[U-Boot] [PATCH] OMAP5: Add support for the SOM5_EVB board (OMAP5430-based)

[Sricharan R <r.sricharan@ti.com>]

Hi,

On Wednesday 15 May 2013 01:25 PM, Lubomir Popov wrote:
> Hi Sricharan,
>
> On 15/05/13 08:11, Sricharan R wrote:
>> Hi,
>> On Tuesday 14 May 2013 10:11 PM, Tom Rini wrote:
>>> On Tue, May 14, 2013 at 07:09:33PM +0300, Lubomir Popov wrote:
>>>> Hi Tom,
>>>>
>>>> On 14/05/13 17:52, Tom Rini wrote:
>>>>> On Tue, May 14, 2013 at 01:24:41PM +0300, Lubomir Popov wrote:
>>>>>> Hi Tom,
>>>>>>
>>>>>> I'm currently busy with other work; on the other hand, careful
>>>>>> rebasing shall require some time, especially the Palmas stuff.
>>>>>> What would be the deadline for a V2 submission?
>>>>>>
>>>>>> Meanwhile could you please have a look at the (already old)
>>>>>> http://patchwork.ozlabs.org/patch/232743/? A simple patch,
>>>>>> shall be needed if we enable USB (for the uEVM along with
>>>>>> our board). In general, what are your plans regarding USB
>>>>>> (.../patch/232742/)?
>>>>> Thanks for the reminder, I'll grab 232743 soon.  232742 looks OK, but do
>>>>> you have a patch around for uEVM still?
>>>> Not yet (didn't have the opportunity to test, although some uEVMs should
>>>> be around at MMS). As you know, a patch shall be needed in the uEVM board
>>>> file along with the common USB stuff.
>>> Yeah, I can test it as well if you write it up, and may find the time if
>>> you point me in the right direction.
>>>
>>>>>> And again on I2C (.../patch/233823/): what is you final
>>>>>> opinion? I'm confident that this patch is a major improvement
>>>>>> for OMAP4/5 at least.
>>>>> I'm inclined to go with it, just need to mentally unswap the i2c notes
>>>>> in my brain and think it over one more time.
>>>> Just applied 233823 to current u-boot-ti master. Works fine.
>>> OK, thanks.
>>>
>>>>> [snip]
>>>>>>>>>> +	 * TODO: Replace this ugly hardcoding with proper defines +
>>>>>>>>>> */ +	writel(0x0100, 0x4ae0a310);
>>>>>>>>> Again, do please.
>>>>>>>> This should be (*scrm)->auxclk0. The problem is that the
>>>>>>>> omap5_scrm_regs struct (holding the auxclk0 member) has to be
>>>>>>>> defined somewhere in the common OMAP5 headers. Sricharan? Or should
>>>>>>>> I hack around?
>>>>>>> Add it to the most likely struct in the headers.
>>>>>> The entire struct (I call it omap5_scrm_regs in theory, similar to the
>>>>>> corresponding omap4_scrm_regs for OMAP4) is not defined anywhere. Of
>>>>>> course I could define only the member that I need, but I guess it is
>>>>>> a (responsible) TI job to define hardware descriptors. Or I'm wrong?
>>>>>> Please advise. If I have time, I could do it myself - it's some 27
>>>>>> registers, almost identical to the OMAP4, and should go into 
>>>>>> arch/arm/include/asm/arch-omap5/clocks.h.
>>>>> Whomever uses / needs it should do it.  I gave the TRM a quick read and
>>>>> I don't see any conflicts per-se just some reserved areas being named
>>>>> and vice versa.  So rename it to omap_scrm_regs and move to
>>>>> <asm/omap_common.h>.  Thanks!
>>>> I would argue that this is not very appropriate. Those regs that are
>>>> reserved on the OMAP5 are related to altclkscr and auxclk5 on the OMAP4;
>>>> on the other hand the OMAP5 has some modem clock regs that are reserved
>>>> on OMAP4. We shall probably have ugly #ifdefs again. And what about OMAP3
>>>> and below?
>>> We don't need to use ifdefs since there's no conflicts, things are
>>> either reserved in one case and used in the other.  And we can make sure
>>> we don't try and use the omap5 bits on omap4 and vice versa.  I don't
>>> see scrm in the first omap3 TRM I pulled up, so we don't need to worry
>>> there.
>>>
>>>> Currently the scrm struct is defined for OMAP4 in the asm/arch-omap4/clocks.h
>>>> file and I have already done the same for OMAP5 by analogy. I must admit
>>>> however that this approach does not correspond to the latest way by which
>>>> groups of OMAP hardware regs are defined, prcm in particular - a struct in
>>>> omap_common.h, holding only the required regs, no padding and such garbage,
>>>> and an init with the physical addresses in a .c file for the particular SoC
>>>> (prcm-regs.c). But still the Panda board, for example, uses the old way for
>>>> scrm. Therefore I did it the same for OMAP5, which was easier (I'm old and
>>>> lazy ;) ).
>>> Yes, I'm OK starting off with moving things into omap_common.h as-is and
>>> then updating them a bit later ala pcrm-regs.c.
>>>
>>>
>>  I am sorry for the very late response on this.
>>  Now then, why not add this register in to omap5_es2_prcm
>>  ??. That is how the  TRM sees it as well.. Of course, this is cleanup
>>  stuff for OMAP4  panda as you pointed out..
> Yes, you are right in respect to fluent software integration and consistency
> with current implementation. My only concern is that from architectural point
> of view the SCRM, although related to the PRCM, is a separate module (described
> correspondingly as such in the TRM). If we go this way, the SCRM regs shall
> have to be referenced via the prcm pointer: (*prcm)->xxxxx, and this might be
> confusing.
>
> I'm OK to do it as above, that is, add the SCRM regs (for both OMAP4 and OMAP5)
> to the prcm_regs declaration in omap_common.h, and the required init to the
> appropriate omap5_esx_prcm in prcm-regs.c, but would suggest that for improved
> clarity the SCRM register names, as they now exist in .../arch-omap4/clocks.h,
> start with a scrm_ prefix.
>
> Alternatively, a new scrm_regs struct could be declared in omap_common.h, along
> with the appropriate pointers, and the corresponding definitions/inits added as
> new structs in prcm-regs.c for every SoC. But then the file name prcm-regs shall
> be a bit confusing.
>
> What do you say?
  At this point , i think just adding only the registers that you need in to the
 prcm structure should be ok.

Regards,
 Sricharan