diff options
author | Randy Dunlap <randy.dunlap@oracle.com> | 2008-07-22 09:46:13 -0700 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2008-07-24 01:32:41 +0200 |
commit | a300bec952127d9a15e666b391bb35c9aecb3002 (patch) | |
tree | 9f2fea940cf7cb991c259f7f7fd71506337afc8c /Documentation/hpet.txt | |
parent | f3561810b163aca5388ad550abbbc82ae5323189 (diff) |
documentation: move hpet.txt to timers/ subdirectory
Move hpet.txt to Documentation/timers/ subdirectory.
Add 00-INDEX to Documentation/timers/ subdirectory.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: tglx <tglx@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'Documentation/hpet.txt')
-rw-r--r-- | Documentation/hpet.txt | 300 |
1 files changed, 0 insertions, 300 deletions
diff --git a/Documentation/hpet.txt b/Documentation/hpet.txt deleted file mode 100644 index 6ad52d9dad6c..000000000000 --- a/Documentation/hpet.txt +++ /dev/null @@ -1,300 +0,0 @@ - High Precision Event Timer Driver for Linux - -The High Precision Event Timer (HPET) hardware is the future replacement -for the 8254 and Real Time Clock (RTC) periodic timer functionality. -Each HPET can have up to 32 timers. It is possible to configure the -first two timers as legacy replacements for 8254 and RTC periodic timers. -A specification done by Intel and Microsoft can be found at -<http://www.intel.com/technology/architecture/hpetspec.htm>. - -The driver supports detection of HPET driver allocation and initialization -of the HPET before the driver module_init routine is called. This enables -platform code which uses timer 0 or 1 as the main timer to intercept HPET -initialization. An example of this initialization can be found in -arch/i386/kernel/time_hpet.c. - -The driver provides two APIs which are very similar to the API found in -the rtc.c driver. There is a user space API and a kernel space API. -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; -} - -The kernel API has three interfaces exported from the driver: - - hpet_register(struct hpet_task *tp, int periodic) - hpet_unregister(struct hpet_task *tp) - hpet_control(struct hpet_task *tp, unsigned int cmd, unsigned long arg) - -The kernel module using this interface fills in the ht_func and ht_data -members of the hpet_task structure before calling hpet_register. -hpet_control simply vectors to the hpet_ioctl routine and has the same -commands and respective arguments as the user API. hpet_unregister -is used to terminate usage of the HPET timer reserved by hpet_register. |