--- /dev/null
+/*
+ * 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 byte.
+ *
+ * Copyright (c) 2002-2003, Axis Communications AB
+ * All rights reserved.
+ *
+ * Author: Tobias Anderberg <tobiasa@axis.com>.
+ *
+ */
+
+#include <linux/config.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/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: 1.1 $"
+
+/* 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 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);
+int pcf8563_open(struct inode *, struct file *);
+int pcf8563_release(struct inode *, struct file *);
+
+static struct file_operations pcf8563_fops = {
+ owner: THIS_MODULE,
+ ioctl: pcf8563_ioctl,
+ open: pcf8563_open,
+ release: pcf8563_release,
+};
+
+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)
+{
+#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_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_WARNING "%s: RTC Voltage Low - reliable date/time "
+ "information is no longer guaranteed!\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_wday &= 0x07; /* Not coded in BCD. */
+ 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)
+{
+ /* Initiate the i2c protocol. */
+ i2c_init();
+
+ /*
+ * 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;
+
+ 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);
+
+ /* Check for low voltage, and warn about it.. */
+ if (rtc_read(RTC_SECONDS) & 0x80)
+ printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "
+ "information is no longer guaranteed!\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;
+
+ memset(&tm, 0, sizeof (struct rtc_time));
+ get_rtc_time(&tm);
+
+ if (copy_to_user((struct rtc_time *) arg, &tm, sizeof tm)) {
+ return -EFAULT;
+ }
+
+ return 0;
+ }
+
+ case RTC_SET_TIME:
+ {
+#ifdef CONFIG_ETRAX_RTC_READONLY
+ return -EPERM;
+#else
+ int leap;
+ int year;
+ int century;
+ struct rtc_time 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;
+
+ 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;
+
+ 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);
+
+ 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;
+}
+
+int
+pcf8563_open(struct inode *inode, struct file *filp)
+{
+ MOD_INC_USE_COUNT;
+ return 0;
+}
+
+int
+pcf8563_release(struct inode *inode, struct file *filp)
+{
+ MOD_DEC_USE_COUNT;
+ return 0;
+}
+
+module_init(pcf8563_init);
+module_exit(pcf8563_exit);
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