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https://gitee.com/bianbu-linux/linux-6.6
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e10f72bf4b
General support for state persistence is added to gpiolib with the introduction of a new pinconf parameter to propagate the request to hardware. The existing persistence support for sleep is adapted to include hardware support if the GPIO driver provides it. Persistence continues to be enabled by default; in-kernel consumers can opt out, but userspace (currently) does not have a choice. The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are renamed, dropping the SLEEP prefix to reflect that the concept is no longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE could initially be misinterpreted, so I've further changed the symbols to *_TRANSITORY and *_PERSISTENT to address this. The sysfs interface is modified only to keep consistency with the chardev interface in enforcing persistence for userspace exports. Signed-off-by: Andrew Jeffery <andrew@aj.id.au> Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
161 lines
4.4 KiB
C
161 lines
4.4 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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OF_GPIO_SINGLE_ENDED = 0x2,
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OF_GPIO_OPEN_DRAIN = 0x4,
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OF_GPIO_TRANSITORY = 0x8,
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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 int of_mm_gpiochip_add_data(struct device_node *np,
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struct of_mm_gpio_chip *mm_gc,
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void *data);
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static inline int of_mm_gpiochip_add(struct device_node *np,
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struct of_mm_gpio_chip *mm_gc)
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{
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return of_mm_gpiochip_add_data(np, mm_gc, NULL);
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}
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extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_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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if (flags)
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*flags = 0;
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return -ENOSYS;
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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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#endif /* CONFIG_OF_GPIO */
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/**
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* of_gpio_named_count() - Count GPIOs for a device
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* @np: device node to count GPIOs for
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* @propname: property name containing gpio specifier(s)
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*
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* The function returns the count of GPIOs specified for a node.
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* Note that the empty GPIO specifiers count too. Returns either
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* Number of gpios defined in property,
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* -EINVAL for an incorrectly formed gpios property, or
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* -ENOENT for a missing gpios property
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*
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* Example:
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* gpios = <0
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* &gpio1 1 2
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* 0
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* &gpio2 3 4>;
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*
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* The above example defines four GPIOs, two of which are not specified.
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* This function will return '4'
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*/
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static inline int of_gpio_named_count(struct device_node *np, const char* propname)
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{
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return of_count_phandle_with_args(np, propname, "#gpio-cells");
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}
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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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* Same as of_gpio_named_count, but hard coded to use the 'gpios' property
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*/
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static inline 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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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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