From: Bartosz Golaszewski <bartekgola@gmail.com>
Date: Thu, 5 Jan 2017 14:22:41 +0000 (+0100)
Subject: gpiomon: new tool
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=152a26d34ddf8824a0a00449b24c454e0175250c;p=qemu-gpiodev%2Flibgpiod.git

gpiomon: new tool

Implement a simple GPIO event monitor.

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
---

diff --git a/.gitignore b/.gitignore
index 060ee04..2879c59 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@ gpiodetect
 gpioinfo
 gpioget
 gpioset
+gpiomon
 *.o
 *.lo
 doc
diff --git a/Makefile.am b/Makefile.am
index 585dac4..d47b230 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -37,6 +37,10 @@ gpioset_SOURCES = gpioset.c
 gpioset_LDFLAGS = -lgpiod
 gpioset_DEPENDENCIES = libgpiod.la
 
+gpiomon_SOURCES = gpiomon.c
+gpiomon_LDFLAGS = -lgpiod
+gpiomon_DEPENDENCIES = libgpiod.la
+
 doc:
 	doxygen
 .PHONY: doc
diff --git a/gpiomon.c b/gpiomon.c
new file mode 100644
index 0000000..1550e25
--- /dev/null
+++ b/gpiomon.c
@@ -0,0 +1,101 @@
+/*
+ * Monitor events on a GPIO line.
+ *
+ * Copyright (C) 2017 Bartosz Golaszewski <bartekgola@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ */
+
+#include <gpiod.h>
+
+#include <stdio.h>
+#include <string.h>
+
+int main(int argc, char **argv)
+{
+	struct gpiod_line_evreq_config config;
+	struct gpiod_line_event event;
+	struct timespec timeout;
+	struct gpiod_chip *chip;
+	struct gpiod_line *line;
+	unsigned int offset;
+	char *device, *end;
+	int status;
+
+	if (argc < 2) {
+		fprintf(stderr, "%s: gpiochip must be specified\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	if (argc < 3) {
+		fprintf(stderr,
+			"%s: gpio line offset must be specified\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	device = argv[1];
+	/* FIXME Handle negative numbers. */
+	offset = strtoul(argv[2], &end, 10);
+	if (*end != '\0') {
+		fprintf(stderr,
+			"%s: invalid GPIO offset: %s\n", argv[0], argv[2]);
+		return EXIT_FAILURE;
+	}
+
+	chip = gpiod_chip_open_lookup(device);
+	if (!chip) {
+		fprintf(stderr,
+			"%s: error accessing gpiochip %s: %s\n",
+			argv[0], device, gpiod_strerror(gpiod_errno()));
+		return EXIT_FAILURE;
+	}
+
+	line = gpiod_chip_get_line(chip, offset);
+	if (!line) {
+		fprintf(stderr,
+			"%s: error accessing line %u: %s\n",
+			argv[0], offset, gpiod_strerror(gpiod_errno()));
+		return EXIT_FAILURE;
+	}
+
+	memset(&config, 0, sizeof(config));
+	config.consumer = "gpiomon";
+	config.event_type = GPIOD_EVENT_BOTH_EDGES;
+
+	status = gpiod_line_event_request(line, &config);
+	if (status < 0) {
+		fprintf(stderr,
+			"%s: error requesting line event: %s\n",
+			argv[0], gpiod_strerror(gpiod_errno()));
+		return EXIT_FAILURE;
+	}
+
+	for (;;) {
+		timeout.tv_sec = 1;
+		timeout.tv_nsec = 0;
+
+		status = gpiod_line_event_wait(line, &timeout, &event);
+		if (status < 0) {
+			fprintf(stderr,
+				"%s: error waiting for line event: %s\n",
+				argv[0], gpiod_strerror(gpiod_errno()));
+			return EXIT_FAILURE;
+		} else if (status == 0) {
+			continue;
+		}
+
+		printf("GPIO EVENT: %s [%ld.%ld]\n",
+		       event.event_type == GPIOD_EVENT_FALLING_EDGE
+							? "FALLING EDGE"
+							: "RAISING EDGE",
+		       event.ts.tv_sec, event.ts.tv_nsec);
+	}
+
+	gpiod_line_event_release(line);
+	gpiod_line_release(line);
+	gpiod_chip_close(chip);
+
+	return EXIT_SUCCESS;
+}