Re: [PATCH v3 3/3] Docs: iio: Add AD4134

[Tomas Melin <tomas.melin@vaisala.com>]

Hi,

On 04/12/2025 17:32, Marcelo Schmitt wrote:
> On 12/03, Tomas Melin wrote:
>> Hi,
>>
>> On 02/12/2025 22:55, Marcelo Schmitt wrote:
>>> Add initial documentation for the ad4134 IIO driver.
>>
>> I wonder is there some information in here that is not readily available
>> in the device datasheet? After all, isn't idea with this file to
>> document peculiarities that are not easily found elsewhere?
> 
> You are correct, these docs are mostly from data sheet info.
> The main idea of having the doc is to make clear what peripheral connection
> schema is currently supported.
> Because AD4134 is both flexible and somewhat extensible in the way it can be
> connected to the host, we could have different wiring configurations, for
> example

Thanks for your explanation. My humble opinion is that it would be
enough to mention in the commit message for the driver being added, or
in the device-tree bindings that basic I/O mode is only configuration
that is currently supported.

Thanks,
Tomas


> 
>                                                               +-------------+
>   +----------------------+                                    |  DATA HOST  |
>   |       AD4134         |                                    |             |
>   |                      |                                    |             |
>   |Data interface  DOUT0 |----------------------------------->| GPI0        |
>   |for ADC data    DOUT1 |----------------------------------->| GPI1        |
>   |read back       DOUT2 |----------------------------------->| GPI2        |
>   |                DOUT3 |----------------------------------->| GPI3        |
>   |                DCLK  |<--------------+        +---------->| GPI4        |
>   |                ODR   |<------------+ |        | +-------->| GPI5        |
>   |                      |             | |        | | +------>| GPI6        |
>   |                      |             | |        | | | +---->| GPI7        |
>   | SPI interface   CS   |<-------+    | +--------|-|-|-|-----| DCLK        |
>   | for register    SCLK |<-----+ |    |          | | | |     |             |
>   | access          SDI  |<---+ | |    |          | | | |     | TRIGGER     |
>   |                 SDO  |--+ | | |    |          | | | |     +-------------+
>   +----------------------+  | | | |    +----------|-|-|-|---------+
>                             | | | +---------------+ | | |
>                             | | +-------------------+ | |
>                             | +-----------------------+ |
>                             +---------------------------+
> 
> or even with two devices [1].
> [1]: https://lore.kernel.org/linux-iio/aRIIDTUR5Pyz1Rxi@debian-BULLSEYE-live-builder-AMD64/
> 
> That is not a current use case but it could be possible. I think it's likely we
> will need extra software to support those cases and, when we get to that, we
> would be adding more diagrams to this doc. Still, no strong opinion, we can
> alternatively add the doc only when we get to those more complex cases.
> I'll follow reviewers' preferences if you or anybody else express any.
> 
> Best regards,
> Marcelo