[U-Boot] A23 u-boot with SPL / dram init available in my personal git repo

[Hans de Goede]

Hi,

On 09-12-14 11:17, Chen-Yu Tsai wrote:
> Hi,
>
> On Tue, Dec 9, 2014 at 2:53 AM, Hans de Goede <hdegoede at redhat.com> wrote:
>> Hi,
>>
>> On 08-12-14 15:28, Chen-Yu Tsai wrote:
>>>
>>> On Mon, Dec 8, 2014 at 4:27 AM, Hans de Goede <hdegoede at redhat.com> wrote:
>>>>
>>>> Hi,
>>>>
>>>> This is still a bit rough around the edges, I'll clean it up as
>>>> time permits and then post it upstream.
>>>>
>>>> In the mean time people interested can find $subject here:
>>>> https://github.com/jwrdegoede/u-boot-sunxi/commits/sunxi-wip
>>>
>>>
>>> Hopefully I'll get around to testing this. BTW, what tablet do
>>> you have?
>>
>>
>> I've an Ippo q8h v1.2, there are at least 2 differences from the
>> v5 you've. The dram clk speed and zq value are different, and the wifi
>> is different. The wifi does not matter for u-boot, but does mean we
>> need separate dtb files for the 2.
>>
>> My u-boot sunxi-wip branch has a defconfig for the v1.2, you should be
>> able to copy that over to the v5 defconfig, adjust dram clk and zq values
>> with the ones from the v5 fix, change v1.2 to v5 in the CONFIG_FDTFILE
>> setting and thats it.
>>
>> Let me know if this works, then I'll also include an update for the v5
>> defconfig to enable the SPL when I send this upstream.
>
> Just gave it a spin, and it works. The dram clock and zq can be
> found in sunxi-boards.

Good, I'll update my patch-set to reflect this.

> Note that the actual settings fetched from
> stock u-boot has the highest bit of tpr13 set, disabling auto
> detection AFAICU. As you've not implemented that part, I used
> auto detection and it seems to work.

It is implemented in the actual dram_init code, but for now I've
all the dram_paras hardcoded except the clk and the zq value. If
autodetect works I see no reason to change this, but for future models,
if necessary the code for dealing with manual config is there, to test
just put the values directly in the dram_para struct at the top of
dram_sun8i.c .

> The only problem I have now is it has no connectivity to the
> outside world lol. I would've liked a v2, with a Realtek USB
> WiFi chip. What chip does the v1.2 have?

An sdio based chip, the RDA RDA5990P, as mentioned here:

http://linux-sunxi.org/Ippo_q8h#Q8H-V1.2

It does have an empty spot on the pcb for a usb wifi module, I plan to
hookup a usb connector to that one of these days, and see if I can get
a USB host working this way.

>>>> ChenYu, this also has a mmc fix which you may find interesting,
>>>> it may explain some of the problems with mmc you've been having
>>>> on both the A80 board, as well as the A31 dev board you've.
>>>
>>>
>>> Yes. With that fix my Hummingbird A31 boots properly without
>>> raising DCDC1 to 3.3V.
>>>
>>> Thanks! I'll send the defconfig out later.
>>
>>
>> Good, so I guess this means that DCDC1 should be 3V for your board,
>> since that is what the factory firmware uses, right ?
>>
>> I guess it is time to make DCDC1 voltage configurable.
>
> 3V seems to be the lowest tolerable voltage for some bits. Making it
> 3.3V might be a bit better. But with my light usage, I don't see any
> stability issues.

Right, I guess 3V is used to safe battery, which makes sense (in tablets /
phones)

As said I'll make this configurable making 3V the default and set 3V3
in the defconfig where the original firmware does that.

Regards,

Hans