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/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2021 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*/
#ifndef __GPIO_H__
#define __GPIO_H__
#include <sbi/sbi_types.h>
#define GPIO_LINE_DIRECTION_IN 1
#define GPIO_LINE_DIRECTION_OUT 0
/** Representation of a GPIO pin */
struct gpio_pin {
/** Pointer to the GPIO chip */
struct gpio_chip *chip;
/** Identification of GPIO pin within GPIO chip */
unsigned int offset;
/**
* Additional configuration flags of the GPIO pin desired
* by GPIO clients.
*
* NOTE: GPIO chip can have custom configuration flags.
*/
unsigned int flags;
#define GPIO_FLAG_ACTIVE_LOW 0x1
#define GPIO_FLAG_SINGLE_ENDED 0x2
#define GPIO_FLAG_OPEN_DRAIN 0x4
#define GPIO_FLAG_TRANSITORY 0x8
#define GPIO_FLAG_PULL_UP 0x10
#define GPIO_FLAG_PULL_DOWN 0x20
};
/** Representation of a GPIO chip */
struct gpio_chip {
/** Pointer to GPIO driver owning this GPIO chip */
void *driver;
/** Uniquie ID of the GPIO chip assigned by the driver */
unsigned int id;
/** Number of GPIOs supported by the GPIO chip */
unsigned int ngpio;
/**
* Get current direction of GPIO pin
*
* @return 0=output, 1=input, or negative error
*/
int (*get_direction)(struct gpio_pin *gp);
/**
* Set input direction of GPIO pin
*
* @return 0 on success and negative error code on failure
*/
int (*direction_input)(struct gpio_pin *gp);
/**
* Set output direction of GPIO pin with given output value
*
* @return 0 on success and negative error code on failure
*/
int (*direction_output)(struct gpio_pin *gp, int value);
/**
* Get current value of GPIO pin
*
* @return 0=low, 1=high, or negative error
*/
int (*get)(struct gpio_pin *gp);
/** Set output value for GPIO pin */
void (*set)(struct gpio_pin *gp, int value);
};
/** Find a registered GPIO chip */
struct gpio_chip *gpio_chip_find(unsigned int id);
/** Register GPIO chip */
int gpio_chip_add(struct gpio_chip *gc);
/** Un-register GPIO chip */
void gpio_chip_remove(struct gpio_chip *gc);
/** Get current direction of GPIO pin */
int gpio_get_direction(struct gpio_pin *gp);
/** Set input direction of GPIO pin */
int gpio_direction_input(struct gpio_pin *gp);
/** Set output direction of GPIO pin */
int gpio_direction_output(struct gpio_pin *gp, int value);
/** Get current value of GPIO pin */
int gpio_get(struct gpio_pin *gp);
/** Set output value of GPIO pin */
int gpio_set(struct gpio_pin *gp, int value);
#endif
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