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DS1286: kill BKL

PATCH In review Dmitri Vorobiev 3 participants 7 messages Oct 27, 2008 – Oct 29, 2008

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#0 lore raw

PATCH 1/1 DS1286: kill BKL

Using the Big Kernel Lock in the open() method of the DS1286 RTC driver is redundant, because the driver makes use of it's own spinlock to guarantee serialized access. This patch kills the redundant BKL calls.

---
 drivers/char/ds1286.c |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)
drivers/char/ds1286.c +0 -3
index 0a826d7..3e4c801 100644
@@ -253,7 +253,6 @@ static int ds1286_ioctl(struct inode *inode, struct file *file,
 
 static int ds1286_open(struct inode *inode, struct file *file)
 {
-	lock_kernel();
 	spin_lock_irq(&ds1286_lock);
 
 	if (ds1286_status & RTC_IS_OPEN)
@@ -262,12 +261,10 @@ static int ds1286_open(struct inode *inode, struct file *file)
 	ds1286_status |= RTC_IS_OPEN;
 
 	spin_unlock_irq(&ds1286_lock);
-	unlock_kernel();
 	return 0;
 
 out_busy:
 	spin_lock_irq(&ds1286_lock);
-	unlock_kernel();
 	return -EBUSY;
 }
 
Signature · 1 line
1.5.6.5
#1 lore raw
Quoted 4 lines · Dmitri Vorobiev

Using the Big Kernel Lock in the open() method of the DS1286 RTC driver is redundant, because the driver makes use of it's own spinlock to guarantee serialized access. This patch kills the redundant BKL calls.

I'm about to kill the BKL in the driver even more thoroughly - by killing the entire driver.

Ralf

#2 lore raw

2008/10/27 Ralf Baechle <[email protected]>:

Quoted 9 lines · Dmitri Vorobiev
Quoted 5 lines

Using the Big Kernel Lock in the open() method of the DS1286 RTC driver is redundant, because the driver makes use of it's own spinlock to guarantee serialized access. This patch kills the redundant BKL calls.

I'm about to kill the BKL in the driver even more thoroughly - by killing the entire driver.

Good idea ;)

Dmitri

Quoted 4 lines

Ralf

#3 lore raw

PATCH 1/1 CHAR: Delete old and now unused M48T35 RTC driver for SGI IP27.

It was only used by this one SGI platform which recently was converted to RTC_LIB and with RTC_LIB enabled the legacy drivers are no more selectable.

---
 arch/mips/configs/ip27_defconfig |    1 -
 arch/mips/include/asm/m48t35.h   |   27 ---
 drivers/char/Kconfig             |   11 --
 drivers/char/Makefile            |    1 -
 drivers/char/ip27-rtc.c          |  329 --------------------------------------
 5 files changed, 0 insertions(+), 369 deletions(-)
arch/mips/configs/ip27_defconfig +0 -1
index 831d3e5..34ea319 100644
@@ -701,7 +701,6 @@ CONFIG_LEGACY_PTY_COUNT=256
 # CONFIG_WATCHDOG is not set
 CONFIG_HW_RANDOM=m
 # CONFIG_RTC is not set
-CONFIG_SGI_IP27_RTC=y
 # CONFIG_R3964 is not set
 # CONFIG_APPLICOM is not set
 # CONFIG_DRM is not set
arch/mips/include/asm/m48t35.h deleted +0 -27
deleted file mode 100644
index f44852e..0000000
@@ -1,27 +0,0 @@
-/*
- *  Registers for the SGS-Thomson M48T35 Timekeeper RAM chip
- */
-#ifndef _ASM_M48T35_H
-#define _ASM_M48T35_H
-
-#include <linux/spinlock.h>
-
-extern spinlock_t rtc_lock;
-
-struct m48t35_rtc {
-	volatile u8	pad[0x7ff8];    /* starts at 0x7ff8 */
-	volatile u8	control;
-	volatile u8	sec;
-	volatile u8	min;
-	volatile u8	hour;
-	volatile u8	day;
-	volatile u8	date;
-	volatile u8	month;
-	volatile u8	year;
-};
-
-#define M48T35_RTC_SET		0x80
-#define M48T35_RTC_STOPPED	0x80
-#define M48T35_RTC_READ		0x40
-
-#endif /* _ASM_M48T35_H */
drivers/char/Kconfig +0 -11
index 9d2c436..43b35d0 100644
@@ -812,17 +812,6 @@ config JS_RTC
 	  To compile this driver as a module, choose M here: the
 	  module will be called js-rtc.
 
-config SGI_IP27_RTC
-	bool "SGI M48T35 RTC support"
-	depends on SGI_IP27
-	help
-	  If you say Y here and create a character special file /dev/rtc with
-	  major number 10 and minor number 135 using mknod ("man mknod"), you
-	  will get access to the real time clock built into your computer.
-	  Every SGI has such a clock built in. It reports status information
-	  via the file /proc/rtc and its behaviour is set by various ioctls on
-	  /dev/rtc.
-
 config GEN_RTC
 	tristate "Generic /dev/rtc emulation"
 	depends on RTC!=y && !IA64 && !ARM && !M32R && !MIPS && !SPARC && !FRV && !S390 && !SUPERH && !AVR32
drivers/char/Makefile +0 -1
index 917f0f4..438f713 100644
@@ -74,7 +74,6 @@ obj-$(CONFIG_RTC)		+= rtc.o
 obj-$(CONFIG_HPET)		+= hpet.o
 obj-$(CONFIG_GEN_RTC)		+= genrtc.o
 obj-$(CONFIG_EFI_RTC)		+= efirtc.o
-obj-$(CONFIG_SGI_IP27_RTC)	+= ip27-rtc.o
 obj-$(CONFIG_DS1302)		+= ds1302.o
 obj-$(CONFIG_XILINX_HWICAP)	+= xilinx_hwicap/
 ifeq ($(CONFIG_GENERIC_NVRAM),y)
drivers/char/ip27-rtc.c deleted +0 -329

329 lines not on this page · raw message

#5 lore raw

PATCH 1/1 CHAR: Delete old and now unused DS1286 driver.

In reply to Dmitri Vorobiev

It was only used by two SGI platforms which recently were converted to RTC_LIB and with RTC_LIB enabled the legacy drivers are no more selectable.

---
 arch/mips/Kconfig                |    5 -
 arch/mips/configs/ip22_defconfig |    1 -
 arch/mips/configs/ip28_defconfig |    2 -
 drivers/char/Kconfig             |   11 -
 drivers/char/Makefile            |    1 -
 drivers/char/ds1286.c            |  585 --------------------------------------
 6 files changed, 0 insertions(+), 605 deletions(-)
arch/mips/Kconfig +0 -5
index 653574b..f4af967 100644
@@ -327,7 +327,6 @@ config SGI_IP22
 	select IP22_CPU_SCACHE
 	select IRQ_CPU
 	select GENERIC_ISA_DMA_SUPPORT_BROKEN
-	select SGI_HAS_DS1286
 	select SGI_HAS_I8042
 	select SGI_HAS_INDYDOG
 	select SGI_HAS_HAL2
@@ -382,7 +381,6 @@ config SGI_IP28
 	select HW_HAS_EISA
 	select I8253
 	select I8259
-	select SGI_HAS_DS1286
 	select SGI_HAS_I8042
 	select SGI_HAS_INDYDOG
 	select SGI_HAS_HAL2
@@ -893,9 +891,6 @@ config EMMA2RH
 config SERIAL_RM9000
 	bool
 
-config SGI_HAS_DS1286
-	bool
-
 config SGI_HAS_INDYDOG
 	bool
 
arch/mips/configs/ip22_defconfig +0 -1
index cc8e6bf..f719bf5 100644
@@ -771,7 +771,6 @@ CONFIG_WATCHDOG=y
 CONFIG_INDYDOG=m
 # CONFIG_HW_RANDOM is not set
 # CONFIG_RTC is not set
-CONFIG_SGI_DS1286=m
 # CONFIG_R3964 is not set
 CONFIG_RAW_DRIVER=m
 CONFIG_MAX_RAW_DEVS=256
arch/mips/configs/ip28_defconfig +0 -2
index 822b01f..70a744e 100644
@@ -70,7 +70,6 @@ CONFIG_CPU_BIG_ENDIAN=y
 CONFIG_SYS_SUPPORTS_BIG_ENDIAN=y
 CONFIG_IRQ_CPU=y
 CONFIG_SWAP_IO_SPACE=y
-CONFIG_SGI_HAS_DS1286=y
 CONFIG_SGI_HAS_INDYDOG=y
 CONFIG_SGI_HAS_SEEQ=y
 CONFIG_SGI_HAS_WD93=y
@@ -585,7 +584,6 @@ CONFIG_LEGACY_PTY_COUNT=256
 # CONFIG_IPMI_HANDLER is not set
 # CONFIG_HW_RANDOM is not set
 # CONFIG_RTC is not set
-CONFIG_SGI_DS1286=y
 # CONFIG_DTLK is not set
 # CONFIG_R3964 is not set
 # CONFIG_RAW_DRIVER is not set
drivers/char/Kconfig +0 -11
index 1222541..9d2c436 100644
@@ -812,17 +812,6 @@ config JS_RTC
 	  To compile this driver as a module, choose M here: the
 	  module will be called js-rtc.
 
-config SGI_DS1286
-	tristate "SGI DS1286 RTC support"
-	depends on SGI_HAS_DS1286
-	help
-	  If you say Y here and create a character special file /dev/rtc with
-	  major number 10 and minor number 135 using mknod ("man mknod"), you
-	  will get access to the real time clock built into your computer.
-	  Every SGI has such a clock built in. It reports status information
-	  via the file /proc/rtc and its behaviour is set by various ioctls on
-	  /dev/rtc.
-
 config SGI_IP27_RTC
 	bool "SGI M48T35 RTC support"
 	depends on SGI_IP27
drivers/char/Makefile +0 -1
index 1a4247d..917f0f4 100644
@@ -74,7 +74,6 @@ obj-$(CONFIG_RTC)		+= rtc.o
 obj-$(CONFIG_HPET)		+= hpet.o
 obj-$(CONFIG_GEN_RTC)		+= genrtc.o
 obj-$(CONFIG_EFI_RTC)		+= efirtc.o
-obj-$(CONFIG_SGI_DS1286)	+= ds1286.o
 obj-$(CONFIG_SGI_IP27_RTC)	+= ip27-rtc.o
 obj-$(CONFIG_DS1302)		+= ds1302.o
 obj-$(CONFIG_XILINX_HWICAP)	+= xilinx_hwicap/
drivers/char/ds1286.c deleted +0 -585

585 lines not on this page · raw message

Acked-by on v1 1/1
#6 lore raw

Re: [PATCH] CHAR: Delete old and now unused DS1286 driver.

2008/10/27 Ralf Baechle <[email protected]>:

Quoted 4 lines

It was only used by two SGI platforms which recently were converted to RTC_LIB and with RTC_LIB enabled the legacy drivers are no more selectable.

Quoted 698 lines
---
 arch/mips/Kconfig                |    5 -
 arch/mips/configs/ip22_defconfig |    1 -
 arch/mips/configs/ip28_defconfig |    2 -
 drivers/char/Kconfig             |   11 -
 drivers/char/Makefile            |    1 -
 drivers/char/ds1286.c            |  585 --------------------------------------
 6 files changed, 0 insertions(+), 605 deletions(-)
arch/mips/Kconfig +0 -5
index 653574b..f4af967 100644
@@ -327,7 +327,6 @@ config SGI_IP22
       select IP22_CPU_SCACHE
       select IRQ_CPU
       select GENERIC_ISA_DMA_SUPPORT_BROKEN
-       select SGI_HAS_DS1286
       select SGI_HAS_I8042
       select SGI_HAS_INDYDOG
       select SGI_HAS_HAL2
@@ -382,7 +381,6 @@ config SGI_IP28
       select HW_HAS_EISA
       select I8253
       select I8259
-       select SGI_HAS_DS1286
       select SGI_HAS_I8042
       select SGI_HAS_INDYDOG
       select SGI_HAS_HAL2
@@ -893,9 +891,6 @@ config EMMA2RH
 config SERIAL_RM9000
       bool
 
-config SGI_HAS_DS1286
-       bool
-
 config SGI_HAS_INDYDOG
       bool
 
arch/mips/configs/ip22_defconfig +0 -1
index cc8e6bf..f719bf5 100644
@@ -771,7 +771,6 @@ CONFIG_WATCHDOG=y
 CONFIG_INDYDOG=m
 # CONFIG_HW_RANDOM is not set
 # CONFIG_RTC is not set
-CONFIG_SGI_DS1286=m
 # CONFIG_R3964 is not set
 CONFIG_RAW_DRIVER=m
 CONFIG_MAX_RAW_DEVS=256
arch/mips/configs/ip28_defconfig +0 -2
index 822b01f..70a744e 100644
@@ -70,7 +70,6 @@ CONFIG_CPU_BIG_ENDIAN=y
 CONFIG_SYS_SUPPORTS_BIG_ENDIAN=y
 CONFIG_IRQ_CPU=y
 CONFIG_SWAP_IO_SPACE=y
-CONFIG_SGI_HAS_DS1286=y
 CONFIG_SGI_HAS_INDYDOG=y
 CONFIG_SGI_HAS_SEEQ=y
 CONFIG_SGI_HAS_WD93=y
@@ -585,7 +584,6 @@ CONFIG_LEGACY_PTY_COUNT=256
 # CONFIG_IPMI_HANDLER is not set
 # CONFIG_HW_RANDOM is not set
 # CONFIG_RTC is not set
-CONFIG_SGI_DS1286=y
 # CONFIG_DTLK is not set
 # CONFIG_R3964 is not set
 # CONFIG_RAW_DRIVER is not set
drivers/char/Kconfig +0 -11
index 1222541..9d2c436 100644
@@ -812,17 +812,6 @@ config JS_RTC
         To compile this driver as a module, choose M here: the
         module will be called js-rtc.
 
-config SGI_DS1286
-       tristate "SGI DS1286 RTC support"
-       depends on SGI_HAS_DS1286
-       help
-         If you say Y here and create a character special file /dev/rtc with
-         major number 10 and minor number 135 using mknod ("man mknod"), you
-         will get access to the real time clock built into your computer.
-         Every SGI has such a clock built in. It reports status information
-         via the file /proc/rtc and its behaviour is set by various ioctls on
-         /dev/rtc.
-
 config SGI_IP27_RTC
       bool "SGI M48T35 RTC support"
       depends on SGI_IP27
drivers/char/Makefile +0 -1
index 1a4247d..917f0f4 100644
@@ -74,7 +74,6 @@ obj-$(CONFIG_RTC)             += rtc.o
 obj-$(CONFIG_HPET)             += hpet.o
 obj-$(CONFIG_GEN_RTC)          += genrtc.o
 obj-$(CONFIG_EFI_RTC)          += efirtc.o
-obj-$(CONFIG_SGI_DS1286)       += ds1286.o
 obj-$(CONFIG_SGI_IP27_RTC)     += ip27-rtc.o
 obj-$(CONFIG_DS1302)           += ds1302.o
 obj-$(CONFIG_XILINX_HWICAP)    += xilinx_hwicap/
drivers/char/ds1286.c deleted +0 -585
deleted file mode 100644
index 0a826d7..0000000
@@ -1,585 +0,0 @@
-/*
- * DS1286 Real Time Clock interface for Linux
- *
- * Copyright (C) 1998, 1999, 2000 Ralf Baechle
- *
- * Based on code written by Paul Gortmaker.
- *
- * This driver allows use of the real time clock (built into nearly all
- * computers) from user space. It exports the /dev/rtc interface supporting
- * various ioctl() and also the /proc/rtc pseudo-file for status
- * information.
- *
- * The ioctls can be used to set the interrupt behaviour and generation rate
- * from the RTC via IRQ 8. Then the /dev/rtc interface can be used to make
- * use of these timer interrupts, be they interval or alarm based.
- *
- * The /dev/rtc interface will block on reads until an interrupt has been
- * received. If a RTC interrupt has already happened, it will output an
- * unsigned long and then block. The output value contains the interrupt
- * status in the low byte and the number of interrupts since the last read
- * in the remaining high bytes. The /dev/rtc interface can also be used with
- * the select(2) call.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2 of the License, or (at your
- * option) any later version.
- */
-#include <linux/ds1286.h>
-#include <linux/smp_lock.h>
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/miscdevice.h>
-#include <linux/slab.h>
-#include <linux/ioport.h>
-#include <linux/fcntl.h>
-#include <linux/init.h>
-#include <linux/poll.h>
-#include <linux/rtc.h>
-#include <linux/spinlock.h>
-#include <linux/bcd.h>
-#include <linux/proc_fs.h>
-#include <linux/jiffies.h>
-
-#include <asm/uaccess.h>
-#include <asm/system.h>
-
-#define DS1286_VERSION         "1.0"
-
-/*
- *     We sponge a minor off of the misc major. No need slurping
- *     up another valuable major dev number for this. If you add
- *     an ioctl, make sure you don't conflict with SPARC's RTC
- *     ioctls.
- */
-
-static DECLARE_WAIT_QUEUE_HEAD(ds1286_wait);
-
-static ssize_t ds1286_read(struct file *file, char *buf,
-                       size_t count, loff_t *ppos);
-
-static int ds1286_ioctl(struct inode *inode, struct file *file,
-                        unsigned int cmd, unsigned long arg);
-
-static unsigned int ds1286_poll(struct file *file, poll_table *wait);
-
-static void ds1286_get_alm_time (struct rtc_time *alm_tm);
-static void ds1286_get_time(struct rtc_time *rtc_tm);
-static int ds1286_set_time(struct rtc_time *rtc_tm);
-
-static inline unsigned char ds1286_is_updating(void);
-
-static DEFINE_SPINLOCK(ds1286_lock);
-
-static int ds1286_read_proc(char *page, char **start, off_t off,
-                            int count, int *eof, void *data);
-
-/*
- *     Bits in rtc_status. (7 bits of room for future expansion)
- */
-
-#define RTC_IS_OPEN            0x01    /* means /dev/rtc is in use     */
-#define RTC_TIMER_ON           0x02    /* missed irq timer active      */
-
-static unsigned char ds1286_status;    /* bitmapped status byte.       */
-
-static unsigned char days_in_mo[] = {
-       0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
-};
-
-/*
- *     Now all the various file operations that we export.
- */
-
-static ssize_t ds1286_read(struct file *file, char *buf,
-                           size_t count, loff_t *ppos)
-{
-       return -EIO;
-}
-
-static int ds1286_ioctl(struct inode *inode, struct file *file,
-                        unsigned int cmd, unsigned long arg)
-{
-       struct rtc_time wtime;
-
-       switch (cmd) {
-       case RTC_AIE_OFF:       /* Mask alarm int. enab. bit    */
-       {
-               unsigned long flags;
-               unsigned char val;
-
-               if (!capable(CAP_SYS_TIME))
-                       return -EACCES;
-
-               spin_lock_irqsave(&ds1286_lock, flags);
-               val = rtc_read(RTC_CMD);
-               val |=  RTC_TDM;
-               rtc_write(val, RTC_CMD);
-               spin_unlock_irqrestore(&ds1286_lock, flags);
-
-               return 0;
-       }
-       case RTC_AIE_ON:        /* Allow alarm interrupts.      */
-       {
-               unsigned long flags;
-               unsigned char val;
-
-               if (!capable(CAP_SYS_TIME))
-                       return -EACCES;
-
-               spin_lock_irqsave(&ds1286_lock, flags);
-               val = rtc_read(RTC_CMD);
-               val &=  ~RTC_TDM;
-               rtc_write(val, RTC_CMD);
-               spin_unlock_irqrestore(&ds1286_lock, flags);
-
-               return 0;
-       }
-       case RTC_WIE_OFF:       /* Mask watchdog int. enab. bit */
-       {
-               unsigned long flags;
-               unsigned char val;
-
-               if (!capable(CAP_SYS_TIME))
-                       return -EACCES;
-
-               spin_lock_irqsave(&ds1286_lock, flags);
-               val = rtc_read(RTC_CMD);
-               val |= RTC_WAM;
-               rtc_write(val, RTC_CMD);
-               spin_unlock_irqrestore(&ds1286_lock, flags);
-
-               return 0;
-       }
-       case RTC_WIE_ON:        /* Allow watchdog interrupts.   */
-       {
-               unsigned long flags;
-               unsigned char val;
-
-               if (!capable(CAP_SYS_TIME))
-                       return -EACCES;
-
-               spin_lock_irqsave(&ds1286_lock, flags);
-               val = rtc_read(RTC_CMD);
-               val &= ~RTC_WAM;
-               rtc_write(val, RTC_CMD);
-               spin_unlock_irqrestore(&ds1286_lock, flags);
-
-               return 0;
-       }
-       case RTC_ALM_READ:      /* Read the present alarm time */
-       {
-               /*
-                * This returns a struct rtc_time. Reading >= 0xc0
-                * means "don't care" or "match all". Only the tm_hour,
-                * tm_min, and tm_sec values are filled in.
-                */
-
-               memset(&wtime, 0, sizeof(wtime));
-               ds1286_get_alm_time(&wtime);
-               break;
-       }
-       case RTC_ALM_SET:       /* Store a time into the alarm */
-       {
-               /*
-                * This expects a struct rtc_time. Writing 0xff means
-                * "don't care" or "match all". Only the tm_hour,
-                * tm_min and tm_sec are used.
-                */
-               unsigned char hrs, min, sec;
-               struct rtc_time alm_tm;
-
-               if (!capable(CAP_SYS_TIME))
-                       return -EACCES;
-
-               if (copy_from_user(&alm_tm, (struct rtc_time*)arg,
-                                  sizeof(struct rtc_time)))
-                       return -EFAULT;
-
-               hrs = alm_tm.tm_hour;
-               min = alm_tm.tm_min;
-               sec = alm_tm.tm_sec;
-
-               if (hrs >= 24)
-                       hrs = 0xff;
-
-               if (min >= 60)
-                       min = 0xff;
-
-               if (sec != 0)
-                       return -EINVAL;
-
-               min = bin2bcd(min);
-               min = bin2bcd(hrs);
-
-               spin_lock(&ds1286_lock);
-               rtc_write(hrs, RTC_HOURS_ALARM);
-               rtc_write(min, RTC_MINUTES_ALARM);
-               spin_unlock(&ds1286_lock);
-
-               return 0;
-       }
-       case RTC_RD_TIME:       /* Read the time/date from RTC  */
-       {
-               memset(&wtime, 0, sizeof(wtime));
-               ds1286_get_time(&wtime);
-               break;
-       }
-       case RTC_SET_TIME:      /* Set the RTC */
-       {
-               struct rtc_time rtc_tm;
-
-               if (!capable(CAP_SYS_TIME))
-                       return -EACCES;
-
-               if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
-                                  sizeof(struct rtc_time)))
-                       return -EFAULT;
-
-               return ds1286_set_time(&rtc_tm);
-       }
-       default:
-               return -EINVAL;
-       }
-       return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
-}
-
-/*
- *     We enforce only one user at a time here with the open/close.
- *     Also clear the previous interrupt data on an open, and clean
- *     up things on a close.
- */
-
-static int ds1286_open(struct inode *inode, struct file *file)
-{
-       lock_kernel();
-       spin_lock_irq(&ds1286_lock);
-
-       if (ds1286_status & RTC_IS_OPEN)
-               goto out_busy;
-
-       ds1286_status |= RTC_IS_OPEN;
-
-       spin_unlock_irq(&ds1286_lock);
-       unlock_kernel();
-       return 0;
-
-out_busy:
-       spin_lock_irq(&ds1286_lock);
-       unlock_kernel();
-       return -EBUSY;
-}
-
-static int ds1286_release(struct inode *inode, struct file *file)
-{
-       ds1286_status &= ~RTC_IS_OPEN;
-
-       return 0;
-}
-
-static unsigned int ds1286_poll(struct file *file, poll_table *wait)
-{
-       poll_wait(file, &ds1286_wait, wait);
-
-       return 0;
-}
-
-/*
- *     The various file operations we support.
- */
-
-static const struct file_operations ds1286_fops = {
-       .llseek         = no_llseek,
-       .read           = ds1286_read,
-       .poll           = ds1286_poll,
-       .ioctl          = ds1286_ioctl,
-       .open           = ds1286_open,
-       .release        = ds1286_release,
-};
-
-static struct miscdevice ds1286_dev=
-{
-       .minor  = RTC_MINOR,
-       .name   = "rtc",
-       .fops   = &ds1286_fops,
-};
-
-static int __init ds1286_init(void)
-{
-       int err;
-
-       printk(KERN_INFO "DS1286 Real Time Clock Driver v%s\n", DS1286_VERSION);
-
-       err = misc_register(&ds1286_dev);
-       if (err)
-               goto out;
-
-       if (!create_proc_read_entry("driver/rtc", 0, 0, ds1286_read_proc, NULL)) {
-               err = -ENOMEM;
-
-               goto out_deregister;
-       }
-
-       return 0;
-
-out_deregister:
-       misc_deregister(&ds1286_dev);
-
-out:
-       return err;
-}
-
-static void __exit ds1286_exit(void)
-{
-       remove_proc_entry("driver/rtc", NULL);
-       misc_deregister(&ds1286_dev);
-}
-
-static char *days[] = {
-       "***", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
-};
-
-/*
- *     Info exported via "/proc/rtc".
- */
-static int ds1286_proc_output(char *buf)
-{
-       char *p, *s;
-       struct rtc_time tm;
-       unsigned char hundredth, month, cmd, amode;
-
-       p = buf;
-
-       ds1286_get_time(&tm);
-       hundredth = rtc_read(RTC_HUNDREDTH_SECOND);
-       hundredth = bcd2bin(hundredth);
-
-       p += sprintf(p,
-                    "rtc_time\t: %02d:%02d:%02d.%02d\n"
-                    "rtc_date\t: %04d-%02d-%02d\n",
-                    tm.tm_hour, tm.tm_min, tm.tm_sec, hundredth,
-                    tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
-
-       /*
-        * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
-        * match any value for that particular field. Values that are
-        * greater than a valid time, but less than 0xc0 shouldn't appear.
-        */
-       ds1286_get_alm_time(&tm);
-       p += sprintf(p, "alarm\t\t: %s ", days[tm.tm_wday]);
-       if (tm.tm_hour <= 24)
-               p += sprintf(p, "%02d:", tm.tm_hour);
-       else
-               p += sprintf(p, "**:");
-
-       if (tm.tm_min <= 59)
-               p += sprintf(p, "%02d\n", tm.tm_min);
-       else
-               p += sprintf(p, "**\n");
-
-       month = rtc_read(RTC_MONTH);
-       p += sprintf(p,
-                    "oscillator\t: %s\n"
-                    "square_wave\t: %s\n",
-                    (month & RTC_EOSC) ? "disabled" : "enabled",
-                    (month & RTC_ESQW) ? "disabled" : "enabled");
-
-       amode = ((rtc_read(RTC_MINUTES_ALARM) & 0x80) >> 5) |
-               ((rtc_read(RTC_HOURS_ALARM) & 0x80) >> 6) |
-               ((rtc_read(RTC_DAY_ALARM) & 0x80) >> 7);
-       if (amode == 7)      s = "each minute";
-       else if (amode == 3) s = "minutes match";
-       else if (amode == 1) s = "hours and minutes match";
-       else if (amode == 0) s = "days, hours and minutes match";
-       else                 s = "invalid";
-       p += sprintf(p, "alarm_mode\t: %s\n", s);
-
-       cmd = rtc_read(RTC_CMD);
-       p += sprintf(p,
-                    "alarm_enable\t: %s\n"
-                    "wdog_alarm\t: %s\n"
-                    "alarm_mask\t: %s\n"
-                    "wdog_alarm_mask\t: %s\n"
-                    "interrupt_mode\t: %s\n"
-                    "INTB_mode\t: %s_active\n"
-                    "interrupt_pins\t: %s\n",
-                    (cmd & RTC_TDF) ? "yes" : "no",
-                    (cmd & RTC_WAF) ? "yes" : "no",
-                    (cmd & RTC_TDM) ? "disabled" : "enabled",
-                    (cmd & RTC_WAM) ? "disabled" : "enabled",
-                    (cmd & RTC_PU_LVL) ? "pulse" : "level",
-                    (cmd & RTC_IBH_LO) ? "low" : "high",
-                    (cmd & RTC_IPSW) ? "unswapped" : "swapped");
-
-       return  p - buf;
-}
-
-static int ds1286_read_proc(char *page, char **start, off_t off,
-                         int count, int *eof, void *data)
-{
-       int len = ds1286_proc_output (page);
-       if (len <= off+count) *eof = 1;
-       *start = page + off;
-       len -= off;
-       if (len>count)
-               len = count;
-       if (len<0)
-               len = 0;
-
-       return len;
-}
-
-/*
- * Returns true if a clock update is in progress
- */
-static inline unsigned char ds1286_is_updating(void)
-{
-       return rtc_read(RTC_CMD) & RTC_TE;
-}
-
-
-static void ds1286_get_time(struct rtc_time *rtc_tm)
-{
-       unsigned char save_control;
-       unsigned long flags;
-
-       /*
-        * read RTC once any update in progress is done. The update
-        * can take just over 2ms. We wait 10 to 20ms. There is no need to
-        * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
-        * If you need to know *exactly* when a second has started, enable
-        * periodic update complete interrupts, (via ioctl) and then
-        * immediately read /dev/rtc which will block until you get the IRQ.
-        * Once the read clears, read the RTC time (again via ioctl). Easy.
-        */
-
-       if (ds1286_is_updating() != 0)
-               msleep(20);
-
-       /*
-        * Only the values that we read from the RTC are set. We leave
-        * tm_wday, tm_yday and tm_isdst untouched. Even though the
-        * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
-        * by the RTC when initially set to a non-zero value.
-        */
-       spin_lock_irqsave(&ds1286_lock, flags);
-       save_control = rtc_read(RTC_CMD);
-       rtc_write((save_control|RTC_TE), RTC_CMD);
-
-       rtc_tm->tm_sec = rtc_read(RTC_SECONDS);
-       rtc_tm->tm_min = rtc_read(RTC_MINUTES);
-       rtc_tm->tm_hour = rtc_read(RTC_HOURS) & 0x3f;
-       rtc_tm->tm_mday = rtc_read(RTC_DATE);
-       rtc_tm->tm_mon = rtc_read(RTC_MONTH) & 0x1f;
-       rtc_tm->tm_year = rtc_read(RTC_YEAR);
-
-       rtc_write(save_control, RTC_CMD);
-       spin_unlock_irqrestore(&ds1286_lock, flags);
-
-       rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
-       rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
-       rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
-       rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
-       rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
-       rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
-
-       /*
-        * Account for differences between how the RTC uses the values
-        * and how they are defined in a struct rtc_time;
-        */
-       if (rtc_tm->tm_year < 45)
-               rtc_tm->tm_year += 30;
-       if ((rtc_tm->tm_year += 40) < 70)
-               rtc_tm->tm_year += 100;
-
-       rtc_tm->tm_mon--;
-}
-
-static int ds1286_set_time(struct rtc_time *rtc_tm)
-{
-       unsigned char mon, day, hrs, min, sec, leap_yr;
-       unsigned char save_control;
-       unsigned int yrs;
-       unsigned long flags;
-
-
-       yrs = rtc_tm->tm_year + 1900;
-       mon = rtc_tm->tm_mon + 1;   /* tm_mon starts at zero */
-       day = rtc_tm->tm_mday;
-       hrs = rtc_tm->tm_hour;
-       min = rtc_tm->tm_min;
-       sec = rtc_tm->tm_sec;
-
-       if (yrs < 1970)
-               return -EINVAL;
-
-       leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
-
-       if ((mon > 12) || (day == 0))
-               return -EINVAL;
-
-       if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
-               return -EINVAL;
-
-       if ((hrs >= 24) || (min >= 60) || (sec >= 60))
-               return -EINVAL;
-
-       if ((yrs -= 1940) > 255)    /* They are unsigned */
-               return -EINVAL;
-
-       if (yrs >= 100)
-               yrs -= 100;
-
-       sec = bin2bcd(sec);
-       min = bin2bcd(min);
-       hrs = bin2bcd(hrs);
-       day = bin2bcd(day);
-       mon = bin2bcd(mon);
-       yrs = bin2bcd(yrs);
-
-       spin_lock_irqsave(&ds1286_lock, flags);
-       save_control = rtc_read(RTC_CMD);
-       rtc_write((save_control|RTC_TE), RTC_CMD);
-
-       rtc_write(yrs, RTC_YEAR);
-       rtc_write(mon, RTC_MONTH);
-       rtc_write(day, RTC_DATE);
-       rtc_write(hrs, RTC_HOURS);
-       rtc_write(min, RTC_MINUTES);
-       rtc_write(sec, RTC_SECONDS);
-       rtc_write(0, RTC_HUNDREDTH_SECOND);
-
-       rtc_write(save_control, RTC_CMD);
-       spin_unlock_irqrestore(&ds1286_lock, flags);
-
-       return 0;
-}
-
-static void ds1286_get_alm_time(struct rtc_time *alm_tm)
-{
-       unsigned char cmd;
-       unsigned long flags;
-
-       /*
-        * Only the values that we read from the RTC are set. That
-        * means only tm_wday, tm_hour, tm_min.
-        */
-       spin_lock_irqsave(&ds1286_lock, flags);
-       alm_tm->tm_min = rtc_read(RTC_MINUTES_ALARM) & 0x7f;
-       alm_tm->tm_hour = rtc_read(RTC_HOURS_ALARM)  & 0x1f;
-       alm_tm->tm_wday = rtc_read(RTC_DAY_ALARM)    & 0x07;
-       cmd = rtc_read(RTC_CMD);
-       spin_unlock_irqrestore(&ds1286_lock, flags);
-
-       alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
-       alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
-       alm_tm->tm_sec = 0;
-}
-
-module_init(ds1286_init);
-module_exit(ds1286_exit);
-
-MODULE_AUTHOR("Ralf Baechle");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(RTC_MINOR);