samples/timers/hpet_example.c

Source file repositories/reference/linux-study-clean/samples/timers/hpet_example.c

File Facts

System
Linux kernel
Corpus path
samples/timers/hpet_example.c
Extension
.c
Size
5591 bytes
Lines
296
Domain
Support Tooling And Documentation
Bucket
samples
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct hpet_command {
	char		*command;
	void		(*func)(int argc, const char ** argv);
} hpet_command[] = {
	{
		"open-close",
		hpet_open_close
	},
	{
		"info",
		hpet_info
	},
	{
		"poll",
		hpet_poll
	},
	{
		"fasync",
		hpet_fasync
	},
};

int
main(int argc, const char ** argv)
{
	unsigned int	i;

	argc--;
	argv++;

	if (!argc) {
		fprintf(stderr, "-hpet: requires command\n");
		return -1;
	}


	for (i = 0; i < (sizeof (hpet_command) / sizeof (hpet_command[0])); i++)
		if (!strcmp(argv[0], hpet_command[i].command)) {
			argc--;
			argv++;
			fprintf(stderr, "-hpet: executing %s\n",
				hpet_command[i].command);
			hpet_command[i].func(argc, argv);
			return 0;
		}

	fprintf(stderr, "do_hpet: command %s not implemented\n", argv[0]);

	return -1;
}

void
hpet_open_close(int argc, const char **argv)
{
	int	fd;

	if (argc != 1) {
		fprintf(stderr, "hpet_open_close: device-name\n");
		return;
	}

	fd = open(argv[0], O_RDONLY);
	if (fd < 0)
		fprintf(stderr, "hpet_open_close: open failed\n");
	else
		close(fd);

	return;
}

void
hpet_info(int argc, const char **argv)
{
	struct hpet_info	info;
	int			fd;

	if (argc != 1) {
		fprintf(stderr, "hpet_info: device-name\n");
		return;
	}

	fd = open(argv[0], O_RDONLY);
	if (fd < 0) {
		fprintf(stderr, "hpet_info: open of %s failed\n", argv[0]);
		return;
	}

	if (ioctl(fd, HPET_INFO, &info) < 0) {
		fprintf(stderr, "hpet_info: failed to get info\n");
		goto out;

Annotation

Implementation Notes