Commit | Line | Data |
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6457d9fc YY |
1 | /* |
2 | * DS1287 clockevent driver | |
3 | * | |
70342287 | 4 | * Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org> |
6457d9fc YY |
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> | |
ca4d3e67 | 24 | #include <linux/irq.h> |
6457d9fc YY |
25 | |
26 | #include <asm/time.h> | |
27 | ||
28 | int ds1287_timer_state(void) | |
29 | { | |
30 | return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0; | |
31 | } | |
32 | ||
33 | int 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 | ||
56 | static int ds1287_set_next_event(unsigned long delta, | |
57 | struct clock_event_device *evt) | |
58 | { | |
59 | return -EINVAL; | |
60 | } | |
61 | ||
9f95618f | 62 | static int ds1287_shutdown(struct clock_event_device *evt) |
6457d9fc YY |
63 | { |
64 | u8 val; | |
65 | ||
66 | spin_lock(&rtc_lock); | |
67 | ||
68 | val = CMOS_READ(RTC_REG_B); | |
9f95618f VK |
69 | val &= ~RTC_PIE; |
70 | CMOS_WRITE(val, RTC_REG_B); | |
6457d9fc | 71 | |
9f95618f VK |
72 | spin_unlock(&rtc_lock); |
73 | return 0; | |
74 | } | |
6457d9fc | 75 | |
9f95618f VK |
76 | static 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; | |
6457d9fc YY |
84 | CMOS_WRITE(val, RTC_REG_B); |
85 | ||
86 | spin_unlock(&rtc_lock); | |
9f95618f | 87 | return 0; |
6457d9fc YY |
88 | } |
89 | ||
90 | static void ds1287_event_handler(struct clock_event_device *dev) | |
91 | { | |
92 | } | |
93 | ||
94 | static struct clock_event_device ds1287_clockevent = { | |
9f95618f VK |
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, | |
6457d9fc YY |
102 | }; |
103 | ||
104 | static 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 | ||
116 | static struct irqaction ds1287_irqaction = { | |
117 | .handler = ds1287_interrupt, | |
8b5690f8 | 118 | .flags = IRQF_PERCPU | IRQF_TIMER, |
6457d9fc YY |
119 | .name = "ds1287", |
120 | }; | |
121 | ||
122 | int __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); | |
320ab2b0 | 132 | cd->cpumask = cpumask_of(0); |
6457d9fc YY |
133 | |
134 | clockevents_register_device(&ds1287_clockevent); | |
135 | ||
136 | return setup_irq(irq, &ds1287_irqaction); | |
137 | } |