-----Original Message-----
From: Guenter Roeck <redacted> On Behalf Of Guenter Roeck
Sent: Thursday, October 26, 2023 11:10 PM
To: Conor Dooley <conor@kernel.org>; Delphine_CC_Chiu/WYHQ/Wiwynn
[off-list ref]
Cc: patrick@stwcx.xyz; Jean Delvare <jdelvare@suse.com>; Rob Herring
[off-list ref]; Krzysztof Kozlowski
[off-list ref]; Conor Dooley [off-list ref];
Jonathan Corbet [off-list ref]; linux-i2c@vger.kernel.org;
linux-hwmon@vger.kernel.org; devicetree@vger.kernel.org;
linux-kernel@vger.kernel.org; linux-doc@vger.kernel.org
Subject: Re: [PATCH v2 1/2] dt-bindings: hwmon: Add lltc ltc4286 driver
bindings

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On 10/26/23 07:25, Conor Dooley wrote:

quoted

Hey,

On Thu, Oct 26, 2023 at 04:15:11PM +0800, Delphine CC Chiu wrote:

quoted

Add a device tree bindings for ltc4286 driver.

Bindings are for devices, not for drivers.

quoted

Signed-off-by: Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com>

Changelog:
   v2 - Revise vrange_select_25p6 to adi,vrange-select-25p6
      - Add type for adi,vrange-select-25p6
      - Revise rsense-micro-ohms to shunt-resistor-micro-ohms
---
  .../bindings/hwmon/lltc,ltc4286.yaml          | 50

+++++++++++++++++++

quoted

quoted

  MAINTAINERS                                   | 10 ++++
  2 files changed, 60 insertions(+)
  create mode 100644
Documentation/devicetree/bindings/hwmon/lltc,ltc4286.yaml

diff --git
a/Documentation/devicetree/bindings/hwmon/lltc,ltc4286.yaml
b/Documentation/devicetree/bindings/hwmon/lltc,ltc4286.yaml
new file mode 100644
index 000000000000..17022de657bb

--- /dev/null
+++ b/Documentation/devicetree/bindings/hwmon/lltc,ltc4286.yaml

@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
+---
+$id:
+http://dev/

+icetree.org%2Fschemas%2Fhwmon%2Flltc%2Cltc4286.yaml%23&data=05%7C
01%

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+7CWayne_SC_Liu%40wiwynn.com%7Cb250e206c9ef48fbc1c108dbd6359e51
%7Cda6

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+e0628fc834caf9dd273061cbab167%7C0%7C0%7C638339298041650948%7CU
nknown

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+%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haW
wiL

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+CJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=gGQEDl33zRIJbfbinu2%2Bi2cC
Ay6y0o

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+DSLzBpLL7hA%2F8%3D&reserved=0
+$schema:
+http://dev/

+icetree.org%2Fmeta-schemas%2Fcore.yaml%23&data=05%7C01%7CWayne_S
C_Li

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+u%40wiwynn.com%7Cb250e206c9ef48fbc1c108dbd6359e51%7Cda6e0628fc8
34caf

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+9dd273061cbab167%7C0%7C0%7C638339298041650948%7CUnknown%7CT
WFpbGZsb3

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+d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0
%3D

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+%7C3000%7C%7C%7C&sdata=nl1IM1HpYptsJOHfiuXtKFmD%2FVlGMCW1IkoK
HYco0sk

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+%3D&reserved=0
+
+title: LTC4286 power monitors
+
+maintainers:
+  - Delphine CC Chiu [off-list ref]
+
+properties:
+  compatible:
+    enum:
+      - lltc,ltc4286
+      - lltc,ltc4287

I don't recall seeing an answer to Guenter about this ltc4287 device:
https://lore/
.kernel.org%2Fall%2F22f6364c-611c-ffb6-451c-9ddc20418d0a%40roeck-us.n

e

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t%2F&data=05%7C01%7CWayne_SC_Liu%40wiwynn.com%7Cb250e206c9ef48f
bc1c108

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dbd6359e51%7Cda6e0628fc834caf9dd273061cbab167%7C0%7C0%7C6383392
9804165

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0948%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMz
IiLCJBT

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iI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=OpwfD3rBS0vQBF
jUhszrMg

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4mq581jU7gx54Ln8V3gUA%3D&reserved=0

At least the chip does officially exist now, and a datasheet is available.

https://www.ana/
log.com%2Fen%2Fproducts%2Fltc4287.html&data=05%7C01%7CWayne_SC_Li
u%40wiwynn.com%7Cb250e206c9ef48fbc1c108dbd6359e51%7Cda6e0628fc83
4caf9dd273061cbab167%7C0%7C0%7C638339298041650948%7CUnknown%7
CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiL
CJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=CwT16Uipl8RymnFZ1WuBJzUJv
fLCKdK3VlTcTBN0xxk%3D&reserved=0

It shows that coefficients for the telemetry commands are different, meaning
that indeed both chips need to be explicitly referenced in the properties
description (and handled in the driver, which proves my point of needing a
datasheet before accepting such a driver).

We will check the difference of coefficients for the telemetry commands with vendor.

quoted

quoted

+
+  reg:
+    maxItems: 1
+
+  adi,vrange-select-25p6:
+    description:
+      This property is a bool parameter to represent the
+      voltage range is 25.6 or not for this chip.

25.6 what? Volts? microvolts?
What about Guenter's suggestion to name this so that it better matches
the other, similar properties?

I still would prefer one of the more common properties.
I still prefer adi,vrange-high-enable.

Guenter