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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 | /* * PCF8563 RTC * * From Phillips' datasheet: * * The PCF8563 is a CMOS real-time clock/calendar optimized for low power * consumption. A programmable clock output, interrupt output and voltage * low detector are also provided. All address and data are transferred * serially via two-line bidirectional I2C-bus. Maximum bus speed is * 400 kbits/s. The built-in word address register is incremented * automatically after each written or read byte. * * Copyright (c) 2002-2007, Axis Communications AB * All rights reserved. * * Author: Tobias Anderberg <tobiasa@axis.com>. * */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/types.h> #include <linux/sched.h> #include <linux/init.h> #include <linux/fs.h> #include <linux/ioctl.h> #include <linux/delay.h> #include <linux/bcd.h> #include <linux/mutex.h> #include <asm/uaccess.h> #include <asm/system.h> #include <asm/io.h> #include <asm/rtc.h> #include "i2c.h" #define PCF8563_MAJOR 121 /* Local major number. */ #define DEVICE_NAME "rtc" /* Name which is registered in /proc/devices. */ #define PCF8563_NAME "PCF8563" #define DRIVER_VERSION "$Revision: 1.24 $" /* I2C bus slave registers. */ #define RTC_I2C_READ 0xa3 #define RTC_I2C_WRITE 0xa2 /* Two simple wrapper macros, saves a few keystrokes. */ #define rtc_read(x) i2c_readreg(RTC_I2C_READ, x) #define rtc_write(x,y) i2c_writereg(RTC_I2C_WRITE, x, y) static DEFINE_MUTEX(pcf8563_mutex); static DEFINE_MUTEX(rtc_lock); /* Protect state etc */ static const unsigned char days_in_month[] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; static long pcf8563_unlocked_ioctl(struct file *, unsigned int, unsigned long); /* Cache VL bit value read at driver init since writing the RTC_SECOND * register clears the VL status. */ static int voltage_low; static const struct file_operations pcf8563_fops = { .owner = THIS_MODULE, .unlocked_ioctl = pcf8563_unlocked_ioctl, .llseek = noop_llseek, }; unsigned char pcf8563_readreg(int reg) { unsigned char res = rtc_read(reg); /* The PCF8563 does not return 0 for unimplemented bits. */ switch (reg) { case RTC_SECONDS: case RTC_MINUTES: res &= 0x7F; break; case RTC_HOURS: case RTC_DAY_OF_MONTH: res &= 0x3F; break; case RTC_WEEKDAY: res &= 0x07; break; case RTC_MONTH: res &= 0x1F; break; case RTC_CONTROL1: res &= 0xA8; break; case RTC_CONTROL2: res &= 0x1F; break; case RTC_CLOCKOUT_FREQ: case RTC_TIMER_CONTROL: res &= 0x83; break; } return res; } void pcf8563_writereg(int reg, unsigned char val) { rtc_write(reg, val); } void get_rtc_time(struct rtc_time *tm) { tm->tm_sec = rtc_read(RTC_SECONDS); tm->tm_min = rtc_read(RTC_MINUTES); tm->tm_hour = rtc_read(RTC_HOURS); tm->tm_mday = rtc_read(RTC_DAY_OF_MONTH); tm->tm_wday = rtc_read(RTC_WEEKDAY); tm->tm_mon = rtc_read(RTC_MONTH); tm->tm_year = rtc_read(RTC_YEAR); if (tm->tm_sec & 0x80) { printk(KERN_ERR "%s: RTC Voltage Low - reliable date/time " "information is no longer guaranteed!\n", PCF8563_NAME); } tm->tm_year = bcd2bin(tm->tm_year) + ((tm->tm_mon & 0x80) ? 100 : 0); tm->tm_sec &= 0x7F; tm->tm_min &= 0x7F; tm->tm_hour &= 0x3F; tm->tm_mday &= 0x3F; tm->tm_wday &= 0x07; /* Not coded in BCD. */ tm->tm_mon &= 0x1F; tm->tm_sec = bcd2bin(tm->tm_sec); tm->tm_min = bcd2bin(tm->tm_min); tm->tm_hour = bcd2bin(tm->tm_hour); tm->tm_mday = bcd2bin(tm->tm_mday); tm->tm_mon = bcd2bin(tm->tm_mon); tm->tm_mon--; /* Month is 1..12 in RTC but 0..11 in linux */ } int __init pcf8563_init(void) { static int res; static int first = 1; if (!first) return res; first = 0; /* Initiate the i2c protocol. */ res = i2c_init(); if (res < 0) { printk(KERN_CRIT "pcf8563_init: Failed to init i2c.\n"); return res; } /* * First of all we need to reset the chip. This is done by * clearing control1, control2 and clk freq and resetting * all alarms. */ if (rtc_write(RTC_CONTROL1, 0x00) < 0) goto err; if (rtc_write(RTC_CONTROL2, 0x00) < 0) goto err; if (rtc_write(RTC_CLOCKOUT_FREQ, 0x00) < 0) goto err; if (rtc_write(RTC_TIMER_CONTROL, 0x03) < 0) goto err; /* Reset the alarms. */ if (rtc_write(RTC_MINUTE_ALARM, 0x80) < 0) goto err; if (rtc_write(RTC_HOUR_ALARM, 0x80) < 0) goto err; if (rtc_write(RTC_DAY_ALARM, 0x80) < 0) goto err; if (rtc_write(RTC_WEEKDAY_ALARM, 0x80) < 0) goto err; /* Check for low voltage, and warn about it. */ if (rtc_read(RTC_SECONDS) & 0x80) { voltage_low = 1; printk(KERN_WARNING "%s: RTC Voltage Low - reliable " "date/time information is no longer guaranteed!\n", PCF8563_NAME); } return res; err: printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME); res = -1; return res; } void __exit pcf8563_exit(void) { unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME); } /* * ioctl calls for this driver. Why return -ENOTTY upon error? Because * POSIX says so! */ static int pcf8563_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { /* Some sanity checks. */ if (_IOC_TYPE(cmd) != RTC_MAGIC) return -ENOTTY; if (_IOC_NR(cmd) > RTC_MAX_IOCTL) return -ENOTTY; switch (cmd) { case RTC_RD_TIME: { struct rtc_time tm; mutex_lock(&rtc_lock); memset(&tm, 0, sizeof tm); get_rtc_time(&tm); if (copy_to_user((struct rtc_time *) arg, &tm, sizeof tm)) { mutex_unlock(&rtc_lock); return -EFAULT; } mutex_unlock(&rtc_lock); return 0; } case RTC_SET_TIME: { int leap; int year; int century; struct rtc_time tm; memset(&tm, 0, sizeof tm); if (!capable(CAP_SYS_TIME)) return -EPERM; if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof tm)) return -EFAULT; /* Convert from struct tm to struct rtc_time. */ tm.tm_year += 1900; tm.tm_mon += 1; /* * Check if tm.tm_year is a leap year. A year is a leap * year if it is divisible by 4 but not 100, except * that years divisible by 400 _are_ leap years. */ year = tm.tm_year; leap = (tm.tm_mon == 2) && ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0); /* Perform some sanity checks. */ if ((tm.tm_year < 1970) || (tm.tm_mon > 12) || (tm.tm_mday == 0) || (tm.tm_mday > days_in_month[tm.tm_mon] + leap) || (tm.tm_wday >= 7) || (tm.tm_hour >= 24) || (tm.tm_min >= 60) || (tm.tm_sec >= 60)) return -EINVAL; century = (tm.tm_year >= 2000) ? 0x80 : 0; tm.tm_year = tm.tm_year % 100; tm.tm_year = bin2bcd(tm.tm_year); tm.tm_mon = bin2bcd(tm.tm_mon); tm.tm_mday = bin2bcd(tm.tm_mday); tm.tm_hour = bin2bcd(tm.tm_hour); tm.tm_min = bin2bcd(tm.tm_min); tm.tm_sec = bin2bcd(tm.tm_sec); tm.tm_mon |= century; mutex_lock(&rtc_lock); rtc_write(RTC_YEAR, tm.tm_year); rtc_write(RTC_MONTH, tm.tm_mon); rtc_write(RTC_WEEKDAY, tm.tm_wday); /* Not coded in BCD. */ rtc_write(RTC_DAY_OF_MONTH, tm.tm_mday); rtc_write(RTC_HOURS, tm.tm_hour); rtc_write(RTC_MINUTES, tm.tm_min); rtc_write(RTC_SECONDS, tm.tm_sec); mutex_unlock(&rtc_lock); return 0; } case RTC_VL_READ: if (voltage_low) { printk(KERN_ERR "%s: RTC Voltage Low - " "reliable date/time information is no " "longer guaranteed!\n", PCF8563_NAME); } if (copy_to_user((int *) arg, &voltage_low, sizeof(int))) return -EFAULT; return 0; case RTC_VL_CLR: { /* Clear the VL bit in the seconds register in case * the time has not been set already (which would * have cleared it). This does not really matter * because of the cached voltage_low value but do it * anyway for consistency. */ int ret = rtc_read(RTC_SECONDS); rtc_write(RTC_SECONDS, (ret & 0x7F)); /* Clear the cached value. */ voltage_low = 0; return 0; } default: return -ENOTTY; } return 0; } static long pcf8563_unlocked_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { int ret; mutex_lock(&pcf8563_mutex); ret = pcf8563_ioctl(filp, cmd, arg); mutex_unlock(&pcf8563_mutex); return ret; } static int __init pcf8563_register(void) { if (pcf8563_init() < 0) { printk(KERN_INFO "%s: Unable to initialize Real-Time Clock " "Driver, %s\n", PCF8563_NAME, DRIVER_VERSION); return -1; } if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) { printk(KERN_INFO "%s: Unable to get major number %d for RTC device.\n", PCF8563_NAME, PCF8563_MAJOR); return -1; } printk(KERN_INFO "%s Real-Time Clock Driver, %s\n", PCF8563_NAME, DRIVER_VERSION); /* Check for low voltage, and warn about it. */ if (voltage_low) { printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time " "information is no longer guaranteed!\n", PCF8563_NAME); } return 0; } module_init(pcf8563_register); module_exit(pcf8563_exit); |