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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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749820928a
This function is used to count how many GPIOs are specified for a device node. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
106 lines
2.7 KiB
C
106 lines
2.7 KiB
C
/*
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* OF helpers for the GPIO API
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*
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* Copyright (c) 2007-2008 MontaVista Software, Inc.
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*
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* Author: Anton Vorontsov <avorontsov@ru.mvista.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#ifndef __LINUX_OF_GPIO_H
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#define __LINUX_OF_GPIO_H
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#include <linux/compiler.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/gpio.h>
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struct device_node;
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/*
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* This is Linux-specific flags. By default controllers' and Linux' mapping
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* match, but GPIO controllers are free to translate their own flags to
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* Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
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*/
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enum of_gpio_flags {
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OF_GPIO_ACTIVE_LOW = 0x1,
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};
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#ifdef CONFIG_OF_GPIO
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/*
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* Generic OF GPIO chip
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*/
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struct of_gpio_chip {
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struct gpio_chip gc;
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int gpio_cells;
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int (*xlate)(struct of_gpio_chip *of_gc, struct device_node *np,
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const void *gpio_spec, enum of_gpio_flags *flags);
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};
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static inline struct of_gpio_chip *to_of_gpio_chip(struct gpio_chip *gc)
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{
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return container_of(gc, struct of_gpio_chip, gc);
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}
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/*
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* OF GPIO chip for memory mapped banks
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*/
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struct of_mm_gpio_chip {
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struct of_gpio_chip of_gc;
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void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
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void __iomem *regs;
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};
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static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
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{
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struct of_gpio_chip *of_gc = to_of_gpio_chip(gc);
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return container_of(of_gc, struct of_mm_gpio_chip, of_gc);
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}
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extern int of_get_gpio_flags(struct device_node *np, int index,
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enum of_gpio_flags *flags);
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extern unsigned int of_gpio_count(struct device_node *np);
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extern int of_mm_gpiochip_add(struct device_node *np,
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struct of_mm_gpio_chip *mm_gc);
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extern int of_gpio_simple_xlate(struct of_gpio_chip *of_gc,
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struct device_node *np,
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const void *gpio_spec,
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enum of_gpio_flags *flags);
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#else
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/* Drivers may not strictly depend on the GPIO support, so let them link. */
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static inline int of_get_gpio_flags(struct device_node *np, int index,
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enum of_gpio_flags *flags)
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{
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return -ENOSYS;
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}
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static inline unsigned int of_gpio_count(struct device_node *np)
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{
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return 0;
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}
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#endif /* CONFIG_OF_GPIO */
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/**
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* of_get_gpio - Get a GPIO number to use with GPIO API
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* @np: device node to get GPIO from
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* @index: index of the GPIO
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*
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* Returns GPIO number to use with Linux generic GPIO API, or one of the errno
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* value on the error condition.
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*/
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static inline int of_get_gpio(struct device_node *np, int index)
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{
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return of_get_gpio_flags(np, index, NULL);
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}
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#endif /* __LINUX_OF_GPIO_H */
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