Re: [v1 1/3] dt-bindings: msm/dsi: Add yaml schema for 7nm DSI PHY

From: rajeevny
Date: Fri Jun 18 2021 - 06:39:23 EST



On 17-06-2021 20:37, Jonathan Marek wrote:
On 6/16/21 1:50 AM, rajeevny@xxxxxxxxxxxxxx wrote:
On 03-06-2021 01:32, rajeevny@xxxxxxxxxxxxxx wrote:
On 02-06-2021 02:28, Rob Herring wrote:
On Mon, May 31, 2021 at 07:03:53PM +0530, Rajeev Nandan wrote:

+
+properties:
+  compatible:
+    oneOf:
+      - const: qcom,dsi-phy-7nm

When would one use this?
This is for SM8250.


+      - const: qcom,dsi-phy-7nm-7280
+      - const: qcom,dsi-phy-7nm-8150

These don't look like full SoC names (sm8150?) and it's
<vendor>,<soc>-<block>.

Thanks, Rob, for the review.

I just took the `compatible` property currently used in the DSI PHY driver
(drivers/gpu/drm/msm/dsi/phy/dsi_phy.c), and added a new entry for sc7280.
A similar pattern of `compatible` names are used in other variants of the
DSI PHY driver e.g. qcom,qcom,dsi-phy-10nm-8998, qcom,dsi-phy-14nm-660 etc.

The existing compatible names "qcom,dsi-phy-7nm-8150" (SoC at the end) make
some sense, if we look at the organization of the dsi phy driver code.
I am new to this and don't know the reason behind the current code
organization and this naming.

Yes, I agree with you, we should use full SoC names. Adding
the SoC name at the end does not feel very convincing, so I will change this
to the suggested format e.g. "qcom,sm8250-dsi-phy-7nm", and will rename the
occurrences in the driver and device tree accordingly.
Do I need to make changes for 10nm, 14nm, 20nm, and 28nm DSI PHY too?
Bindings doc for these PHYs recently got merged to msm-next [1]


[1]
https://gitlab.freedesktop.org/drm/msm/-/commit/8fc939e72ff80116c090aaf03952253a124d2a8e

Hi Rob,

I missed adding "robh+dt@xxxxxxxxxx" earlier in this thread.

Please check my response to your review comments. Regarding your suggestion to use <vendor>,<soc>-<block> format for compatible property, should I also upload a new patch to make changes in 10nm, 14nm, 20nm, and 28nm DSI PHY DT bindings?

Thanks,
Rajeev


Hi,

I missed this and ended up sending a similar patch a week later (as
part of my cphy series, because I needed it to add a "phy-type"
property).

"qcom,dsi-phy-7nm" and "qcom,dsi-phy-7nm-8150" aren't new compatibles,
they were previously documented in the .txt bindings, which are
getting removed, but the new .yaml bindings didn't include them.
Documenting them is just a fixup to that patch [1] which is already
R-B'd by RobH (and has similar compatibles such as "qcom,dsi-phy-10nm"
and "qcom,dsi-phy-10nm-8998
").

You can use a different/better naming scheme for sc7280, but changing
the others has nothing to do with adding support for sc7280.

[1]
https://gitlab.freedesktop.org/drm/msm/-/commit/8fc939e72ff80116c090aaf03952253a124d2a8e

Hi Jonathan,

I will discard this patch and will add the bindings for the sc7280 on top of your patch [1].

[1] https://lore.kernel.org/linux-arm-msm/20210617144349.28448-2-jonathan@xxxxxxxx/


Thanks,
Rajeev