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 bb411e771b0e
   ("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 <narmstrong@baylibre.com>
Tested-by: Peter Rosin <peda@axentia.se>
Acked-by: Rob Herring <robh@kernel.org>
ested-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 69 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-sx150x.txt b/Documentation/devicetree/bindings/pinctrl/pinctrl-sx150x.txt
new file mode 100644
index 000000000000..c293c8aaac73
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-sx150x.txt
@@ -0,0 +1,69 @@
+SEMTECH SX150x GPIO expander bindings
+
+Please refer to pinctrl-bindings.txt, ../gpio/gpio.txt, and
+../interrupt-controller/interrupts.txt for generic information regarding
+pin controller, GPIO, and interrupt bindings.
+
+Required properties:
+- compatible: should be one of :
+			"semtech,sx1506q",
+			"semtech,sx1508q",
+			"semtech,sx1509q",
+			"semtech,sx1502q".
+
+- reg: The I2C slave address for this device.
+
+- #gpio-cells: Should be 2. The first cell is the GPIO number and the
+		second cell is used to specify optional parameters:
+		bit 0: polarity (0: normal, 1: inverted)
+
+- gpio-controller: Marks the device as a GPIO controller.
+
+Optional properties :
+- interrupt-parent: phandle of the parent interrupt controller.
+
+- interrupts: Interrupt specifier for the controllers interrupt.
+
+- interrupt-controller: Marks the device as a interrupt controller.
+
+- semtech,probe-reset: Will trigger a reset of the GPIO expander on probe,
+		only for sx1508q and sx1509q
+
+The GPIO expander can optionally be used as an interrupt controller, in
+which case it uses the default two cell specifier.
+
+Required properties for pin configuration sub-nodes:
+ - pins: List of pins to which the configuration applies.
+
+Optional properties for pin configuration sub-nodes:
+----------------------------------------------------
+ - bias-disable: disable any pin bias, except the OSCIO pin
+ - bias-pull-up: pull up the pin, except the OSCIO pin
+ - bias-pull-down: pull down the pin, except the OSCIO pin
+ - bias-pull-pin-default: use pin-default pull state, except the OSCIO pin
+ - drive-push-pull: drive actively high and low
+ - drive-open-drain: drive with open drain only for sx1508q and sx1509q and except the OSCIO pin
+ - output-low: set the pin to output mode with low level
+ - output-high: set the pin to output mode with high level
+
+Example:
+
+	i2c0gpio-expander@20{
+		#gpio-cells = <2>;
+		#interrupt-cells = <2>;
+		compatible = "semtech,sx1506q";
+		reg = <0x20>;
+		interrupt-parent = <&gpio_1>;
+		interrupts = <16 0>;
+
+		gpio-controller;
+		interrupt-controller;
+
+		pinctrl-names = "default";
+		pinctrl-0 = <&gpio1_cfg_pins>;
+
+		gpio1_cfg_pins: gpio1-cfg {
+			pins = "gpio1";
+			bias-pull-up;
+		};
+	};