Re: [PATCH v3 2/4] mfd: sony-cronos-cpld: Add driver for Sony Cronos CPLD

["Yakovlev, Georgy" <Georgy.Yakovlev@sony.com>]

> On Oct 9, 2025, at 3:42 AM, Lee Jones <lee@kernel.org> wrote:
> 
> This doesn't need to / shouldn't reside in the kernel.
> 
> Why not use I2C and handle all of this in userspace?
We would prefer to keep the sysfs interfaces in-kernel due to I2C bus contention between the MFD sub-drivers and userspace applications.
Keeping everything in-kernel allows the kernel itself to arbitrate between the various MFD sub-drivers; punting to userspace complicates each userspace application as they each individually would need to handle I2C bus contention and associated EBUSY responses vs. a sysfs read.

> 
>> \ No newline at end of file
> 
> ???
> 
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 0e897f2ba9eb..a1052663fb27 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -23458,6 +23458,13 @@ S: Maintained
>> F: drivers/ssb/
>> F: include/linux/ssb/
>> 
>> +SONY CRONOS CPLD DRIVER
>> +M: Georgy Yakovlev <Georgy.Yakovlev@sony.com>
> 
> This person is going to have to Ack the fact that you're making them the
> person responsible for maintaining this.
Yes, I acknowledge.
Not new to open source in general, but new to kernel submissions.
Sorry for delayed response, was away.
> 
>> +S: Maintained
>> +F: Documentation/devicetree/bindings/mfd/sony,cronos-cpld.yaml
>> +F: drivers/mfd/sony-cronos-cpld.c
>> +F: include/linux/mfd/sony/cronos/
>> +
>> SONY IMX208 SENSOR DRIVER
>> M: Sakari Ailus <sakari.ailus@linux.intel.com>
>> L: linux-media@vger.kernel.org
>> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
>> index 425c5fba6cb1..cd0c624022f6 100644
>> --- a/drivers/mfd/Kconfig
>> +++ b/drivers/mfd/Kconfig
>> @@ -2341,6 +2341,17 @@ config MFD_QCOM_PM8008
>>   under it in the device tree. Additional drivers must be enabled in
>>   order to use the functionality of the device.
>> 
>> +config MFD_SONY_CRONOS_CPLD
>> + tristate "Sony Cronos CPLD Support"
>