diff options
Diffstat (limited to 'include/linux/of_gpio.h')
-rw-r--r-- | include/linux/of_gpio.h | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h new file mode 100644 index 000000000..a5166eb93 --- /dev/null +++ b/include/linux/of_gpio.h @@ -0,0 +1,153 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * OF helpers for the GPIO API + * + * Copyright (c) 2007-2008 MontaVista Software, Inc. + * + * Author: Anton Vorontsov <avorontsov@ru.mvista.com> + */ + +#ifndef __LINUX_OF_GPIO_H +#define __LINUX_OF_GPIO_H + +#include <linux/compiler.h> +#include <linux/gpio/driver.h> +#include <linux/gpio.h> /* FIXME: Shouldn't be here */ +#include <linux/of.h> + +struct device_node; + +/* + * This is Linux-specific flags. By default controllers' and Linux' mapping + * match, but GPIO controllers are free to translate their own flags to + * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended. + */ +enum of_gpio_flags { + OF_GPIO_ACTIVE_LOW = 0x1, + OF_GPIO_SINGLE_ENDED = 0x2, + OF_GPIO_OPEN_DRAIN = 0x4, + OF_GPIO_TRANSITORY = 0x8, + OF_GPIO_PULL_UP = 0x10, + OF_GPIO_PULL_DOWN = 0x20, + OF_GPIO_PULL_DISABLE = 0x40, +}; + +#ifdef CONFIG_OF_GPIO + +#include <linux/kernel.h> + +/* + * OF GPIO chip for memory mapped banks + */ +struct of_mm_gpio_chip { + struct gpio_chip gc; + void (*save_regs)(struct of_mm_gpio_chip *mm_gc); + void __iomem *regs; +}; + +static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc) +{ + return container_of(gc, struct of_mm_gpio_chip, gc); +} + +extern int of_get_named_gpio_flags(const struct device_node *np, + const char *list_name, int index, enum of_gpio_flags *flags); + +extern int of_mm_gpiochip_add_data(struct device_node *np, + struct of_mm_gpio_chip *mm_gc, + void *data); +static inline int of_mm_gpiochip_add(struct device_node *np, + struct of_mm_gpio_chip *mm_gc) +{ + return of_mm_gpiochip_add_data(np, mm_gc, NULL); +} +extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc); + +#else /* CONFIG_OF_GPIO */ + +#include <linux/errno.h> + +/* Drivers may not strictly depend on the GPIO support, so let them link. */ +static inline int of_get_named_gpio_flags(const struct device_node *np, + const char *list_name, int index, enum of_gpio_flags *flags) +{ + if (flags) + *flags = 0; + + return -ENOSYS; +} + +#endif /* CONFIG_OF_GPIO */ + +/** + * of_gpio_named_count() - Count GPIOs for a device + * @np: device node to count GPIOs for + * @propname: property name containing gpio specifier(s) + * + * The function returns the count of GPIOs specified for a node. + * Note that the empty GPIO specifiers count too. Returns either + * Number of gpios defined in property, + * -EINVAL for an incorrectly formed gpios property, or + * -ENOENT for a missing gpios property + * + * Example: + * gpios = <0 + * &gpio1 1 2 + * 0 + * &gpio2 3 4>; + * + * The above example defines four GPIOs, two of which are not specified. + * This function will return '4' + */ +static inline int of_gpio_named_count(const struct device_node *np, + const char *propname) +{ + return of_count_phandle_with_args(np, propname, "#gpio-cells"); +} + +/** + * of_gpio_count() - Count GPIOs for a device + * @np: device node to count GPIOs for + * + * Same as of_gpio_named_count, but hard coded to use the 'gpios' property + */ +static inline int of_gpio_count(const struct device_node *np) +{ + return of_gpio_named_count(np, "gpios"); +} + +static inline int of_get_gpio_flags(const struct device_node *np, int index, + enum of_gpio_flags *flags) +{ + return of_get_named_gpio_flags(np, "gpios", index, flags); +} + +/** + * of_get_named_gpio() - Get a GPIO number to use with GPIO API + * @np: device node to get GPIO from + * @propname: Name of property containing gpio specifier(s) + * @index: index of the GPIO + * + * Returns GPIO number to use with Linux generic GPIO API, or one of the errno + * value on the error condition. + */ +static inline int of_get_named_gpio(const struct device_node *np, + const char *propname, int index) +{ + return of_get_named_gpio_flags(np, propname, index, NULL); +} + +/** + * of_get_gpio() - Get a GPIO number to use with GPIO API + * @np: device node to get GPIO from + * @index: index of the GPIO + * + * Returns GPIO number to use with Linux generic GPIO API, or one of the errno + * value on the error condition. + */ +static inline int of_get_gpio(const struct device_node *np, int index) +{ + return of_get_gpio_flags(np, index, NULL); +} + +#endif /* __LINUX_OF_GPIO_H */ |