dt-bindings: gpio: uniphier: add UniPhier GPIO binding

UniPhier GPIO controller

Required properties:

- compatible: Should be "socionext,uniphier-gpio".

- reg: Specifies offset and length of the register set for the device.

- gpio-controller: Marks the device node as a GPIO controller.

- #gpio-cells: Should be 2.  The first cell is the pin number and the second

  cell is used to specify optional parameters.

- interrupt-parent: Specifies the parent interrupt controller.

- interrupt-controller: Marks the device node as an interrupt controller.

- #interrupt-cells: Should be 2.  The first cell defines the interrupt number.

  The second cell bits[3:0] is used to specify trigger type as follows:

    1 = low-to-high edge triggered

    2 = high-to-low edge triggered

    4 = active high level-sensitive

    8 = active low level-sensitive

  Valid combinations are 1, 2, 3, 4, 8.

- ngpios: Specifies the number of GPIO lines.

- gpio-ranges: Mapping to pin controller pins (as described in gpio.txt)

- socionext,interrupt-ranges: Specifies an interrupt number mapping between

  this GPIO controller and its interrupt parent, in the form of arbitrary

  number of <child-interrupt-base parent-interrupt-base length> triplets.

Optional properties:

- gpio-ranges-group-names: Used for named gpio ranges (as described in gpio.txt)

Example:

	gpio: gpio@55000000 {

		compatible = "socionext,uniphier-gpio";

		reg = <0x55000000 0x200>;

		interrupt-parent = <&aidet>;

		interrupt-controller;

		#interrupt-cells = <2>;

		gpio-controller;

		#gpio-cells = <2>;

		gpio-ranges = <&pinctrl 0 0 0>;

		gpio-ranges-group-names = "gpio_range";

		ngpios = <248>;

		socionext,interrupt-ranges = <0 48 16>, <16 154 5>, <21 217 3>;

	};

Consumer Example:

	sdhci0_pwrseq {

		compatible = "mmc-pwrseq-emmc";

		reset-gpios = <&gpio UNIPHIER_GPIO_PORT(29, 4) GPIO_ACTIVE_LOW>;

	};

Please note UNIPHIER_GPIO_PORT(29, 4) represents PORT294 in the SoC document.

Unfortunately, only the one's place is octal in the port numbering.  (That is,

PORT 8, 9, 18, 19, 28, 29, ... are missing.)  UNIPHIER_GPIO_PORT() is a helper

macro to calculate 29 * 8 + 4.

L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-uniphier.git

S:	Maintained

F:	Documentation/devicetree/bindings/gpio/gpio-uniphier.txt

F:	arch/arm/boot/dts/uniphier*

F:	arch/arm/include/asm/hardware/cache-uniphier.h

F:	arch/arm/mach-uniphier/

/*

 * Copyright (C) 2017 Socionext Inc.

 *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>

 */

#ifndef _DT_BINDINGS_GPIO_UNIPHIER_H

#define _DT_BINDINGS_GPIO_UNIPHIER_H

#define UNIPHIER_GPIO_LINES_PER_BANK	8

#define UNIPHIER_GPIO_IRQ_OFFSET	((UNIPHIER_GPIO_LINES_PER_BANK) * 15)

#define UNIPHIER_GPIO_PORT(bank, line)	\

			((UNIPHIER_GPIO_LINES_PER_BANK) * (bank) + (line))

#define UNIPHIER_GPIO_IRQ(n)		((UNIPHIER_GPIO_IRQ_OFFSET) + (n))

#endif /* _DT_BINDINGS_GPIO_UNIPHIER_H */