arch/cris/arch-v32/drivers/pcf8563.c

   1 /*
   2  * PCF8563 RTC
   3  *
   4  * From Phillips' datasheet:
   5  *
   6  * The PCF8563 is a CMOS real-time clock/calendar optimized for low power
   7  * consumption. A programmable clock output, interupt output and voltage
   8  * low detector are also provided. All address and data are transferred
   9  * serially via two-line bidirectional I2C-bus. Maximum bus speed is
  10  * 400 kbits/s. The built-in word address register is incremented
  11  * automatically after each written or read byte.
  12  *
  13  * Copyright (c) 2002-2003, Axis Communications AB
  14  * All rights reserved.
  15  *
  16  * Author: Tobias Anderberg <tobiasa@axis.com>.
  17  *
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/kernel.h>
  22 #include <linux/types.h>
  23 #include <linux/sched.h>
  24 #include <linux/init.h>
  25 #include <linux/fs.h>
  26 #include <linux/ioctl.h>
  27 #include <linux/delay.h>
  28 #include <linux/bcd.h>
  29
  30 #include <asm/uaccess.h>
  31 #include <asm/system.h>
  32 #include <asm/io.h>
  33 #include <asm/rtc.h>
  34
  35 #include "i2c.h"
  36
  37 #define PCF8563_MAJOR   121     /* Local major number. */
  38 #define DEVICE_NAME     "rtc"   /* Name which is registered in /proc/devices. */
  39 #define PCF8563_NAME    "PCF8563"
  40 #define DRIVER_VERSION  "$Revision: 1.1 $"
  41
  42 /* Two simple wrapper macros, saves a few keystrokes. */
  43 #define rtc_read(x) i2c_readreg(RTC_I2C_READ, x)
  44 #define rtc_write(x,y) i2c_writereg(RTC_I2C_WRITE, x, y)
  45
  46 static const unsigned char days_in_month[] =
  47         { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
  48
  49 int pcf8563_ioctl(struct inode *, struct file *, unsigned int, unsigned long);
  50 int pcf8563_open(struct inode *, struct file *);
  51 int pcf8563_release(struct inode *, struct file *);
  52
  53 static const struct file_operations pcf8563_fops = {
  54         .owner =        THIS_MODULE,
  55         .ioctl =        pcf8563_ioctl,
  56         .open =         pcf8563_open,
  57         .release =      pcf8563_release,
  58 };
  59
  60 unsigned char
  61 pcf8563_readreg(int reg)
  62 {
  63         unsigned char res = rtc_read(reg);
  64
  65         /* The PCF8563 does not return 0 for unimplemented bits */
  66         switch (reg) {
  67                 case RTC_SECONDS:
  68                 case RTC_MINUTES:
  69                         res &= 0x7F;
  70                         break;
  71                 case RTC_HOURS:
  72                 case RTC_DAY_OF_MONTH:
  73                         res &= 0x3F;
  74                         break;
  75                 case RTC_WEEKDAY:
  76                         res &= 0x07;
  77                         break;
  78                 case RTC_MONTH:
  79                         res &= 0x1F;
  80                         break;
  81                 case RTC_CONTROL1:
  82                         res &= 0xA8;
  83                         break;
  84                 case RTC_CONTROL2:
  85                         res &= 0x1F;
  86                         break;
  87                 case RTC_CLOCKOUT_FREQ:
  88                 case RTC_TIMER_CONTROL:
  89                         res &= 0x83;
  90                         break;
  91         }
  92         return res;
  93 }
  94
  95 void
  96 pcf8563_writereg(int reg, unsigned char val)
  97 {
  98 #ifdef CONFIG_ETRAX_RTC_READONLY
  99         if (reg == RTC_CONTROL1 || (reg >= RTC_SECONDS && reg <= RTC_YEAR))
 100                 return;
 101 #endif
 102
 103         rtc_write(reg, val);
 104 }
 105
 106 void
 107 get_rtc_time(struct rtc_time *tm)
 108 {
 109         tm->tm_sec  = rtc_read(RTC_SECONDS);
 110         tm->tm_min  = rtc_read(RTC_MINUTES);
 111         tm->tm_hour = rtc_read(RTC_HOURS);
 112         tm->tm_mday = rtc_read(RTC_DAY_OF_MONTH);
 113         tm->tm_wday = rtc_read(RTC_WEEKDAY);
 114         tm->tm_mon  = rtc_read(RTC_MONTH);
 115         tm->tm_year = rtc_read(RTC_YEAR);
 116
 117         if (tm->tm_sec & 0x80)
 118                 printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "
 119                        "information is no longer guaranteed!\n", PCF8563_NAME);
 120
 121         tm->tm_year  = BCD_TO_BIN(tm->tm_year) + ((tm->tm_mon & 0x80) ? 100 : 0);
 122         tm->tm_sec  &= 0x7F;
 123         tm->tm_min  &= 0x7F;
 124         tm->tm_hour &= 0x3F;
 125         tm->tm_mday &= 0x3F;
 126         tm->tm_wday &= 0x07; /* Not coded in BCD. */
 127         tm->tm_mon  &= 0x1F;
 128
 129         BCD_TO_BIN(tm->tm_sec);
 130         BCD_TO_BIN(tm->tm_min);
 131         BCD_TO_BIN(tm->tm_hour);
 132         BCD_TO_BIN(tm->tm_mday);
 133         BCD_TO_BIN(tm->tm_mon);
 134         tm->tm_mon--; /* Month is 1..12 in RTC but 0..11 in linux */
 135 }
 136
 137 int __init
 138 pcf8563_init(void)
 139 {
 140         /* Initiate the i2c protocol. */
 141         i2c_init();
 142
 143         /*
 144          * First of all we need to reset the chip. This is done by
 145          * clearing control1, control2 and clk freq and resetting
 146          * all alarms.
 147          */
 148         if (rtc_write(RTC_CONTROL1, 0x00) < 0)
 149                 goto err;
 150
 151         if (rtc_write(RTC_CONTROL2, 0x00) < 0)
 152                 goto err;
 153
 154         if (rtc_write(RTC_CLOCKOUT_FREQ, 0x00) < 0)
 155                 goto err;
 156
 157         if (rtc_write(RTC_TIMER_CONTROL, 0x03) < 0)
 158                 goto err;
 159
 160         /* Reset the alarms. */
 161         if (rtc_write(RTC_MINUTE_ALARM, 0x80) < 0)
 162                 goto err;
 163
 164         if (rtc_write(RTC_HOUR_ALARM, 0x80) < 0)
 165                 goto err;
 166
 167         if (rtc_write(RTC_DAY_ALARM, 0x80) < 0)
 168                 goto err;
 169
 170         if (rtc_write(RTC_WEEKDAY_ALARM, 0x80) < 0)
 171                 goto err;
 172
 173         if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) {
 174                 printk(KERN_INFO "%s: Unable to get major number %d for RTC device.\n",
 175                        PCF8563_NAME, PCF8563_MAJOR);
 176                 return -1;
 177         }
 178
 179         printk(KERN_INFO "%s Real-Time Clock Driver, %s\n", PCF8563_NAME, DRIVER_VERSION);
 180
 181         /* Check for low voltage, and warn about it.. */
 182         if (rtc_read(RTC_SECONDS) & 0x80)
 183                 printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "
 184                        "information is no longer guaranteed!\n", PCF8563_NAME);
 185
 186         return 0;
 187
 188 err:
 189         printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME);
 190         return -1;
 191 }
 192
 193 void __exit
 194 pcf8563_exit(void)
 195 {
 196         unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME);
 197 }
 198
 199 /*
 200  * ioctl calls for this driver. Why return -ENOTTY upon error? Because
 201  * POSIX says so!
 202  */
 203 int
 204 pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg)
 205 {
 206         /* Some sanity checks. */
 207         if (_IOC_TYPE(cmd) != RTC_MAGIC)
 208                 return -ENOTTY;
 209
 210         if (_IOC_NR(cmd) > RTC_MAX_IOCTL)
 211                 return -ENOTTY;
 212
 213         switch (cmd) {
 214                 case RTC_RD_TIME:
 215                 {
 216                         struct rtc_time tm;
 217
 218                         memset(&tm, 0, sizeof (struct rtc_time));
 219                         get_rtc_time(&tm);
 220
 221                         if (copy_to_user((struct rtc_time *) arg, &tm, sizeof tm)) {
 222                                 return -EFAULT;
 223                         }
 224
 225                         return 0;
 226                 }
 227
 228                 case RTC_SET_TIME:
 229                 {
 230 #ifdef CONFIG_ETRAX_RTC_READONLY
 231                         return -EPERM;
 232 #else
 233                         int leap;
 234                         int year;
 235                         int century;
 236                         struct rtc_time tm;
 237
 238                         if (!capable(CAP_SYS_TIME))
 239                                 return -EPERM;
 240
 241                         if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof tm))
 242                                 return -EFAULT;
 243
 244                         /* Convert from struct tm to struct rtc_time. */
 245                         tm.tm_year += 1900;
 246                         tm.tm_mon += 1;
 247
 248                         /*
 249                          * Check if tm.tm_year is a leap year. A year is a leap
 250                          * year if it is divisible by 4 but not 100, except
 251                          * that years divisible by 400 _are_ leap years.
 252                          */
 253                         year = tm.tm_year;
 254                         leap = (tm.tm_mon == 2) && ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);
 255
 256                         /* Perform some sanity checks. */
 257                         if ((tm.tm_year < 1970) ||
 258                             (tm.tm_mon > 12) ||
 259                             (tm.tm_mday == 0) ||
 260                             (tm.tm_mday > days_in_month[tm.tm_mon] + leap) ||
 261                             (tm.tm_wday >= 7) ||
 262                             (tm.tm_hour >= 24) ||
 263                             (tm.tm_min >= 60) ||
 264                             (tm.tm_sec >= 60))
 265                                 return -EINVAL;
 266
 267                         century = (tm.tm_year >= 2000) ? 0x80 : 0;
 268                         tm.tm_year = tm.tm_year % 100;
 269
 270                         BIN_TO_BCD(tm.tm_year);
 271                         BIN_TO_BCD(tm.tm_mday);
 272                         BIN_TO_BCD(tm.tm_hour);
 273                         BIN_TO_BCD(tm.tm_min);
 274                         BIN_TO_BCD(tm.tm_sec);
 275                         tm.tm_mon |= century;
 276
 277                         rtc_write(RTC_YEAR, tm.tm_year);
 278                         rtc_write(RTC_MONTH, tm.tm_mon);
 279                         rtc_write(RTC_WEEKDAY, tm.tm_wday); /* Not coded in BCD. */
 280                         rtc_write(RTC_DAY_OF_MONTH, tm.tm_mday);
 281                         rtc_write(RTC_HOURS, tm.tm_hour);
 282                         rtc_write(RTC_MINUTES, tm.tm_min);
 283                         rtc_write(RTC_SECONDS, tm.tm_sec);
 284
 285                         return 0;
 286 #endif /* !CONFIG_ETRAX_RTC_READONLY */
 287                 }
 288
 289                 case RTC_VLOW_RD:
 290                 {
 291                         int vl_bit = 0;
 292
 293                         if (rtc_read(RTC_SECONDS) & 0x80) {
 294                                 vl_bit = 1;
 295                                 printk(KERN_WARNING "%s: RTC Voltage Low - reliable "
 296                                        "date/time information is no longer guaranteed!\n",
 297                                        PCF8563_NAME);
 298                         }
 299                         if (copy_to_user((int *) arg, &vl_bit, sizeof(int)))
 300                                 return -EFAULT;
 301
 302                         return 0;
 303                 }
 304
 305                 case RTC_VLOW_SET:
 306                 {
 307                         /* Clear the VL bit in the seconds register */
 308                         int ret = rtc_read(RTC_SECONDS);
 309
 310                         rtc_write(RTC_SECONDS, (ret & 0x7F));
 311
 312                         return 0;
 313                 }
 314
 315                 default:
 316                         return -ENOTTY;
 317         }
 318
 319         return 0;
 320 }
 321
 322 int
 323 pcf8563_open(struct inode *inode, struct file *filp)
 324 {
 325         return 0;
 326 }
 327
 328 int
 329 pcf8563_release(struct inode *inode, struct file *filp)
 330 {
 331         return 0;
 332 }
 333
 334 module_init(pcf8563_init);
 335 module_exit(pcf8563_exit);