1 // SPDX-License-Identifier: GPL-2.0-only
3  * gpio-event-mon - monitor GPIO line events from userspace
8  *	gpio-event-mon -n <device-name> -o <offset>
25 #include <linux/gpio.h>
26 #include "gpio-utils.h"
29 		   unsigned int *lines,  in monitor_device()  argument
42 		return -ENOMEM;  in monitor_device()
45 	if (cfd == -1) {  in monitor_device()
46 		ret = -errno;  in monitor_device()
51 	ret = gpiotools_request_line(device_name, lines, num_lines, config,  in monitor_device()
52 				     "gpio-event-mon");  in monitor_device()
66 			"Failed to issue GPIO LINE GET VALUES IOCTL (%d)\n",  in monitor_device()
72 		fprintf(stdout, "Monitoring line %d on %s\n", lines[0], device_name);  in monitor_device()
76 		fprintf(stdout, "Monitoring lines %d", lines[0]);  in monitor_device()
77 		for (i = 1; i < num_lines - 1; i++)  in monitor_device()
78 			fprintf(stdout, ", %d", lines[i]);  in monitor_device()
79 		fprintf(stdout, " and %d on %s\n", lines[i], device_name);  in monitor_device()
82 		for (i = 1; i < num_lines - 1; i++)  in monitor_device()
93 		if (ret == -1) {  in monitor_device()
94 			if (errno == -EAGAIN) {  in monitor_device()
98 				ret = -errno;  in monitor_device()
107 			ret = -EIO;  in monitor_device()
110 		fprintf(stdout, "GPIO EVENT at %" PRIu64 " on line %d (%d|%d) ",  in monitor_device()
131 	if (close(lfd) == -1)  in monitor_device()
134 	if (close(cfd) == -1)  in monitor_device()
135 		perror("Failed to close GPIO character device file");  in monitor_device()
143 	fprintf(stderr, "Usage: gpio-event-mon [options]...\n"  in print_usage()
144 		"Listen to events on GPIO lines, 0->1 1->0\n"  in print_usage()
145 		"  -n <name>  Listen on GPIOs on a named device (must be stated)\n"  in print_usage()
146 		"  -o <n>     Offset of line to monitor (may be repeated)\n"  in print_usage()
147 		"  -d         Set line as open drain\n"  in print_usage()
148 		"  -s         Set line as open source\n"  in print_usage()
149 		"  -r         Listen for rising edges\n"  in print_usage()
150 		"  -f         Listen for falling edges\n"  in print_usage()
151 		"  -w         Report the wall-clock time for events\n"  in print_usage()
152 		"  -t         Report the hardware timestamp for events\n"  in print_usage()
153 		"  -b <n>     Debounce the line with period n microseconds\n"  in print_usage()
154 		" [-c <n>]    Do <n> loops (optional, infinite loop if not stated)\n"  in print_usage()
155 		"  -?         This helptext\n"  in print_usage()
158 		"gpio-event-mon -n gpiochip0 -o 4 -r -f -b 10000\n"  in print_usage()
169 	unsigned int lines[GPIO_V2_LINES_MAX];  in main()  local
178 	while ((c = getopt(argc, argv, "c:n:o:b:dsrfwt?")) != -1) {  in main()
189 				return -1;  in main()
191 			lines[num_lines] = strtoul(optarg, NULL, 10);  in main()
217 			return -1;  in main()
232 		return -1;  in main()
239 	return monitor_device(device_name, lines, num_lines, &config, loops);  in main()