The discovered bit in PGCCSR register indicates if the device has been
[linux-2.6/next.git] / drivers / rtc / rtc-bq4802.c
blob128270ce355d08f0689b8e0961d39bb565923bf5
1 /* rtc-bq4802.c: TI BQ4802 RTC driver.
3 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
4 */
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 #include <linux/slab.h>
15 MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
16 MODULE_DESCRIPTION("TI BQ4802 RTC driver");
17 MODULE_LICENSE("GPL");
19 struct bq4802 {
20 void __iomem *regs;
21 unsigned long ioport;
22 struct rtc_device *rtc;
23 spinlock_t lock;
24 struct resource *r;
25 u8 (*read)(struct bq4802 *, int);
26 void (*write)(struct bq4802 *, int, u8);
29 static u8 bq4802_read_io(struct bq4802 *p, int off)
31 return inb(p->ioport + off);
34 static void bq4802_write_io(struct bq4802 *p, int off, u8 val)
36 outb(val, p->ioport + off);
39 static u8 bq4802_read_mem(struct bq4802 *p, int off)
41 return readb(p->regs + off);
44 static void bq4802_write_mem(struct bq4802 *p, int off, u8 val)
46 writeb(val, p->regs + off);
49 static int bq4802_read_time(struct device *dev, struct rtc_time *tm)
51 struct platform_device *pdev = to_platform_device(dev);
52 struct bq4802 *p = platform_get_drvdata(pdev);
53 unsigned long flags;
54 unsigned int century;
55 u8 val;
57 spin_lock_irqsave(&p->lock, flags);
59 val = p->read(p, 0x0e);
60 p->write(p, 0xe, val | 0x08);
62 tm->tm_sec = p->read(p, 0x00);
63 tm->tm_min = p->read(p, 0x02);
64 tm->tm_hour = p->read(p, 0x04);
65 tm->tm_mday = p->read(p, 0x06);
66 tm->tm_mon = p->read(p, 0x09);
67 tm->tm_year = p->read(p, 0x0a);
68 tm->tm_wday = p->read(p, 0x08);
69 century = p->read(p, 0x0f);
71 p->write(p, 0x0e, val);
73 spin_unlock_irqrestore(&p->lock, flags);
75 tm->tm_sec = bcd2bin(tm->tm_sec);
76 tm->tm_min = bcd2bin(tm->tm_min);
77 tm->tm_hour = bcd2bin(tm->tm_hour);
78 tm->tm_mday = bcd2bin(tm->tm_mday);
79 tm->tm_mon = bcd2bin(tm->tm_mon);
80 tm->tm_year = bcd2bin(tm->tm_year);
81 tm->tm_wday = bcd2bin(tm->tm_wday);
82 century = bcd2bin(century);
84 tm->tm_year += (century * 100);
85 tm->tm_year -= 1900;
87 tm->tm_mon--;
89 return 0;
92 static int bq4802_set_time(struct device *dev, struct rtc_time *tm)
94 struct platform_device *pdev = to_platform_device(dev);
95 struct bq4802 *p = platform_get_drvdata(pdev);
96 u8 sec, min, hrs, day, mon, yrs, century, val;
97 unsigned long flags;
98 unsigned int year;
100 year = tm->tm_year + 1900;
101 century = year / 100;
102 yrs = year % 100;
104 mon = tm->tm_mon + 1; /* tm_mon starts at zero */
105 day = tm->tm_mday;
106 hrs = tm->tm_hour;
107 min = tm->tm_min;
108 sec = tm->tm_sec;
110 sec = bin2bcd(sec);
111 min = bin2bcd(min);
112 hrs = bin2bcd(hrs);
113 day = bin2bcd(day);
114 mon = bin2bcd(mon);
115 yrs = bin2bcd(yrs);
116 century = bin2bcd(century);
118 spin_lock_irqsave(&p->lock, flags);
120 val = p->read(p, 0x0e);
121 p->write(p, 0x0e, val | 0x08);
123 p->write(p, 0x00, sec);
124 p->write(p, 0x02, min);
125 p->write(p, 0x04, hrs);
126 p->write(p, 0x06, day);
127 p->write(p, 0x09, mon);
128 p->write(p, 0x0a, yrs);
129 p->write(p, 0x0f, century);
131 p->write(p, 0x0e, val);
133 spin_unlock_irqrestore(&p->lock, flags);
135 return 0;
138 static const struct rtc_class_ops bq4802_ops = {
139 .read_time = bq4802_read_time,
140 .set_time = bq4802_set_time,
143 static int __devinit bq4802_probe(struct platform_device *pdev)
145 struct bq4802 *p = kzalloc(sizeof(*p), GFP_KERNEL);
146 int err = -ENOMEM;
148 if (!p)
149 goto out;
151 spin_lock_init(&p->lock);
153 p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
154 if (!p->r) {
155 p->r = platform_get_resource(pdev, IORESOURCE_IO, 0);
156 err = -EINVAL;
157 if (!p->r)
158 goto out_free;
160 if (p->r->flags & IORESOURCE_IO) {
161 p->ioport = p->r->start;
162 p->read = bq4802_read_io;
163 p->write = bq4802_write_io;
164 } else if (p->r->flags & IORESOURCE_MEM) {
165 p->regs = ioremap(p->r->start, resource_size(p->r));
166 p->read = bq4802_read_mem;
167 p->write = bq4802_write_mem;
168 } else {
169 err = -EINVAL;
170 goto out_free;
173 platform_set_drvdata(pdev, p);
175 p->rtc = rtc_device_register("bq4802", &pdev->dev,
176 &bq4802_ops, THIS_MODULE);
177 if (IS_ERR(p->rtc)) {
178 err = PTR_ERR(p->rtc);
179 goto out_iounmap;
182 err = 0;
183 out:
184 return err;
186 out_iounmap:
187 if (p->r->flags & IORESOURCE_MEM)
188 iounmap(p->regs);
189 out_free:
190 kfree(p);
191 goto out;
194 static int __devexit bq4802_remove(struct platform_device *pdev)
196 struct bq4802 *p = platform_get_drvdata(pdev);
198 rtc_device_unregister(p->rtc);
199 if (p->r->flags & IORESOURCE_MEM)
200 iounmap(p->regs);
202 platform_set_drvdata(pdev, NULL);
204 kfree(p);
206 return 0;
209 /* work with hotplug and coldplug */
210 MODULE_ALIAS("platform:rtc-bq4802");
212 static struct platform_driver bq4802_driver = {
213 .driver = {
214 .name = "rtc-bq4802",
215 .owner = THIS_MODULE,
217 .probe = bq4802_probe,
218 .remove = __devexit_p(bq4802_remove),
221 static int __init bq4802_init(void)
223 return platform_driver_register(&bq4802_driver);
226 static void __exit bq4802_exit(void)
228 platform_driver_unregister(&bq4802_driver);
231 module_init(bq4802_init);
232 module_exit(bq4802_exit);