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

[Wolfgang Grandegger <wg@domain.hid>]

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.