[PATCH v5 01/11] i2c: Enhance i2c_new_ancillary_device API

Biju Das biju.das.jz at bp.renesas.com
Tue Jun 13 07:24:36 UTC 2023


Hi Wolfram,

Thanks for the feedback.

> Subject: Re: [PATCH v5 01/11] i2c: Enhance i2c_new_ancillary_device API
> 
> Hi everyone,
> 
> > Perhaps we should first think through what an ancillary device really
> > is.  My understanding is that it is used to talk to secondary
> > addresses of a multi-address I2C slave device.
> 
> As I mentioned somewhere before, this is not the case. Ancillary devices
> are when one *driver* handles more than one address. Everything else has
> been handled differently in the past (for  all the uses I am aware of).
> 
> Yet, I have another idea which is so simple that I wonder if it maybe has
> already been discussed so far?
> 
> * have two regs in the bindings

OK, it is inline with DT maintainers expectation as it is matching with real hw
as single device node having two regs.

> * use the second reg with i2c_new_client_device to instantiate the
>   RTC sibling. 'struct i2c_board_info', which is one parameter, should
>   have enough options to pass data, e.g it has a software_node.

OK, I can see the below can be passed from PMIC to new client device.

	client->addr = info->addr;

	client->init_irq = info->irq;

> 
> Should work or did I miss something here?

I guess it will work. We instantiate appropriate device based
On PMIC revision and slave address and IRQ resource passed through
'struct i2c_board_info'

Will check this and update you.

Cheers,
Biju


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