From 7edf744053873e390d7d05ab0136c5162cf89c27 Mon Sep 17 00:00:00 2001 From: Jesper Nilsson Date: Thu, 24 Jan 2008 14:24:09 +0100 Subject: 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 file changed, 163 insertions(+), 133 deletions(-) (limited to 'arch/cris') diff --git a/arch/cris/arch-v32/drivers/pcf8563.c b/arch/cris/arch-v32/drivers/pcf8563.c index 6dbd700d3d6..53db3870ba0 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 . @@ -26,6 +26,7 @@ #include #include #include +#include #include #include @@ -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); -- cgit v1.2.3