-----Original Message-----
From: Conor Dooley <conor@kernel.org>
Sent: Thursday, October 26, 2023 11:26 PM
To: Guenter Roeck <linux@roeck-us.net>
Cc: Delphine_CC_Chiu/WYHQ/Wiwynn <Delphine_CC_Chiu@wiwynn.com>;
patrick@stwcx.xyz; Jean Delvare [off-list ref]; 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

On Thu, Oct 26, 2023 at 08:09:52AM -0700, Guenter Roeck wrote:

quoted

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

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  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
+---
+$id: http://devicetree.org/schemas/hwmon/lltc,ltc4286.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LTC4286 power monitors
+
+maintainers:
+  - Delphine CC Chiu <Delphine_CC_Chiu@Wiwynn.com>
+
+properties:
+  compatible:
+    enum:
+      - lltc,ltc4286
+      - lltc,ltc4287

I don't recall seeing an answer to Guenter about this ltc4287 device:
https://lore.kernel.org/all/22f6364c-611c-ffb6-451c-9ddc20418d0a@roe
ck-us.net/

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

https://www.analog.com/en/products/ltc4287.html

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).

Oh neat, would've been good if that'd been mentioned!

quoted

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.

I think, from reading the previous version, that this is actually the lower voltage
range, as there is a 102.x $unit range too that is the default in the hardware.
Obviously, the use of the property could be inverted to match that naming
however.

We will use adi,vrange-low-enable instead of adi,vrange-select-25p6

Cheers,
Conor.