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-rw-r--r--arch/mips/kernel/cevt-ds1287.c129
1 files changed, 129 insertions, 0 deletions
diff --git a/arch/mips/kernel/cevt-ds1287.c b/arch/mips/kernel/cevt-ds1287.c
new file mode 100644
index 000000000000..df4acb68bfb5
--- /dev/null
+++ b/arch/mips/kernel/cevt-ds1287.c
@@ -0,0 +1,129 @@
1/*
2 * DS1287 clockevent driver
3 *
4 * Copyright (C) 2008 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
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
25#include <asm/time.h>
26
27int ds1287_timer_state(void)
28{
29 return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
30}
31
32int ds1287_set_base_clock(unsigned int hz)
33{
34 u8 rate;
35
36 switch (hz) {
37 case 128:
38 rate = 0x9;
39 break;
40 case 256:
41 rate = 0x8;
42 break;
43 case 1024:
44 rate = 0x6;
45 break;
46 default:
47 return -EINVAL;
48 }
49
50 CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
51
52 return 0;
53}
54
55static int ds1287_set_next_event(unsigned long delta,
56 struct clock_event_device *evt)
57{
58 return -EINVAL;
59}
60
61static void ds1287_set_mode(enum clock_event_mode mode,
62 struct clock_event_device *evt)
63{
64 u8 val;
65
66 spin_lock(&rtc_lock);
67
68 val = CMOS_READ(RTC_REG_B);
69
70 switch (mode) {
71 case CLOCK_EVT_MODE_PERIODIC:
72 val |= RTC_PIE;
73 break;
74 default:
75 val &= ~RTC_PIE;
76 break;
77 }
78
79 CMOS_WRITE(val, RTC_REG_B);
80
81 spin_unlock(&rtc_lock);
82}
83
84static void ds1287_event_handler(struct clock_event_device *dev)
85{
86}
87
88static struct clock_event_device ds1287_clockevent = {
89 .name = "ds1287",
90 .features = CLOCK_EVT_FEAT_PERIODIC,
91 .cpumask = CPU_MASK_CPU0,
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_DISABLED | IRQF_PERCPU,
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
126 clockevents_register_device(&ds1287_clockevent);
127
128 return setup_irq(irq, &ds1287_irqaction);
129}