>>>>>>
>>>>>>>>>>                                
>>>>>>>>>>> Breno wrote:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>                                    
>>>>>>>>>>>> Hi Wolfgang, I got the cannetdriver26 as you suggested some
>>>>>>>>>>>> e-mail
>>>>>>>>>>>> ago. Sorry my ignorance but how can I get it working o my
>>>>>>>>>>>> kernel. I
>>>>>>>>>>>> mentioned before that you have a script do get it build.
>>>>>>>>>>>> Could you
>>>>>>>>>>>> help me again on this issue?
>>>>>>>>>>>>
>>>>>>>>>>>>                                         
>>>>>>>>>>> For what kernel?
>>>>>>>>>>>
>>>>>>>>>>> Wolfgang.
>>>>>>>>>>>
>>>>>>>>>>>                                     
>>>>>>>>>> Hi Wolfgang, I got a DENX Linux 2.6 Kernel Tree from DENX
>>>>>>>>>> project.
>>>>>>>>>> The last
>>>>>>>>>> commit I have is:
>>>>>>>>>>
>>>>>>>>>> commit 76e8fbcc9e3e928a6898a93e6077264f5cb8f432
>>>>>>>>>>   Author: Wolfgang Grandegger <wolf@domain.hid>
>>>>>>>>>>   Date:   Thu Mar 27 17:41:09 2008 +0100
>>>>>>>>>>
>>>>>>>>>>   Socket-CAN: merge with SVN trunk revision 690
>>>>>>>>>>
>>>>>>>>>>                                 
>>>>>>>>> Can you use linux-2.6.25.4 from kernel.org for your hardware?
>>>>>>>>>
>>>>>>>>> Wolfgang.
>>>>>>>>>
>>>>>>>>>                             
>>>>>>>> But it doesn't have support for Xenomai, rigth? If so, which
>>>>>>>> version
>>>>>>>> should I use?
>>>>>>>>                         
>>>>>>> You are right, an ADEOS i-Pipe patch is not yet avaliable for
>>>>>>> 2.6.25.
>>>>>>> Just to understand your requirements. You want to use the Xenomai
>>>>>>> real-time extension because you have hard real-time requirements,
>>>>>>> right?
>>>>>>> Do you want to access the CAN bus from a Xenomai real-time task?
>>>>>>> If yes,
>>>>>>> then you should use RT-Socket-CAN.
>>>>>>>
>>>>>>>                    
>>>>>>>> Anyway,I got the Denx-2.6.25 and I wanna configure it on my system
>>>>>>>> regardless of this
>>>>>>>> version doesn't have Xenomai support. To get an correct kernel
>>>>>>>> image on
>>>>>>>> my
>>>>>>>> present tree(2.6.24-commit
>>>>>>>> 76e8fbcc9e3e928a6898a93e6077264f5cb8f432 ) I
>>>>>>>> executed make lite5200_defconfig, at the kernel option and I set
>>>>>>>> lite5200.dts
>>>>>>>> and then do make zImage. That new tree seems have some
>>>>>>>> differences, do
>>>>>>>> you
>>>>>>>> know what commands do I have to execute? I'm using lite5200 powerpc
>>>>>>>> board.
>>>>>>>>                         
>>>>>>> It does not make sense to switch to 2.6.25 now if you have real-time
>>>>>>> requirements. Please stop jumping from one setup to another. If
>>>>>>> something is not working, I'm willing to help.
>>>>>>>
>>>>>>> Wolfgang.
>>>>>>>
>>>>>>>                     
>>>>>> Hi Wolfgang, thanks for your support. I'm intending to use CAN
>>>>>> along with
>>>>>> rt-tasks. I had dropped the rt-socket CAN because of the error it
>>>>>> appears
>>>>>> when I send messages as explained some e-mails ago. For example:
>>>>>>
>>>>>> ./rtcanconfig rtcan0 -b100000 start ---> works properly!
>>>>>> ./rtcanrecv rtcan1 &
>>>>>> ./rtcansend rtcan0 -i0x123 1 2 3 4 5 6 7 8
>>>>>> #0 [8] <0x123> 00 00 00 04 05 06 07 08 ---> it seems to lose the
>>>>>> threes
>>>>>> first data.
>>>>>>                 
>>>>> Then let's try to fix that. Have you built and ran rtcansend and
>>>>> rtcanrecv as I suggested (the one created by "$ make" in the
>>>>> Xenomai top
>>>>> directory)? Did it make a difference?
>>>>>
>>>>> Do you see errors when you use the rtcanrecv option "-e 0xffff"?
>>>>>
>>>>>    ./rtcanrecv -e 0xffff rtcan1
>>>>>
>>>>>            
>>>>>> My socket-can applications works perfectly!!!
>>>>>>                 
>>>>> Fine, but it's not useful to call Socket-CAN from an Xenomai real-time
>>>>> application. You will loose determinism.
>>>>>
>>>>> And we should continue this thread with CC to the Xenomai-help mailing
>>>>> list because it might be useful for others as well.
>>>>>             
>>>> Maybe there is something wrong with your MSCAN clock settings.
>>>>
>>>> What frequency have you specified for
>>>> CONFIG_XENO_DRIVERS_CAN_MSCAN_CLOCK (check your kernel .config)?
>>>>
>>>> And what MPC5200 CPU do you have? Could you show use the initial output
>>>> of your bootloader?
>>>>
>>>> Wolfgang.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>         
>>> Hi Wolfgang, I have a stick on my board with lite5200 v2.0b. And at the
>>> top of my processor chip I have MPC5200b. The clock frequency is 
>>> 400MHz.
>>>     
>>
>> Well, this information does not match the boot output below.
>>
>>  
>>> My first messages on boot process is:
>>>
>>> U-Boot 1.1.4 (Feb 10 2006 - 11:06:33)
>>>     CPU:   MPC5200 v1.2 at 462 MHz
>>>     
>>
>> Seems to be a Rev. A CPU at 462 MHz. 1.1.4 is very old, though.
>>
>>  
>>>          Bus 132 MHz, IPB 66 MHz, PCI 33 MHz
>>>
>>>   Board: Motorola MPC5200 (IceCube)
>>>     
>>
>> BTW: do you have one or two PCI connectors on the board?
>>
>>  
>>>   I2C:   85 kHz, ready
>>>   DRAM:  64 MB
>>>   FLASH: 16 MB
>>>   PCI:   Bus Dev VenId DevId Class Int
>>>           00  1a  1057  5803  0680  00
>>>   In:    serial
>>>   Out:   serial
>>>   Err:   serial
>>>   Net:   FEC ETHERNET
>>>   IDE:   Bus 0: not available      Autostarting. Press any key to
>>> abort...
>>>     Hit any key to stop autoboot:  5
>>>   => tftp
>>>   Using FEC ETHERNET device
>>>   TFTP from server 192.168.1.100; our IP address is 192.168.1.101
>>>   Filename '5200/cuImage.52xx'.
>>>   Load address: 0x100000
>>>   Loading:
>>> *#################################################################
>>>        #################################################################
>>>        #################################################################
>>>        #################################################################
>>>   done
>>>   Bytes transferred = 1329135 (1447ef hex)
>>>   => bootm
>>>   ## Booting image at 00100000 ...
>>>      Image Name:   Linux-2.6.24.4-g5e9901e9-dirty
>>>      Created:      2008-04-15  16:35:09 UTC
>>>      Image Type:   PowerPC Linux Kernel Image (gzip compressed)
>>>      Data Size:    1329071 Bytes =  1.3 MB
>>>      Load Address: 00400000
>>>      Entry Point:  0040055c
>>>      Verifying Checksum ... OK
>>>      Uncompressing Kernel Image ... OK
>>>
>>>  
>>> The frequency specified on CONFIG_XENO_DRIVERS_CAN_MSCAN_CLOCK is
>>> 66000000Hz. Is that correct?
>>>     
>>
>> For MPC5200 Rev. B CPU, it should be 33000000, but you have an old Rev.
>> A CPU and in that case 66000000 is correct.
>>
>> There is some help for corresponding Kconfig option:
>>
>>   config XENO_DRIVERS_CAN_MSCAN_CLOCK
>>         depends on XENO_DRIVERS_CAN_MSCAN
>>         int "Clock Frequency in Hz"
>>         default 66000000
>>         help
>>
>>         The MSCAN driver selects the oscillator clock (SYS_XTAL_IN) as
>>         clock source for MSCAN, which is typically 33 MHz. Due to a
>>         hardware bug on the MPC5200 Rev. A chips, the IP bus clock
>>         (IP_CLK) is used instead, which is typically 66 or 132 MHz.
>>
>> How does your CAN cabling look like. Is the CAN bus properly terminated
>> on both ends?
>>
>> Wolfgang.
>>   
> Hi Wolfgang, it's not a professional cable!!! I just use a 10 pins flat
> cable to connect CAN0 and CAN1 on board interfaces  for testings, I
> mean, I don't have  a bus exactly but just a simple cable. Could you
> pass me a  good reference of cables for a property use?

Handmade cables are OK but you need proper termination with 120 Ohm at
both ends of the cable. Either there is on-board termination, sometimes
selectable via jumpers, or you have to add resistors at the end of your
cable. Take an Ohmmeter and measure the resistance between pin 2 and 7
of your connector.

Wolfgang.