[RFC][PATCH 03/10] bcma: add embedded bus

[Hauke Mehrtens <hauke@hauke-m.de>]

On 06/07/2011 12:30 PM, Arend van Spriel wrote:
> On 06/07/2011 02:33 AM, Rafa? Mi?ecki wrote:
>> W dniu 7 czerwca 2011 00:00 u?ytkownik Hauke Mehrtens
>> <hauke@hauke-m.de>  napisa?:
>>> On 06/06/2011 12:22 PM, Rafa? Mi?ecki wrote:
>>>>> +       if (bus->hosttype == BCMA_HOSTTYPE_EMBEDDED) {
>>>>> +               iounmap(bus->mmio);
>>>>> +               mmio = ioremap(BCMA_ADDR_BASE, BCMA_CORE_SIZE *
>>>>> bus->nr_cores);
>>>>> +               if (!mmio)
>>>>> +                       return -ENOMEM;
>>>>> +               bus->mmio = mmio;
>>>>> +
>>>>> +               mmio = ioremap(BCMA_WRAP_BASE, BCMA_CORE_SIZE *
>>>>> bus->nr_cores);
>>>>> +               if (!mmio)
>>>>> +                       return -ENOMEM;
>>>>> +               bus->host_embedded = mmio;
>>>> Do we really need both? mmio and host_embedded? What about keeping
>>>> mmio only and using it in calculation for read/write[8,16,32]?
>>> These are two different memory regions, it should be possible to
>>> calculate the other address, but I do not like that. As host_embedded is
>>> in a union this does not waste any memory.
>> Ah, OK, I can see what does happen here. You are using:
>> 1) bus->mmio for first core
>> 2) bus->host_embedded for first agent/wrapper
>>
>> I'm not sure if this is a correct approach. Doing "core_index *
>> BCMA_CORE_SIZE" comes from ssb, where it was the way to calculate
>> offset. In case of BCMA we are reading all the info from (E)EPROM,
>> which also includes addresses of the cores.
>>
>> IMO you should use core->addr and core->wrap for read/write ops. I
>> believe this is approach Broadcom decided to use for BCMA, when
>> designing (E)EPROM.
> 
> Agree. There is no guarantee for the core index to relate to the
> physical address. Chip designer may be systematic in this and the
> index*size method may work, but not by design.
> 
> Gr. AvS
> 
Ok I will use these addresses.

Hauke