On 2/26/25 06:59, Rob Herring wrote:
On Wed, Feb 26, 2025 at 09:20:40AM +0100, Krzysztof Kozlowski wrote:
On Tue, Feb 25, 2025 at 09:01:13PM +0800, Cedric Encarnacion wrote:
Add Analog Devices LT3074 Ultralow Noise, High PSRR Dropout Linear
Regulator.
Signed-off-by: Cedric Encarnacion <cedricjustine.encarnacion@xxxxxxxxxx>
---
.../bindings/hwmon/pmbus/adi,lt3074.yaml | 64 ++++++++++++++++++++++
MAINTAINERS | 7 +++
2 files changed, 71 insertions(+)
diff --git a/Documentation/devicetree/bindings/hwmon/pmbus/adi,lt3074.yaml b/Documentation/devicetree/bindings/hwmon/pmbus/adi,lt3074.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..714426fd655a8daa96e15e1f789743f36001ac7a
--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/pmbus/adi,lt3074.yaml
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/hwmon/pmbus/adi,lt3074.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices LT3074 voltage regulator
+
+maintainers:
+ - Cedric Encarnacion <cedricjustine.encarnacion@xxxxxxxxxx>
+
+description: |
+ The LT3074 is a low voltage, ultra-low noise and ultra-fast transient
+ response linear regulator. It allows telemetry for input/output voltage,
+ output current and temperature through the PMBus serial interface.
+
+ Datasheet:
+ https://www.analog.com/en/products/lt3074.html
+
+properties:
+ compatible:
+ enum:
+ - adi,lt3074
+
+ reg:
+ maxItems: 1
+
+ regulators:
+ type: object
+ description: |
+ list of regulators provided by this controller.
You have only one regulator, so drop the "regulators". vout could be
here, but since you do not have any other resources, I doubt it stands
on its own either. This is even visible in your DTS - you named the
device as regulator, so logically this is the regulator. Regulator does
not have regulators (otherwise they could also have regulators... so
triple regulator).
hwmon code might need some changes, but that's not really relevant for
proper hardware description.
Normally, I would agree, but it seems generic pmbus code expects this
structure. This just came up with changing another binding maintained by
'Not Me' to follow this structure. We're stuck with the existing way, so
I don't know that it is worth supporting 2 ways forever. OTOH, is it
guaranteed that these devices will only ever be pmbus devices or that
other regulator devices which are not handled as pmbus devices currently
will be in the future. If so, more flexibility in the bindings will be
needed.
I would appreciate if someone would explain to me what the problems with
the current PMBus code actually are. I have seen several comments claiming
that the code should be changed, but I have no idea what the expected changes
actually are or, in other words, what the PMBus code should be doing
differently.
Thanks,
Guenter
