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#include <linux/slab.h>
14
15MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
16MODULE_DESCRIPTION("TI BQ4802 RTC driver");
17MODULE_LICENSE("GPL");
18
19struct 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);
27};
28
29static u8 bq4802_read_io(struct bq4802 *p, int off)
30{
31	return inb(p->ioport + off);
32}
33
34static void bq4802_write_io(struct bq4802 *p, int off, u8 val)
35{
36	outb(val, p->ioport + off);
37}
38
39static u8 bq4802_read_mem(struct bq4802 *p, int off)
40{
41	return readb(p->regs + off);
42}
43
44static void bq4802_write_mem(struct bq4802 *p, int off, u8 val)
45{
46	writeb(val, p->regs + off);
47}
48
49static int bq4802_read_time(struct device *dev, struct rtc_time *tm)
50{
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;
56
57	spin_lock_irqsave(&p->lock, flags);
58
59	val = p->read(p, 0x0e);
60	p->write(p, 0xe, val | 0x08);
61
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);
70
71	p->write(p, 0x0e, val);
72
73	spin_unlock_irqrestore(&p->lock, flags);
74
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);
83
84	tm->tm_year += (century * 100);
85	tm->tm_year -= 1900;
86
87	tm->tm_mon--;
88
89	return 0;
90}
91
92static int bq4802_set_time(struct device *dev, struct rtc_time *tm)
93{
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;
99
100	year = tm->tm_year + 1900;
101	century = year / 100;
102	yrs = year % 100;
103
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;
109
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);
117
118	spin_lock_irqsave(&p->lock, flags);
119
120	val = p->read(p, 0x0e);
121	p->write(p, 0x0e, val | 0x08);
122
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);
130
131	p->write(p, 0x0e, val);
132
133	spin_unlock_irqrestore(&p->lock, flags);
134
135	return 0;
136}
137
138static const struct rtc_class_ops bq4802_ops = {
139	.read_time	= bq4802_read_time,
140	.set_time	= bq4802_set_time,
141};
142
143static int bq4802_probe(struct platform_device *pdev)
144{
145	struct bq4802 *p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
146	int err = -ENOMEM;
147
148	if (!p)
149		goto out;
150
151	spin_lock_init(&p->lock);
152
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;
159	}
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 = devm_ioremap(&pdev->dev, p->r->start,
166					resource_size(p->r));
167		p->read = bq4802_read_mem;
168		p->write = bq4802_write_mem;
169	} else {
170		err = -EINVAL;
171		goto out;
172	}
173
174	platform_set_drvdata(pdev, p);
175
176	p->rtc = devm_rtc_device_register(&pdev->dev, "bq4802",
177					&bq4802_ops, THIS_MODULE);
178	if (IS_ERR(p->rtc)) {
179		err = PTR_ERR(p->rtc);
180		goto out;
181	}
182
183	err = 0;
184out:
185	return err;
186
187}
188
189/* work with hotplug and coldplug */
190MODULE_ALIAS("platform:rtc-bq4802");
191
192static struct platform_driver bq4802_driver = {
193	.driver		= {
194		.name	= "rtc-bq4802",
195		.owner	= THIS_MODULE,
196	},
197	.probe		= bq4802_probe,
198};
199
200module_platform_driver(bq4802_driver);
201