LXR linux/include/linux/i8253.h

   1/*
   2 * This file is subject to the terms and conditions of the GNU General Public
   3 * License.  See the file "COPYING" in the main directory of this archive
   4 * for more details.
   5 *
   6 *  Machine specific IO port address definition for generic.
   7 *  Written by Osamu Tomita <tomita@cinet.co.jp>
   8 */
   9#ifndef __LINUX_I8253_H
  10#define __LINUX_I8253_H
  11
  12#include <linux/param.h>
  13#include <linux/spinlock.h>
  14#include <linux/timex.h>
  15
  16/* i8253A PIT registers */
  17#define PIT_MODE        0x43
  18#define PIT_CH0         0x40
  19#define PIT_CH2         0x42
  20
  21#define PIT_LATCH       ((PIT_TICK_RATE + HZ/2) / HZ)
  22
  23extern raw_spinlock_t i8253_lock;
  24extern bool i8253_clear_counter_on_shutdown;
  25extern struct clock_event_device i8253_clockevent;
  26extern void clockevent_i8253_init(bool oneshot);
  27
  28extern void setup_pit_timer(void);
  29
  30#endif /* __LINUX_I8253_H */
  31