Atmosphere/fusee/fusee-secondary/src/gpio.c
2019-07-23 18:33:34 +01:00

87 lines
2.9 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"
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];
}
static volatile uint32_t gpio_get_port(uint32_t pin) {
return ((pin >> GPIO_PORT_SHIFT) & GPIO_PORT_MASK);
}
static volatile uint32_t gpio_get_mask(uint32_t pin) {
uint32_t pin_number = (pin & GPIO_PIN_MASK);
return (1 << pin_number);
}
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;
/* Dummy read. */
(void)cluster[port];
}
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);
}
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));
}
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));
}
void gpio_write(uint32_t pin, uint32_t value) {
gpio_simple_register_set(pin, value == GPIO_LEVEL_HIGH, offsetof(tegra_gpio_bank_t, out));
}
uint32_t gpio_read(uint32_t pin) {
return gpio_simple_register_get(pin, offsetof(tegra_gpio_bank_t, in));
}