[PATCH 2/2] bootcount: Add driver model I2C driver

[Simon Glass]

Hi Philip,

On Wed, 18 Oct 2023 at 05:00, Philip Oberfichtner <pro at denx.de> wrote:
>
> Hi Heiko,
>
> On Wed, Oct 18, 2023 at 06:31:57AM +0200, Heiko Schocher wrote:
> > [...]
> >
> > May Philip can use uclass_get_device_by_phandle and try a list of
> > possible UCLASS candidates, like UCLASS_RTC, UCLASS_I2C_EEPROM,
> > UCLASS_POWER,... and if found, check if parent is UCLASS_I2C...
> >
> > may not so expensive ...
>
> Looks more cheap and elegant than the other variants indeed. But I'm not
> sure if we can maintain generality using this approach.
>
> What if the specific I2C driver is not included in the build, because
> the devices "actual" functionality is not required?

Then the device will not be bound and the function will fail. There needs
to be a node and a bound device.

> Or what if a driver
> for the specific device does not even exist in U-Boot?
>
> Wouldn't the device fail to probe then?

The DT should specify the compatible string so the correct i2c driver is
used. If there isn't one,I believe it uses I2C_GENERIC but you'll need to
check it.

>
> Please correct me if I'm wrong, I'd give it a shot in that case.
> Otherwise I'll try it with the aforementioned
> device_find_global_by_ofnode() followed by device_bind_driver() using
> UCLASS_I2C_GENERIC (I hope that works).

That is the same approach, I think. But anyway I think Heiko knows more
about this than me.

Regards,
Simon