[PATCH v3 1/2] dt-bindings: display: bridge: add TI TDP158

[Marc Gonzalez]

On 01/07/2024 15:50, Maxime Ripard wrote:

> The i2c register access (and the whole behaviour of the device) is
> constrained on the I2C_EN pin status, and you can't read it from the
> device, so it's also something we need to have in the DT.

I think the purpose of the I2C_EN pin might have been misunderstood.

I2C_EN is not meant to be toggled, ever, by anyone from this planet.

I2C_EN is a layout-time setting, decided by a board manufacturer:

- If the TDP158 is fully configured once-and-for-all at layout-time,
then no I2C bus is required, and I2C_EN is pulled down forever.

- If the board manufacturer wants to keep open the possibility
to adjust some parameters at run-time, then they must connect
the device to an I2C bus, and I2C_EN is pulled up forever.

The only reason I see to expose I2C_EN in a binding is:
if we want to support the fully static setup, AND it is not acceptable
to support it from an i2c_driver, then there might need to be a way to
say "you are not an i2c client, you must fail in probe".

Or I don't understand anything about device tree bindings
(which is entirely possible).

Regards