UPSTREAM Revert 3.9 "rtc: palmas: Add RTC driver Palmas series PMIC"
[linux-3.10.git] / drivers / rtc / rtc-bq4802.c
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
15 MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
16 MODULE_DESCRIPTION("TI BQ4802 RTC driver");
17 MODULE_LICENSE("GPL");
18
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);
27 };
28
29 static u8 bq4802_read_io(struct bq4802 *p, int off)
30 {
31         return inb(p->ioport + off);
32 }
33
34 static void bq4802_write_io(struct bq4802 *p, int off, u8 val)
35 {
36         outb(val, p->ioport + off);
37 }
38
39 static u8 bq4802_read_mem(struct bq4802 *p, int off)
40 {
41         return readb(p->regs + off);
42 }
43
44 static void bq4802_write_mem(struct bq4802 *p, int off, u8 val)
45 {
46         writeb(val, p->regs + off);
47 }
48
49 static 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
92 static 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
138 static const struct rtc_class_ops bq4802_ops = {
139         .read_time      = bq4802_read_time,
140         .set_time       = bq4802_set_time,
141 };
142
143 static 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;
184 out:
185         return err;
186
187 }
188
189 static int bq4802_remove(struct platform_device *pdev)
190 {
191         platform_set_drvdata(pdev, NULL);
192
193         return 0;
194 }
195
196 /* work with hotplug and coldplug */
197 MODULE_ALIAS("platform:rtc-bq4802");
198
199 static struct platform_driver bq4802_driver = {
200         .driver         = {
201                 .name   = "rtc-bq4802",
202                 .owner  = THIS_MODULE,
203         },
204         .probe          = bq4802_probe,
205         .remove         = bq4802_remove,
206 };
207
208 module_platform_driver(bq4802_driver);