pinctrl: cygnus: add gpio/pinconf driver

This adds the initial support of the Broadcom Cygnus GPIO/PINCONF driver
that supports all 3 GPIO controllers on Cygnus including the ASIU GPIO
controller, the chipCommonG GPIO controller, and the always-on GPIO
controller. Basic PINCONF configurations such as bias pull up/down, and
drive strength are also supported in this driver.

Pins from the ASIU GPIO controller can be individually muxed to GPIO
function, through interaction with the Cygnus IOMUX controller

Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Tested-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/bcm/Kconfig

@@ -20,6 +20,28 @@ config PINCTRL_BCM2835
 	select PINMUX
 	select PINCONF
 
+config PINCTRL_CYGNUS_GPIO
+	bool "Broadcom Cygnus GPIO (with PINCONF) driver"
+	depends on OF_GPIO && ARCH_BCM_CYGNUS
+	select GPIOLIB_IRQCHIP
+	select PINCONF
+	select GENERIC_PINCONF
+	default ARCH_BCM_CYGNUS
+	help
+	  Say yes here to enable the Broadcom Cygnus GPIO driver.
+
+	  The Broadcom Cygnus SoC has 3 GPIO controllers including the ASIU
+	  GPIO controller (ASIU), the chipCommonG GPIO controller (CCM), and
+	  the always-ON GPIO controller (CRMU/AON). All 3 GPIO controllers are
+	  supported by this driver.
+
+	  All 3 Cygnus GPIO controllers support basic PINCONF functions such
+	  as bias pull up, pull down, and drive strength configurations, when
+	  these pins are muxed to GPIO.
+
+	  Pins from the ASIU GPIO can be individually muxed to GPIO function,
+	  through interaction with the Cygnus IOMUX controller.
+
 config PINCTRL_CYGNUS_MUX
 	bool "Broadcom Cygnus IOMUX driver"
 	depends on (ARCH_BCM_CYGNUS || COMPILE_TEST)

drivers/pinctrl/bcm/Makefile

@@ -2,4 +2,5 @@
 
 obj-$(CONFIG_PINCTRL_BCM281XX)		+= pinctrl-bcm281xx.o
 obj-$(CONFIG_PINCTRL_BCM2835)		+= pinctrl-bcm2835.o
+obj-$(CONFIG_PINCTRL_CYGNUS_GPIO)	+= pinctrl-cygnus-gpio.o
 obj-$(CONFIG_PINCTRL_CYGNUS_MUX)	+= pinctrl-cygnus-mux.o