Hi Laurent, Thanks for the feedback. > Subject: Re: [PATCH v5 01/11] i2c: Enhance i2c_new_ancillary_device API > > On Tue, Jun 13, 2023 at 07:31:46PM +0000, Biju Das wrote: > > > Subject: RE: [PATCH v5 01/11] i2c: Enhance i2c_new_ancillary_device > > > API > > > > Subject: RE: [PATCH v5 01/11] i2c: Enhance > > > > i2c_new_ancillary_device API > > > > > 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. > > > > > > info.irq = irq; -->Irq fine > > > info.addr = addr; -->slave address fine size = strscpy(info.type, > > > name, sizeof(info.type)); -->instantiation based on PMIC version > > > fine. > > > > > > 1) How do we share clk details on instantiated device to find is it > > > connected to external crystal or external clock source? as we cannot > > > pass of_node between PMIC and "i2c_board_info" as it results in > > > pinctrl failure. info->platformdata and > > > Client->dev.platformdata to retrieve this info?? > > > > Or > > > > I2C instantiation based on actual oscillator bit value, ie, two > > i2c_device_id's with one for setting oscillator bit and another for > > clearing oscillator bit > > > > PMIC driver parses the clock details. Based on firmware version and > > clock, It instantiates either i2c_device_id with setting oscillator > > bit or clearing oscillator bit. > > I don't like that hack. I still think that two DT nodes is the best > option, I think you're trying hard to hack around a problem that is > actually not a problem. Why do you think it is a hack? I believe rather it is actual solution PMIC is a single device, with 2 regs, clocks, pinctrl and IRQ properties. So it will be represented as single node with single compatible. By instating a client device, we are sharing the relevant resources to RTC device driver. Cheers, Biju
