Re: [PATCH v1 1/6] dt-bindings: soc: mediatek: Add DVFSRC bindings for MT8183 and MT8195

From: AngeloGioacchino Del Regno
Date: Wed Apr 17 2024 - 04:26:21 EST


Il 16/04/24 19:30, Conor Dooley ha scritto:
On Tue, Apr 16, 2024 at 06:28:58PM +0100, Conor Dooley wrote:
On Tue, Apr 16, 2024 at 05:38:00PM +0200, AngeloGioacchino Del Regno wrote:
Add bindings for the MediaTek Dynamic Voltage and Frequency Scaling
Resource Collector (DVFSRC), a hardware module used to collect all the
requests from both software and the various remote processors embedded
into the SoC and decide about a minimum operating voltage and a minimum
DRAM frequency to fulfill those requests in an effort to provide the
best achievable performance per watt.

This hardware IP is capable of transparently performing direct register
R/W on all of the DVFSRC-controlled regulators and SoC bandwidth knobs.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
.../soc/mediatek/mediatek,mt8183-dvfsrc.yaml | 57 +++++++++++++++++++
1 file changed, 57 insertions(+)
create mode 100644 Documentation/devicetree/bindings/soc/mediatek/mediatek,mt8183-dvfsrc.yaml

diff --git a/Documentation/devicetree/bindings/soc/mediatek/mediatek,mt8183-dvfsrc.yaml b/Documentation/devicetree/bindings/soc/mediatek/mediatek,mt8183-dvfsrc.yaml
new file mode 100644
index 000000000000..12bcc3fdfd07
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/mediatek/mediatek,mt8183-dvfsrc.yaml
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/mediatek/mediatek,mt8183-dvfsrc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek Dynamic Voltage and Frequency Scaling Resource Collector (DVFSRC)
+
+description:
+ The Dynamic Voltage and Frequency Scaling Resource Collector (DVFSRC) is a
+ Hardware module used to collect all the requests from both software and the
+ various remote processors embedded into the SoC and decide about a minimum
+ operating voltage and a minimum DRAM frequency to fulfill those requests in
+ an effort to provide the best achievable performance per watt.
+ This hardware IP is capable of transparently performing direct register R/W
+ on all of the DVFSRC-controlled regulators and SoC bandwidth knobs.
+
+maintainers:
+ - AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
+ - Henry Chen <henryc.chen@xxxxxxxxxxxx>
+
+properties:
+ compatible:
+ oneOf:
+ - items:

This items should not be needed with the enum, right?


Whoops. Yep items is not needed.

+ - enum:
+ - mediatek,mt8183-dvfsrc
+ - mediatek,mt8195-dvfsrc
+ - items:
+ - const: mediatek,mt8192-dvfsrc
+ - const: mediatek,mt8195-dvfsrc
+
+ reg:
+ maxItems: 1
+ description: DVFSRC common register address and length.
+
+patternProperties:
+ "@[0-9a-f]+$":
+ type: object

Why is there no enforcement of what a child could be here?

Seems like you know exactly what the children are: regulators and an
interconnect? What am I missing?


I wasn't sure whether that would've been a good idea, given that there will
be more possible children in the future - as in - more drivers that need the
DVFSRC communication.

But anyway yes, for now, it's just the regulator and interconnect drivers.


+required:
+ - compatible
+ - reg
+
+additionalProperties: false
+
+examples:
+ - |
+ soc {
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ dvfsrc@10012000 {

"dvfsrc" looks like something my (imaginary given allergies) cat would

(allergies: ugh, same here - feel you)

produce from sitting on my keyboard. Could you use full words for the
node name and make it something that attempts to be generic please?


I'm not entirely sure that I can find a generic name for this... I wonder if
"remoteproc" could work - as this is a remote processor (a MCU, actually).

To give you context, this doesn't need firmware to be loaded, and does not have
any remoteproc driver.

Because then, I don't think that "performance-controller" would be correct,
even though I have this N.2 choice... ideas?

Cheers,
Angelo

+ compatible = "mediatek,mt8195-dvfsrc";
+ reg = <0 0x10012000 0 0x1000>;
+ };
+ };
--
2.44.0