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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 | /* * PCF8563 RTC * * From Phillips' datasheet: * * The PCF8563 is a CMOS real-time clock/calendar optimized for low power * consumption. A programmable clock output, interupt 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 bute. * * Copyright (c) 2002, Axis Communications AB * All rights reserved. * * Author: Tobias Anderberg <tobiasa@axis.com>. * * $Id: pcf8563.c,v 1.11 2005/03/07 13:13:07 starvik Exp $ */ #include <linux/config.h> #include <linux/version.h> #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 <asm/uaccess.h> #include <asm/system.h> #include <asm/io.h> #include <asm/arch/svinto.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: 1.11 $" /* 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_SPINLOCK(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 }; int pcf8563_ioctl(struct inode *, struct file *, unsigned int, unsigned long); static struct file_operations pcf8563_fops = { .owner = THIS_MODULE, .ioctl = pcf8563_ioctl, }; unsigned char pcf8563_readreg(int reg) { unsigned char res = i2c_readreg(RTC_I2C_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_MONTH: res = (res & 0x1f) - 1; /* PCF8563 returns month in range 1-12 */ break; } return res; } void pcf8563_writereg(int reg, unsigned char val) { #ifdef CONFIG_ETRAX_RTC_READONLY if (reg == RTC_CONTROL1 || (reg >= RTC_SECONDS && reg <= RTC_YEAR)) return; #endif 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_mon = rtc_read(RTC_MONTH); tm->tm_year = rtc_read(RTC_YEAR); if (tm->tm_sec & 0x80) printk(KERN_WARNING "%s: RTC Low Voltage - date/time is not reliable!\n", PCF8563_NAME); tm->tm_year = BCD_TO_BIN(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_mon &= 0x1f; BCD_TO_BIN(tm->tm_sec); BCD_TO_BIN(tm->tm_min); BCD_TO_BIN(tm->tm_hour); BCD_TO_BIN(tm->tm_mday); BCD_TO_BIN(tm->tm_mon); tm->tm_mon--; /* Month is 1..12 in RTC but 0..11 in linux */ } int __init pcf8563_init(void) { int ret; if ((ret = i2c_init())) { printk(KERN_CRIT "pcf8563_init: failed to init i2c\n"); return ret; } /* * First of all we need to reset the chip. This is done by * clearing control1, control2 and clk freq, clear the * Voltage Low bit, 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; /* Clear the VL bit in the seconds register. */ ret = rtc_read(RTC_SECONDS); if (rtc_write(RTC_SECONDS, (ret & 0x7f)) < 0) goto err; /* Reset the alarms. */ if (rtc_write(RTC_MINUTE_ALARM, 0x00) < 0) goto err; if (rtc_write(RTC_HOUR_ALARM, 0x00) < 0) goto err; if (rtc_write(RTC_DAY_ALARM, 0x00) < 0) goto err; if (rtc_write(RTC_WEEKDAY_ALARM, 0x00) < 0) goto err; /* Check for low voltage, and warn about it.. */ if (rtc_read(RTC_SECONDS) & 0x80) printk(KERN_WARNING "%s: RTC Low Voltage - date/time is not reliable!\n", PCF8563_NAME); return 0; err: printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME); return -1; } void __exit pcf8563_exit(void) { if (unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME) < 0) { printk(KERN_INFO "%s: Unable to unregister device.\n", PCF8563_NAME); } } /* * ioctl calls for this driver. Why return -ENOTTY upon error? Because * POSIX says so! */ int pcf8563_ioctl(struct inode *inode, 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; spin_lock(&rtc_lock); get_rtc_time(&tm); if (copy_to_user((struct rtc_time *) arg, &tm, sizeof(struct rtc_time))) { spin_unlock(&rtc_lock); return -EFAULT; } spin_unlock(&rtc_lock); return 0; } break; case RTC_SET_TIME: { #ifdef CONFIG_ETRAX_RTC_READONLY return -EPERM; #else int leap; int century; struct rtc_time tm; memset(&tm, 0, sizeof (struct rtc_time)); if (!capable(CAP_SYS_TIME)) return -EPERM; if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof(struct rtc_time))) return -EFAULT; /* Convert from struct tm to struct rtc_time. */ tm.tm_year += 1900; tm.tm_mon += 1; leap = ((tm.tm_mon == 2) && ((tm.tm_year % 4) == 0)) ? 1 : 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_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; BIN_TO_BCD(tm.tm_year); BIN_TO_BCD(tm.tm_mday); BIN_TO_BCD(tm.tm_hour); BIN_TO_BCD(tm.tm_min); BIN_TO_BCD(tm.tm_sec); tm.tm_mon |= century; spin_lock(&rtc_lock); rtc_write(RTC_YEAR, tm.tm_year); rtc_write(RTC_MONTH, tm.tm_mon); 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); spin_unlock(&rtc_lock); return 0; #endif /* !CONFIG_ETRAX_RTC_READONLY */ } case RTC_VLOW_RD: { int vl_bit = 0; if (rtc_read(RTC_SECONDS) & 0x80) { vl_bit = 1; printk(KERN_WARNING "%s: RTC Voltage Low - reliable " "date/time information is no longer guaranteed!\n", PCF8563_NAME); } if (copy_to_user((int *) arg, &vl_bit, sizeof(int))) return -EFAULT; return 0; } case RTC_VLOW_SET: { /* Clear the VL bit in the seconds register */ int ret = rtc_read(RTC_SECONDS); rtc_write(RTC_SECONDS, (ret & 0x7F)); return 0; } default: return -ENOTTY; } return 0; } static int __init pcf8563_register(void) { pcf8563_init(); if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) { printk(KERN_INFO "%s: Unable to get major numer %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); return 0; } module_init(pcf8563_register); module_exit(pcf8563_exit); |