pinctrl: Add SX150X GPIO Extender Pinctrl Driver

Since the I2C sx150x GPIO expander driver uses platform_data to manage
the pins configurations, rewrite the driver as a pinctrl driver using
pinconf to get/set pin configurations from DT or debugfs.

The pinctrl driver is functionnally equivalent as the gpio-only driver
and can use DT for pinconf. The platform_data confirmation is dropped.

This patchset removed the gpio-only driver and selects the Pinctrl driver
config instead. This patchset also migrates the gpio dt-bindings to pinctrl
and add the pinctrl optional properties.

The driver was tested with a SX1509 device on a BeagleBone black with
interrupt support and on an X86_64 machine over an I2C to USB converter.

This is a fixed version that builds and runs on non-OF platforms and on
arm based OF. The GPIO version is removed and the bindings are also moved
to the pinctrl bindings.

Changes since v2
 - rebased on v4.9-rc1
 - removed MODULE_DEVICE_TABLE as in upstream bb411e771b
   ("gpio: sx150x: fix implicit assumption module.h is present")

Changes since v1
 - Fix Kconfig descriptions on pinctrl and gpio
 - Fix Kconfig dependency
 - Remove oscio support for non-789 devices
 - correct typo in dt bindings
 - remove probe reset for non-789 devices

Changes since RFC
 - Put #ifdef CONFIG_OF/CONFIG_OF_GPIO to remove OF code for non-of platforms
 - No more rely on OF_GPIO config
 - Moved and enhanced bindings to pinctrl bindings
 - Removed gpio-sx150x.c
 - Temporary select PINCTRL_SX150X when GPIO_SX150X
 - Temporary mark GPIO_SX150X as deprecated

Signed-off-by: Neil Armstrong <[email protected]>
Tested-by: Peter Rosin <[email protected]>
Acked-by: Rob Herring <[email protected]>
ested-by: Andrey Smirnov <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>

drivers/pinctrl/Kconfig

@@ -164,6 +164,20 @@ config PINCTRL_SIRF
 	select GENERIC_PINCONF
 	select GPIOLIB_IRQCHIP
 
+config PINCTRL_SX150X
+	bool "Semtech SX150x I2C GPIO expander pinctrl driver"
+	depends on GPIOLIB && I2C=y
+	select PINMUX
+	select PINCONF
+	select GENERIC_PINCONF
+	select GPIOLIB_IRQCHIP
+	help
+	  Say yes here to provide support for Semtech SX150x-series I2C
+	  GPIO expanders as pinctrl module.
+	  Compatible models include:
+	  - 8 bits:  sx1508q, sx1502q
+	  - 16 bits: sx1509q, sx1506q
+
 config PINCTRL_PISTACHIO
 	def_bool y if MACH_PISTACHIO
 	depends on GPIOLIB

drivers/pinctrl/Makefile

@@ -25,6 +25,7 @@ obj-$(CONFIG_PINCTRL_PISTACHIO)	+= pinctrl-pistachio.o
 obj-$(CONFIG_PINCTRL_ROCKCHIP)	+= pinctrl-rockchip.o
 obj-$(CONFIG_PINCTRL_SINGLE)	+= pinctrl-single.o
 obj-$(CONFIG_PINCTRL_SIRF)	+= sirf/
+obj-$(CONFIG_PINCTRL_SX150X)	+= pinctrl-sx150x.o
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
 obj-$(CONFIG_PINCTRL_TZ1090)	+= pinctrl-tz1090.o
 obj-$(CONFIG_PINCTRL_TZ1090_PDC)	+= pinctrl-tz1090-pdc.o