u-boot/include/spl_gpio.h

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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Simple GPIO access from SPL. This only supports a single GPIO space,
* typically the SoC GPIO banks.
*
* Copyright 2018 Google LLC
*/
#ifndef __SPL_GPIO_H
#define __SPL_GPIO_H
#include <asm/gpio.h>
/*
* The functions listed here should be implemented in the SoC GPIO driver.
* They correspond to the normal GPIO API (asm-generic/gpio.h). The GPIO
* number is encoded in an unsigned int by an SoC-specific means. Pull
* values are also SoC-specific.
*
* This API should only be used in TPL/SPL where GPIO access is needed but
* driver model is not available (yet) or adds too much overhead.
*
* The caller must supply the GPIO register base since this information is
* often specific to a particular SoC generation. This allows the GPIO
* code to be fairly generic.
*
* Only a single implementation of each of these functions can be provided.
*
* The 'gpio' value can include both a bank and a GPIO number, if desired. The
* encoding is SoC-specific.
*/
/**
* spl_gpio_set_pull() - Set the pull up/down state of a GPIO
*
* @regs: Pointer to GPIO registers
* @gpio: GPIO to adjust (SoC-specific)
* @pull: Pull value (SoC-specific)
* @return return 0 if OK, -ve on error
*/
int spl_gpio_set_pull(void *regs, uint gpio, int pull);
/**
* spl_gpio_output() - Set a GPIO as an output
*
* @regs: Pointer to GPIO registers
* @gpio: GPIO to adjust (SoC-specific)
* @value: 0 to set the output low, 1 to set it high
* @return return 0 if OK, -ve on error
*/
int spl_gpio_output(void *regs, uint gpio, int value);
/**
* spl_gpio_input() - Set a GPIO as an input
*
* @regs: Pointer to GPIO registers
* @gpio: GPIO to adjust (SoC-specific)
* @return return 0 if OK, -ve on error
*/
int spl_gpio_input(void *regs, uint gpio);
#endif /* __SPL_GPIO_H */