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#include <linux/clocksource.h>
17#include <linux/sched_clock.h>
18#include <linux/init.h>
19
20#include <asm/ds1287.h>
21#include <asm/time.h>
22#include <asm/dec/ioasic.h>
23#include <asm/dec/ioasic_addrs.h>
24
25static cycle_t dec_ioasic_hpt_read(struct clocksource *cs)
26{
27	return ioasic_read(IO_REG_FCTR);
28}
29
30static struct clocksource clocksource_dec = {
31	.name		= "dec-ioasic",
32	.read		= dec_ioasic_hpt_read,
33	.mask		= CLOCKSOURCE_MASK(32),
34	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
35};
36
37static u64 notrace dec_ioasic_read_sched_clock(void)
38{
39	return ioasic_read(IO_REG_FCTR);
40}
41
42int __init dec_ioasic_clocksource_init(void)
43{
44	unsigned int freq;
45	u32 start, end;
46	int i = HZ / 8;
47
48	ds1287_timer_state();
49	while (!ds1287_timer_state())
50		;
51
52	start = dec_ioasic_hpt_read(&clocksource_dec);
53
54	while (i--)
55		while (!ds1287_timer_state())
56			;
57
58	end = dec_ioasic_hpt_read(&clocksource_dec);
59
60	freq = (end - start) * 8;
61
62	/* An early revision of the I/O ASIC didn't have the counter.  */
63	if (!freq)
64		return -ENXIO;
65
66	printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);
67
68	clocksource_dec.rating = 200 + freq / 10000000;
69	clocksource_register_hz(&clocksource_dec, freq);
70
71	sched_clock_register(dec_ioasic_read_sched_clock, 32, freq);
72
73	return 0;
74}

 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}