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: 1.1.1.1 $" 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 46static const unsigned char days_in_month[] = 47 { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; 48 49int pcf8563_ioctl(struct inode *, struct file *, unsigned int, unsigned long); 50int pcf8563_open(struct inode *, struct file *); 51int pcf8563_release(struct inode *, struct file *); 52 53static const struct file_operations pcf8563_fops = { 54 owner: THIS_MODULE, 55 ioctl: pcf8563_ioctl, 56 open: pcf8563_open, 57 release: pcf8563_release, 58}; 59 60unsigned char 61pcf8563_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 95void 96pcf8563_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 106void 107get_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 137int __init 138pcf8563_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 188err: 189 printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME); 190 return -1; 191} 192 193void __exit 194pcf8563_exit(void) 195{ 196 if (unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME) < 0) { 197 printk(KERN_INFO "%s: Unable to unregister device.\n", PCF8563_NAME); 198 } 199} 200 201/* 202 * ioctl calls for this driver. Why return -ENOTTY upon error? Because 203 * POSIX says so! 204 */ 205int 206pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) 207{ 208 /* Some sanity checks. */ 209 if (_IOC_TYPE(cmd) != RTC_MAGIC) 210 return -ENOTTY; 211 212 if (_IOC_NR(cmd) > RTC_MAX_IOCTL) 213 return -ENOTTY; 214 215 switch (cmd) { 216 case RTC_RD_TIME: 217 { 218 struct rtc_time tm; 219 220 memset(&tm, 0, sizeof (struct rtc_time)); 221 get_rtc_time(&tm); 222 223 if (copy_to_user((struct rtc_time *) arg, &tm, sizeof tm)) { 224 return -EFAULT; 225 } 226 227 return 0; 228 } 229 230 case RTC_SET_TIME: 231 { 232#ifdef CONFIG_ETRAX_RTC_READONLY 233 return -EPERM; 234#else 235 int leap; 236 int year; 237 int century; 238 struct rtc_time tm; 239 240 if (!capable(CAP_SYS_TIME)) 241 return -EPERM; 242 243 if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof tm)) 244 return -EFAULT; 245 246 /* Convert from struct tm to struct rtc_time. */ 247 tm.tm_year += 1900; 248 tm.tm_mon += 1; 249 250 /* 251 * Check if tm.tm_year is a leap year. A year is a leap 252 * year if it is divisible by 4 but not 100, except 253 * that years divisible by 400 _are_ leap years. 254 */ 255 year = tm.tm_year; 256 leap = (tm.tm_mon == 2) && ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0); 257 258 /* Perform some sanity checks. */ 259 if ((tm.tm_year < 1970) || 260 (tm.tm_mon > 12) || 261 (tm.tm_mday == 0) || 262 (tm.tm_mday > days_in_month[tm.tm_mon] + leap) || 263 (tm.tm_wday >= 7) || 264 (tm.tm_hour >= 24) || 265 (tm.tm_min >= 60) || 266 (tm.tm_sec >= 60)) 267 return -EINVAL; 268 269 century = (tm.tm_year >= 2000) ? 0x80 : 0; 270 tm.tm_year = tm.tm_year % 100; 271 272 BIN_TO_BCD(tm.tm_year); 273 BIN_TO_BCD(tm.tm_mday); 274 BIN_TO_BCD(tm.tm_hour); 275 BIN_TO_BCD(tm.tm_min); 276 BIN_TO_BCD(tm.tm_sec); 277 tm.tm_mon |= century; 278 279 rtc_write(RTC_YEAR, tm.tm_year); 280 rtc_write(RTC_MONTH, tm.tm_mon); 281 rtc_write(RTC_WEEKDAY, tm.tm_wday); /* Not coded in BCD. */ 282 rtc_write(RTC_DAY_OF_MONTH, tm.tm_mday); 283 rtc_write(RTC_HOURS, tm.tm_hour); 284 rtc_write(RTC_MINUTES, tm.tm_min); 285 rtc_write(RTC_SECONDS, tm.tm_sec); 286 287 return 0; 288#endif /* !CONFIG_ETRAX_RTC_READONLY */ 289 } 290 291 case RTC_VLOW_RD: 292 { 293 int vl_bit = 0; 294 295 if (rtc_read(RTC_SECONDS) & 0x80) { 296 vl_bit = 1; 297 printk(KERN_WARNING "%s: RTC Voltage Low - reliable " 298 "date/time information is no longer guaranteed!\n", 299 PCF8563_NAME); 300 } 301 if (copy_to_user((int *) arg, &vl_bit, sizeof(int))) 302 return -EFAULT; 303 304 return 0; 305 } 306 307 case RTC_VLOW_SET: 308 { 309 /* Clear the VL bit in the seconds register */ 310 int ret = rtc_read(RTC_SECONDS); 311 312 rtc_write(RTC_SECONDS, (ret & 0x7F)); 313 314 return 0; 315 } 316 317 default: 318 return -ENOTTY; 319 } 320 321 return 0; 322} 323 324int 325pcf8563_open(struct inode *inode, struct file *filp) 326{ 327 return 0; 328} 329 330int 331pcf8563_release(struct inode *inode, struct file *filp) 332{ 333 return 0; 334} 335 336module_init(pcf8563_init); 337module_exit(pcf8563_exit); 338