Re: [PATCH 07/13] dt-bindings: media: camss: Add qcom,sm8550-camss binding

From: Bryan O'Donoghue
Date: Thu Sep 12 2024 - 07:41:40 EST


On 12/09/2024 09:22, Vladimir Zapolskiy wrote:
+
+  vdda-phy-supply:
+    description:
+      Phandle to a regulator supply to PHY core block.
+
+  vdda-pll-supply:
+    description:
+      Phandle to 1.2V regulator supply to PHY refclk pll block.
+

Here the supplies should be split into ones, which are specific to CSI blocks,
and I believe they shall be set as optional.

In principle I agree with that, each CSIPHY should have its own vdda-phy and vdda-pll regulator specified.

In practice though I don't believe its necessary, below.

The proposed names are:

vdda-phy-01-supply
vdda-pll-01-supply
vdda-phy-23-supply
vdda-pll-23-supply
vdda-phy-46-supply
vdda-pll-46-supply
vdda-phy-57-supply
vdda-pll-57-supply

In principle, you're right, we need to expand the name set here.

I understand that what I ask is much more clumsy, and it could be seen even as
unneeded, however it'll be the right set of properties to describe the CAMSS IP
in this respect
I think the following naming would be better as it matches the power-grid naming in the docs.

csiphyX-vdda-phy-supply
csiphyX-vdda-pll-supply

=>

// voltage domain = vdd_a_csi_01_09 = regulator l1e
csiphy0-vdda-phy-supply = <&vreg_l1e_0p9>;

// voltage domain = vdd_a_csi_01_1p2 = regulator l3e
csiphy0-vdda-pll-supply = <&vreg_l3e_1p2>;

//
csiphy1-vdda-phy-supply = <&vreg_l1e_0p9>;
csiphy1-vdda-pll-supply = <&vreg_l3e_1p2>;

Where X indicates the CSIPHY number.

So in fact, in practice we don't need to differentiate these entries.

Checking x1e80100 ...

csiphy0

vdda-phy-supply = <&vreg_l2c_0p9>;
vdda-pll-supply = <&vreg_l1c_1p2>;

This is also the case for csiphy 1/2/4

So, I _don't_ believe this is work we need to do, since its the same regulator for each PHY.

---
bod