From 6d591c46bce037696d173bd5c8461b2b4bb680ad Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Wed, 21 Oct 2015 15:45:54 +0200 Subject: tools/gpio: create GPIO tools This creates GPIO tools under tools/gpio/* and adds a single example program to list the GPIOs on a system. When proper devices are created it provides this minimal output: Cc: Johan Hovold Cc: Michael Welling Cc: Markus Pargmann Signed-off-by: Linus Walleij --- tools/gpio/Makefile | 12 +++++ tools/gpio/gpio-utils.c | 11 +++++ tools/gpio/gpio-utils.h | 25 ++++++++++ tools/gpio/lsgpio.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 176 insertions(+) create mode 100644 tools/gpio/Makefile create mode 100644 tools/gpio/gpio-utils.c create mode 100644 tools/gpio/gpio-utils.h create mode 100644 tools/gpio/lsgpio.c (limited to 'tools/gpio') diff --git a/tools/gpio/Makefile b/tools/gpio/Makefile new file mode 100644 index 000000000000..4d198d5c4203 --- /dev/null +++ b/tools/gpio/Makefile @@ -0,0 +1,12 @@ +CC = $(CROSS_COMPILE)gcc +CFLAGS += -Wall -g -D_GNU_SOURCE + +all: lsgpio + +lsgpio: lsgpio.o gpio-utils.o + +%.o: %.c gpio-utils.h + +.PHONY: clean +clean: + rm -f *.o lsgpio diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c new file mode 100644 index 000000000000..8208718f2c99 --- /dev/null +++ b/tools/gpio/gpio-utils.c @@ -0,0 +1,11 @@ +/* + * GPIO tools - helpers library for the GPIO tools + * + * Copyright (C) 2015 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. + */ + +#include "gpio-utils.h" diff --git a/tools/gpio/gpio-utils.h b/tools/gpio/gpio-utils.h new file mode 100644 index 000000000000..b18209a45ad3 --- /dev/null +++ b/tools/gpio/gpio-utils.h @@ -0,0 +1,25 @@ +/* + * GPIO tools - utility helpers library for the GPIO tools + * + * Copyright (C) 2015 Linus Walleij + * + * Portions copied from iio_utils and lssio: + * Copyright (c) 2010 Manuel Stahl + * Copyright (c) 2008 Jonathan Cameron + * * + * 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. + */ +#ifndef _GPIO_UTILS_H_ +#define _GPIO_UTILS_H_ + +#include + +static inline int check_prefix(const char *str, const char *prefix) +{ + return strlen(str) > strlen(prefix) && + strncmp(str, prefix, strlen(prefix)) == 0; +} + +#endif /* _GPIO_UTILS_H_ */ diff --git a/tools/gpio/lsgpio.c b/tools/gpio/lsgpio.c new file mode 100644 index 000000000000..4cfe29da279b --- /dev/null +++ b/tools/gpio/lsgpio.c @@ -0,0 +1,128 @@ +/* + * lsgpio - example on how to list the GPIO lines on a system + * + * Copyright (C) 2015 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: + * lsgpio <-n device-name> + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "gpio-utils.h" + +int list_device(const char *device_name) +{ + struct gpiochip_info cinfo; + char *chrdev_name; + int fd; + int ret; + + ret = asprintf(&chrdev_name, "/dev/%s", device_name); + if (ret < 0) + return -ENOMEM; + + fd = open(chrdev_name, 0); + if (fd == -1) { + ret = -errno; + fprintf(stderr, "Failed to open %s\n", chrdev_name); + goto free_chrdev_name; + } + + /* Inspect this GPIO chip */ + ret = ioctl(fd, GPIO_GET_CHIPINFO_IOCTL, &cinfo); + if (ret == -1) { + ret = -errno; + fprintf(stderr, "Failed to retrieve GPIO fd\n"); + if (close(fd) == -1) + perror("Failed to close GPIO character device file"); + + goto free_chrdev_name; + } + fprintf(stdout, "GPIO chip: %s, %u GPIO lines\n", + cinfo.name, cinfo.lines); + + if (close(fd) == -1) { + ret = -errno; + goto free_chrdev_name; + } + +free_chrdev_name: + free(chrdev_name); + + return ret; + +} + +void print_usage(void) +{ + fprintf(stderr, "Usage: lsgpio [options]...\n" + "List GPIO chips, lines and states\n" + " -n List GPIOs on a named device\n" + " -? This helptext\n" + ); +} + +int main(int argc, char **argv) +{ + const char *device_name; + int ret; + int c; + + while ((c = getopt(argc, argv, "n:")) != -1) { + switch (c) { + case 'n': + device_name = optarg; + break; + case '?': + print_usage(); + return -1; + } + } + + if (device_name) + ret = list_device(device_name); + else { + const struct dirent *ent; + DIR *dp; + + /* List all GPIO devices one at a time */ + dp = opendir("/dev"); + if (!dp) { + ret = -errno; + goto error_out; + } + + ret = -ENOENT; + while (ent = readdir(dp), ent) { + if (check_prefix(ent->d_name, "gpiochip")) { + ret = list_device(ent->d_name); + if (ret) + break; + } + } + + ret = 0; + if (closedir(dp) == -1) { + perror("scanning devices: Failed to close directory"); + ret = -errno; + } + } +error_out: + return ret; +} -- cgit v1.2.3