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. -- Regards, Laurent Pinchart
