mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
539 lines
13 KiB
C
539 lines
13 KiB
C
/*
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* Real Time Clock interface for
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* - q40 and other m68k machines,
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* - HP PARISC machines
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* - PowerPC machines
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* emulate some RTC irq capabilities in software
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*
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* Copyright (C) 1999 Richard Zidlicky
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*
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* based on Paul Gortmaker's rtc.c device and
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* Sam Creasey Generic rtc driver
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*
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* This driver allows use of the real time clock (built into
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* nearly all computers) from user space. It exports the /dev/rtc
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* interface supporting various ioctl() and also the /proc/driver/rtc
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* pseudo-file for status information.
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*
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* The ioctls can be used to set the interrupt behaviour where
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* supported.
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*
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* The /dev/rtc interface will block on reads until an interrupt
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* has been received. If a RTC interrupt has already happened,
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* it will output an unsigned long and then block. The output value
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* contains the interrupt status in the low byte and the number of
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* interrupts since the last read in the remaining high bytes. The
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* /dev/rtc interface can also be used with the select(2) call.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* 1.01 fix for 2.3.X rz@linux-m68k.org
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* 1.02 merged with code from genrtc.c rz@linux-m68k.org
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* 1.03 make it more portable zippel@linux-m68k.org
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* 1.04 removed useless timer code rz@linux-m68k.org
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* 1.05 portable RTC_UIE emulation rz@linux-m68k.org
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* 1.06 set_rtc_time can return an error trini@kernel.crashing.org
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* 1.07 ported to HP PARISC (hppa) Helge Deller <deller@gmx.de>
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*/
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#define RTC_VERSION "1.07"
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/miscdevice.h>
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#include <linux/fcntl.h>
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#include <linux/rtc.h>
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#include <linux/init.h>
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#include <linux/poll.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/mutex.h>
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#include <linux/workqueue.h>
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#include <asm/uaccess.h>
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#include <asm/rtc.h>
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/*
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* We sponge a minor off of the misc major. No need slurping
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* up another valuable major dev number for this. If you add
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* an ioctl, make sure you don't conflict with SPARC's RTC
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* ioctls.
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*/
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static DEFINE_MUTEX(gen_rtc_mutex);
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static DECLARE_WAIT_QUEUE_HEAD(gen_rtc_wait);
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/*
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* Bits in gen_rtc_status.
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*/
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#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
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static unsigned char gen_rtc_status; /* bitmapped status byte. */
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static unsigned long gen_rtc_irq_data; /* our output to the world */
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/* months start at 0 now */
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static unsigned char days_in_mo[] =
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{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
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static int irq_active;
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#ifdef CONFIG_GEN_RTC_X
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static struct work_struct genrtc_task;
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static struct timer_list timer_task;
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static unsigned int oldsecs;
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static int lostint;
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static unsigned long tt_exp;
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static void gen_rtc_timer(unsigned long data);
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static volatile int stask_active; /* schedule_work */
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static volatile int ttask_active; /* timer_task */
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static int stop_rtc_timers; /* don't requeue tasks */
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static DEFINE_SPINLOCK(gen_rtc_lock);
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static void gen_rtc_interrupt(unsigned long arg);
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/*
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* Routine to poll RTC seconds field for change as often as possible,
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* after first RTC_UIE use timer to reduce polling
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*/
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static void genrtc_troutine(struct work_struct *work)
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{
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unsigned int tmp = get_rtc_ss();
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if (stop_rtc_timers) {
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stask_active = 0;
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return;
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}
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if (oldsecs != tmp){
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oldsecs = tmp;
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timer_task.function = gen_rtc_timer;
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timer_task.expires = jiffies + HZ - (HZ/10);
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tt_exp=timer_task.expires;
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ttask_active=1;
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stask_active=0;
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add_timer(&timer_task);
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gen_rtc_interrupt(0);
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} else if (schedule_work(&genrtc_task) == 0)
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stask_active = 0;
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}
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static void gen_rtc_timer(unsigned long data)
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{
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lostint = get_rtc_ss() - oldsecs ;
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if (lostint<0)
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lostint = 60 - lostint;
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if (time_after(jiffies, tt_exp))
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printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n",
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jiffies-tt_exp);
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ttask_active=0;
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stask_active=1;
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if ((schedule_work(&genrtc_task) == 0))
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stask_active = 0;
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}
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/*
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* call gen_rtc_interrupt function to signal an RTC_UIE,
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* arg is unused.
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* Could be invoked either from a real interrupt handler or
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* from some routine that periodically (eg 100HZ) monitors
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* whether RTC_SECS changed
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*/
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static void gen_rtc_interrupt(unsigned long arg)
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{
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/* We store the status in the low byte and the number of
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* interrupts received since the last read in the remainder
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* of rtc_irq_data. */
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gen_rtc_irq_data += 0x100;
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gen_rtc_irq_data &= ~0xff;
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gen_rtc_irq_data |= RTC_UIE;
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if (lostint){
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printk("genrtc: system delaying clock ticks?\n");
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/* increment count so that userspace knows something is wrong */
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gen_rtc_irq_data += ((lostint-1)<<8);
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lostint = 0;
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}
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wake_up_interruptible(&gen_rtc_wait);
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}
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/*
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* Now all the various file operations that we export.
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*/
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static ssize_t gen_rtc_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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{
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unsigned long data;
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ssize_t retval;
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if (count != sizeof (unsigned int) && count != sizeof (unsigned long))
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return -EINVAL;
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if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data)
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return -EAGAIN;
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retval = wait_event_interruptible(gen_rtc_wait,
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(data = xchg(&gen_rtc_irq_data, 0)));
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if (retval)
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goto out;
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/* first test allows optimizer to nuke this case for 32-bit machines */
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if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) {
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unsigned int uidata = data;
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retval = put_user(uidata, (unsigned int __user *)buf) ?:
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sizeof(unsigned int);
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}
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else {
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retval = put_user(data, (unsigned long __user *)buf) ?:
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sizeof(unsigned long);
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}
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out:
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return retval;
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}
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static unsigned int gen_rtc_poll(struct file *file,
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struct poll_table_struct *wait)
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{
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poll_wait(file, &gen_rtc_wait, wait);
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if (gen_rtc_irq_data != 0)
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return POLLIN | POLLRDNORM;
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return 0;
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}
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#endif
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/*
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* Used to disable/enable interrupts, only RTC_UIE supported
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* We also clear out any old irq data after an ioctl() that
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* meddles with the interrupt enable/disable bits.
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*/
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static inline void gen_clear_rtc_irq_bit(unsigned char bit)
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{
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#ifdef CONFIG_GEN_RTC_X
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stop_rtc_timers = 1;
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if (ttask_active){
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del_timer_sync(&timer_task);
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ttask_active = 0;
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}
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while (stask_active)
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schedule();
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spin_lock(&gen_rtc_lock);
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irq_active = 0;
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spin_unlock(&gen_rtc_lock);
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#endif
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}
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static inline int gen_set_rtc_irq_bit(unsigned char bit)
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{
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#ifdef CONFIG_GEN_RTC_X
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spin_lock(&gen_rtc_lock);
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if ( !irq_active ) {
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irq_active = 1;
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stop_rtc_timers = 0;
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lostint = 0;
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INIT_WORK(&genrtc_task, genrtc_troutine);
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oldsecs = get_rtc_ss();
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init_timer(&timer_task);
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stask_active = 1;
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if (schedule_work(&genrtc_task) == 0){
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stask_active = 0;
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}
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}
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spin_unlock(&gen_rtc_lock);
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gen_rtc_irq_data = 0;
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return 0;
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#else
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return -EINVAL;
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#endif
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}
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static int gen_rtc_ioctl(struct file *file,
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unsigned int cmd, unsigned long arg)
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{
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struct rtc_time wtime;
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struct rtc_pll_info pll;
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void __user *argp = (void __user *)arg;
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switch (cmd) {
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case RTC_PLL_GET:
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if (get_rtc_pll(&pll))
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return -EINVAL;
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else
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return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0;
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case RTC_PLL_SET:
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if (!capable(CAP_SYS_TIME))
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return -EACCES;
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if (copy_from_user(&pll, argp, sizeof(pll)))
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return -EFAULT;
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return set_rtc_pll(&pll);
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case RTC_UIE_OFF: /* disable ints from RTC updates. */
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gen_clear_rtc_irq_bit(RTC_UIE);
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return 0;
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case RTC_UIE_ON: /* enable ints for RTC updates. */
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return gen_set_rtc_irq_bit(RTC_UIE);
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case RTC_RD_TIME: /* Read the time/date from RTC */
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/* this doesn't get week-day, who cares */
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memset(&wtime, 0, sizeof(wtime));
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get_rtc_time(&wtime);
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return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0;
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case RTC_SET_TIME: /* Set the RTC */
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{
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int year;
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unsigned char leap_yr;
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if (!capable(CAP_SYS_TIME))
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return -EACCES;
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if (copy_from_user(&wtime, argp, sizeof(wtime)))
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return -EFAULT;
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year = wtime.tm_year + 1900;
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leap_yr = ((!(year % 4) && (year % 100)) ||
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!(year % 400));
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if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1))
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return -EINVAL;
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if (wtime.tm_mday < 0 || wtime.tm_mday >
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(days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr)))
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return -EINVAL;
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if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
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wtime.tm_min < 0 || wtime.tm_min >= 60 ||
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wtime.tm_sec < 0 || wtime.tm_sec >= 60)
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return -EINVAL;
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return set_rtc_time(&wtime);
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}
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}
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return -EINVAL;
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}
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static long gen_rtc_unlocked_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret;
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mutex_lock(&gen_rtc_mutex);
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ret = gen_rtc_ioctl(file, cmd, arg);
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mutex_unlock(&gen_rtc_mutex);
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return ret;
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}
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/*
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* We enforce only one user at a time here with the open/close.
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* Also clear the previous interrupt data on an open, and clean
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* up things on a close.
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*/
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static int gen_rtc_open(struct inode *inode, struct file *file)
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{
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mutex_lock(&gen_rtc_mutex);
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if (gen_rtc_status & RTC_IS_OPEN) {
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mutex_unlock(&gen_rtc_mutex);
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return -EBUSY;
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}
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gen_rtc_status |= RTC_IS_OPEN;
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gen_rtc_irq_data = 0;
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irq_active = 0;
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mutex_unlock(&gen_rtc_mutex);
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return 0;
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}
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static int gen_rtc_release(struct inode *inode, struct file *file)
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{
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/*
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* Turn off all interrupts once the device is no longer
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* in use and clear the data.
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*/
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gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE);
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gen_rtc_status &= ~RTC_IS_OPEN;
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return 0;
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}
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#ifdef CONFIG_PROC_FS
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/*
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* Info exported via "/proc/driver/rtc".
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*/
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static int gen_rtc_proc_show(struct seq_file *m, void *v)
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{
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struct rtc_time tm;
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unsigned int flags;
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struct rtc_pll_info pll;
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flags = get_rtc_time(&tm);
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seq_printf(m,
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"rtc_time\t: %02d:%02d:%02d\n"
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"rtc_date\t: %04d-%02d-%02d\n"
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"rtc_epoch\t: %04u\n",
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tm.tm_hour, tm.tm_min, tm.tm_sec,
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tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900);
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tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
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seq_puts(m, "alarm\t\t: ");
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if (tm.tm_hour <= 24)
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seq_printf(m, "%02d:", tm.tm_hour);
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else
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seq_puts(m, "**:");
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if (tm.tm_min <= 59)
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seq_printf(m, "%02d:", tm.tm_min);
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else
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seq_puts(m, "**:");
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if (tm.tm_sec <= 59)
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seq_printf(m, "%02d\n", tm.tm_sec);
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else
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seq_puts(m, "**\n");
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seq_printf(m,
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"DST_enable\t: %s\n"
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"BCD\t\t: %s\n"
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"24hr\t\t: %s\n"
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"square_wave\t: %s\n"
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"alarm_IRQ\t: %s\n"
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"update_IRQ\t: %s\n"
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"periodic_IRQ\t: %s\n"
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"periodic_freq\t: %ld\n"
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"batt_status\t: %s\n",
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(flags & RTC_DST_EN) ? "yes" : "no",
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(flags & RTC_DM_BINARY) ? "no" : "yes",
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(flags & RTC_24H) ? "yes" : "no",
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(flags & RTC_SQWE) ? "yes" : "no",
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(flags & RTC_AIE) ? "yes" : "no",
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irq_active ? "yes" : "no",
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(flags & RTC_PIE) ? "yes" : "no",
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0L /* freq */,
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(flags & RTC_BATT_BAD) ? "bad" : "okay");
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if (!get_rtc_pll(&pll))
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seq_printf(m,
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"PLL adjustment\t: %d\n"
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"PLL max +ve adjustment\t: %d\n"
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"PLL max -ve adjustment\t: %d\n"
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"PLL +ve adjustment factor\t: %d\n"
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"PLL -ve adjustment factor\t: %d\n"
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"PLL frequency\t: %ld\n",
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pll.pll_value,
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pll.pll_max,
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pll.pll_min,
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pll.pll_posmult,
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pll.pll_negmult,
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pll.pll_clock);
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return 0;
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}
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static int gen_rtc_proc_open(struct inode *inode, struct file *file)
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{
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return single_open(file, gen_rtc_proc_show, NULL);
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}
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static const struct file_operations gen_rtc_proc_fops = {
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.open = gen_rtc_proc_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static int __init gen_rtc_proc_init(void)
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{
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struct proc_dir_entry *r;
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r = proc_create("driver/rtc", 0, NULL, &gen_rtc_proc_fops);
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if (!r)
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return -ENOMEM;
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return 0;
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}
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#else
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static inline int gen_rtc_proc_init(void) { return 0; }
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#endif /* CONFIG_PROC_FS */
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/*
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* The various file operations we support.
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*/
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static const struct file_operations gen_rtc_fops = {
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.owner = THIS_MODULE,
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#ifdef CONFIG_GEN_RTC_X
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.read = gen_rtc_read,
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.poll = gen_rtc_poll,
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#endif
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.unlocked_ioctl = gen_rtc_unlocked_ioctl,
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.open = gen_rtc_open,
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.release = gen_rtc_release,
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.llseek = noop_llseek,
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};
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static struct miscdevice rtc_gen_dev =
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{
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.minor = RTC_MINOR,
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.name = "rtc",
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.fops = &gen_rtc_fops,
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};
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static int __init rtc_generic_init(void)
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{
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int retval;
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printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION);
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retval = misc_register(&rtc_gen_dev);
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if (retval < 0)
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return retval;
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retval = gen_rtc_proc_init();
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if (retval) {
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misc_deregister(&rtc_gen_dev);
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return retval;
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}
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return 0;
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}
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static void __exit rtc_generic_exit(void)
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{
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remove_proc_entry ("driver/rtc", NULL);
|
|
misc_deregister(&rtc_gen_dev);
|
|
}
|
|
|
|
|
|
module_init(rtc_generic_init);
|
|
module_exit(rtc_generic_exit);
|
|
|
|
MODULE_AUTHOR("Richard Zidlicky");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(RTC_MINOR);
|