| /* |
| * 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 <linux/smp_lock.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(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, |
| }; |
| |
| 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; |
| |
| lock_kernel(); |
| return pcf8563_ioctl(filp, cmd, arg); |
| unlock_kernel(); |
| |
| 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); |