Add documentation for the 2-channel LTC2305 ADC in the
existing ltc2497 binding.
This enables automatic device tree matching for LTC2305
while using the LTC2309 driver (drivers/iio/adc/ltc2309.c),
since both ADCs share the same I2C interface and 12-bit SAR architecture.
The main difference is the number of channels (LTC2305: 2, LTC2309: 8).

Signed-off-by: Kyle Hsieh <kylehsieh1995@gmail.com>
---
 Documentation/devicetree/bindings/iio/adc/lltc,ltc2497.yaml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/lltc,ltc2497.yaml b/Documentation/devicetree/bindings/iio/adc/lltc,ltc2497.yaml
index 5cc6a9684077..c884b6e03767 100644
--- a/Documentation/devicetree/bindings/iio/adc/lltc,ltc2497.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/lltc,ltc2497.yaml
@@ -11,6 +11,12 @@ maintainers:
   - Liam Beguin <liambeguin@gmail.com>
 
 description: |
+  LTC2305:
+    low noise, low power, 2-channel, 12-bit successive approximation ADC with an
+    I2C compatible serial interface.
+
+    https://www.analog.com/media/en/technical-documentation/data-sheets/23015fb.pdf
+
   LTC2309:
     low noise, low power, 8-channel, 12-bit successive approximation ADC with an
     I2C compatible serial interface.
@@ -28,6 +34,7 @@ description: |
 properties:
   compatible:
     enum:
+      - lltc,ltc2305
       - lltc,ltc2309
       - lltc,ltc2497
       - lltc,ltc2499

-- 
2.34.1

On Wed, Dec 24, 2025 at 01:37:14PM +0800, Kyle Hsieh wrote:
> Add documentation for the 2-channel LTC2305 ADC in the
> existing ltc2497 binding.
> This enables automatic device tree matching for LTC2305
> while using the LTC2309 driver (drivers/iio/adc/ltc2309.c),

Not relevant sentence. And if I disable automatic matching in the
kernel, does that invalidate binding? What about BSD?

> since both ADCs share the same I2C interface and 12-bit SAR architecture.
> The main difference is the number of channels (LTC2305: 2, LTC2309: 8).

These two are fine. Just describe the hardware.

Best regards,
Krzysztof

On Sat, Dec 27, 2025 at 8:39 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
>
> On Wed, Dec 24, 2025 at 01:37:14PM +0800, Kyle Hsieh wrote:
> > Add documentation for the 2-channel LTC2305 ADC in the
> > existing ltc2497 binding.
> > This enables automatic device tree matching for LTC2305
> > while using the LTC2309 driver (drivers/iio/adc/ltc2309.c),
>
> Not relevant sentence. And if I disable automatic matching in the
> kernel, does that invalidate binding? What about BSD?
>
> > since both ADCs share the same I2C interface and 12-bit SAR architecture.
> > The main difference is the number of channels (LTC2305: 2, LTC2309: 8).
>
> These two are fine. Just describe the hardware.
Thanks for the review.

I will remove the sentence about device tree matching and driver usage,
and keep the binding documentation focused on hardware description only.

Best regards,
Kyle Hsieh
>
> Best regards,
> Krzysztof
>