Atmosphere/fusee/fusee-secondary/src/gpio.c
2019-04-07 19:00:49 -07:00

145 lines
4.5 KiB
C

/*
* Copyright (c) 2018-2019 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include "gpio.h"
#include "utils.h"
/**
* Returns a GPIO bank object that corresponds to the given GPIO pin,
* which can be created using the TEGRA_GPIO macro or passed from the name macro.
*
* @param pin The GPIO to get the bank for.
* @return The GPIO bank object to use for working with the given bank.
*/
static volatile tegra_gpio_bank_t *gpio_get_bank(uint32_t pin)
{
volatile tegra_gpio_t *gpio = gpio_get_regs();
uint32_t bank_number = pin >> GPIO_BANK_SHIFT;
return &gpio->bank[bank_number];
}
/**
* @return the port number for working with the given GPIO.
*/
static volatile uint32_t gpio_get_port(uint32_t pin)
{
return (pin >> GPIO_PORT_SHIFT) & GPIO_PORT_MASK;
}
/**
* @return a mask to be used to work with the given GPIO
*/
static volatile uint32_t gpio_get_mask(uint32_t pin)
{
uint32_t pin_number = pin & GPIO_PIN_MASK;
return (1 << pin_number);
}
/**
* Performs a simple GPIO configuration operation.
*
* @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
* @param should_be_set True iff the relevant bit should be set; or false if it should be cleared.
* @param offset The offset into a gpio_bank structure
*/
static void gpio_simple_register_set(uint32_t pin, bool should_be_set, uint32_t offset)
{
// Retrieve the register set that corresponds to the given pin and offset.
uintptr_t cluster_addr = (uintptr_t)gpio_get_bank(pin) + offset;
uint32_t *cluster = (uint32_t *)cluster_addr;
// Figure out the offset into the cluster,
// and the mask to be used.
uint32_t port = gpio_get_port(pin);
uint32_t mask = gpio_get_mask(pin);
// Set or clear the bit, as appropriate.
if (should_be_set)
cluster[port] |= mask;
else
cluster[port] &= ~mask;
}
/**
* Performs a simple GPIO configuration operation.
*
* @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
* @param should_be_set True iff the relevant bit should be set; or false if it should be cleared.
* @param offset The offset into a gpio_bank structure
*/
static bool gpio_simple_register_get(uint32_t pin, uint32_t offset)
{
// Retrieve the register set that corresponds to the given pin and offset.
uintptr_t cluster_addr = (uintptr_t)gpio_get_bank(pin) + offset;
uint32_t *cluster = (uint32_t *)cluster_addr;
// Figure out the offset into the cluster,
// and the mask to be used.
uint32_t port = gpio_get_port(pin);
uint32_t mask = gpio_get_mask(pin);
// Convert the given value to a boolean.
return !!(cluster[port] & mask);
}
/**
* Configures a given pin as either GPIO or SFIO.
*
* @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
* @param mode The relevant mode.
*/
void gpio_configure_mode(uint32_t pin, uint32_t mode)
{
gpio_simple_register_set(pin, mode == GPIO_MODE_GPIO, offsetof(tegra_gpio_bank_t, config));
}
/**
* Configures a given pin as either INPUT or OUPUT.
*
* @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
* @param direction The relevant direction.
*/
void gpio_configure_direction(uint32_t pin, uint32_t dir)
{
gpio_simple_register_set(pin, dir == GPIO_DIRECTION_OUTPUT, offsetof(tegra_gpio_bank_t, direction));
}
/**
* Drives a relevant GPIO pin as either HIGH or LOW.
*
* @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
* @param mode The relevant mode.
*/
void gpio_write(uint32_t pin, uint32_t value)
{
gpio_simple_register_set(pin, value == GPIO_LEVEL_HIGH, offsetof(tegra_gpio_bank_t, out));
}
/**
* Drives a relevant GPIO pin as either HIGH or LOW.
*
* @param pin The GPIO pin to work with, as created with TEGRA_GPIO, or a named GPIO.
* @param mode The relevant mode.
*/
uint32_t gpio_read(uint32_t pin)
{
return gpio_simple_register_get(pin, offsetof(tegra_gpio_bank_t, in));
}