pinctrl: Implementation of the generic scmi-pinctrl driver

scmi-pinctrl driver implements pinctrl driver interface and using
SCMI protocol to redirect messages from pinctrl subsystem SDK to
SCMI platform firmware, which does the changes in HW.

Co-developed-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20240418-pinctrl-scmi-v11-4-499dca9864a7@nxp.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

MAINTAINERS

@@ -21453,6 +21453,7 @@ F:	drivers/cpufreq/sc[mp]i-cpufreq.c
 F:	drivers/firmware/arm_scmi/
 F:	drivers/firmware/arm_scpi.c
 F:	drivers/hwmon/scmi-hwmon.c
+F:	drivers/pinctrl/pinctrl-scmi.c
 F:	drivers/pmdomain/arm/
 F:	drivers/powercap/arm_scmi_powercap.c
 F:	drivers/regulator/scmi-regulator.c

drivers/pinctrl/Kconfig

@@ -450,6 +450,17 @@ config PINCTRL_ROCKCHIP
 	help
           This support pinctrl and GPIO driver for Rockchip SoCs.
 
+config PINCTRL_SCMI
+	tristate "Pinctrl driver using SCMI protocol interface"
+	depends on ARM_SCMI_PROTOCOL || COMPILE_TEST
+	select PINMUX
+	select GENERIC_PINCONF
+	help
+	  This driver provides support for pinctrl which is controlled
+	  by firmware that implements the SCMI interface.
+	  It uses SCMI Message Protocol to interact with the
+	  firmware providing all the pinctrl controls.
+
 config PINCTRL_SINGLE
 	tristate "One-register-per-pin type device tree based pinctrl driver"
 	depends on OF

drivers/pinctrl/Makefile

@@ -45,6 +45,7 @@ obj-$(CONFIG_PINCTRL_PIC32)	+= pinctrl-pic32.o
 obj-$(CONFIG_PINCTRL_PISTACHIO)	+= pinctrl-pistachio.o
 obj-$(CONFIG_PINCTRL_RK805)	+= pinctrl-rk805.o
 obj-$(CONFIG_PINCTRL_ROCKCHIP)	+= pinctrl-rockchip.o
+obj-$(CONFIG_PINCTRL_SCMI)	+= pinctrl-scmi.o
 obj-$(CONFIG_PINCTRL_SINGLE)	+= pinctrl-single.o
 obj-$(CONFIG_PINCTRL_ST) 	+= pinctrl-st.o
 obj-$(CONFIG_PINCTRL_STMFX) 	+= pinctrl-stmfx.o