[U-Boot] [PATCH v3 19/26] sunxi: H3/A64: fix non-ODT setting

[Jens Kuske]

On 19.12.2016 11:33, Andre Przywara wrote:
> Hi,
> 
> On 19/12/16 10:01, Maxime Ripard wrote:
>> On Mon, Dec 19, 2016 at 01:50:09AM +0000, Andre Przywara wrote:
>>> According to Jens disabling the on-die-termination should set bit 5,
>>> not bit 1 in the respective register. Fix this.
>>>
>>> Reported-by: Jens Kuske <jenskuske at gmail.com>
>>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>>> ---
>>>  arch/arm/mach-sunxi/dram_sun8i_h3.c | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/arch/arm/mach-sunxi/dram_sun8i_h3.c b/arch/arm/mach-sunxi/dram_sun8i_h3.c
>>> index 6ee73ae..1bdd738 100644
>>> --- a/arch/arm/mach-sunxi/dram_sun8i_h3.c
>>> +++ b/arch/arm/mach-sunxi/dram_sun8i_h3.c
>>> @@ -438,7 +438,7 @@ static int mctl_channel_init(uint16_t socid, struct dram_para *para)
>>>  		clrsetbits_le32(&mctl_ctl->dx[i].gcr, (0x3 << 4) |
>>>  				(0x1 << 1) | (0x3 << 2) | (0x3 << 12) |
>>>  				(0x3 << 14),
>>> -				IS_ENABLED(CONFIG_DRAM_ODT_EN) ? 0x0 : 0x2);
>>> +				IS_ENABLED(CONFIG_DRAM_ODT_EN) ? 0x0 : 0x20);
>>
>> You should use a define here if that bit function is known.
> 
> I agree, and I tried but I failed to find one. That part seems to differ
> from the Keystone documentation, which doesn't know an ODT _dis_able bit
> at all.
> 
> Maybe Jens can add his source?

I think DXnGCR bits 5:4 mean:

	0x0 = dynamic ODT
	0x1 = ODT always on
	0x2 = ODT off

But its only guessed, there is no documentation.
Compare to A83 boot0 code [1], setting dram_odt_en parameter in H3
boot0 to these values results in matching changes in bits 5:4.

Jens

[1] https://github.com/allwinner-zh/bootloader/blob/182661abb29d5467a15eb83cf9824e6471d80d8d/basic_loader/bsp/bsp_for_a83/init_dram/mctl_hal.c#L691-L726