Files
Linux/include/linux/i8253.h
T
Michael Kelley 35b69a420b clockevents/drivers/i8253: Add support for PIT shutdown quirk
Add support for platforms where pit_shutdown() doesn't work because of a
quirk in the PIT emulation. On these platforms setting the counter register
to zero causes the PIT to start running again, negating the shutdown.

Provide a global variable that controls whether the counter register is
zero'ed, which platform specific code can override.

Signed-off-by: Michael Kelley <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: vkuznets <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: KY Srinivasan <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
2018-11-04 11:04:46 +01:00

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C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Machine specific IO port address definition for generic.
* Written by Osamu Tomita <[email protected]>
*/
#ifndef __LINUX_I8253_H
#define __LINUX_I8253_H
#include <linux/param.h>
#include <linux/spinlock.h>
#include <linux/timex.h>
/* i8253A PIT registers */
#define PIT_MODE 0x43
#define PIT_CH0 0x40
#define PIT_CH2 0x42
#define PIT_LATCH ((PIT_TICK_RATE + HZ/2) / HZ)
extern raw_spinlock_t i8253_lock;
extern bool i8253_clear_counter_on_shutdown;
extern struct clock_event_device i8253_clockevent;
extern void clockevent_i8253_init(bool oneshot);
extern void setup_pit_timer(void);
#endif /* __LINUX_I8253_H */