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
diff --git a/arch/cris/arch-v32/drivers/pcf8563.c b/arch/cris/arch-v32/drivers/pcf8563.c
index 6dbd700..53db387 100644
--- a/arch/cris/arch-v32/drivers/pcf8563.c
+++ b/arch/cris/arch-v32/drivers/pcf8563.c
@@ -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 @@
{
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 @@
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 @@
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 @@
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 @@
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 @@
* 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)
@@ -211,125 +219,147 @@
return -ENOTTY;
switch (cmd) {
- case RTC_RD_TIME:
- {
- struct rtc_time tm;
+ case RTC_RD_TIME:
+ {
+ struct rtc_time tm;
- memset(&tm, 0, sizeof (struct rtc_time));
- get_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)) {
- return -EFAULT;
- }
-
- return 0;
+ if (copy_to_user((struct rtc_time *) arg, &tm,
+ sizeof tm)) {
+ spin_unlock(&rtc_lock);
+ return -EFAULT;
}
- case RTC_SET_TIME:
- {
-#ifdef CONFIG_ETRAX_RTC_READONLY
+ 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;
-#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;
- 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;
- /* 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);
- /*
- * 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;
- /* 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;
- 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_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;
- 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;
+ 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);
+ 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 */
- }
+ mutex_unlock(&rtc_lock);
- case RTC_VLOW_RD:
- {
- int vl_bit = 0;
+ 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 (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;
+ if (copy_to_user((int *) arg, &voltage_low, sizeof(int)))
+ return -EFAULT;
+ return 0;
- 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. */
- case RTC_VLOW_SET:
- {
- /* Clear the VL bit in the seconds register */
- int ret = rtc_read(RTC_SECONDS);
+ int ret = rtc_read(RTC_SECONDS);
- rtc_write(RTC_SECONDS, (ret & 0x7F));
+ rtc_write(RTC_SECONDS, (ret & 0x7F));
- return 0;
- }
+ /* Clear the cached value. */
+ voltage_low = 0;
- default:
- return -ENOTTY;
+ return 0;
+ }
+ default:
+ return -ENOTTY;
}
return 0;
}
-int
-pcf8563_open(struct inode *inode, struct file *filp)
+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 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);
+ }
+
return 0;
}
-int
-pcf8563_release(struct inode *inode, struct file *filp)
-{
- return 0;
-}
-
-module_init(pcf8563_init);
+module_init(pcf8563_register);
module_exit(pcf8563_exit);