[PATCH v3 2/3] mmc: dw_mmc-rockchip: Add v2 tuning support

[Shawn Lin]

在 2024/8/15 21:23, Detlev Casanova 写道:
> On Wednesday, 14 August 2024 20:55:37 EDT Shawn Lin wrote:
>> Hi Detlev
>>
>> 在 2024/8/15 6:34, Detlev Casanova 写道:
>>> From: Shawn Lin <shawn.lin at rock-chips.com>
>>>
>>> v2 tuning will inherit pre-stage loader's phase settings for the first
>>> time, and do re-tune if necessary.
>>> Re-tune will still try the rough degrees, for instance, 90, 180, 270,
>>> 360 but continue to do the fine tuning if sample window isn't good
>>> enough.
>>>
>>> Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>
>>> Signed-off-by: Detlev Casanova <detlev.casanova at collabora.com>
>>> ---
>>>
>>>    drivers/mmc/host/dw_mmc-rockchip.c | 49 ++++++++++++++++++++++++++++++
>>>    1 file changed, 49 insertions(+)
>>>
>>> diff --git a/drivers/mmc/host/dw_mmc-rockchip.c
>>> b/drivers/mmc/host/dw_mmc-rockchip.c index b07190ba4b7ac..367633f4e8892
>>> 100644
>>> --- a/drivers/mmc/host/dw_mmc-rockchip.c
>>> +++ b/drivers/mmc/host/dw_mmc-rockchip.c
> 
> [...]
> 
>>>    		
>>>    		priv->default_sample_phase = 0;
>>>
>>> +	priv->use_v2_tuning =
>>> +		of_device_is_compatible(host->dev->of_node,
>>> +					"rockchip,rk3576-dw-
> mshc");
>>> +
>>
>> v2 is a kind of software decision instead of hardware dependency.
>> So in theory, any SoC can claim to use it via DT.
> 
> Yes but from my tests, only rk3576 won't work without it. So it makes sense to
> only use v2 for this SoC (and other future ones not supported yet)
> 

However from both of the IC design POV and the test from my side,
we just need internal phase support patch, and rk3576 could
work.

>>
>>>    	priv->drv_clk = devm_clk_get(host->dev, "ciu-drive");
>>>    	if (IS_ERR(priv->drv_clk))
>>>    	
>>>    		dev_dbg(host->dev, "ciu-drive not available\n");
> 
> 
> Detlev.
> 
>