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

[Biju Das]

Hi Geert,

Thanks for the feedback.

> Subject: Re: [PATCH v5 01/11] i2c: Enhance i2c_new_ancillary_device API
> 
> Hi Biju,
> 
> On Tue, Jun 13, 2023 at 12:45 PM Biju Das <biju.das.jz at bp.renesas.com>
> wrote:
> > > Subject: Re: [PATCH v5 01/11] i2c: Enhance i2c_new_ancillary_device
> > > API 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
> 
> Where do you have a reference to pin P43_0 in your DT?

The reference to pin P43_0 is added in the PMIC node.

I have done modification on my board to test PMIC INT# on RZ/G2L SMARC EVK
by wiring R83 on SoM module and PMOD0 PIN7.

> The last versions you posted did not have any pinctrl properties?

By default, PMIC_INT# is not populated RZ/G2L SMARC EVK, so I haven't added
Support for PMIC_INT# for the patches posted till date. 

Yesterday I checked with HW people, is there a way to enable PMIC_INT#
and they told me to do the above HW modification.

Today I found this issue, with this modified HW and PMIC INT# enabled on the DT,
while assigning of_node of PMIC with info.of_node. It is just a coincidence.

Cheers,
Biju