[U-Boot] [RFC][Timer API] Revised Specification - Implementation details

J. William Campbell
2011-05-27T14:23:42Z

On 5/27/2011 12:35 AM, Graeme Russ wrote:
> Hi Wolfgang,
>
> On 27/05/11 17:13, Wolfgang Denk wrote:
>> Dear Graeme Russ,
>>
>> In message<BANLkTinWvY9b4QzeLNawF7MKT9z1zeMXyg@mail.gmail.com> you wrote:
>>> I think we will need to define get_timer() weak - Nios will have to
>>> override the default implementation to cater for it's (Nios') limitations
>> Please don't - isn't the purpose of this whole discussion to use
>> common code for this ?
>>
> Yes, but Nios is particularly bad - It has a 10ms tick counter :(
Hi All,
And a hardware timer that you can't read to subdivide the 10 ms.
Note that this is not necessarily a problem with all NIOS
implementations. The timer characteristics can be controlled when you
generate the bitstream for the FPGA. You can make the counter both
faster and readable if you want. It just uses a bit more silicon. Sad to
say, it probably will require per board get_ticks routine. For the
"old" nios2 timers however, overriding get_timer with a /board routine
is probably the only way to go.

l
> I don't see reason for hamstring other platforms when a simply weak
> function can get around it
Agree.
Best Regards,
Bill Campbel
> Regards,
>
> Graeme
>
>