[U-Boot] CAN framework in U-Boot

[Wolfgang Grandegger]

Hi Bhupesh,

On 05/02/2013 10:51 AM, Bhupesh SHARMA wrote:
> Hi Wolfgang,
> 
> Thanks for your timely inputs.
> 
> On Thu, May 2, 2013 at 12:31 PM, Wolfgang Grandegger <wg at grandegger.com>wrote:
> 
>> Hi Bhupesh,
>>
>> On 05/01/2013 06:17 AM, Bhupesh SHARMA wrote:
>>> Hi Wolfgang G. and list,
>>>
>>> I was looking to do some basic tests on a C_CAN module inside our SOC at
>>> u-boot
>>> level, till the Linux OS is up and working to test basic CAN features.
>>>
>>> I couldn't figure out if CAN framework is supported in u-boot and would
>>> really appreciate if
>>> someone can help me out regarding the same.
>>>
>>> I could see the sja1000 header present inside 'include/sja1000.h', and
>> some
>>> old patches
>>> from Wolfgang G. (see [1]), but couldn't figure out if these patches were
>>> accepted into u-boot.
>>>
>>> Any help will be much appreaciated.
>>>
>>> [1]. http://article.gmane.org/gmane.comp.boot-loaders.u-boot/70864
>>
>> There is no generic CAN interface in U-Boot yet. The "sja1000.h" header
>> file is used for some basic CAN loopback test commands and there are
>> others, e.g. for the MSCAN. I have hacked something recently for Flexcan:
>>
>> +U_BOOT_CMD(
>> +       can_test,       CONFIG_SYS_MAXARGS,     1,      do_can_test,
>> +       "transfer and check messages between two CAN controllers",
>> +       "[kb-per-sec] [repeat-count]"
>> +);
>>
>> Unfortunately, those commands are all board specific. A more generic
>> approach is appreciated, of course.
>>
> Yes. I would like to explore the possibility of adding some generic CAN
> framework to u-boot.
> Do you think your last patches, will be a good starting point?

Well, there is "The U-Boot Driver Model Project" and CAN should use it
as well, I think. Have a look to "doc/driver-model" for further information.

> I can try to test the same on flexcan as well.

Note that this driver just implements the command "can_test".
It's also not yet mainline but I can post it on request.

Wolfgang.