3d0f7cf0f3
This patch changes the of_xlate API to make it possible for multiple gpio_chips to refer to the same device tree node. This is useful for banked GPIO controllers that use multiple gpio_chips for a single device. With this change the core code will try calling of_xlate on each gpio_chip that references the device_node and will return the gpio number for the first one to return 'true'. Tested-by: Roland Stigge <stigge@antcom.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
157 lines
4.3 KiB
C
157 lines
4.3 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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#include <linux/of.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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* 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 gpio_chip 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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return container_of(gc, struct of_mm_gpio_chip, gc);
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}
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extern int of_get_named_gpio_flags(struct device_node *np,
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const char *list_name, int index, enum of_gpio_flags *flags);
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extern unsigned int of_gpio_named_count(struct device_node *np,
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const char* propname);
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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 void of_gpiochip_add(struct gpio_chip *gc);
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extern void of_gpiochip_remove(struct gpio_chip *gc);
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extern int of_gpio_simple_xlate(struct gpio_chip *gc,
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const struct of_phandle_args *gpiospec,
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u32 *flags);
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#else /* CONFIG_OF_GPIO */
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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_named_gpio_flags(struct device_node *np,
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const char *list_name, int index, 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_named_count(struct device_node *np,
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const char* propname)
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{
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return 0;
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}
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static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
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const struct of_phandle_args *gpiospec,
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u32 *flags)
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{
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return -ENOSYS;
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}
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static inline void of_gpiochip_add(struct gpio_chip *gc) { }
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static inline void of_gpiochip_remove(struct gpio_chip *gc) { }
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#endif /* CONFIG_OF_GPIO */
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/**
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* of_gpio_count - Count GPIOs for a device
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* @np: device node to count GPIOs for
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*
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* The function returns the count of GPIOs specified for a node.
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*
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* Note that the empty GPIO specifiers counts too. For example,
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*
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* gpios = <0
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* &pio1 1 2
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* 0
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* &pio2 3 4>;
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*
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* defines four GPIOs (so this function will return 4), two of which
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* are not specified.
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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 of_gpio_named_count(np, "gpios");
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}
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/**
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* of_get_gpio_flags() - Get a GPIO number and flags 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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* @flags: a flags pointer to fill in
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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. If @flags is not NULL the function also fills
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* in flags for the GPIO.
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*/
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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 of_get_named_gpio_flags(np, "gpios", index, flags);
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}
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/**
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* of_get_named_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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* @propname: Name of property containing gpio specifier(s)
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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_named_gpio(struct device_node *np,
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const char *propname, int index)
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{
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return of_get_named_gpio_flags(np, propname, index, NULL);
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}
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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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