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
  23 extern raw_spinlock_t i8253_lock;
  24 extern bool i8253_clear_counter_on_shutdown;
  25 extern struct clock_event_device i8253_clockevent;
  26 extern void clockevent_i8253_init(bool oneshot);
  27
  28 extern void setup_pit_timer(void);
  29
  30 #endif /* __LINUX_I8253_H */