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

Am Donnerstag, 15. August 2024, 15:23:40 CEST schrieb Detlev Casanova:

On Wednesday, 14 August 2024 20:55:37 EDT Shawn Lin wrote:

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Hi Detlev

在 2024/8/15 6:34, Detlev Casanova 写道:

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From: Shawn Lin <shawn.lin@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@rock-chips.com>
Signed-off-by: Detlev Casanova <detlev.casanova@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

[...]

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  		priv->default_sample_phase = 0;

+	priv->use_v2_tuning =
+		of_device_is_compatible(host->dev->of_node,
+					"rockchip,rk3576-dw-

mshc");

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+

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)

Good know and thanks for testing that scenario.

If you go with my suggestion from patch3 and separate the rk3576
from the original rk3288 type, you can even just assume this v2-tuning
for all those types (rk3576 only so far)

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  	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.