[U-Boot] [PATCH v7 0/7] add support for atheros ath79 based SOCs

[Marek Vasut]

On Thursday, January 21, 2016 at 03:58:44 AM, Wills Wang wrote:
> On Thursday, January 21, 2016 09:32 AM, Marek Vasut wrote:
> > On Sunday, January 17, 2016 at 01:21:29 PM, Wills Wang wrote:
> >> On 01/17/2016 06:24 PM, Daniel Schwierzeck wrote:
> >>> 2016-01-17 6:49 GMT+01:00 Wills Wang <wills.wang at live.com>:
> >>>> On 01/17/2016 03:05 AM, Marek Vasut wrote:
> >>>>> On Saturday, January 16, 2016 at 07:13:46 PM, Wills Wang wrote:
> >>>>>> These series of patch add support for atheros ath79 based SOCs in
> >>>>>> u-boot, at the present moment it's just available for ar933x and
> >>>>>> qca953x chip.
> >>>>>> 
> >>>>>> This patch serises is based on mips_io_v4 branch on u-boot-mips
> >>>>>> repository
> >>>>>> [1] and tested on ar933x and qca953x board.
> >>>>>> 
> >>>>>> [1]
> >>>>>> 
> >>>>>> http://git.denx.de/?p=u-boot/u-boot-mips.git;a=shortlog;h=refs/heads
> >>>>>> /m ips_ io_v4
> >>>>> 
> >>>>> So if I didn't complain about this being sent as separate emails this
> >>>>> morning.
> >>>>> Please, do send your patches as a series, not as separate emails.
> >>>> 
> >>>> How to send a patch series by patman?
> >>> 
> >>> If your git-sendmail config is correctly set up, patman automatically
> >>> sends the cover letter and then all patches as response to that cover
> >>> letter.
> >>> 
> >>> You have to enable mail threading in git-sendmail. Check that with:
> >>> 
> >>> $ git config --get sendemail.thread
> >>> 
> >>> To enable it globally:
> >>> 
> >>> $ git config --global sendemail.thread true
> >> 
> >> Thanks, i will try it for the coming v8.
> > 
> > I got as far as booting my ar9330 rev 1 machine, though it did take
> > considerably amount of hackery. I also had to use locked cachelines for
> > stack, because it is far faster than using the SRAM on ar9331 . You can
> > find my hacks in the attachment, most of the stuff there is because
> > arduino yun is repugnant crappy piece of hardware and needs some extra
> > treatment.
> 
> My board is also ar9330 rev 1, but i can boot well without any change for
> start.s and cache, is it possible about hardware?

No clue.

> My board work fine when i use DDR or SRAM for stack.

I remember you weren't able to boot if you used SRAM for stack.
Did something change ?

> > You should mostly care about the hacks in start.S , in particular the one
> > setting bit 3 in CP0 in setup_c0_status seems important on mips 24kc
> > core. Daniel seems to have some ideas on this too I think, he helped me
> > finding out there's a problem.
> > 
> > Also, mips_cache_lock_24k does the job for locking the cachelines, but
> > (!) it is clearly a dirty hack. The start.S needs to be modularized in
> > some way for this to be properly integrat(ed|able).
> > 
> > In case I select SYS_MIPS_CACHE_INIT_RAM_LOAD , the machine hangs. No
> > idea why, but I suspect it makes no sense on a machine which has no
> > running DRAM anyway, so I removed this option.
> 
> My hardware can work no matter if i select SYS_MIPS_CACHE_INIT_RAM_LOAD.
> I doubt whether there are same exceptions for your memory subsystem, or
> some DDR parameters are not for your DDR chip.

DDR is not started at the point where INIT_RAM_LOAD comes into play, so
it has nothing to do with it. Instead, refilling the cache from DDR makes
no sense if DDR is not running, therefore this should be disabled to make
sure we don't run into problems.

> > Change to ddr.c seems correct, the values for DDR1 and DDR2 were swapped,
> > but I suggest you double-check it.
> 
> Did your board use DDR1?

DDR2

> I check the original u-boot code again, this value 0xa33 is for DDR2,
> 0x33 for DDR1. The 0 value for WR filed in DDR2 MRS is reserved.

That's correct, so I suspect there's something swapped somewhere, since my
register ends up configured with 0x33 and not 0xa33 . That's why I hacked
this change for now.

> > Ignore my AHB hack in lowlevel_init.S , it's necessary to keep my SPI NOR
> > running at low speed, since I am using an FPGA instead of real SPI NOR
> > and the FPGA implementation of the SPI NOR emulator cannot run at tens
> > of MHz.
> > 
> > I am now looking into implementing ethernet and USB support for ar9331,
> > did you look into it at all or not ? I'd like to avoid duplicating
> > efforts.
> 
> At present, i have no plan to involve ethernet and USB, i want to work
> done first for this patch.

OK, I am looking into the ethernet part now, no luck so far. I cannot even
read the PHY ID yet, probably missing some register bit somewhere.