Introduce Pin Function Controller for Renesas R-Car family.
This first implementation support to set a given pin as gpio
or peripheral (GPSR), to set a peripheral function to a
pin (IPSR), to set pull-up, pull-down (PUEN, PUD).
In addition this driver allows to set driving capabilies(DRVCTRL).
Pins are identified thanks to the per SoC binding for
pin definition which also contains pin alternate function
parameters.
Some pins can also have driving capabilities, some have bias
capabilities.
In order to find the correct bias and drive registers pfc_r8a77951.c
describes the different registers.
Each SoCs or package will need to define getters
for these registers: pfc_rcar_get_bias_regs() and
pfc_rcar_get_drive_regs().
Signed-off-by: Julien Massot <julien.massot@iot.bzh>
Julien Massot