158 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			158 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* 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/kernel.h>
 | |
| #include <linux/errno.h>
 | |
| #include <linux/gpio.h>
 | |
| #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,
 | |
| };
 | |
| 
 | |
| #ifdef CONFIG_OF_GPIO
 | |
| 
 | |
| /*
 | |
|  * 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(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);
 | |
| 
 | |
| extern int of_gpio_simple_xlate(struct gpio_chip *gc,
 | |
| 				const struct of_phandle_args *gpiospec,
 | |
| 				u32 *flags);
 | |
| 
 | |
| #else /* CONFIG_OF_GPIO */
 | |
| 
 | |
| /* Drivers may not strictly depend on the GPIO support, so let them link. */
 | |
| static inline int of_get_named_gpio_flags(struct device_node *np,
 | |
| 		const char *list_name, int index, enum of_gpio_flags *flags)
 | |
| {
 | |
| 	if (flags)
 | |
| 		*flags = 0;
 | |
| 
 | |
| 	return -ENOSYS;
 | |
| }
 | |
| 
 | |
| static inline int of_gpio_simple_xlate(struct gpio_chip *gc,
 | |
| 				       const struct of_phandle_args *gpiospec,
 | |
| 				       u32 *flags)
 | |
| {
 | |
| 	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(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(struct device_node *np)
 | |
| {
 | |
| 	return of_gpio_named_count(np, "gpios");
 | |
| }
 | |
| 
 | |
| static inline int of_get_gpio_flags(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(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(struct device_node *np, int index)
 | |
| {
 | |
| 	return of_get_gpio_flags(np, index, NULL);
 | |
| }
 | |
| 
 | |
| #endif /* __LINUX_OF_GPIO_H */
 | 
