xref: /openbmc/linux/drivers/rtc/rtc-bq4802.c (revision 9ac8d3fb)
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 
14 MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
15 MODULE_DESCRIPTION("TI BQ4802 RTC driver");
16 MODULE_LICENSE("GPL");
17 
18 struct bq4802 {
19 	void __iomem		*regs;
20 	unsigned long		ioport;
21 	struct rtc_device	*rtc;
22 	spinlock_t		lock;
23 	struct resource		*r;
24 	u8 (*read)(struct bq4802 *, int);
25 	void (*write)(struct bq4802 *, int, u8);
26 };
27 
28 static u8 bq4802_read_io(struct bq4802 *p, int off)
29 {
30 	return inb(p->ioport + off);
31 }
32 
33 static void bq4802_write_io(struct bq4802 *p, int off, u8 val)
34 {
35 	outb(val, p->ioport + off);
36 }
37 
38 static u8 bq4802_read_mem(struct bq4802 *p, int off)
39 {
40 	return readb(p->regs + off);
41 }
42 
43 static void bq4802_write_mem(struct bq4802 *p, int off, u8 val)
44 {
45 	writeb(val, p->regs + off);
46 }
47 
48 static int bq4802_read_time(struct device *dev, struct rtc_time *tm)
49 {
50 	struct platform_device *pdev = to_platform_device(dev);
51 	struct bq4802 *p = platform_get_drvdata(pdev);
52 	unsigned long flags;
53 	unsigned int century;
54 	u8 val;
55 
56 	spin_lock_irqsave(&p->lock, flags);
57 
58 	val = p->read(p, 0x0e);
59 	p->write(p, 0xe, val | 0x08);
60 
61 	tm->tm_sec = p->read(p, 0x00);
62 	tm->tm_min = p->read(p, 0x02);
63 	tm->tm_hour = p->read(p, 0x04);
64 	tm->tm_mday = p->read(p, 0x06);
65 	tm->tm_mon = p->read(p, 0x09);
66 	tm->tm_year = p->read(p, 0x0a);
67 	tm->tm_wday = p->read(p, 0x08);
68 	century = p->read(p, 0x0f);
69 
70 	p->write(p, 0x0e, val);
71 
72 	spin_unlock_irqrestore(&p->lock, flags);
73 
74 	tm->tm_sec = bcd2bin(tm->tm_sec);
75 	tm->tm_min = bcd2bin(tm->tm_min);
76 	tm->tm_hour = bcd2bin(tm->tm_hour);
77 	tm->tm_mday = bcd2bin(tm->tm_mday);
78 	tm->tm_mon = bcd2bin(tm->tm_mon);
79 	tm->tm_year = bcd2bin(tm->tm_year);
80 	tm->tm_wday = bcd2bin(tm->tm_wday);
81 	century = bcd2bin(century);
82 
83 	tm->tm_year += (century * 100);
84 	tm->tm_year -= 1900;
85 
86 	tm->tm_mon--;
87 
88 	return 0;
89 }
90 
91 static int bq4802_set_time(struct device *dev, struct rtc_time *tm)
92 {
93 	struct platform_device *pdev = to_platform_device(dev);
94 	struct bq4802 *p = platform_get_drvdata(pdev);
95 	u8 sec, min, hrs, day, mon, yrs, century, val;
96 	unsigned long flags;
97 	unsigned int year;
98 
99 	year = tm->tm_year + 1900;
100 	century = year / 100;
101 	yrs = year % 100;
102 
103 	mon = tm->tm_mon + 1;   /* tm_mon starts at zero */
104 	day = tm->tm_mday;
105 	hrs = tm->tm_hour;
106 	min = tm->tm_min;
107 	sec = tm->tm_sec;
108 
109 	sec = bin2bcd(sec);
110 	min = bin2bcd(min);
111 	hrs = bin2bcd(hrs);
112 	day = bin2bcd(day);
113 	mon = bin2bcd(mon);
114 	yrs = bin2bcd(yrs);
115 	century = bin2bcd(century);
116 
117 	spin_lock_irqsave(&p->lock, flags);
118 
119 	val = p->read(p, 0x0e);
120 	p->write(p, 0x0e, val | 0x08);
121 
122 	p->write(p, 0x00, sec);
123 	p->write(p, 0x02, min);
124 	p->write(p, 0x04, hrs);
125 	p->write(p, 0x06, day);
126 	p->write(p, 0x09, mon);
127 	p->write(p, 0x0a, yrs);
128 	p->write(p, 0x0f, century);
129 
130 	p->write(p, 0x0e, val);
131 
132 	spin_unlock_irqrestore(&p->lock, flags);
133 
134 	return 0;
135 }
136 
137 static const struct rtc_class_ops bq4802_ops = {
138 	.read_time	= bq4802_read_time,
139 	.set_time	= bq4802_set_time,
140 };
141 
142 static int __devinit bq4802_probe(struct platform_device *pdev)
143 {
144 	struct bq4802 *p = kzalloc(sizeof(*p), GFP_KERNEL);
145 	int err = -ENOMEM;
146 
147 	if (!p)
148 		goto out;
149 
150 	spin_lock_init(&p->lock);
151 
152 	p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
153 	if (!p->r) {
154 		p->r = platform_get_resource(pdev, IORESOURCE_IO, 0);
155 		err = -EINVAL;
156 		if (!p->r)
157 			goto out_free;
158 	}
159 	if (p->r->flags & IORESOURCE_IO) {
160 		p->ioport = p->r->start;
161 		p->read = bq4802_read_io;
162 		p->write = bq4802_write_io;
163 	} else if (p->r->flags & IORESOURCE_MEM) {
164 		p->regs = ioremap(p->r->start, resource_size(p->r));
165 		p->read = bq4802_read_mem;
166 		p->write = bq4802_write_mem;
167 	} else {
168 		err = -EINVAL;
169 		goto out_free;
170 	}
171 
172 	p->rtc = rtc_device_register("bq4802", &pdev->dev,
173 				     &bq4802_ops, THIS_MODULE);
174 	if (IS_ERR(p->rtc)) {
175 		err = PTR_ERR(p->rtc);
176 		goto out_iounmap;
177 	}
178 
179 	platform_set_drvdata(pdev, p);
180 	err = 0;
181 out:
182 	return err;
183 
184 out_iounmap:
185 	if (p->r->flags & IORESOURCE_MEM)
186 		iounmap(p->regs);
187 out_free:
188 	kfree(p);
189 	goto out;
190 }
191 
192 static int __devexit bq4802_remove(struct platform_device *pdev)
193 {
194 	struct bq4802 *p = platform_get_drvdata(pdev);
195 
196 	rtc_device_unregister(p->rtc);
197 	if (p->r->flags & IORESOURCE_MEM)
198 		iounmap(p->regs);
199 
200 	platform_set_drvdata(pdev, NULL);
201 
202 	kfree(p);
203 
204 	return 0;
205 }
206 
207 /* work with hotplug and coldplug */
208 MODULE_ALIAS("platform:rtc-bq4802");
209 
210 static struct platform_driver bq4802_driver = {
211 	.driver		= {
212 		.name	= "rtc-bq4802",
213 		.owner	= THIS_MODULE,
214 	},
215 	.probe		= bq4802_probe,
216 	.remove		= __devexit_p(bq4802_remove),
217 };
218 
219 static int __init bq4802_init(void)
220 {
221 	return platform_driver_register(&bq4802_driver);
222 }
223 
224 static void __exit bq4802_exit(void)
225 {
226 	platform_driver_unregister(&bq4802_driver);
227 }
228 
229 module_init(bq4802_init);
230 module_exit(bq4802_exit);
231