hpet_example - HPET sample Application のバックアップ(No.3)

バックアップ一覧
差分を表示
現在との差分を表示
ソースを表示
hpet_example - HPET sample Application へ行く。

hpet_example †

HPET (High Precision Event Timer) ドライバ /drivers/char/hpet.c の動作を理解するために、実際に動かすアプリケーション・プログラム hpet_example.tar.gz を使います。このプログラムは /Documentation/timers/hpet_example.c を修正して作成してあります。/Documentation/timers/hpet.txt で hpet_example.c について概要が書かれています。情報量は多く有りません。ioctl() API の仕様詳細は書かれていません。

↑

ioctl API †

↑

HPET driver's APIs †

↑

Interrupt On - HPET_IE_ON †

SYNOPSIS
```
int ioctl(int fd, HPET_IE_ON);
```
PRECONDITION
- Set interrupt frequency, by HPET_IRQFREQ.
- Enable or disable periodic interrupt, by HPET_EPI or HPET_DPI.
- Set or clear file descriptor flags with O_ASYNC;
- (optional) Set owner (PID) of file descriptor to send signal by F_SETOWN or F_SETOWN_EX.
- (optional) Set signal to send by F_SETSIG.
DESCRIPTION

↑

Interrupt Off - HPET_IE_OFF †

SYNOPSIS
```
int ioctl(int fd, HPET_IE_OFF);
```

↑

Get Information - HPET_INFO †

SYNOPSIS

struct hpet_info {
	unsigned long  hi_ireqfreq; /* Period or time in Hz */
	unsigned long  hi_flags;    /* Information: 0x0: Not supported periodic int., 0x10: Supported periodic int. */
	unsigned short hi_hpet;     /* HPET device number, [0..TheNumberOfHPETDevicesInPlatform-1] */
	unsigned short hi_timer;    /* Timer number in HPET device, [0..31] */
};
int ioctl(int fd, HPET_INFO, /* out */ hpet_info *info);

↑

Enable Periodic - HPET_EPI †

SYNOPSIS
```
int ioctl(int fd, HPET_EPI);
```
DESCRIPTION

↑

Disable Periodic - HPET_DPI †

SYNOPSIS
```
int ioctl(int fd, HPET_DPI);
```

↑

Set Interrupt Frequency in Hz (Set Interrupt time delta in 1/f seconds) - HPET_IRQFREQ †

SYNOPSIS

int ioctl(int fd, HPET_IRQFREQ, unsigned long frequency);

↑

F_GETFL †

int fcntl(int fd, F_GETFL);

↑

F_SETFL †

SYNOPSIS
```
int fcntl(int fd, F_SETFL, int flags);
```

DESCRIPTION
To raise signal on timer event, let flags be ORed with O_ASYNC, see following pseudo code pice.

-
|
-
|
!
|
-
|
!
!

{       int     flags;
        flags = fcltl(fd, F_GETFL);
        if (flags &lt; 0) {
                /* error handling. */
        }
        flags |= O_ASYNC;
        if (fcntl(fd, F_SETFL, flags) != 0) {
                /* error handling. */
        }
}

↑

F_GETSIG †

SYNOPSIS
```
int fcntl(int fd, F_GETSIG);
```
DESCRIPTION
Get the signal number will be raised on timer event.

↑

F_SETSIG †

SYNOPSIS

int fcntl(int fd, F_SETSIG, int signal);

DESCRIPTION
Set the signal number will be raised on timer event.

hpet_example - HPET sample Application のバックアップ(No.3)

hpet_example †

ioctl API †

HPET driver's APIs †

Interrupt On - HPET_IE_ON †

Interrupt Off - HPET_IE_OFF †

Get Information - HPET_INFO †

Enable Periodic - HPET_EPI †

Disable Periodic - HPET_DPI †

Set Interrupt Frequency in Hz (Set Interrupt time delta in 1/f seconds) - HPET_IRQFREQ †

File System API's †

F_GETOWN, F_GETOWN_EX †

F_SETOWN, F_SETOWN_EX †

F_GETFL †

F_SETFL †

F_GETSIG †

F_SETSIG †