Commit 7edf7440 authored by Jesper Nilsson's avatar Jesper Nilsson
Browse files

CRIS v32: Update driver for RTC chip pcf8563. 

- Moved all calls to register_chrdev to a function called by module_init.
- Added mutex locking.
- Added better error handling at start up.
- Added BIN_TO_BCD of the month value before it is saved to the RTC.
- Corrected the month value returned by pcf8563_readreg.
- Cache the voltage low value at driver init so the battery status
  information does not get 'accidentally' cleared when setting the RTC time.
- Removed obsolete CONFIG_ETRAX_RTC_READONLY
- Voltage low ioctl():s RTC_VLOW_RD -> RTC_VL_READ, RTC_VLOW_SET -> RTC_VL_CLR
parent d8ac17a0

arch/cris/arch-v32/drivers/pcf8563.c

+163 −133
Original line number Diff line number Diff line
@@ -10,7 +10,7 @@ 
 * 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

 * Copyright (c) 2002-2007, Axis Communications AB

 * All rights reserved.

 *

 * Author: Tobias Anderberg <tobiasa@axis.com>.
@@ -26,6 +26,7 @@ 
#include <linux/ioctl.h>

#include <linux/delay.h>

#include <linux/bcd.h>

#include <linux/mutex.h>



#include <asm/uaccess.h>

#include <asm/system.h>
@@ -37,24 +38,27 @@ 
#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 $"

#define DRIVER_VERSION	"$Revision: 1.17 $"



/* 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 };



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 *);



/* 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,

	.ioctl =	pcf8563_ioctl,

	.open =		pcf8563_open,

	.release =	pcf8563_release,

	.ioctl =	pcf8563_ioctl

};



unsigned char
@@ -62,7 +66,7 @@ pcf8563_readreg(int reg) 
{

	unsigned char res = rtc_read(reg);



	/* The PCF8563 does not return 0 for unimplemented bits */

	/* The PCF8563 does not return 0 for unimplemented bits. */

	switch (reg) {

		case RTC_SECONDS:

		case RTC_MINUTES:
@@ -95,11 +99,6 @@ pcf8563_readreg(int reg) 
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);

}
@@ -114,11 +113,13 @@ get_rtc_time(struct rtc_time *tm) 
	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 "

	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  = BCD_TO_BIN(tm->tm_year) + ((tm->tm_mon & 0x80) ? 100 : 0);

	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;
@@ -137,8 +138,19 @@ get_rtc_time(struct rtc_time *tm) 
int __init

pcf8563_init(void)

{

	static int res;

	static int first = 1;



	if (!first)

		return res;

	first = 0;



	/* Initiate the i2c protocol. */

	i2c_init();

	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
@@ -170,24 +182,20 @@ pcf8563_init(void) 
	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 number %d for RTC device.\n",

		       PCF8563_NAME, PCF8563_MAJOR);

		return -1;

	/* 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);

	}



	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;

	return res;



err:

	printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME);

	return -1;

	res = -1;

	return res;

}



void __exit
@@ -200,8 +208,8 @@ pcf8563_exit(void) 
 * 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)

int pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,

	unsigned long arg)

{

	/* Some sanity checks. */

	if (_IOC_TYPE(cmd) != RTC_MAGIC)
@@ -215,30 +223,33 @@ pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned 
	{

		struct rtc_time tm;



			memset(&tm, 0, sizeof (struct rtc_time));

		mutex_lock(&rtc_lock);

		memset(&tm, 0, sizeof tm);

		get_rtc_time(&tm);



			if (copy_to_user((struct rtc_time *) arg, &tm, sizeof tm)) {

		if (copy_to_user((struct rtc_time *) arg, &tm,

				 sizeof tm)) {

			spin_unlock(&rtc_lock);

			return -EFAULT;

		}



		mutex_unlock(&rtc_lock);



		return 0;

	}



	case RTC_SET_TIME:

	{

#ifdef CONFIG_ETRAX_RTC_READONLY

			return -EPERM;

#else

		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))

		if (copy_from_user(&tm, (struct rtc_time *) arg,

				   sizeof tm))

			return -EFAULT;



		/* Convert from struct tm to struct rtc_time. */
@@ -251,7 +262,8 @@ pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned 
		 * 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);

		leap = (tm.tm_mon == 2) &&

			((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);



		/* Perform some sanity checks. */

		if ((tm.tm_year < 1970) ||
@@ -268,12 +280,15 @@ pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned 
		tm.tm_year = tm.tm_year % 100;



		BIN_TO_BCD(tm.tm_year);

		BIN_TO_BCD(tm.tm_mon);

		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;



		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. */
@@ -282,36 +297,37 @@ pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned 
		rtc_write(RTC_MINUTES, tm.tm_min);

		rtc_write(RTC_SECONDS, tm.tm_sec);



		mutex_unlock(&rtc_lock);



		return 0;

#endif /* !CONFIG_ETRAX_RTC_READONLY */

	}

	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);



		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)))

		if (copy_to_user((int *) arg, &voltage_low, sizeof(int)))

			return -EFAULT;



		return 0;

		}



		case RTC_VLOW_SET:

	case RTC_VL_CLR:

	{

			/* Clear the VL bit in the seconds register */

		/* 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;

	}
@@ -319,17 +335,31 @@ pcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned 
	return 0;

}



int

pcf8563_open(struct inode *inode, struct file *filp)

static int __init pcf8563_register(void)

{

	return 0;

	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 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 (voltage_low) {

		printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "

		       "information is no longer guaranteed!\n", PCF8563_NAME);

	}



int

pcf8563_release(struct inode *inode, struct file *filp)

{

	return 0;

}



module_init(pcf8563_init);

module_init(pcf8563_register);

module_exit(pcf8563_exit);

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