On 15/08/2022 18:32, Heiko Stübner wrote:

Am Montag, 15. August 2022, 06:34:32 CEST schrieb Samuel Holland:

quoted

The Allwinner D1 SoC contains two pairs of in-package LDOs. One pair is
for general purpose use. LDOA generally powers the board's 1.8 V rail.
LDOB generally powers the in-package DRAM, where applicable.

The other pair of LDOs powers the analog power domains inside the SoC,
including the audio codec, thermal sensor, and ADCs. These LDOs require
a 0.9 V bandgap voltage reference. The calibration value for the voltage
reference is stored in an eFuse, accessed via an NVMEM cell.

Neither LDO control register is in its own MMIO range; instead, each
regulator device relies on a regmap/syscon exported by its parent.

Signed-off-by: Samuel Holland <samuel@sholland.org>
---

Changes in v3:
 - Add "reg" property to bindings
 - Add "unevaluatedProperties: true" to regulator nodes
 - Minor changes to regulator node name patterns
 - Remove system-ldos example (now added in patch 3)

Changes in v2:
 - Remove syscon property from bindings
 - Update binding examples to fix warnings and provide context

 .../allwinner,sun20i-d1-analog-ldos.yaml      | 74 +++++++++++++++++++
 .../allwinner,sun20i-d1-system-ldos.yaml      | 37 ++++++++++
 2 files changed, 111 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-analog-ldos.yaml
 create mode 100644 Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-system-ldos.yaml

diff --git a/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-analog-ldos.yaml b/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-analog-ldos.yaml
new file mode 100644
index 000000000000..d6964b44ef21
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/allwinner,sun20i-d1-analog-ldos.yaml

@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/allwinner,sun20i-d1-analog-ldos.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Allwinner D1 Analog LDOs
+
+description:
+  Allwinner D1 contains a set of LDOs which are designed to supply analog power
+  inside and outside the SoC. They are controlled by a register within the audio
+  codec MMIO space, but which is not part of the audio codec clock/reset domain.
+
+maintainers:
+  - Samuel Holland <samuel@sholland.org>
+
+properties:
+  compatible:
+    enum:
+      - allwinner,sun20i-d1-analog-ldos
+
+  reg:
+    maxItems: 1
+
+  nvmem-cells:
+    items:
+      - description: NVMEM cell for the calibrated bandgap reference trim value
+
+  nvmem-cell-names:
+    items:
+      - const: bg_trim

aren't dashes "-" preferred over underscores "_" in
string names?

Maybe even make this "bandgap-trim" for a bit more
explanatory naming?

In node names yes. In strings, I think there is no preference. At least
I am not aware of it.

Best regards,
Krzysztof