[PATCH 1/2] dt-bindings: power: supply: ltc3350-charger: Add bindings

[PATCH 1/2] dt-bindings: power: supply: ltc3350-charger: Add bindings

[Mike Looijmans]

The LTC3350 is a backup power controller that can charge and monitor
a series stack of one to four supercapacitors.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---

 .../bindings/power/supply/ltc3350.yaml        | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/supply/ltc3350.yaml

diff --git a/Documentation/devicetree/bindings/power/supply/ltc3350.yaml b/Documentation/devicetree/bindings/power/supply/ltc3350.yaml
new file mode 100644
index 000000000000..607a62fd25ba
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/supply/ltc3350.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+# Copyright (C) 2024 Topic Embedded Products
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/power/supply/ltc3350.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Linear Technology (Analog Devices) LTC3350 Supercap Charger
+
+maintainers:
+  - Mike Looijmans <mike.looijmans@topic.nl>
+
+description: |
+  The LTC3350 is a  High Current Supercapacitor Backup Controller and System
+  Monitor.
+  Specifications about the charger can be found at:
+    https://www.analog.com/en/products/ltc3350.html
+
+properties:
+  compatible:
+    enum:
+      - lltc,ltc3350
+
+  reg:
+    maxItems: 1
+    description: I2C address of the charger.
+
+  lltc,rsnsc-micro-ohms:
+    description: Capacitor charger sense resistor in microohm.
+    minimum: 1000
+
+  lltc,rsnsi-micro-ohms:
+    description: Input current sense resistor in microohm.
+    minimum: 1000
+
+required:
+  - compatible
+  - reg
+  - lltc,rsnsc-micro-ohms
+  - lltc,rsnsi-micro-ohms
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      charger: battery-charger@9 {
+              compatible = "lltc,ltc3350";
+              reg = <0x9>;
+              lltc,rsnsc-micro-ohms = <10000>;
+              lltc,rsnsi-micro-ohms = <10000>;
+      };
+    };
-- 
2.34.1


Met vriendelijke groet / kind regards,

Mike Looijmans
System Expert


TOPIC Embedded Products B.V.
Materiaalweg 4, 5681 RJ Best
The Netherlands

T: +31 (0) 499 33 69 69
E: mike.looijmans@topic.nl
W: www.topic.nl

Please consider the environment before printing this e-mail

Re: [PATCH 1/2] dt-bindings: power: supply: ltc3350-charger: Add bindings

[Krzysztof Kozlowski]

On 08/04/2024 08:49, Mike Looijmans wrote:
> The LTC3350 is a backup power controller that can charge and monitor
> a series stack of one to four supercapacitors.
> 
> Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
> ---
> 
>  .../bindings/power/supply/ltc3350.yaml        | 55 +++++++++++++++++++


Missing vendor prefix, use compatible as filename.

>  1 file changed, 55 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power/supply/ltc3350.yaml
> 
> diff --git a/Documentation/devicetree/bindings/power/supply/ltc3350.yaml b/Documentation/devicetree/bindings/power/supply/ltc3350.yaml
> new file mode 100644
> index 000000000000..607a62fd25ba
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power/supply/ltc3350.yaml
> @@ -0,0 +1,55 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright (C) 2024 Topic Embedded Products
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/power/supply/ltc3350.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Linear Technology (Analog Devices) LTC3350 Supercap Charger
> +
> +maintainers:
> +  - Mike Looijmans <mike.looijmans@topic.nl>
> +
> +description: |
> +  The LTC3350 is a  High Current Supercapacitor Backup Controller and System

Just one space after 'a'.

> +  Monitor.
> +  Specifications about the charger can be found at:
> +    https://www.analog.com/en/products/ltc3350.html
> +
> +properties:
> +  compatible:
> +    enum:
> +      - lltc,ltc3350
> +
> +  reg:
> +    maxItems: 1
> +    description: I2C address of the charger.

Drop description, it is obvious.

> +
> +  lltc,rsnsc-micro-ohms:
> +    description: Capacitor charger sense resistor in microohm.
> +    minimum: 1000
> +
> +  lltc,rsnsi-micro-ohms:
> +    description: Input current sense resistor in microohm.
> +    minimum: 1000

Looks like it is shunt-resistor-micro-ohms. Unless it is something
different?

> +
> +required:
> +  - compatible
> +  - reg
> +  - lltc,rsnsc-micro-ohms
> +  - lltc,rsnsi-micro-ohms
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      charger: battery-charger@9 {
> +              compatible = "lltc,ltc3350";

Messed indentation. Keep it consistent.

Best regards,
Krzysztof

Re: [PATCH 1/2] dt-bindings: power: supply: ltc3350-charger: Add bindings

[Mike Looijmans]

Thanks for your feedback. Will fix them all, except see below.

I'll send a v2


On 09-04-2024 10:27, Krzysztof Kozlowski wrote:
...
>> +
>> +  lltc,rsnsc-micro-ohms:
>> +    description: Capacitor charger sense resistor in microohm.
>> +    minimum: 1000
>> +
>> +  lltc,rsnsi-micro-ohms:
>> +    description: Input current sense resistor in microohm.
>> +    minimum: 1000
> Looks like it is shunt-resistor-micro-ohms. Unless it is something
> different?

It's a shunt, but different and there's two of them (akin to the 
ltc4162-l which has the same property with the same meaning). One to 
measure input, one to measure charge current.

When the datasheet talks about "shunt" it means the resistor that can be 
used to balance or discharge the caps. So I'd rather avoid the word 
completely so users aren't tempted to put the wrong resistor value there.

The datasheet uses "rsnsi" and "rsnsc" whenever referring to these 
resistors.


...


-- 
Mike Looijmans
System Expert

TOPIC Embedded Products B.V.
Materiaalweg 4, 5681 RJ Best
The Netherlands

T: +31 (0) 499 33 69 69
E: mike.looijmans@topic.nl
W: www.topic.nl