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
  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         platform_set_drvdata(pdev, p);
 173
 174         p->rtc = rtc_device_register("bq4802", &pdev->dev,
 175                                      &bq4802_ops, THIS_MODULE);
 176         if (IS_ERR(p->rtc)) {
 177                 err = PTR_ERR(p->rtc);
 178                 goto out_iounmap;
 179         }
 180
 181         err = 0;
 182 out:
 183         return err;
 184
 185 out_iounmap:
 186         if (p->r->flags & IORESOURCE_MEM)
 187                 iounmap(p->regs);
 188 out_free:
 189         kfree(p);
 190         goto out;
 191 }
 192
 193 static int __devexit bq4802_remove(struct platform_device *pdev)
 194 {
 195         struct bq4802 *p = platform_get_drvdata(pdev);
 196
 197         rtc_device_unregister(p->rtc);
 198         if (p->r->flags & IORESOURCE_MEM)
 199                 iounmap(p->regs);
 200
 201         platform_set_drvdata(pdev, NULL);
 202
 203         kfree(p);
 204
 205         return 0;
 206 }
 207
 208 /* work with hotplug and coldplug */
 209 MODULE_ALIAS("platform:rtc-bq4802");
 210
 211 static struct platform_driver bq4802_driver = {
 212         .driver         = {
 213                 .name   = "rtc-bq4802",
 214                 .owner  = THIS_MODULE,
 215         },
 216         .probe          = bq4802_probe,
 217         .remove         = __devexit_p(bq4802_remove),
 218 };
 219
 220 static int __init bq4802_init(void)
 221 {
 222         return platform_driver_register(&bq4802_driver);
 223 }
 224
 225 static void __exit bq4802_exit(void)
 226 {
 227         platform_driver_unregister(&bq4802_driver);
 228 }
 229
 230 module_init(bq4802_init);
 231 module_exit(bq4802_exit);