[PATCH v5 01/11] i2c: Enhance i2c_new_ancillary_device API
Biju Das
biju.das.jz at bp.renesas.com
Tue Jun 13 10:45:36 UTC 2023
Hi Geert,
Thanks for the feedback.
> Subject: Re: [PATCH v5 01/11] i2c: Enhance i2c_new_ancillary_device API
>
> Hi Wolfram,
>
> On Mon, Jun 12, 2023 at 10:43 PM Wolfram Sang <wsa at kernel.org> wrote:
> > > 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
> > * 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.
> >
> > Should work or did I miss something here?
>
> That should work, mostly (i2c_new_dummy_device() also calls
> i2c_new_client_device()). And as i2c_board_info has an of_node member
> (something I had missed before!), the new I2C device can access the clocks
> in the DT node using the standard way.
Looks like, I cannot assign of_node member like below as it results in pinctrl failure[1]
during device bind.
info.of_node = client->dev.of_node;
[1]
pinctrl-rzg2l 11030000.pinctrl: pin P43_0 already requested by 3-0012; cannot claim for 3-006f
pinctrl-rzg2l 11030000.pinctrl: pin-344 (3-006f) status -22
pinctrl-rzg2l 11030000.pinctrl: could not request pin 344 (P43_0) from group pmic on device pinctrl-rzg2l
raa215300 3-006f: Error applying setting, reverse things back
Cheers,
Biju
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