[POWERPC] Implement support for the GPIO LIB API (b7ce3415) · Commits · 戴 / test

Documentation/powerpc/booting-without-of.txt

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		@@ -88,6 +88,10 @@ Table of Contents
		3) OpenPIC Interrupt Controllers
		4) ISA Interrupt Controllers

		VIII - Specifying GPIO information for devices
		1) gpios property
		2) gpio-controller nodes

		Appendix A - Sample SOC node for MPC8540


		@@ -3431,6 +3435,54 @@ encodings listed below:
		2 = high to low edge sensitive type enabled
		3 = low to high edge sensitive type enabled

		VIII - Specifying GPIO information for devices
		==============================================

		1) gpios property
		-----------------

		Nodes that makes use of GPIOs should define them using `gpios' property,
		format of which is: <&gpio-controller1-phandle gpio1-specifier
		&gpio-controller2-phandle gpio2-specifier
		0 /* holes are permitted, means no GPIO 3 */
		&gpio-controller4-phandle gpio4-specifier
		...>;

		Note that gpio-specifier length is controller dependent.

		gpio-specifier may encode: bank, pin position inside the bank,
		whether pin is open-drain and whether pin is logically inverted.

		Example of the node using GPIOs:

		node {
		gpios = <&qe_pio_e 18 0>;
		};

		In this example gpio-specifier is "18 0" and encodes GPIO pin number,
		and empty GPIO flags as accepted by the "qe_pio_e" gpio-controller.

		2) gpio-controller nodes
		------------------------

		Every GPIO controller node must have #gpio-cells property defined,
		this information will be used to translate gpio-specifiers.

		Example of two SOC GPIO banks defined as gpio-controller nodes:

		qe_pio_a: gpio-controller@1400 {
		#gpio-cells = <2>;
		compatible = "fsl,qe-pario-bank-a", "fsl,qe-pario-bank";
		reg = <0x1400 0x18>;
		gpio-controller;
		};

		qe_pio_e: gpio-controller@1460 {
		#gpio-cells = <2>;
		compatible = "fsl,qe-pario-bank-e", "fsl,qe-pario-bank";
		reg = <0x1460 0x18>;
		gpio-controller;
		};

		Appendix A - Sample SOC node for MPC8540
		========================================

arch/powerpc/Kconfig

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		@@ -81,6 +81,11 @@ config GENERIC_FIND_NEXT_BIT
		bool
		default y

		config GENERIC_GPIO
		bool
		help
		Generic GPIO API support

		config ARCH_NO_VIRT_TO_BUS
		def_bool PPC64

include/asm-powerpc/gpio.h

0 → 100644

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		/*
		* Generic GPIO API implementation for PowerPC.
		*
		* Copyright (c) 2007-2008 MontaVista Software, Inc.
		*
		* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2 of the License, or
		* (at your option) any later version.
		*/

		#ifndef __ASM_POWERPC_GPIO_H
		#define __ASM_POWERPC_GPIO_H

		#include <linux/errno.h>
		#include <asm-generic/gpio.h>

		#ifdef CONFIG_HAVE_GPIO_LIB

		/*
		* We don't (yet) implement inlined/rapid versions for on-chip gpios.
		* Just call gpiolib.
		*/
		static inline int gpio_get_value(unsigned int gpio)
		{
		return __gpio_get_value(gpio);
		}

		static inline void gpio_set_value(unsigned int gpio, int value)
		{
		__gpio_set_value(gpio, value);
		}

		static inline int gpio_cansleep(unsigned int gpio)
		{
		return __gpio_cansleep(gpio);
		}

		/*
		* Not implemented, yet.
		*/
		static inline int gpio_to_irq(unsigned int gpio)
		{
		return -ENOSYS;
		}

		static inline int irq_to_gpio(unsigned int irq)
		{
		return -EINVAL;
		}

		#endif /* CONFIG_HAVE_GPIO_LIB */

		#endif /* __ASM_POWERPC_GPIO_H */

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