Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=7edf744053873e390d7d05ab0136c5162cf89c27
Commit:     7edf744053873e390d7d05ab0136c5162cf89c27
Parent:     d8ac17a0eeab6580cced355de85ac90227096bb9
Author:     Jesper Nilsson <[EMAIL PROTECTED]>
AuthorDate: Thu Jan 24 14:24:09 2008 +0100
Committer:  Jesper Nilsson <[EMAIL PROTECTED]>
CommitDate: Fri Feb 8 11:06:34 2008 +0100

    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
---
 arch/cris/arch-v32/drivers/pcf8563.c |  296 +++++++++++++++++++---------------
 1 files changed, 163 insertions(+), 133 deletions(-)

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 <[EMAIL PROTECTED]>.
@@ -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)
@@ -211,125 +219,147 @@ pcf8563_ioctl(struct inode *inode, struct file *filp, 
unsigned int cmd, unsigned
                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_RD_TIME:
+       {
+               struct 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)) {
+                       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;
-
-                       /* 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 (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_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. */
+               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);
+
+               mutex_unlock(&rtc_lock);
+
+               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)
 {
-       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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