diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/gpio/.gitignore | 1 | ||||
| -rw-r--r-- | tools/gpio/Build | 1 | ||||
| -rw-r--r-- | tools/gpio/Makefile | 11 | ||||
| -rw-r--r-- | tools/gpio/gpio-watch.c | 99 |
4 files changed, 111 insertions, 1 deletions
diff --git a/tools/gpio/.gitignore b/tools/gpio/.gitignore index a94c0e83b209..eab36c6d7751 100644 --- a/tools/gpio/.gitignore +++ b/tools/gpio/.gitignore @@ -1,4 +1,5 @@ gpio-event-mon gpio-hammer +gpio-watch lsgpio include/linux/gpio.h diff --git a/tools/gpio/Build b/tools/gpio/Build index 4141f35837db..67c7b7f6a717 100644 --- a/tools/gpio/Build +++ b/tools/gpio/Build @@ -2,3 +2,4 @@ gpio-utils-y += gpio-utils.o lsgpio-y += lsgpio.o gpio-utils.o gpio-hammer-y += gpio-hammer.o gpio-utils.o gpio-event-mon-y += gpio-event-mon.o gpio-utils.o +gpio-watch-y += gpio-watch.o diff --git a/tools/gpio/Makefile b/tools/gpio/Makefile index 6080de58861f..842287e42c83 100644 --- a/tools/gpio/Makefile +++ b/tools/gpio/Makefile @@ -18,7 +18,7 @@ MAKEFLAGS += -r override CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include -ALL_TARGETS := lsgpio gpio-hammer gpio-event-mon +ALL_TARGETS := lsgpio gpio-hammer gpio-event-mon gpio-watch ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS)) all: $(ALL_PROGRAMS) @@ -66,6 +66,15 @@ $(GPIO_EVENT_MON_IN): prepare FORCE $(OUTPUT)gpio-utils-in.o $(OUTPUT)gpio-event-mon: $(GPIO_EVENT_MON_IN) $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@ +# +# gpio-watch +# +GPIO_WATCH_IN := $(OUTPUT)gpio-watch-in.o +$(GPIO_WATCH_IN): prepare FORCE + $(Q)$(MAKE) $(build)=gpio-watch +$(OUTPUT)gpio-watch: $(GPIO_WATCH_IN) + $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@ + clean: rm -f $(ALL_PROGRAMS) rm -f $(OUTPUT)include/linux/gpio.h diff --git a/tools/gpio/gpio-watch.c b/tools/gpio/gpio-watch.c new file mode 100644 index 000000000000..5cea24fddfa7 --- /dev/null +++ b/tools/gpio/gpio-watch.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * gpio-watch - monitor unrequested lines for property changes using the + * character device + * + * Copyright (C) 2019 BayLibre SAS + * Author: Bartosz Golaszewski <bgolaszewski@baylibre.com> + */ + +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <linux/gpio.h> +#include <poll.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <unistd.h> + +int main(int argc, char **argv) +{ + struct gpioline_info_changed chg; + struct gpioline_info req; + struct pollfd pfd; + int fd, i, j, ret; + char *event, *end; + ssize_t rd; + + if (argc < 3) + goto err_usage; + + fd = open(argv[1], O_RDWR | O_CLOEXEC); + if (fd < 0) { + perror("unable to open gpiochip"); + return EXIT_FAILURE; + } + + for (i = 0, j = 2; i < argc - 2; i++, j++) { + memset(&req, 0, sizeof(req)); + + req.line_offset = strtoul(argv[j], &end, 0); + if (*end != '\0') + goto err_usage; + + ret = ioctl(fd, GPIO_GET_LINEINFO_WATCH_IOCTL, &req); + if (ret) { + perror("unable to set up line watch"); + return EXIT_FAILURE; + } + } + + pfd.fd = fd; + pfd.events = POLLIN | POLLPRI; + + for (;;) { + ret = poll(&pfd, 1, 5000); + if (ret < 0) { + perror("error polling the linechanged fd"); + return EXIT_FAILURE; + } else if (ret > 0) { + memset(&chg, 0, sizeof(chg)); + rd = read(pfd.fd, &chg, sizeof(chg)); + if (rd < 0 || rd != sizeof(chg)) { + if (rd != sizeof(chg)) + errno = EIO; + + perror("error reading line change event"); + return EXIT_FAILURE; + } + + switch (chg.event_type) { + case GPIOLINE_CHANGED_REQUESTED: + event = "requested"; + break; + case GPIOLINE_CHANGED_RELEASED: + event = "released"; + break; + case GPIOLINE_CHANGED_CONFIG: + event = "config changed"; + break; + default: + fprintf(stderr, + "invalid event type received from the kernel\n"); + return EXIT_FAILURE; + } + + printf("line %u: %s at %llu\n", + chg.info.line_offset, event, chg.timestamp); + } + } + + return 0; + +err_usage: + printf("%s: <gpiochip> <line0> <line1> ...\n", argv[0]); + return EXIT_FAILURE; +} |