diff options
Diffstat (limited to 'tools/gpio/gpio-hammer.c')
| -rw-r--r-- | tools/gpio/gpio-hammer.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/tools/gpio/gpio-hammer.c b/tools/gpio/gpio-hammer.c new file mode 100644 index 000000000..3da5462a0 --- /dev/null +++ b/tools/gpio/gpio-hammer.c @@ -0,0 +1,171 @@ +/* + * 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-hammer"); + 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; +} + +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" + ); +} + +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': + /* + * Avoid overflow. Do not immediately error, we want to + * be able to accurately report on the amount of times + * '-o' was given to give an accurate error message + */ + if (i < GPIOHANDLES_MAX) + lines[i] = strtoul(optarg, NULL, 10); + + i++; + break; + case '?': + print_usage(); + return -1; + } + } + + if (i >= GPIOHANDLES_MAX) { + fprintf(stderr, + "Only %d occurences of '-o' are allowed, %d were found\n", + GPIOHANDLES_MAX, i + 1); + return -1; + } + + nlines = i; + + if (!device_name || !nlines) { + print_usage(); + return -1; + } + return hammer_device(device_name, lines, nlines, loops); +} |