pinctrl: spacemit: add support for SpacemiT K1 SoC

SpacemiT's K1 SoC has a pinctrl controller which use single register
to describe all functions, which include bias pull up/down(strong pull),
drive strength, schmitter trigger, slew rate, mux mode.

Signed-off-by: Yixun Lan <[email protected]>
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Linus Walleij <[email protected]>

Author: dlan17

drivers/pinctrl/Kconfig

@@ -631,6 +631,7 @@ source "drivers/pinctrl/realtek/Kconfig"
 source "drivers/pinctrl/renesas/Kconfig"
 source "drivers/pinctrl/samsung/Kconfig"
 source "drivers/pinctrl/sophgo/Kconfig"
+source "drivers/pinctrl/spacemit/Kconfig"
 source "drivers/pinctrl/spear/Kconfig"
 source "drivers/pinctrl/sprd/Kconfig"
 source "drivers/pinctrl/starfive/Kconfig"

drivers/pinctrl/Makefile

@@ -78,6 +78,7 @@ obj-$(CONFIG_ARCH_REALTEK)      += realtek/
 obj-$(CONFIG_PINCTRL_RENESAS)	+= renesas/
 obj-$(CONFIG_PINCTRL_SAMSUNG)	+= samsung/
 obj-y				+= sophgo/
+obj-y				+= spacemit/
 obj-$(CONFIG_PINCTRL_SPEAR)	+= spear/
 obj-y				+= sprd/
 obj-$(CONFIG_SOC_STARFIVE)	+= starfive/

drivers/pinctrl/spacemit/Kconfig

@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Sophgo SoC PINCTRL drivers
+#
+
+config PINCTRL_SPACEMIT_K1
+	tristate "SpacemiT K1 SoC Pinctrl driver"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	depends on OF
+	select GENERIC_PINCTRL_GROUPS
+	select GENERIC_PINMUX_FUNCTIONS
+	select GENERIC_PINCONF
+	help
+	  Say Y to select the pinctrl driver for K1 SoC.
+	  This pin controller allows selecting the mux function for
+	  each pin. This driver can also be built as a module called
+	  pinctrl-k1.

drivers/pinctrl/spacemit/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_PINCTRL_SPACEMIT_K1)	+= pinctrl-k1.o