blob: 826153552157d3d4d328fe372fa2dd2fbf025ac6 [file] [log] [blame]
Russell Kinga1909012008-04-20 12:08:36 +01001/*
2 * linux/drivers/rtc/rtc-pl030.c
3 *
4 * Copyright (C) 2000-2001 Deep Blue Solutions Ltd.
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 version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/module.h>
11#include <linux/rtc.h>
12#include <linux/init.h>
13#include <linux/interrupt.h>
14#include <linux/amba/bus.h>
15#include <linux/io.h>
16
17#define RTC_DR (0)
18#define RTC_MR (4)
19#define RTC_STAT (8)
20#define RTC_EOI (8)
21#define RTC_LR (12)
22#define RTC_CR (16)
23#define RTC_CR_MIE (1 << 0)
24
25struct pl030_rtc {
26 struct rtc_device *rtc;
27 void __iomem *base;
28};
29
30static irqreturn_t pl030_interrupt(int irq, void *dev_id)
31{
32 struct pl030_rtc *rtc = dev_id;
33 writel(0, rtc->base + RTC_EOI);
34 return IRQ_HANDLED;
35}
36
Russell Kinga1909012008-04-20 12:08:36 +010037static int pl030_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
38{
39 return -ENOIOCTLCMD;
40}
41
42static int pl030_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
43{
44 struct pl030_rtc *rtc = dev_get_drvdata(dev);
45
46 rtc_time_to_tm(readl(rtc->base + RTC_MR), &alrm->time);
47 return 0;
48}
49
50static int pl030_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
51{
52 struct pl030_rtc *rtc = dev_get_drvdata(dev);
53 unsigned long time;
54 int ret;
55
56 /*
57 * At the moment, we can only deal with non-wildcarded alarm times.
58 */
59 ret = rtc_valid_tm(&alrm->time);
60 if (ret == 0)
61 ret = rtc_tm_to_time(&alrm->time, &time);
62 if (ret == 0)
63 writel(time, rtc->base + RTC_MR);
64 return ret;
65}
66
67static int pl030_read_time(struct device *dev, struct rtc_time *tm)
68{
69 struct pl030_rtc *rtc = dev_get_drvdata(dev);
70
71 rtc_time_to_tm(readl(rtc->base + RTC_DR), tm);
72
73 return 0;
74}
75
76/*
77 * Set the RTC time. Unfortunately, we can't accurately set
78 * the point at which the counter updates.
79 *
80 * Also, since RTC_LR is transferred to RTC_CR on next rising
81 * edge of the 1Hz clock, we must write the time one second
82 * in advance.
83 */
84static int pl030_set_time(struct device *dev, struct rtc_time *tm)
85{
86 struct pl030_rtc *rtc = dev_get_drvdata(dev);
87 unsigned long time;
88 int ret;
89
90 ret = rtc_tm_to_time(tm, &time);
91 if (ret == 0)
92 writel(time + 1, rtc->base + RTC_LR);
93
94 return ret;
95}
96
97static const struct rtc_class_ops pl030_ops = {
Russell Kinga1909012008-04-20 12:08:36 +010098 .ioctl = pl030_ioctl,
99 .read_time = pl030_read_time,
100 .set_time = pl030_set_time,
101 .read_alarm = pl030_read_alarm,
102 .set_alarm = pl030_set_alarm,
103};
104
105static int pl030_probe(struct amba_device *dev, void *id)
106{
107 struct pl030_rtc *rtc;
108 int ret;
109
110 ret = amba_request_regions(dev, NULL);
111 if (ret)
112 goto err_req;
113
114 rtc = kmalloc(sizeof(*rtc), GFP_KERNEL);
115 if (!rtc) {
116 ret = -ENOMEM;
117 goto err_rtc;
118 }
119
120 rtc->base = ioremap(dev->res.start, SZ_4K);
121 if (!rtc->base) {
122 ret = -ENOMEM;
123 goto err_map;
124 }
125
126 __raw_writel(0, rtc->base + RTC_CR);
127 __raw_writel(0, rtc->base + RTC_EOI);
128
129 amba_set_drvdata(dev, rtc);
130
131 ret = request_irq(dev->irq[0], pl030_interrupt, IRQF_DISABLED,
132 "rtc-pl030", rtc);
133 if (ret)
134 goto err_irq;
135
136 rtc->rtc = rtc_device_register("pl030", &dev->dev, &pl030_ops,
137 THIS_MODULE);
138 if (IS_ERR(rtc->rtc)) {
139 ret = PTR_ERR(rtc->rtc);
140 goto err_reg;
141 }
142
143 return 0;
144
145 err_reg:
146 free_irq(dev->irq[0], rtc);
147 err_irq:
148 iounmap(rtc->base);
149 err_map:
150 kfree(rtc);
151 err_rtc:
152 amba_release_regions(dev);
153 err_req:
154 return ret;
155}
156
157static int pl030_remove(struct amba_device *dev)
158{
159 struct pl030_rtc *rtc = amba_get_drvdata(dev);
160
161 amba_set_drvdata(dev, NULL);
162
163 writel(0, rtc->base + RTC_CR);
164
165 free_irq(dev->irq[0], rtc);
166 rtc_device_unregister(rtc->rtc);
167 iounmap(rtc->base);
168 kfree(rtc);
169 amba_release_regions(dev);
170
171 return 0;
172}
173
174static struct amba_id pl030_ids[] = {
175 {
176 .id = 0x00041030,
177 .mask = 0x000fffff,
178 },
179 { 0, 0 },
180};
181
182static struct amba_driver pl030_driver = {
183 .drv = {
184 .name = "rtc-pl030",
185 },
186 .probe = pl030_probe,
187 .remove = pl030_remove,
188 .id_table = pl030_ids,
189};
190
191static int __init pl030_init(void)
192{
193 return amba_driver_register(&pl030_driver);
194}
195
196static void __exit pl030_exit(void)
197{
198 amba_driver_unregister(&pl030_driver);
199}
200
201module_init(pl030_init);
202module_exit(pl030_exit);
203
204MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
205MODULE_DESCRIPTION("ARM AMBA PL030 RTC Driver");
206MODULE_LICENSE("GPL");