115 lines
2.4 KiB
C
115 lines
2.4 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#include <unistd.h>
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#include <sys/wait.h>
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#include <stdint.h>
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#include <string.h>
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#include <sys/time.h>
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#include <unistd.h>
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#include "libsoc_gpio.h"
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/*
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* libsoc GPIO documentation: http://jackmitch.github.io/libsoc/c/gpio/#gpio
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*/
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volatile bool led_status = false;
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static uint32_t times = 0;
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gpio *gpio_interrupt = NULL;
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gpio *gpio_led = NULL;
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int gpio_interrupt_callback(void* arg)
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{
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if (!led_status) {
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led_status = true;
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libsoc_gpio_set_level(gpio_led, HIGH);
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} else {
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led_status = false;
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libsoc_gpio_set_level(gpio_led, LOW);
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}
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times++;
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printf("Interrupt occurred %d times\n", times);
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return 0;
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}
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int main(void)
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{
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uint32_t gpio_input;
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uint32_t led_output;
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uint32_t ret = 0;
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printf("Enter the GPIO number to use as interrupt:\t");
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scanf("%d", &gpio_input);
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printf("Enter the GPIO number used for LED output:\t");
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scanf("%d", &led_output);
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/*
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* It is expected that the gpio being requested is pin multiplexed correctly
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* in the kernel device tree or board file as applicable else gpio request
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* is bound to fail.
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*/
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gpio_interrupt = libsoc_gpio_request(gpio_input, LS_SHARED);
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if (gpio_interrupt == NULL) {
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perror("gpio request failed");
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goto exit;
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}
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gpio_led = libsoc_gpio_request(led_output, LS_SHARED);
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if (gpio_led == NULL) {
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perror("led gpio request failed");
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goto exit;
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}
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ret = libsoc_gpio_set_direction(gpio_led, OUTPUT);
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if (ret == EXIT_FAILURE) {
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perror("Failed to set gpio led direction");
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goto exit;
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}
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ret = libsoc_gpio_set_direction(gpio_interrupt, INPUT);
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if (ret == EXIT_FAILURE) {
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perror("Failed to set gpio direction");
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goto exit;
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}
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ret = libsoc_gpio_set_edge(gpio_interrupt, RISING);
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if (ret == EXIT_FAILURE) {
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perror("Failed to set gpio edge");
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goto exit;
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}
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ret = libsoc_gpio_callback_interrupt(gpio_interrupt, &gpio_interrupt_callback, NULL);
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if (ret == EXIT_FAILURE) {
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perror("Failed to set gpio callback");
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goto exit;
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}
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printf("Waiting for interrupt. Press 'q' and 'Enter' at any time to exit\n");
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char key = -1;
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while (true) {
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key = fgetc(stdin);
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if (key == 'q')
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goto exit;
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}
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exit:
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if (gpio_interrupt) {
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ret = libsoc_gpio_free(gpio_interrupt);
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if (ret == EXIT_FAILURE)
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perror("Could not free gpio");
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}
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if (gpio_led) {
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ret = libsoc_gpio_free(gpio_led);
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if (ret == EXIT_FAILURE)
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perror("Could not free led gpio");
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}
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return ret;
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}
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