Add an API-less MFD driver for nPM6001. In this case, the MFD device
driver doesn't expose any API as plain I2C API is used within other
device drivers (regulator, GPIO, watchdog). This driver just initializes
some device properties.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Introduce the skeleton for multi-function device drivers. This driver
class is inspired by the same class found in Linux. Multi-function
devices expose multiple functionalities, for example, a LED driver,
regulator, GPIO controller, etc. The MFD driver class serves as a kind
of "parent" device where common functionality can be managed: bus
access, IRQ sharing, initialization code, etc.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
Gerard Marull-Paretas