Re: [PATCH 18/18] ipu3: Add driver for dummy INT3472 ACPI device

Andy Shevchenko
2020-12-01T18:52:15Z

On Tue, Dec 01, 2020 at 08:36:16PM +0200, Laurent Pinchart wrote:
> On Tue, Dec 01, 2020 at 08:31:39PM +0200, Andy Shevchenko wrote:
> > On Mon, Nov 30, 2020 at 11:20:55PM +0000, Dan Scally wrote:
> > > On 30/11/2020 16:17, Jean-Michel Hautbois wrote:

...

> > > but the ACPI table doesn't define an I2CSerialBusV2 for it. Instead it's
> > > rolled under the sensor's entry, there's a second entry in _CRS for the
> > > sensor that matches the address of the new device:
> > >
> > >
> > > Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
> > > {
> > > Name (SBUF, ResourceTemplate ()
> > > {
> > > I2cSerialBusV2 (0x0036, ControllerInitiated, 0x00061A80,
> > > AddressingMode7Bit, "\\_SB.PCI0.I2C2",
> > > 0x00, ResourceConsumer, , Exclusive,
> > > )
> > > I2cSerialBusV2 (0x000C, ControllerInitiated, 0x00061A80,
> > > AddressingMode7Bit, "\\_SB.PCI0.I2C2",
> > > 0x00, ResourceConsumer, , Exclusive,
> > > )
> > > })
> > > Return (SBUF) /* \_SB_.PCI0.CAM0._CRS.SBUF */
> > > }
> > >
> > > So that's another thing we need to work on. At the moment it doesn't
> > > exist as far as the kernel is concerned.
> >
> > Maybe something along i2c-multi-instantiate can help here (maybe not).
>
> It's two different devices really. That's also one of the "annoyances"
> related to this platform. The INT* HID for the camera sensor actually
> refers to a camera module, with VCM, EEPROM, ... On Chrome OS devices,
> the same HID refers to the camera sensor only. *sigh* :-(

But it's not a problem for i2c-multi-instantiate. It's kinda MFD approach for
I²C peripheral devices.

--
With Best Regards,
Andy Shevchenko