Messages in this thread | | | Subject | Re: [PATCH/RFC v2] tools/leds: Add led_notify_mon program for monitoring brightness changes | From | Hans de Goede <> | Date | Wed, 9 Nov 2016 12:50:05 +0100 |
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Hi,
On 08-11-16 12:36, Jacek Anaszewski wrote: > LED subsystem supports POLLPRI on "brightness" sysfs file of LED > class devices. This tool demonstrates how to use the feature. > > Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> > Cc: Hans de Goede <hdegoede@redhat.com>
Thank you.
Patch looks good to me:
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Regards,
Hans
> --- > Changes since v1: > - added lseek which fixes non-blocking poll() behaviour > > tools/leds/Makefile | 4 +-- > tools/leds/led_notify_mon.c | 83 +++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 85 insertions(+), 2 deletions(-) > create mode 100644 tools/leds/led_notify_mon.c > > diff --git a/tools/leds/Makefile b/tools/leds/Makefile > index c03a79e..0fa948a 100644 > --- a/tools/leds/Makefile > +++ b/tools/leds/Makefile > @@ -3,11 +3,11 @@ > CC = $(CROSS_COMPILE)gcc > CFLAGS = -Wall -Wextra -g -I../../include/uapi > > -all: uledmon > +all: uledmon led_notify_mon > %: %.c > $(CC) $(CFLAGS) -o $@ $^ > > clean: > - $(RM) uledmon > + $(RM) uledmon led_notify_mon > > .PHONY: all clean > diff --git a/tools/leds/led_notify_mon.c b/tools/leds/led_notify_mon.c > new file mode 100644 > index 0000000..8b6e6f9 > --- /dev/null > +++ b/tools/leds/led_notify_mon.c > @@ -0,0 +1,83 @@ > +/* > + * led_notify_mon.c > + * > + * This program monitors LED brightness change notifications, > + * either having its origin in the hardware or in the software. > + * A timestamp and brightness value is printed each time the brightness changes. > + * > + * Usage: led_notify_mon <device-name> > + * > + * <device-name> is the name of the LED class device to be monitored. Pressing > + * CTRL+C will exit. > + */ > + > +#include <fcntl.h> > +#include <poll.h> > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <time.h> > +#include <unistd.h> > + > +#include <linux/uleds.h> > + > +int main(int argc, char const *argv[]) > +{ > + int fd, ret; > + char brightness_file_path[LEDS_MAX_NAME_SIZE + 11]; > + struct pollfd pollfd; > + struct timespec ts; > + char buf[11]; > + > + if (argc != 2) { > + fprintf(stderr, "Requires <device-name> argument\n"); > + return 1; > + } > + > + snprintf(brightness_file_path, LEDS_MAX_NAME_SIZE, > + "/sys/class/leds/%s/brightness", argv[1]); > + > + fd = open(brightness_file_path, O_RDONLY); > + if (fd == -1) { > + printf("Failed to open %s file\n", brightness_file_path); > + return 1; > + } > + > + ret = read(fd, buf, sizeof(buf)); > + if (ret < 0) { > + printf("Failed to read %s file\n", brightness_file_path); > + goto err_read; > + } > + > + pollfd.fd = fd; > + pollfd.events = POLLPRI; > + > + while (1) { > + ret = poll(&pollfd, 1, -1); > + if (ret == -1) { > + printf("Failed to poll %s file (%d)\n", > + brightness_file_path, ret); > + ret = 1; > + break; > + } > + > + clock_gettime(CLOCK_MONOTONIC, &ts); > + > + ret = read(fd, buf, sizeof(buf)); > + if (ret < 0) > + break; > + > + ret = lseek(pollfd.fd, 0, SEEK_SET); > + if (ret < 0) { > + printf("lseek failed (%d)\n", ret); > + break; > + } > + > + printf("[%ld.%09ld] %d\n", ts.tv_sec, ts.tv_nsec, atoi(buf)); > + } > + > +err_read: > + close(fd); > + > + return ret; > +} >
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