cregit-Linux how code gets into the kernel

Release 4.10 tools/gpio/gpio-hammer.c

Directory: tools/gpio
/*
 * gpio-hammer - example swiss army knife to shake GPIO lines on a system
 *
 * Copyright (C) 2016 Linus Walleij
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * Usage:
 *      gpio-hammer -n <device-name> -o <offset1> -o <offset2>
 */

#include <unistd.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdio.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
#include <poll.h>
#include <fcntl.h>
#include <getopt.h>
#include <sys/ioctl.h>
#include <linux/gpio.h>
#include "gpio-utils.h"


int hammer_device(const char *device_name, unsigned int *lines, int nlines, unsigned int loops) { struct gpiohandle_data data; char swirr[] = "-\\|/"; int fd; int ret; int i, j; unsigned int iteration = 0; memset(&data.values, 0, sizeof(data.values)); ret = gpiotools_request_linehandle(device_name, lines, nlines, GPIOHANDLE_REQUEST_OUTPUT, &data, "gpio-hammler"); if (ret < 0) goto exit_error; else fd = ret; ret = gpiotools_get_values(fd, &data); if (ret < 0) goto exit_close_error; fprintf(stdout, "Hammer lines ["); for (i = 0; i < nlines; i++) { fprintf(stdout, "%d", lines[i]); if (i != (nlines - 1)) fprintf(stdout, ", "); } fprintf(stdout, "] on %s, initial states: [", device_name); for (i = 0; i < nlines; i++) { fprintf(stdout, "%d", data.values[i]); if (i != (nlines - 1)) fprintf(stdout, ", "); } fprintf(stdout, "]\n"); /* Hammertime! */ j = 0; while (1) { /* Invert all lines so we blink */ for (i = 0; i < nlines; i++) data.values[i] = !data.values[i]; ret = gpiotools_set_values(fd, &data); if (ret < 0) goto exit_close_error; /* Re-read values to get status */ ret = gpiotools_get_values(fd, &data); if (ret < 0) goto exit_close_error; fprintf(stdout, "[%c] ", swirr[j]); j++; if (j == sizeof(swirr)-1) j = 0; fprintf(stdout, "["); for (i = 0; i < nlines; i++) { fprintf(stdout, "%d: %d", lines[i], data.values[i]); if (i != (nlines - 1)) fprintf(stdout, ", "); } fprintf(stdout, "]\r"); fflush(stdout); sleep(1); iteration++; if (loops && iteration == loops) break; } fprintf(stdout, "\n"); ret = 0; exit_close_error: gpiotools_release_linehandle(fd); exit_error: return ret; }

Contributors

PersonTokensPropCommitsCommitProp
linus walleijlinus walleij41492.20%150.00%
bamvor jian zhangbamvor jian zhang357.80%150.00%
Total449100.00%2100.00%


void print_usage(void) { fprintf(stderr, "Usage: gpio-hammer [options]...\n" "Hammer GPIO lines, 0->1->0->1...\n" " -n <name> Hammer GPIOs on a named device (must be stated)\n" " -o <n> Offset[s] to hammer, at least one, several can be stated\n" " [-c <n>] Do <n> loops (optional, infinite loop if not stated)\n" " -? This helptext\n" "\n" "Example:\n" "gpio-hammer -n gpiochip0 -o 4\n" ); }

Contributors

PersonTokensPropCommitsCommitProp
linus walleijlinus walleij22100.00%1100.00%
Total22100.00%1100.00%


int main(int argc, char **argv) { const char *device_name = NULL; unsigned int lines[GPIOHANDLES_MAX]; unsigned int loops = 0; int nlines; int c; int i; i = 0; while ((c = getopt(argc, argv, "c:n:o:?")) != -1) { switch (c) { case 'c': loops = strtoul(optarg, NULL, 10); break; case 'n': device_name = optarg; break; case 'o': lines[i] = strtoul(optarg, NULL, 10); i++; break; case '?': print_usage(); return -1; } } nlines = i; if (!device_name || !nlines) { print_usage(); return -1; } return hammer_device(device_name, lines, nlines, loops); }

Contributors

PersonTokensPropCommitsCommitProp
linus walleijlinus walleij159100.00%1100.00%
Total159100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
linus walleijlinus walleij63294.33%150.00%
bamvor jian zhangbamvor jian zhang385.67%150.00%
Total670100.00%2100.00%
Directory: tools/gpio
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