1 /* rtc-bq4802.c: TI BQ4802 RTC driver.
3 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
6 #include <linux/kernel.h>
7 #include <linux/module.h>
8 #include <linux/init.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");
22 struct rtc_device *rtc;
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 bq4802 *p = dev_get_drvdata(dev);
56 spin_lock_irqsave(&p->lock, flags);
58 val = p->read(p, 0x0e);
59 p->write(p, 0xe, val | 0x08);
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);
70 p->write(p, 0x0e, val);
72 spin_unlock_irqrestore(&p->lock, flags);
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);
83 tm->tm_year += (century * 100);
91 static int bq4802_set_time(struct device *dev, struct rtc_time *tm)
93 struct bq4802 *p = dev_get_drvdata(dev);
94 u8 sec, min, hrs, day, mon, yrs, century, val;
98 year = tm->tm_year + 1900;
102 mon = tm->tm_mon + 1; /* tm_mon starts at zero */
114 century = bin2bcd(century);
116 spin_lock_irqsave(&p->lock, flags);
118 val = p->read(p, 0x0e);
119 p->write(p, 0x0e, val | 0x08);
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);
129 p->write(p, 0x0e, val);
131 spin_unlock_irqrestore(&p->lock, flags);
136 static const struct rtc_class_ops bq4802_ops = {
137 .read_time = bq4802_read_time,
138 .set_time = bq4802_set_time,
141 static int bq4802_probe(struct platform_device *pdev)
143 struct bq4802 *p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
149 spin_lock_init(&p->lock);
151 p->r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
153 p->r = platform_get_resource(pdev, IORESOURCE_IO, 0);
158 if (p->r->flags & IORESOURCE_IO) {
159 p->ioport = 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 = devm_ioremap(&pdev->dev, p->r->start,
164 resource_size(p->r));
169 p->read = bq4802_read_mem;
170 p->write = bq4802_write_mem;
176 platform_set_drvdata(pdev, p);
178 p->rtc = devm_rtc_device_register(&pdev->dev, "bq4802",
179 &bq4802_ops, THIS_MODULE);
180 if (IS_ERR(p->rtc)) {
181 err = PTR_ERR(p->rtc);
191 /* work with hotplug and coldplug */
192 MODULE_ALIAS("platform:rtc-bq4802");
194 static struct platform_driver bq4802_driver = {
196 .name = "rtc-bq4802",
198 .probe = bq4802_probe,
201 module_platform_driver(bq4802_driver);