1/*
 2 *  DEC I/O ASIC's counter clocksource
 3 *
 4 *  Copyright (C) 2008  Yoichi Yuasa <yuasa@linux-mips.org>
 5 *
 6 *  This program is free software; you can redistribute it and/or modify
 7 *  it under the terms of the GNU General Public License as published by
 8 *  the Free Software Foundation; either version 2 of the License, or
 9 *  (at your option) any later version.
10 *
11 *  This program is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *  GNU General Public License for more details.
15 *
16 *  You should have received a copy of the GNU General Public License
17 *  along with this program; if not, write to the Free Software
18 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20#include <linux/clocksource.h>
 
21#include <linux/init.h>
22
23#include <asm/ds1287.h>
24#include <asm/time.h>
25#include <asm/dec/ioasic.h>
26#include <asm/dec/ioasic_addrs.h>
27
28static cycle_t dec_ioasic_hpt_read(struct clocksource *cs)
29{
30	return ioasic_read(IO_REG_FCTR);
31}
32
33static struct clocksource clocksource_dec = {
34	.name		= "dec-ioasic",
35	.read		= dec_ioasic_hpt_read,
36	.mask		= CLOCKSOURCE_MASK(32),
37	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
38};
39
40void __init dec_ioasic_clocksource_init(void)
 
 
 
 
 
41{
42	unsigned int freq;
43	u32 start, end;
44	int i = HZ / 10;
45
46
 
47	while (!ds1287_timer_state())
48		;
49
50	start = dec_ioasic_hpt_read(&clocksource_dec);
51
52	while (i--)
53		while (!ds1287_timer_state())
54			;
55
56	end = dec_ioasic_hpt_read(&clocksource_dec);
57
58	freq = (end - start) * 10;
 
 
 
 
 
59	printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);
60
61	clocksource_dec.rating = 200 + freq / 10000000;
62	clocksource_register_hz(&clocksource_dec, freq);
 
 
 
 
63}

 1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 *  DEC I/O ASIC's counter clocksource
 4 *
 5 *  Copyright (C) 2008	Yoichi Yuasa <yuasa@linux-mips.org>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 6 */
 7#include <linux/clocksource.h>
 8#include <linux/sched_clock.h>
 9#include <linux/init.h>
10
11#include <asm/ds1287.h>
12#include <asm/time.h>
13#include <asm/dec/ioasic.h>
14#include <asm/dec/ioasic_addrs.h>
15
16static u64 dec_ioasic_hpt_read(struct clocksource *cs)
17{
18	return ioasic_read(IO_REG_FCTR);
19}
20
21static struct clocksource clocksource_dec = {
22	.name		= "dec-ioasic",
23	.read		= dec_ioasic_hpt_read,
24	.mask		= CLOCKSOURCE_MASK(32),
25	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
26};
27
28static u64 notrace dec_ioasic_read_sched_clock(void)
29{
30	return ioasic_read(IO_REG_FCTR);
31}
32
33int __init dec_ioasic_clocksource_init(void)
34{
35	unsigned int freq;
36	u32 start, end;
37	int i = HZ / 8;
 
38
39	ds1287_timer_state();
40	while (!ds1287_timer_state())
41		;
42
43	start = dec_ioasic_hpt_read(&clocksource_dec);
44
45	while (i--)
46		while (!ds1287_timer_state())
47			;
48
49	end = dec_ioasic_hpt_read(&clocksource_dec);
50
51	freq = (end - start) * 8;
52
53	/* An early revision of the I/O ASIC didn't have the counter.  */
54	if (!freq)
55		return -ENXIO;
56
57	printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);
58
59	clocksource_dec.rating = 200 + freq / 10000000;
60	clocksource_register_hz(&clocksource_dec, freq);
61
62	sched_clock_register(dec_ioasic_read_sched_clock, 32, freq);
63
64	return 0;
65}