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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * DS1287 clockevent driver
4 *
5 * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org>
6 */
7#include <linux/clockchips.h>
8#include <linux/init.h>
9#include <linux/interrupt.h>
10#include <linux/mc146818rtc.h>
11#include <linux/irq.h>
12
13#include <asm/time.h>
14
15int ds1287_timer_state(void)
16{
17 return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
18}
19
20int ds1287_set_base_clock(unsigned int hz)
21{
22 u8 rate;
23
24 switch (hz) {
25 case 128:
26 rate = 0x9;
27 break;
28 case 256:
29 rate = 0x8;
30 break;
31 case 1024:
32 rate = 0x6;
33 break;
34 default:
35 return -EINVAL;
36 }
37
38 CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
39
40 return 0;
41}
42
43static int ds1287_set_next_event(unsigned long delta,
44 struct clock_event_device *evt)
45{
46 return -EINVAL;
47}
48
49static int ds1287_shutdown(struct clock_event_device *evt)
50{
51 u8 val;
52
53 spin_lock(&rtc_lock);
54
55 val = CMOS_READ(RTC_REG_B);
56 val &= ~RTC_PIE;
57 CMOS_WRITE(val, RTC_REG_B);
58
59 spin_unlock(&rtc_lock);
60 return 0;
61}
62
63static int ds1287_set_periodic(struct clock_event_device *evt)
64{
65 u8 val;
66
67 spin_lock(&rtc_lock);
68
69 val = CMOS_READ(RTC_REG_B);
70 val |= RTC_PIE;
71 CMOS_WRITE(val, RTC_REG_B);
72
73 spin_unlock(&rtc_lock);
74 return 0;
75}
76
77static void ds1287_event_handler(struct clock_event_device *dev)
78{
79}
80
81static struct clock_event_device ds1287_clockevent = {
82 .name = "ds1287",
83 .features = CLOCK_EVT_FEAT_PERIODIC,
84 .set_next_event = ds1287_set_next_event,
85 .set_state_shutdown = ds1287_shutdown,
86 .set_state_periodic = ds1287_set_periodic,
87 .tick_resume = ds1287_shutdown,
88 .event_handler = ds1287_event_handler,
89};
90
91static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
92{
93 struct clock_event_device *cd = &ds1287_clockevent;
94
95 /* Ack the RTC interrupt. */
96 CMOS_READ(RTC_REG_C);
97
98 cd->event_handler(cd);
99
100 return IRQ_HANDLED;
101}
102
103int __init ds1287_clockevent_init(int irq)
104{
105 unsigned long flags = IRQF_PERCPU | IRQF_TIMER;
106 struct clock_event_device *cd;
107
108 cd = &ds1287_clockevent;
109 cd->rating = 100;
110 cd->irq = irq;
111 clockevent_set_clock(cd, 32768);
112 cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
113 cd->max_delta_ticks = 0x7fffffff;
114 cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
115 cd->min_delta_ticks = 0x300;
116 cd->cpumask = cpumask_of(0);
117
118 clockevents_register_device(&ds1287_clockevent);
119
120 return request_irq(irq, ds1287_interrupt, flags, "ds1287", NULL);
121}
1/*
2 * DS1287 clockevent driver
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/clockchips.h>
21#include <linux/init.h>
22#include <linux/interrupt.h>
23#include <linux/mc146818rtc.h>
24#include <linux/irq.h>
25
26#include <asm/time.h>
27
28int ds1287_timer_state(void)
29{
30 return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
31}
32
33int ds1287_set_base_clock(unsigned int hz)
34{
35 u8 rate;
36
37 switch (hz) {
38 case 128:
39 rate = 0x9;
40 break;
41 case 256:
42 rate = 0x8;
43 break;
44 case 1024:
45 rate = 0x6;
46 break;
47 default:
48 return -EINVAL;
49 }
50
51 CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
52
53 return 0;
54}
55
56static int ds1287_set_next_event(unsigned long delta,
57 struct clock_event_device *evt)
58{
59 return -EINVAL;
60}
61
62static int ds1287_shutdown(struct clock_event_device *evt)
63{
64 u8 val;
65
66 spin_lock(&rtc_lock);
67
68 val = CMOS_READ(RTC_REG_B);
69 val &= ~RTC_PIE;
70 CMOS_WRITE(val, RTC_REG_B);
71
72 spin_unlock(&rtc_lock);
73 return 0;
74}
75
76static int ds1287_set_periodic(struct clock_event_device *evt)
77{
78 u8 val;
79
80 spin_lock(&rtc_lock);
81
82 val = CMOS_READ(RTC_REG_B);
83 val |= RTC_PIE;
84 CMOS_WRITE(val, RTC_REG_B);
85
86 spin_unlock(&rtc_lock);
87 return 0;
88}
89
90static void ds1287_event_handler(struct clock_event_device *dev)
91{
92}
93
94static struct clock_event_device ds1287_clockevent = {
95 .name = "ds1287",
96 .features = CLOCK_EVT_FEAT_PERIODIC,
97 .set_next_event = ds1287_set_next_event,
98 .set_state_shutdown = ds1287_shutdown,
99 .set_state_periodic = ds1287_set_periodic,
100 .tick_resume = ds1287_shutdown,
101 .event_handler = ds1287_event_handler,
102};
103
104static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
105{
106 struct clock_event_device *cd = &ds1287_clockevent;
107
108 /* Ack the RTC interrupt. */
109 CMOS_READ(RTC_REG_C);
110
111 cd->event_handler(cd);
112
113 return IRQ_HANDLED;
114}
115
116static struct irqaction ds1287_irqaction = {
117 .handler = ds1287_interrupt,
118 .flags = IRQF_PERCPU | IRQF_TIMER,
119 .name = "ds1287",
120};
121
122int __init ds1287_clockevent_init(int irq)
123{
124 struct clock_event_device *cd;
125
126 cd = &ds1287_clockevent;
127 cd->rating = 100;
128 cd->irq = irq;
129 clockevent_set_clock(cd, 32768);
130 cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
131 cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
132 cd->cpumask = cpumask_of(0);
133
134 clockevents_register_device(&ds1287_clockevent);
135
136 return setup_irq(irq, &ds1287_irqaction);
137}