aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-bq4802.c
blob: bf612ef229417730a8146f62d3a9270daba67d28 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
/* rtc-bq4802.c: TI BQ4802 RTC driver.
 *
 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/slab.h>

MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
MODULE_DESCRIPTION("TI BQ4802 RTC driver");
MODULE_LICENSE("GPL");

struct bq4802 {
	void __iomem		*regs;
	unsigned long		ioport;
	struct rtc_device	*rtc;
	spinlock_t		lock;
	struct resource		*r;
	u8 (*read)(struct bq4802 *, int);
	void (*write)(struct bq4802 *, int, u8);
};

static u8 bq4802_read_io(struct bq4802 *p, int off)
{
	return inb(p->ioport + off);
}

static void bq4802_write_io(struct bq4802 *p, int off, u8 val)
{
	outb(val, p->ioport + off);
}

static u8 bq4802_read_mem(struct bq4802 *p, int off)
{
	return readb(p->regs + off);
}

static void bq4802_write_mem(struct bq4802 *p, int off, u8 val)
{
	writeb(val, p->regs + off);
}

static int bq4802_read_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct bq4802 *p = platform_get_drvdata(pdev);
	unsigned long flags;
	unsigned int century;
	u8 val;

	spin_lock_irqsave(&p->lock, flags);

	val = p->read(p, 0x0e);
	p->write(p, 0xe, val | 0x08);

	tm->tm_sec = p->read(p, 0x00);
	tm->tm_min = p->read(p, 0x02);
	tm->tm_hour = p->read(p, 0x04);
	tm->tm_mday = p->read(p, 0x06);
	tm->tm_mon = p->read(p, 0x09);
	tm->tm_year = p->read(p, 0x0a);
	tm->tm_wday = p->read(p, 0x08);
	century = p->read(p, 0x0f);

	p->write(p, 0x0e, val);

	spin_unlock_irqrestore(&p->lock, flags);

	tm->tm_sec = bcd2bin(tm->tm_sec);
	tm->tm_min = bcd2bin(tm->tm_min);
	tm->tm_hour = bcd2bin(tm->tm_hour);
	tm->tm_mday = bcd2bin(tm->tm_mday);
	tm->tm_mon = bcd2bin(tm->tm_mon);
	tm->tm_year = bcd2bin(tm->tm_year);
	tm->tm_wday = bcd2bin(tm->tm_wday);
	century = bcd2bin(century);

	tm->tm_year += (century * 100);
	tm->tm_year -= 1900;

	tm->tm_mon--;

	return 0;
}

static int bq4802_set_time(struct device *dev, struct rtc_time *tm)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct bq4802 *p = platform_get_drvdata(pdev);
	u8 sec, min, hrs, day, mon, yrs, century, val;
	unsigned long flags;
	unsigned int year;

	year = tm->tm_year + 1900;
	century = year / 100;
	yrs = year % 100;

	mon = tm->tm_mon + 1;   /* tm_mon starts at zero */
	day = tm->tm_mday;
	hrs = tm->tm_hour;
	min = tm->tm_min;
	sec = tm->tm_sec;

	sec = bin2bcd(sec);
	min = bin2bcd(min);
	hrs = bin2bcd(hrs);
	day = bin2bcd(day);
	mon = bin2bcd(mon);
	yrs = bin2bcd(yrs);
	century = bin2bcd(century);

	spin_lock_irqsave(&p->lock, flags);

	val = p->read(p, 0x0e);
	p->write(p, 0x0e, val | 0x08);

	p->write(p, 0x00, sec);
	p->write(p, 0x02, min);
	p->write(p, 0x04, hrs);
	p->write(p, 0x06, day);
	p->write(p, 0x09, mon);
	p->write(p, 0x0a, yrs);
	p->write(p, 0x0f, century);

	p->write(p, 0x0e, val);

	spin_unlock_irqrestore(&p->lock, flags);

	return 0;
}

static const struct rtc_class_ops bq4802_ops = {
	.read_time	= bq4802_read_time,
	.set_time	= bq4802_set_time,
};

static int __devinit bq4802_probe(struct platform_device *pdev)
{
	struct bq4802 *p = kzalloc(sizeof(*p), GFP_KERNEL);
	int err = -ENOMEM;

	if (!p)
		goto out;

	spin_lock_init(&p->lock);

	p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!p->r) {
		p->r = platform_get_resource(pdev, IORESOURCE_IO, 0);
		err = -EINVAL;
		if (!p->r)
			goto out_free;
	}
	if (p->r->flags & IORESOURCE_IO) {
		p->ioport = p->r->start;
		p->read = bq4802_read_io;
		p->write = bq4802_write_io;
	} else if (p->r->flags & IORESOURCE_MEM) {
		p->regs = ioremap(p->r->start, resource_size(p->r));
		p->read = bq4802_read_mem;
		p->write = bq4802_write_mem;
	} else {
		err = -EINVAL;
		goto out_free;
	}

	platform_set_drvdata(pdev, p);

	p->rtc = rtc_device_register("bq4802", &pdev->dev,
				     &bq4802_ops, THIS_MODULE);
	if (IS_ERR(p->rtc)) {
		err = PTR_ERR(p->rtc);
		goto out_iounmap;
	}

	err = 0;
out:
	return err;

out_iounmap:
	if (p->r->flags & IORESOURCE_MEM)
		iounmap(p->regs);
out_free:
	kfree(p);
	goto out;
}

static int __devexit bq4802_remove(struct platform_device *pdev)
{
	struct bq4802 *p = platform_get_drvdata(pdev);

	rtc_device_unregister(p->rtc);
	if (p->r->flags & IORESOURCE_MEM)
		iounmap(p->regs);

	platform_set_drvdata(pdev, NULL);

	kfree(p);

	return 0;
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:rtc-bq4802");

static struct platform_driver bq4802_driver = {
	.driver		= {
		.name	= "rtc-bq4802",
		.owner	= THIS_MODULE,
	},
	.probe		= bq4802_probe,
	.remove		= __devexit_p(bq4802_remove),
};

module_platform_driver(bq4802_driver);