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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2013 Alexandru Gagniuc <mr.nuke.me@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Basic GPIO helpers for Allwinner CPUs
*/
#include "gpio.h"
#include <device/mmio.h>
static struct a10_gpio *const gpio = (void *)GPIO_BASE;
/**
* \brief Set a single output pin
*
* @param[in] port GPIO port of the pin (GPA -> GPS)
* @param[in] pin the pin number in the given port (1 -> 31)
*/
void gpio_set(u8 port, u8 pin)
{
u32 reg32;
if ((port > GPS))
return;
reg32 = gpio_read(port);
reg32 |= (1 << pin);
gpio_write(port, reg32);
}
/**
* \brief Clear a single output pin
*
* @param[in] port GPIO port of the pin (GPA -> GPS)
* @param[in] pin the pin number in the given port (1 -> 31)
*/
void gpio_clear(u8 port, u8 pin)
{
u32 reg32;
if ((port > GPS))
return;
reg32 = gpio_read(port);
reg32 &= ~(1 << pin);
gpio_write(port, reg32);
}
/**
* \brief Get the status of a single input pin
*
* @param[in] port GPIO port of the pin (GPA -> GPS)
* @param[in] pin the pin number in the given port (1 -> 31)
* @return 1 if the pin is high, or 0 if the pin is low
*/
int gpio_get(u8 port, u8 pin)
{
if ((port > GPS))
return 0;
return (gpio_read(port) & (1 << pin)) ? 1 : 0;
}
/**
* \brief Write to a GPIO port
*
* Write the state of all output pins in the GPIO port. This only affects pins
* configured as output pins.
*
* @param[in] port GPIO port of the pin (GPA -> GPS)
* @param[in] val 32-bit mask indicating which pins to set. For a set bit, the
* corresponding pin will be set. Otherwise, it will be cleared
*/
void gpio_write(u8 port, u32 val)
{
if ((port > GPS))
return;
write32(&gpio->port[port].dat, val);
}
/**
* \brief Write to a GPIO port
*
* Read the state of all input pins in the GPIO port.
*
* @param[in] port GPIO port of the pin (GPA -> GPS)
* @return 32-bit mask indicating which pins are high. For each set bit, the
* corresponding pin is high. The value of bits corresponding to pins
* which are not configured as inputs is undefined.
*/
u32 gpio_read(u8 port)
{
if ((port > GPS))
return 0;
return read32(&gpio->port[port].dat);
}
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