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Documentation/timers/hpet.txt:
Expose example and tool source files in the Documentation/timers/ directory in
their own files instead of being buried (almost hidden) in readme/txt files.
This should help to prevent bitrot.

This will make them more visible/usable to users who may need
to use them, to developers who may need to test with them, and
to anyone who would fix/update them if they were more visible.

Also, if any of these possibly should not be in the kernel tree at
all, it will be clearer that they are here and we can discuss if
they should be removed.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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@rddunlap @torvalds
rddunlap authored and torvalds committed Mar 12, 2010
1 parent ad25ad9 commit e618630
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Showing 5 changed files with 282 additions and 272 deletions.
2 changes: 1 addition & 1 deletion Documentation/Makefile
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@@ -1,3 +1,3 @@
obj-m := DocBook/ accounting/ auxdisplay/ connector/ \
filesystems/configfs/ ia64/ networking/ \
pcmcia/ spi/ video4linux/ vm/ watchdog/src/
pcmcia/ spi/ timers/ video4linux/ vm/ watchdog/src/
2 changes: 2 additions & 0 deletions Documentation/timers/00-INDEX
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Expand Up @@ -4,6 +4,8 @@ highres.txt
- High resolution timers and dynamic ticks design notes
hpet.txt
- High Precision Event Timer Driver for Linux
hpet_example.c
- sample hpet timer test program
hrtimers.txt
- subsystem for high-resolution kernel timers
timer_stats.txt
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8 changes: 8 additions & 0 deletions Documentation/timers/Makefile
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@@ -0,0 +1,8 @@
# kbuild trick to avoid linker error. Can be omitted if a module is built.
obj- := dummy.o

# List of programs to build
hostprogs-y := hpet_example

# Tell kbuild to always build the programs
always := $(hostprogs-y)
273 changes: 2 additions & 271 deletions Documentation/timers/hpet.txt
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Expand Up @@ -26,274 +26,5 @@ initialization. An example of this initialization can be found in
arch/x86/kernel/hpet.c.

The driver provides a userspace API which resembles the API found in the
RTC driver framework. An example user space program is provided below.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <memory.h>
#include <malloc.h>
#include <time.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/time.h>
#include <linux/hpet.h>


extern void hpet_open_close(int, const char **);
extern void hpet_info(int, const char **);
extern void hpet_poll(int, const char **);
extern void hpet_fasync(int, const char **);
extern void hpet_read(int, const char **);

#include <sys/poll.h>
#include <sys/ioctl.h>
#include <signal.h>

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)
{
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)
{
}

void
hpet_poll(int argc, const char **argv)
{
unsigned long freq;
int iterations, i, fd;
struct pollfd pfd;
struct hpet_info info;
struct timeval stv, etv;
struct timezone tz;
long usec;

if (argc != 3) {
fprintf(stderr, "hpet_poll: device-name freq iterations\n");
return;
}

freq = atoi(argv[1]);
iterations = atoi(argv[2]);

fd = open(argv[0], O_RDONLY);

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

if (ioctl(fd, HPET_IRQFREQ, freq) < 0) {
fprintf(stderr, "hpet_poll: HPET_IRQFREQ failed\n");
goto out;
}

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

fprintf(stderr, "hpet_poll: info.hi_flags 0x%lx\n", info.hi_flags);

if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) {
fprintf(stderr, "hpet_poll: HPET_EPI failed\n");
goto out;
}

if (ioctl(fd, HPET_IE_ON, 0) < 0) {
fprintf(stderr, "hpet_poll, HPET_IE_ON failed\n");
goto out;
}

pfd.fd = fd;
pfd.events = POLLIN;

for (i = 0; i < iterations; i++) {
pfd.revents = 0;
gettimeofday(&stv, &tz);
if (poll(&pfd, 1, -1) < 0)
fprintf(stderr, "hpet_poll: poll failed\n");
else {
long data;

gettimeofday(&etv, &tz);
usec = stv.tv_sec * 1000000 + stv.tv_usec;
usec = (etv.tv_sec * 1000000 + etv.tv_usec) - usec;

fprintf(stderr,
"hpet_poll: expired time = 0x%lx\n", usec);

fprintf(stderr, "hpet_poll: revents = 0x%x\n",
pfd.revents);

if (read(fd, &data, sizeof(data)) != sizeof(data)) {
fprintf(stderr, "hpet_poll: read failed\n");
}
else
fprintf(stderr, "hpet_poll: data 0x%lx\n",
data);
}
}

out:
close(fd);
return;
}

static int hpet_sigio_count;

static void
hpet_sigio(int val)
{
fprintf(stderr, "hpet_sigio: called\n");
hpet_sigio_count++;
}

void
hpet_fasync(int argc, const char **argv)
{
unsigned long freq;
int iterations, i, fd, value;
sig_t oldsig;
struct hpet_info info;

hpet_sigio_count = 0;
fd = -1;

if ((oldsig = signal(SIGIO, hpet_sigio)) == SIG_ERR) {
fprintf(stderr, "hpet_fasync: failed to set signal handler\n");
return;
}

if (argc != 3) {
fprintf(stderr, "hpet_fasync: device-name freq iterations\n");
goto out;
}

fd = open(argv[0], O_RDONLY);

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


if ((fcntl(fd, F_SETOWN, getpid()) == 1) ||
((value = fcntl(fd, F_GETFL)) == 1) ||
(fcntl(fd, F_SETFL, value | O_ASYNC) == 1)) {
fprintf(stderr, "hpet_fasync: fcntl failed\n");
goto out;
}

freq = atoi(argv[1]);
iterations = atoi(argv[2]);

if (ioctl(fd, HPET_IRQFREQ, freq) < 0) {
fprintf(stderr, "hpet_fasync: HPET_IRQFREQ failed\n");
goto out;
}

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

fprintf(stderr, "hpet_fasync: info.hi_flags 0x%lx\n", info.hi_flags);

if (info.hi_flags && (ioctl(fd, HPET_EPI, 0) < 0)) {
fprintf(stderr, "hpet_fasync: HPET_EPI failed\n");
goto out;
}

if (ioctl(fd, HPET_IE_ON, 0) < 0) {
fprintf(stderr, "hpet_fasync, HPET_IE_ON failed\n");
goto out;
}

for (i = 0; i < iterations; i++) {
(void) pause();
fprintf(stderr, "hpet_fasync: count = %d\n", hpet_sigio_count);
}

out:
signal(SIGIO, oldsig);

if (fd >= 0)
close(fd);

return;
}
RTC driver framework. An example user space program is provided in
file:Documentation/timers/hpet_example.c
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