Hi all On 22/02/2021 13:07, Daniel Scally wrote: > diff --git a/drivers/platform/x86/intel-int3472/Kconfig > b/drivers/platform/x86/intel-int3472/Kconfig > new file mode 100644 > index 000000000000..b94622245c21 > --- /dev/null > +++ b/drivers/platform/x86/intel-int3472/Kconfig > @@ -0,0 +1,31 @@ > +config INTEL_SKL_INT3472 > + tristate "Intel SkyLake ACPI INT3472 Driver" > + depends on ACPI > + depends on REGULATOR > + depends on GPIOLIB > + depends on COMMON_CLK && CLKDEV_LOOKUP > + depends on I2C > + select MFD_CORE > + select REGMAP_I2C > + help > + This driver adds support for the INT3472 ACPI devices found on some > + Intel SkyLake devices. > + > + The INT3472 is an Intel camera power controller, a logical device > + found on some Skylake-based systems that can map to different > + hardware devices depending on the platform. On machines > + designed for Chrome OS, it maps to a TPS68470 camera PMIC. On > + machines designed for Windows, it maps to either a TP68470 > + camera PMIC, a uP6641Q sensor PMIC, or a set of discrete GPIOs > + and power gates. > + > + If your device was designed for Chrome OS, this driver will provide > + an ACPI OpRegion, which must be available before any of the devices > + using it are probed. For this reason, you should select Y if your > + device was designed for ChromeOS. For the same reason the > + I2C_DESIGNWARE_PLATFORM option must be set to Y too. > + > + Say Y or M here if you have a SkyLake device designed for use > + with Windows or ChromeOS. Say N here if you are not sure. > + > + The module will be named "intel-skl-int3472" The Kconfig option for the existing tps68470 driver is a bool which depends on I2C_DESIGNWARE_PLATFORM=y, giving the following reason:
This option is a bool as it provides an ACPI operation region, which must be available before any of the devices using this are probed. This option also configures the designware-i2c driver to be built-in, for the same reason. One problem I've faced is that that scenario only applies to some devices that this new driver can support, so hard-coding it as built in didn't make much sense. For that reason I opted to set it tristate, but of course that issue still exists for ChromeOS devices where the OpRegion will be registered. I opted for simply documenting that requirement, as is done in aaac4a2eadaa6: "mfd: axp20x-i2c: Document that this must be builtin on x86", but that's not entirely satisfactory. Possible alternatives might be setting "depends on I2C_DESIGNWARE_PLATFORM=y if CHROME_PLATFORMS" or something similar, though of course the User would still have to realise they need to build-in the INTEL_SKL_INT3472 Kconfig option too. Feedback around this issue would be particularly welcome, as I'm not sure what the best approach might be.
