patch-2.4.20 linux-2.4.20/arch/cris/drivers/pcf8563.c

• Lines: 259
• Date: Thu Nov 28 15:53:09 2002
• Orig file: linux-2.4.19/arch/cris/drivers/pcf8563.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/cris/drivers/pcf8563.c linux-2.4.20/arch/cris/drivers/pcf8563.c
@@ -0,0 +1,258 @@
+/*
+ * 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 1.1 2002/08/12 13:46:02 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 <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/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 "$Rev$"
+
+/* 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,
+};
+
+void
+get_rtc_time(struct rtc_time *tm)
+{
+	unsigned long flags;
+	
+	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)
+{
+	unsigned char ret;
+        struct rtc_time tm;
+        
+	/*
+	 * 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;
+
+	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 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 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) != PCF8563_MAGIC)
+		return -ENOTTY;
+
+	if (_IOC_NR(cmd) > RTC_MAX_IOCTL)
+		return -ENOTTY;
+
+	switch (cmd) {
+		case RTC_RD_TIME:
+			{
+				struct rtc_time tm;
+
+				get_rtc_time(&tm);
+
+				if (copy_to_user((struct rtc_time *) arg, &tm, sizeof(struct rtc_time))) {
+					return -EFAULT;
+				}
+
+				return 0;
+			}
+			break;
+		case RTC_SET_TIME:
+			{
+				int leap;
+				int century;
+				unsigned long flags;
+				struct rtc_time tm;
+
+				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;
+				
+				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);
+
+				return 0;
+			}
+			break;
+		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;
+}
+
+EXPORT_NO_SYMBOLS;
+module_init(pcf8563_init);
+module_exit(pcf8563_exit);