100 lines
2.7 KiB
C
100 lines
2.7 KiB
C
/*
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* OF helpers for the GPIO API
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*
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* based on Linux OF_GPIO API
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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 __OF_GPIO_H
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#define __OF_GPIO_H
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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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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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#else /* CONFIG_OF_GPIO */
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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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#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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static inline int of_get_named_gpio(struct device_node *np,
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const char *list_name, int index)
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{
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return of_get_named_gpio_flags(np, list_name, 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
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