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 */
31