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