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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
103static struct irqaction ds1287_irqaction = {
104 .handler = ds1287_interrupt,
105 .flags = IRQF_PERCPU | IRQF_TIMER,
106 .name = "ds1287",
107};
108
109int __init ds1287_clockevent_init(int irq)
110{
111 struct clock_event_device *cd;
112
113 cd = &ds1287_clockevent;
114 cd->rating = 100;
115 cd->irq = irq;
116 clockevent_set_clock(cd, 32768);
117 cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
118 cd->max_delta_ticks = 0x7fffffff;
119 cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
120 cd->min_delta_ticks = 0x300;
121 cd->cpumask = cpumask_of(0);
122
123 clockevents_register_device(&ds1287_clockevent);
124
125 return setup_irq(irq, &ds1287_irqaction);
126}
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 void ds1287_set_mode(enum clock_event_mode mode,
63 struct clock_event_device *evt)
64{
65 u8 val;
66
67 spin_lock(&rtc_lock);
68
69 val = CMOS_READ(RTC_REG_B);
70
71 switch (mode) {
72 case CLOCK_EVT_MODE_PERIODIC:
73 val |= RTC_PIE;
74 break;
75 default:
76 val &= ~RTC_PIE;
77 break;
78 }
79
80 CMOS_WRITE(val, RTC_REG_B);
81
82 spin_unlock(&rtc_lock);
83}
84
85static void ds1287_event_handler(struct clock_event_device *dev)
86{
87}
88
89static struct clock_event_device ds1287_clockevent = {
90 .name = "ds1287",
91 .features = CLOCK_EVT_FEAT_PERIODIC,
92 .set_next_event = ds1287_set_next_event,
93 .set_mode = ds1287_set_mode,
94 .event_handler = ds1287_event_handler,
95};
96
97static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
98{
99 struct clock_event_device *cd = &ds1287_clockevent;
100
101 /* Ack the RTC interrupt. */
102 CMOS_READ(RTC_REG_C);
103
104 cd->event_handler(cd);
105
106 return IRQ_HANDLED;
107}
108
109static struct irqaction ds1287_irqaction = {
110 .handler = ds1287_interrupt,
111 .flags = IRQF_PERCPU | IRQF_TIMER,
112 .name = "ds1287",
113};
114
115int __init ds1287_clockevent_init(int irq)
116{
117 struct clock_event_device *cd;
118
119 cd = &ds1287_clockevent;
120 cd->rating = 100;
121 cd->irq = irq;
122 clockevent_set_clock(cd, 32768);
123 cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
124 cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
125 cd->cpumask = cpumask_of(0);
126
127 clockevents_register_device(&ds1287_clockevent);
128
129 return setup_irq(irq, &ds1287_irqaction);
130}