[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 6:11 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 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.
> 
> IC.
> 
> So you now have two Linux devices pointing to the same DT node, causing
> pinctrl issues...
> 
> I know this won't solve the core issue, but what is the exact pintrl
> configuration you are using? Is this using a GPIO with interrupt
> capabilities, or a dedicated interrupt pin? In case of the former, you
> don't need a pinctrl property in DT, as the GPIO controller itself should
> take care of that by asking the pin controller to configure the pin
> properly through pinctrl_gpio_request().

I was testing with both. This issue is triggered while configuring IRQ4 as PMIC_INT#.

	pmic_pins: pmic {
		pinmux = <RZG2L_PORT_PINMUX(43, 0, 4)>;  /* IRQ4 */
	};

&i2c3 {
	raa215300: pmic at 12 {
		pinctrl-0 = <&pmic_pins>;
		pinctrl-names = "default";

		compatible = "renesas,raa215300";
		reg = <0x12>, <0x6f>;
		reg-names = "main", "rtc";

		clocks = <&x2>;
		clock-names = "xin";

		//interrupt-parent = <&pinctrl>;
		//interrupts = <RZG2L_GPIO(43, 0) IRQ_TYPE_EDGE_FALLING>;
		interrupt-parent = <&irqc>;
		interrupts = <RZG2L_IRQ4 IRQ_TYPE_EDGE_FALLING>;
	};
};

Cheers,
Biju