arch/cris/arch-v10/drivers/pcf8563.c - maze/linux - Git at Google

 /*
  * 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/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/capability.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 const 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 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);
         return 0;
 }

 module_init(pcf8563_register);
 module_exit(pcf8563_exit);
	/*
	* 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/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/capability.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 const 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 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);
	return 0;
	}

	module_init(pcf8563_register);
	module_exit(pcf8563_exit);