include/linux/i8253.h

0001 /*
0002  * This file is subject to the terms and conditions of the GNU General Public
0003  * License.  See the file "COPYING" in the main directory of this archive
0004  * for more details.
0005  *
0006  *  Machine specific IO port address definition for generic.
0007  *  Written by Osamu Tomita <tomita@cinet.co.jp>
0008  */
0009 #ifndef __LINUX_I8253_H
0010 #define __LINUX_I8253_H
0011
0012 #include <linux/param.h>
0013 #include <linux/spinlock.h>
0014 #include <linux/timex.h>
0015
0016 /* i8253A PIT registers */
0017 #define PIT_MODE    0x43
0018 #define PIT_CH0     0x40
0019 #define PIT_CH2     0x42
0020
0021 #define PIT_LATCH   ((PIT_TICK_RATE + HZ/2) / HZ)
0022
0023 extern raw_spinlock_t i8253_lock;
0024 extern bool i8253_clear_counter_on_shutdown;
0025 extern struct clock_event_device i8253_clockevent;
0026 extern void clockevent_i8253_init(bool oneshot);
0027
0028 extern void setup_pit_timer(void);
0029
0030 #endif /* __LINUX_I8253_H */