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@xxxxxxxxxx> 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