[PATCH 5/9] ARM: dts: Add GPMC node for OMAP2, OMAP4 and OMAP5

[Benoit Cousson]

On 03/14/2013 04:50 PM, Jon Hunter wrote:
> 
> On 03/14/2013 10:45 AM, Benoit Cousson wrote:
>> On 03/11/2013 06:56 PM, Jon Hunter wrote:
>>>
>>> On 03/09/2013 06:42 AM, Ezequiel Garcia wrote:
>>>> On Fri, Mar 8, 2013 at 10:25 PM, Javier Martinez Canillas
>>>> <javier at dowhile0.org> wrote:
>>>>> On Fri, Mar 8, 2013 at 10:41 PM, Jon Hunter <jon-hunter at ti.com> wrote:
>>>>>>
>>>>>> Yes you are correct. In general, I have been trying to stay some-what
>>>>>> consistent with what hwmod was doing as this was being auto-generated by
>>>>>> some hardware design specs and I believe they wanted to eventually get
>>>>>> to the point where DT files would be auto-generated too for OMAP.
>>>>>> Furthermore my understanding is that the smallest page that can be
>>>>>> mapped by the kernel for ARM is 4kB. So if you declare it as 0x2d0 or
>>>>>> 0x1000 it will map a 4kB page (I could be wrong here).
>>>>>>
>>>>>> I don't have any strong feelings here but will do what the consensus
>>>>>> prefers.
>>>>>>
>>>>>
>>>>> Yes, you are right here.
>>>>>
>>>>> I forget that ioremap() does a page-aligned mapping and since the
>>>>> minimum page size for ARM is 4KB as you said, there is no difference
>>>>> between using 0x2d0 and 0x1000. Sorry for the noise.
>>>>>
>>>>
>>>> Certainly, I don't have strong feelings about this.
>>>> FWIW, mvebu maintainers imposes a "minimal" address space request
>>>> policy.
>>>>
>>>> On the other side, it seems to me we shouldn't look at internal kernel
>>>> implementation (i.e. ioremap page-alignment) to make this decision.
>>>
>>> I agree with that. I am not sure if Tony/Benoit have any comments on
>>> what they would like to do here to be consistent for the omap bindings.
>>
>> Yes, I full agree with that as well. The size should be purely HW
>> related. So we should not take any assumption about the page size /
>> alignment.
> 
> Ok, what is best to use? The size from hwmod structures or the size from
> the documentation?

Well, in theory both are supposed to be identical :-)
I'm just applying a rounding to the closet power of two, that's why it
cannot be 0x2d0.

Regards,
Benoit