On 06/10/2021 08:56, Krzysztof Kozlowski wrote:

On 05/10/2021 17:59, Hector Martin wrote:

quoted

The PMGR block in Apple Silicon SoCs is responsible for SoC power
management. There are two PMGRs in T8103, with different register
layouts but compatible registers. In order to support this as well
as future SoC generations with backwards-compatible registers, we
declare these blocks as syscons and bind to individual registers
in child nodes. Each register controls one SoC device.

The respective apple compatibles are defined in case device-specific
quirks are necessary in the future, but currently these nodes are
expected to be bound by the generic syscon driver.

Signed-off-by: Hector Martin <redacted>
---
 .../bindings/arm/apple/apple,pmgr.yaml        | 74 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 75 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml

diff --git a/Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml b/Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml
new file mode 100644
index 000000000000..0304164e4140
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/apple/apple,pmgr.yaml

@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/arm/apple/apple,pmgr.yaml#

Please don't store all Apple-related bindings in bindings/arm/apple, but
instead group per device type like in most of other bindings. In this
case - this looks like something close to power domain controller, so it
should be in bindings/power/

quoted

+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SoC Power Manager (PMGR)
+
+maintainers:
+  - Hector Martin [off-list ref]
+
+description: |
+  Apple SoCs include a PMGR block responsible for power management,
+  which can control various clocks, resets, power states, and
+  performance features. This node represents the PMGR as a syscon,
+  with sub-nodes representing individual features.
+
+  Apple SoCs may have a secondary "mini-PMGR"; it is represented
+  separately in the device tree, but works the same way.
+
+select:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - apple,t8103-pmgr
+          - apple,t8103-minipmgr
+          - apple,pmgr
+
+  required:
+    - compatible
+
+properties:
+  $nodename:
+    pattern: "^power-management@[0-9a-f]+$"
+
+  compatible:
+    items:
+      - enum:
+          - apple,t8103-pmgr
+          - apple,t8103-minipmgr
+      - const: apple,pmgr
+      - const: syscon
+      - const: simple-mfd

No power-domain-cells? Why? What exactly this device is going to do?
Maybe I'll check the driver first.... :)

After looking at the code, there is no device for
apple,t8103-pmgr/apple,pmgr. What is this binding about? Is there really
a central (central as in "one device for SoC") block managing power
which you want to model here?


Best regards,
Krzysztof

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