mirror of https://gitee.com/openkylin/linux.git
66 lines
1.7 KiB
C
66 lines
1.7 KiB
C
|
/*
|
||
|
|
* DEC I/O ASIC's counter clocksource
|
||
|
|
*
|
||
|
|
* Copyright (C) 2008 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License as published by
|
||
|
|
* the Free Software Foundation; either version 2 of the License, or
|
||
|
|
* (at your option) any later version.
|
||
|
|
*
|
||
|
|
* This program is distributed in the hope that it will be useful,
|
||
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
* GNU General Public License for more details.
|
||
|
|
*
|
||
|
|
* You should have received a copy of the GNU General Public License
|
||
|
|
* along with this program; if not, write to the Free Software
|
||
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||
|
|
*/
|
||
|
|
#include <linux/clocksource.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
|
||
|
|
#include <asm/ds1287.h>
|
||
|
|
#include <asm/time.h>
|
||
|
|
#include <asm/dec/ioasic.h>
|
||
|
|
#include <asm/dec/ioasic_addrs.h>
|
||
|
|
|
||
|
|
static cycle_t dec_ioasic_hpt_read(void)
|
||
|
|
{
|
||
|
|
return ioasic_read(IO_REG_FCTR);
|
||
|
|
}
|
||
|
|
|
||
|
|
static struct clocksource clocksource_dec = {
|
||
|
|
.name = "dec-ioasic",
|
||
|
|
.read = dec_ioasic_hpt_read,
|
||
|
|
.mask = CLOCKSOURCE_MASK(32),
|
||
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
||
|
|
};
|
||
|
|
|
||
|
|
void __init dec_ioasic_clocksource_init(void)
|
||
|
|
{
|
||
|
|
unsigned int freq;
|
||
|
|
u32 start, end;
|
||
|
|
int i = HZ / 10;
|
||
|
|
|
||
|
|
|
||
|
|
while (!ds1287_timer_state())
|
||
|
|
;
|
||
|
|
|
||
|
|
start = dec_ioasic_hpt_read();
|
||
|
|
|
||
|
|
while (i--)
|
||
|
|
while (!ds1287_timer_state())
|
||
|
|
;
|
||
|
|
|
||
|
|
end = dec_ioasic_hpt_read();
|
||
|
|
|
||
|
|
freq = (end - start) * 10;
|
||
|
|
printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);
|
||
|
|
|
||
|
|
clocksource_dec.rating = 200 + freq / 10000000;
|
||
|
|
clocksource_set_clock(&clocksource_dec, freq);
|
||
|
|
|
||
|
|
clocksource_register(&clocksource_dec);
|
||
|
|
}
|