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path: root/drivers/rtc/rtc-bq4802.c
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Diffstat (limited to 'drivers/rtc/rtc-bq4802.c')
-rw-r--r--drivers/rtc/rtc-bq4802.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-bq4802.c b/drivers/rtc/rtc-bq4802.c
new file mode 100644
index 000000000000..541580cb6df4
--- /dev/null
+++ b/drivers/rtc/rtc-bq4802.c
@@ -0,0 +1,229 @@
1/* rtc-bq4802.c: TI BQ4802 RTC driver.
2 *
3 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
4 */
5
6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/init.h>
9#include <linux/io.h>
10#include <linux/platform_device.h>
11#include <linux/rtc.h>
12#include <linux/bcd.h>
13
14MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
15MODULE_DESCRIPTION("TI BQ4802 RTC driver");
16MODULE_LICENSE("GPL");
17
18struct bq4802 {
19 void __iomem *regs;
20 struct rtc_device *rtc;
21 spinlock_t lock;
22 struct resource *r;
23 u8 (*read)(struct bq4802 *, int);
24 void (*write)(struct bq4802 *, int, u8);
25};
26
27static u8 bq4802_read_io(struct bq4802 *p, int off)
28{
29 return inb(p->regs + off);
30}
31
32static void bq4802_write_io(struct bq4802 *p, int off, u8 val)
33{
34 return outb(val, p->regs + off);
35}
36
37static u8 bq4802_read_mem(struct bq4802 *p, int off)
38{
39 return readb(p->regs + off);
40}
41
42static void bq4802_write_mem(struct bq4802 *p, int off, u8 val)
43{
44 return writeb(val, p->regs + off);
45}
46
47static int bq4802_read_time(struct device *dev, struct rtc_time *tm)
48{
49 struct platform_device *pdev = to_platform_device(dev);
50 struct bq4802 *p = platform_get_drvdata(pdev);
51 unsigned long flags;
52 unsigned int century;
53 u8 val;
54
55 spin_lock_irqsave(&p->lock, flags);
56
57 val = p->read(p, 0x0e);
58 p->write(p, 0xe, val | 0x08);
59
60 tm->tm_sec = p->read(p, 0x00);
61 tm->tm_min = p->read(p, 0x02);
62 tm->tm_hour = p->read(p, 0x04);
63 tm->tm_mday = p->read(p, 0x06);
64 tm->tm_mon = p->read(p, 0x09);
65 tm->tm_year = p->read(p, 0x0a);
66 tm->tm_wday = p->read(p, 0x08);
67 century = p->read(p, 0x0f);
68
69 p->write(p, 0x0e, val);
70
71 spin_unlock_irqrestore(&p->lock, flags);
72
73 BCD_TO_BIN(tm->tm_sec);
74 BCD_TO_BIN(tm->tm_min);
75 BCD_TO_BIN(tm->tm_hour);
76 BCD_TO_BIN(tm->tm_mday);
77 BCD_TO_BIN(tm->tm_mon);
78 BCD_TO_BIN(tm->tm_year);
79 BCD_TO_BIN(tm->tm_wday);
80 BCD_TO_BIN(century);
81
82 tm->tm_year += (century * 100);
83 tm->tm_year -= 1900;
84
85 tm->tm_mon--;
86
87 return 0;
88}
89
90static int bq4802_set_time(struct device *dev, struct rtc_time *tm)
91{
92 struct platform_device *pdev = to_platform_device(dev);
93 struct bq4802 *p = platform_get_drvdata(pdev);
94 u8 sec, min, hrs, day, mon, yrs, century, val;
95 unsigned long flags;
96 unsigned int year;
97
98 year = tm->tm_year + 1900;
99 century = year / 100;
100 yrs = year % 100;
101
102 mon = tm->tm_mon + 1; /* tm_mon starts at zero */
103 day = tm->tm_mday;
104 hrs = tm->tm_hour;
105 min = tm->tm_min;
106 sec = tm->tm_sec;
107
108 BIN_TO_BCD(sec);
109 BIN_TO_BCD(min);
110 BIN_TO_BCD(hrs);
111 BIN_TO_BCD(day);
112 BIN_TO_BCD(mon);
113 BIN_TO_BCD(yrs);
114 BIN_TO_BCD(century);
115
116 spin_lock_irqsave(&p->lock, flags);
117
118 val = p->read(p, 0x0e);
119 p->write(p, 0x0e, val | 0x08);
120
121 p->write(p, 0x00, sec);
122 p->write(p, 0x02, min);
123 p->write(p, 0x04, hrs);
124 p->write(p, 0x06, day);
125 p->write(p, 0x09, mon);
126 p->write(p, 0x0a, yrs);
127 p->write(p, 0x0f, century);
128
129 p->write(p, 0x0e, val);
130
131 spin_unlock_irqrestore(&p->lock, flags);
132
133 return 0;
134}
135
136static const struct rtc_class_ops bq4802_ops = {
137 .read_time = bq4802_read_time,
138 .set_time = bq4802_set_time,
139};
140
141static int __devinit bq4802_probe(struct platform_device *pdev)
142{
143 struct bq4802 *p = kzalloc(sizeof(*p), GFP_KERNEL);
144 int err = -ENOMEM;
145
146 if (!p)
147 goto out;
148
149 spin_lock_init(&p->lock);
150
151 p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
152 if (!p->r) {
153 p->r = platform_get_resource(pdev, IORESOURCE_IO, 0);
154 err = -EINVAL;
155 if (!p->r)
156 goto out_free;
157 }
158 if (p->r->flags & IORESOURCE_IO) {
159 p->regs = (void __iomem *) p->r->start;
160 p->read = bq4802_read_io;
161 p->write = bq4802_write_io;
162 } else if (p->r->flags & IORESOURCE_MEM) {
163 p->regs = ioremap(p->r->start, resource_size(p->r));
164 p->read = bq4802_read_mem;
165 p->write = bq4802_write_mem;
166 } else {
167 err = -EINVAL;
168 goto out_free;
169 }
170
171 p->rtc = rtc_device_register("bq4802", &pdev->dev,
172 &bq4802_ops, THIS_MODULE);
173 if (IS_ERR(p->rtc)) {
174 err = PTR_ERR(p->rtc);
175 goto out_iounmap;
176 }
177
178 platform_set_drvdata(pdev, p);
179 err = 0;
180out:
181 return err;
182
183out_iounmap:
184 if (p->r->flags & IORESOURCE_MEM)
185 iounmap(p->regs);
186out_free:
187 kfree(p);
188 goto out;
189}
190
191static int __devexit bq4802_remove(struct platform_device *pdev)
192{
193 struct bq4802 *p = platform_get_drvdata(pdev);
194
195 rtc_device_unregister(p->rtc);
196 if (p->r->flags & IORESOURCE_MEM)
197 iounmap(p->regs);
198
199 platform_set_drvdata(pdev, NULL);
200
201 kfree(p);
202
203 return 0;
204}
205
206/* work with hotplug and coldplug */
207MODULE_ALIAS("platform:rtc-bq4802");
208
209static struct platform_driver bq4802_driver = {
210 .driver = {
211 .name = "rtc-bq4802",
212 .owner = THIS_MODULE,
213 },
214 .probe = bq4802_probe,
215 .remove = __devexit_p(bq4802_remove),
216};
217
218static int __init bq4802_init(void)
219{
220 return platform_driver_register(&bq4802_driver);
221}
222
223static void __exit bq4802_exit(void)
224{
225 platform_driver_unregister(&bq4802_driver);
226}
227
228module_init(bq4802_init);
229module_exit(bq4802_exit);