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

[Marc Gonzalez]

On 15/07/2024 18:38, Dmitry Baryshkov wrote:

> Please correct me if I'm wrong. We have following usecases.
> 
> 1. I2C_EN pulled low. TI158 is in the pin strap mode, it is not
> connected to the I2C bus. A0, A1, SDA and SCL pins are used for
> strapping the settings.
>     board DT file should describe the bridge as a platform device
> sitting directly under the root node.
> 
> 2. I2C_EN pulled high. TI158 is in the I2C mode. It is connected to
> the I2C bus, A0/A1 pins set the I2C bus address. The device is
> controlled over the I2C bus
> 
> 2.a. The same as 2, but the device is not controlled at all, default
> settings are fine.
> 
> The driver covers usecase 2.a. The bindings allow extending the driver
> to the usecase 2 (e.g. via optional properties which specify
> board-specific settings)

OK, I think I understand (maybe).

You're saying: the current binding doesn't specify any
particular setting because the default settings are OK.
We can switch to use-case 2. simply by adding a prop
that will change one specific setting (backward compatible)

> The usecase 1 is a completely separate topic, it requires a different
> schema file, specifying no i2c address, only voltages supplies and
> enable-gpios.

I have tested this.

We can support use-case 1. by registering a module_platform_driver
with the same compatible property. The probe function gets called
only for a node that is a child of root. No different binding required.

Regards