Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/drivers/char/rtc.c b/drivers/char/rtc.c
new file mode 100644
index 0000000..ff4f098
--- /dev/null
+++ b/drivers/char/rtc.c
@@ -0,0 +1,1354 @@
+/*
+ * Real Time Clock interface for Linux
+ *
+ * Copyright (C) 1996 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/driver/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.
+ *
+ * Based on other minimal char device drivers, like Alan's
+ * watchdog, Ted's random, etc. etc.
+ *
+ * 1.07 Paul Gortmaker.
+ * 1.08 Miquel van Smoorenburg: disallow certain things on the
+ * DEC Alpha as the CMOS clock is also used for other things.
+ * 1.09 Nikita Schmidt: epoch support and some Alpha cleanup.
+ * 1.09a Pete Zaitcev: Sun SPARC
+ * 1.09b Jeff Garzik: Modularize, init cleanup
+ * 1.09c Jeff Garzik: SMP cleanup
+ * 1.10 Paul Barton-Davis: add support for async I/O
+ * 1.10a Andrea Arcangeli: Alpha updates
+ * 1.10b Andrew Morton: SMP lock fix
+ * 1.10c Cesar Barros: SMP locking fixes and cleanup
+ * 1.10d Paul Gortmaker: delete paranoia check in rtc_exit
+ * 1.10e Maciej W. Rozycki: Handle DECstation's year weirdness.
+ * 1.11 Takashi Iwai: Kernel access functions
+ * rtc_register/rtc_unregister/rtc_control
+ * 1.11a Daniele Bellucci: Audit create_proc_read_entry in rtc_init
+ * 1.12 Venkatesh Pallipadi: Hooks for emulating rtc on HPET base-timer
+ * CONFIG_HPET_EMULATE_RTC
+ *
+ */
+
+#define RTC_VERSION "1.12"
+
+#define RTC_IO_EXTENT 0x8
+
+/*
+ * Note that *all* calls to CMOS_READ and CMOS_WRITE are done with
+ * interrupts disabled. Due to the index-port/data-port (0x70/0x71)
+ * design of the RTC, we don't want two different things trying to
+ * get to it at once. (e.g. the periodic 11 min sync from time.c vs.
+ * this driver.)
+ */
+
+#include <linux/config.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/miscdevice.h>
+#include <linux/ioport.h>
+#include <linux/fcntl.h>
+#include <linux/mc146818rtc.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/sysctl.h>
+#include <linux/wait.h>
+#include <linux/bcd.h>
+
+#include <asm/current.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#if defined(__i386__)
+#include <asm/hpet.h>
+#endif
+
+#ifdef __sparc__
+#include <linux/pci.h>
+#include <asm/ebus.h>
+#ifdef __sparc_v9__
+#include <asm/isa.h>
+#endif
+
+static unsigned long rtc_port;
+static int rtc_irq = PCI_IRQ_NONE;
+#endif
+
+#ifdef CONFIG_HPET_RTC_IRQ
+#undef RTC_IRQ
+#endif
+
+#ifdef RTC_IRQ
+static int rtc_has_irq = 1;
+#endif
+
+#ifndef CONFIG_HPET_EMULATE_RTC
+#define is_hpet_enabled() 0
+#define hpet_set_alarm_time(hrs, min, sec) 0
+#define hpet_set_periodic_freq(arg) 0
+#define hpet_mask_rtc_irq_bit(arg) 0
+#define hpet_set_rtc_irq_bit(arg) 0
+#define hpet_rtc_timer_init() do { } while (0)
+#define hpet_rtc_dropped_irq() 0
+static inline irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs) {return 0;}
+#else
+extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+#endif
+
+/*
+ * 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 struct fasync_struct *rtc_async_queue;
+
+static DECLARE_WAIT_QUEUE_HEAD(rtc_wait);
+
+#ifdef RTC_IRQ
+static struct timer_list rtc_irq_timer;
+#endif
+
+static ssize_t rtc_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos);
+
+static int rtc_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg);
+
+#ifdef RTC_IRQ
+static unsigned int rtc_poll(struct file *file, poll_table *wait);
+#endif
+
+static void get_rtc_alm_time (struct rtc_time *alm_tm);
+#ifdef RTC_IRQ
+static void rtc_dropped_irq(unsigned long data);
+
+static void set_rtc_irq_bit(unsigned char bit);
+static void mask_rtc_irq_bit(unsigned char bit);
+#endif
+
+static int rtc_proc_open(struct inode *inode, struct file *file);
+
+/*
+ * Bits in rtc_status. (6 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 */
+
+/*
+ * rtc_status is never changed by rtc_interrupt, and ioctl/open/close is
+ * protected by the big kernel lock. However, ioctl can still disable the timer
+ * in rtc_status and then with del_timer after the interrupt has read
+ * rtc_status but before mod_timer is called, which would then reenable the
+ * timer (but you would need to have an awful timing before you'd trip on it)
+ */
+static unsigned long rtc_status = 0; /* bitmapped status byte. */
+static unsigned long rtc_freq = 0; /* Current periodic IRQ rate */
+static unsigned long rtc_irq_data = 0; /* our output to the world */
+static unsigned long rtc_max_user_freq = 64; /* > this, need CAP_SYS_RESOURCE */
+
+#ifdef RTC_IRQ
+/*
+ * rtc_task_lock nests inside rtc_lock.
+ */
+static DEFINE_SPINLOCK(rtc_task_lock);
+static rtc_task_t *rtc_callback = NULL;
+#endif
+
+/*
+ * If this driver ever becomes modularised, it will be really nice
+ * to make the epoch retain its value across module reload...
+ */
+
+static unsigned long epoch = 1900; /* year corresponding to 0x00 */
+
+static const unsigned char days_in_mo[] =
+{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+/*
+ * Returns true if a clock update is in progress
+ */
+static inline unsigned char rtc_is_updating(void)
+{
+ unsigned char uip;
+
+ spin_lock_irq(&rtc_lock);
+ uip = (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP);
+ spin_unlock_irq(&rtc_lock);
+ return uip;
+}
+
+#ifdef RTC_IRQ
+/*
+ * A very tiny interrupt handler. It runs with SA_INTERRUPT set,
+ * but there is possibility of conflicting with the set_rtc_mmss()
+ * call (the rtc irq and the timer irq can easily run at the same
+ * time in two different CPUs). So we need to serialize
+ * accesses to the chip with the rtc_lock spinlock that each
+ * architecture should implement in the timer code.
+ * (See ./arch/XXXX/kernel/time.c for the set_rtc_mmss() function.)
+ */
+
+irqreturn_t rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ /*
+ * Can be an alarm interrupt, update complete interrupt,
+ * or a periodic interrupt. We store the status in the
+ * low byte and the number of interrupts received since
+ * the last read in the remainder of rtc_irq_data.
+ */
+
+ spin_lock (&rtc_lock);
+ rtc_irq_data += 0x100;
+ rtc_irq_data &= ~0xff;
+ if (is_hpet_enabled()) {
+ /*
+ * In this case it is HPET RTC interrupt handler
+ * calling us, with the interrupt information
+ * passed as arg1, instead of irq.
+ */
+ rtc_irq_data |= (unsigned long)irq & 0xF0;
+ } else {
+ rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0);
+ }
+
+ if (rtc_status & RTC_TIMER_ON)
+ mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
+
+ spin_unlock (&rtc_lock);
+
+ /* Now do the rest of the actions */
+ spin_lock(&rtc_task_lock);
+ if (rtc_callback)
+ rtc_callback->func(rtc_callback->private_data);
+ spin_unlock(&rtc_task_lock);
+ wake_up_interruptible(&rtc_wait);
+
+ kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
+
+ return IRQ_HANDLED;
+}
+#endif
+
+/*
+ * sysctl-tuning infrastructure.
+ */
+static ctl_table rtc_table[] = {
+ {
+ .ctl_name = 1,
+ .procname = "max-user-freq",
+ .data = &rtc_max_user_freq,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+ { .ctl_name = 0 }
+};
+
+static ctl_table rtc_root[] = {
+ {
+ .ctl_name = 1,
+ .procname = "rtc",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = rtc_table,
+ },
+ { .ctl_name = 0 }
+};
+
+static ctl_table dev_root[] = {
+ {
+ .ctl_name = CTL_DEV,
+ .procname = "dev",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = rtc_root,
+ },
+ { .ctl_name = 0 }
+};
+
+static struct ctl_table_header *sysctl_header;
+
+static int __init init_sysctl(void)
+{
+ sysctl_header = register_sysctl_table(dev_root, 0);
+ return 0;
+}
+
+static void __exit cleanup_sysctl(void)
+{
+ unregister_sysctl_table(sysctl_header);
+}
+
+/*
+ * Now all the various file operations that we export.
+ */
+
+static ssize_t rtc_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+#ifndef RTC_IRQ
+ return -EIO;
+#else
+ DECLARE_WAITQUEUE(wait, current);
+ unsigned long data;
+ ssize_t retval;
+
+ if (rtc_has_irq == 0)
+ return -EIO;
+
+ if (count < sizeof(unsigned))
+ return -EINVAL;
+
+ add_wait_queue(&rtc_wait, &wait);
+
+ do {
+ /* First make it right. Then make it fast. Putting this whole
+ * block within the parentheses of a while would be too
+ * confusing. And no, xchg() is not the answer. */
+
+ __set_current_state(TASK_INTERRUPTIBLE);
+
+ spin_lock_irq (&rtc_lock);
+ data = rtc_irq_data;
+ rtc_irq_data = 0;
+ spin_unlock_irq (&rtc_lock);
+
+ if (data != 0)
+ break;
+
+ if (file->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto out;
+ }
+ if (signal_pending(current)) {
+ retval = -ERESTARTSYS;
+ goto out;
+ }
+ schedule();
+ } while (1);
+
+ if (count < sizeof(unsigned long))
+ retval = put_user(data, (unsigned int __user *)buf) ?: sizeof(int);
+ else
+ retval = put_user(data, (unsigned long __user *)buf) ?: sizeof(long);
+ out:
+ current->state = TASK_RUNNING;
+ remove_wait_queue(&rtc_wait, &wait);
+
+ return retval;
+#endif
+}
+
+static int rtc_do_ioctl(unsigned int cmd, unsigned long arg, int kernel)
+{
+ struct rtc_time wtime;
+
+#ifdef RTC_IRQ
+ if (rtc_has_irq == 0) {
+ switch (cmd) {
+ case RTC_AIE_OFF:
+ case RTC_AIE_ON:
+ case RTC_PIE_OFF:
+ case RTC_PIE_ON:
+ case RTC_UIE_OFF:
+ case RTC_UIE_ON:
+ case RTC_IRQP_READ:
+ case RTC_IRQP_SET:
+ return -EINVAL;
+ };
+ }
+#endif
+
+ switch (cmd) {
+#ifdef RTC_IRQ
+ case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
+ {
+ mask_rtc_irq_bit(RTC_AIE);
+ return 0;
+ }
+ case RTC_AIE_ON: /* Allow alarm interrupts. */
+ {
+ set_rtc_irq_bit(RTC_AIE);
+ return 0;
+ }
+ case RTC_PIE_OFF: /* Mask periodic int. enab. bit */
+ {
+ mask_rtc_irq_bit(RTC_PIE);
+ if (rtc_status & RTC_TIMER_ON) {
+ spin_lock_irq (&rtc_lock);
+ rtc_status &= ~RTC_TIMER_ON;
+ del_timer(&rtc_irq_timer);
+ spin_unlock_irq (&rtc_lock);
+ }
+ return 0;
+ }
+ case RTC_PIE_ON: /* Allow periodic ints */
+ {
+
+ /*
+ * We don't really want Joe User enabling more
+ * than 64Hz of interrupts on a multi-user machine.
+ */
+ if (!kernel && (rtc_freq > rtc_max_user_freq) &&
+ (!capable(CAP_SYS_RESOURCE)))
+ return -EACCES;
+
+ if (!(rtc_status & RTC_TIMER_ON)) {
+ spin_lock_irq (&rtc_lock);
+ rtc_irq_timer.expires = jiffies + HZ/rtc_freq + 2*HZ/100;
+ add_timer(&rtc_irq_timer);
+ rtc_status |= RTC_TIMER_ON;
+ spin_unlock_irq (&rtc_lock);
+ }
+ set_rtc_irq_bit(RTC_PIE);
+ return 0;
+ }
+ case RTC_UIE_OFF: /* Mask ints from RTC updates. */
+ {
+ mask_rtc_irq_bit(RTC_UIE);
+ return 0;
+ }
+ case RTC_UIE_ON: /* Allow ints for RTC updates. */
+ {
+ set_rtc_irq_bit(RTC_UIE);
+ return 0;
+ }
+#endif
+ 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(struct rtc_time));
+ get_rtc_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 (copy_from_user(&alm_tm, (struct rtc_time __user *)arg,
+ sizeof(struct rtc_time)))
+ return -EFAULT;
+
+ hrs = alm_tm.tm_hour;
+ min = alm_tm.tm_min;
+ sec = alm_tm.tm_sec;
+
+ spin_lock_irq(&rtc_lock);
+ if (hpet_set_alarm_time(hrs, min, sec)) {
+ /*
+ * Fallthru and set alarm time in CMOS too,
+ * so that we will get proper value in RTC_ALM_READ
+ */
+ }
+ if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
+ RTC_ALWAYS_BCD)
+ {
+ if (sec < 60) BIN_TO_BCD(sec);
+ else sec = 0xff;
+
+ if (min < 60) BIN_TO_BCD(min);
+ else min = 0xff;
+
+ if (hrs < 24) BIN_TO_BCD(hrs);
+ else hrs = 0xff;
+ }
+ CMOS_WRITE(hrs, RTC_HOURS_ALARM);
+ CMOS_WRITE(min, RTC_MINUTES_ALARM);
+ CMOS_WRITE(sec, RTC_SECONDS_ALARM);
+ spin_unlock_irq(&rtc_lock);
+
+ return 0;
+ }
+ case RTC_RD_TIME: /* Read the time/date from RTC */
+ {
+ memset(&wtime, 0, sizeof(struct rtc_time));
+ rtc_get_rtc_time(&wtime);
+ break;
+ }
+ case RTC_SET_TIME: /* Set the RTC */
+ {
+ struct rtc_time rtc_tm;
+ unsigned char mon, day, hrs, min, sec, leap_yr;
+ unsigned char save_control, save_freq_select;
+ unsigned int yrs;
+#ifdef CONFIG_MACH_DECSTATION
+ unsigned int real_yrs;
+#endif
+
+ if (!capable(CAP_SYS_TIME))
+ return -EACCES;
+
+ if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
+ sizeof(struct rtc_time)))
+ return -EFAULT;
+
+ 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 -= epoch) > 255) /* They are unsigned */
+ return -EINVAL;
+
+ spin_lock_irq(&rtc_lock);
+#ifdef CONFIG_MACH_DECSTATION
+ real_yrs = yrs;
+ yrs = 72;
+
+ /*
+ * We want to keep the year set to 73 until March
+ * for non-leap years, so that Feb, 29th is handled
+ * correctly.
+ */
+ if (!leap_yr && mon < 3) {
+ real_yrs--;
+ yrs = 73;
+ }
+#endif
+ /* These limits and adjustments are independent of
+ * whether the chip is in binary mode or not.
+ */
+ if (yrs > 169) {
+ spin_unlock_irq(&rtc_lock);
+ return -EINVAL;
+ }
+ if (yrs >= 100)
+ yrs -= 100;
+
+ if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
+ || RTC_ALWAYS_BCD) {
+ BIN_TO_BCD(sec);
+ BIN_TO_BCD(min);
+ BIN_TO_BCD(hrs);
+ BIN_TO_BCD(day);
+ BIN_TO_BCD(mon);
+ BIN_TO_BCD(yrs);
+ }
+
+ save_control = CMOS_READ(RTC_CONTROL);
+ CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
+ save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
+ CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
+
+#ifdef CONFIG_MACH_DECSTATION
+ CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
+#endif
+ CMOS_WRITE(yrs, RTC_YEAR);
+ CMOS_WRITE(mon, RTC_MONTH);
+ CMOS_WRITE(day, RTC_DAY_OF_MONTH);
+ CMOS_WRITE(hrs, RTC_HOURS);
+ CMOS_WRITE(min, RTC_MINUTES);
+ CMOS_WRITE(sec, RTC_SECONDS);
+
+ CMOS_WRITE(save_control, RTC_CONTROL);
+ CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
+
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+ }
+#ifdef RTC_IRQ
+ case RTC_IRQP_READ: /* Read the periodic IRQ rate. */
+ {
+ return put_user(rtc_freq, (unsigned long __user *)arg);
+ }
+ case RTC_IRQP_SET: /* Set periodic IRQ rate. */
+ {
+ int tmp = 0;
+ unsigned char val;
+
+ /*
+ * The max we can do is 8192Hz.
+ */
+ if ((arg < 2) || (arg > 8192))
+ return -EINVAL;
+ /*
+ * We don't really want Joe User generating more
+ * than 64Hz of interrupts on a multi-user machine.
+ */
+ if (!kernel && (arg > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
+ return -EACCES;
+
+ while (arg > (1<<tmp))
+ tmp++;
+
+ /*
+ * Check that the input was really a power of 2.
+ */
+ if (arg != (1<<tmp))
+ return -EINVAL;
+
+ spin_lock_irq(&rtc_lock);
+ if (hpet_set_periodic_freq(arg)) {
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+ }
+ rtc_freq = arg;
+
+ val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
+ val |= (16 - tmp);
+ CMOS_WRITE(val, RTC_FREQ_SELECT);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+ }
+#endif
+ case RTC_EPOCH_READ: /* Read the epoch. */
+ {
+ return put_user (epoch, (unsigned long __user *)arg);
+ }
+ case RTC_EPOCH_SET: /* Set the epoch. */
+ {
+ /*
+ * There were no RTC clocks before 1900.
+ */
+ if (arg < 1900)
+ return -EINVAL;
+
+ if (!capable(CAP_SYS_TIME))
+ return -EACCES;
+
+ epoch = arg;
+ return 0;
+ }
+ default:
+ return -ENOTTY;
+ }
+ return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
+}
+
+static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ return rtc_do_ioctl(cmd, arg, 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.
+ */
+
+/* We use rtc_lock to protect against concurrent opens. So the BKL is not
+ * needed here. Or anywhere else in this driver. */
+static int rtc_open(struct inode *inode, struct file *file)
+{
+ spin_lock_irq (&rtc_lock);
+
+ if(rtc_status & RTC_IS_OPEN)
+ goto out_busy;
+
+ rtc_status |= RTC_IS_OPEN;
+
+ rtc_irq_data = 0;
+ spin_unlock_irq (&rtc_lock);
+ return 0;
+
+out_busy:
+ spin_unlock_irq (&rtc_lock);
+ return -EBUSY;
+}
+
+static int rtc_fasync (int fd, struct file *filp, int on)
+
+{
+ return fasync_helper (fd, filp, on, &rtc_async_queue);
+}
+
+static int rtc_release(struct inode *inode, struct file *file)
+{
+#ifdef RTC_IRQ
+ unsigned char tmp;
+
+ if (rtc_has_irq == 0)
+ goto no_irq;
+
+ /*
+ * Turn off all interrupts once the device is no longer
+ * in use, and clear the data.
+ */
+
+ spin_lock_irq(&rtc_lock);
+ if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
+ tmp = CMOS_READ(RTC_CONTROL);
+ tmp &= ~RTC_PIE;
+ tmp &= ~RTC_AIE;
+ tmp &= ~RTC_UIE;
+ CMOS_WRITE(tmp, RTC_CONTROL);
+ CMOS_READ(RTC_INTR_FLAGS);
+ }
+ if (rtc_status & RTC_TIMER_ON) {
+ rtc_status &= ~RTC_TIMER_ON;
+ del_timer(&rtc_irq_timer);
+ }
+ spin_unlock_irq(&rtc_lock);
+
+ if (file->f_flags & FASYNC) {
+ rtc_fasync (-1, file, 0);
+ }
+no_irq:
+#endif
+
+ spin_lock_irq (&rtc_lock);
+ rtc_irq_data = 0;
+ rtc_status &= ~RTC_IS_OPEN;
+ spin_unlock_irq (&rtc_lock);
+ return 0;
+}
+
+#ifdef RTC_IRQ
+/* Called without the kernel lock - fine */
+static unsigned int rtc_poll(struct file *file, poll_table *wait)
+{
+ unsigned long l;
+
+ if (rtc_has_irq == 0)
+ return 0;
+
+ poll_wait(file, &rtc_wait, wait);
+
+ spin_lock_irq (&rtc_lock);
+ l = rtc_irq_data;
+ spin_unlock_irq (&rtc_lock);
+
+ if (l != 0)
+ return POLLIN | POLLRDNORM;
+ return 0;
+}
+#endif
+
+/*
+ * exported stuffs
+ */
+
+EXPORT_SYMBOL(rtc_register);
+EXPORT_SYMBOL(rtc_unregister);
+EXPORT_SYMBOL(rtc_control);
+
+int rtc_register(rtc_task_t *task)
+{
+#ifndef RTC_IRQ
+ return -EIO;
+#else
+ if (task == NULL || task->func == NULL)
+ return -EINVAL;
+ spin_lock_irq(&rtc_lock);
+ if (rtc_status & RTC_IS_OPEN) {
+ spin_unlock_irq(&rtc_lock);
+ return -EBUSY;
+ }
+ spin_lock(&rtc_task_lock);
+ if (rtc_callback) {
+ spin_unlock(&rtc_task_lock);
+ spin_unlock_irq(&rtc_lock);
+ return -EBUSY;
+ }
+ rtc_status |= RTC_IS_OPEN;
+ rtc_callback = task;
+ spin_unlock(&rtc_task_lock);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+#endif
+}
+
+int rtc_unregister(rtc_task_t *task)
+{
+#ifndef RTC_IRQ
+ return -EIO;
+#else
+ unsigned char tmp;
+
+ spin_lock_irq(&rtc_lock);
+ spin_lock(&rtc_task_lock);
+ if (rtc_callback != task) {
+ spin_unlock(&rtc_task_lock);
+ spin_unlock_irq(&rtc_lock);
+ return -ENXIO;
+ }
+ rtc_callback = NULL;
+
+ /* disable controls */
+ if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
+ tmp = CMOS_READ(RTC_CONTROL);
+ tmp &= ~RTC_PIE;
+ tmp &= ~RTC_AIE;
+ tmp &= ~RTC_UIE;
+ CMOS_WRITE(tmp, RTC_CONTROL);
+ CMOS_READ(RTC_INTR_FLAGS);
+ }
+ if (rtc_status & RTC_TIMER_ON) {
+ rtc_status &= ~RTC_TIMER_ON;
+ del_timer(&rtc_irq_timer);
+ }
+ rtc_status &= ~RTC_IS_OPEN;
+ spin_unlock(&rtc_task_lock);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+#endif
+}
+
+int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
+{
+#ifndef RTC_IRQ
+ return -EIO;
+#else
+ spin_lock_irq(&rtc_task_lock);
+ if (rtc_callback != task) {
+ spin_unlock_irq(&rtc_task_lock);
+ return -ENXIO;
+ }
+ spin_unlock_irq(&rtc_task_lock);
+ return rtc_do_ioctl(cmd, arg, 1);
+#endif
+}
+
+
+/*
+ * The various file operations we support.
+ */
+
+static struct file_operations rtc_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .read = rtc_read,
+#ifdef RTC_IRQ
+ .poll = rtc_poll,
+#endif
+ .ioctl = rtc_ioctl,
+ .open = rtc_open,
+ .release = rtc_release,
+ .fasync = rtc_fasync,
+};
+
+static struct miscdevice rtc_dev = {
+ .minor = RTC_MINOR,
+ .name = "rtc",
+ .fops = &rtc_fops,
+};
+
+static struct file_operations rtc_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = rtc_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+#if defined(RTC_IRQ) && !defined(__sparc__)
+static irqreturn_t (*rtc_int_handler_ptr)(int irq, void *dev_id, struct pt_regs *regs);
+#endif
+
+static int __init rtc_init(void)
+{
+ struct proc_dir_entry *ent;
+#if defined(__alpha__) || defined(__mips__)
+ unsigned int year, ctrl;
+ unsigned long uip_watchdog;
+ char *guess = NULL;
+#endif
+#ifdef __sparc__
+ struct linux_ebus *ebus;
+ struct linux_ebus_device *edev;
+#ifdef __sparc_v9__
+ struct sparc_isa_bridge *isa_br;
+ struct sparc_isa_device *isa_dev;
+#endif
+#endif
+
+#ifdef __sparc__
+ for_each_ebus(ebus) {
+ for_each_ebusdev(edev, ebus) {
+ if(strcmp(edev->prom_name, "rtc") == 0) {
+ rtc_port = edev->resource[0].start;
+ rtc_irq = edev->irqs[0];
+ goto found;
+ }
+ }
+ }
+#ifdef __sparc_v9__
+ for_each_isa(isa_br) {
+ for_each_isadev(isa_dev, isa_br) {
+ if (strcmp(isa_dev->prom_name, "rtc") == 0) {
+ rtc_port = isa_dev->resource.start;
+ rtc_irq = isa_dev->irq;
+ goto found;
+ }
+ }
+ }
+#endif
+ printk(KERN_ERR "rtc_init: no PC rtc found\n");
+ return -EIO;
+
+found:
+ if (rtc_irq == PCI_IRQ_NONE) {
+ rtc_has_irq = 0;
+ goto no_irq;
+ }
+
+ /*
+ * XXX Interrupt pin #7 in Espresso is shared between RTC and
+ * PCI Slot 2 INTA# (and some INTx# in Slot 1). SA_INTERRUPT here
+ * is asking for trouble with add-on boards. Change to SA_SHIRQ.
+ */
+ if (request_irq(rtc_irq, rtc_interrupt, SA_INTERRUPT, "rtc", (void *)&rtc_port)) {
+ /*
+ * Standard way for sparc to print irq's is to use
+ * __irq_itoa(). I think for EBus it's ok to use %d.
+ */
+ printk(KERN_ERR "rtc: cannot register IRQ %d\n", rtc_irq);
+ return -EIO;
+ }
+no_irq:
+#else
+ if (!request_region(RTC_PORT(0), RTC_IO_EXTENT, "rtc")) {
+ printk(KERN_ERR "rtc: I/O port %d is not free.\n", RTC_PORT (0));
+ return -EIO;
+ }
+
+#ifdef RTC_IRQ
+ if (is_hpet_enabled()) {
+ rtc_int_handler_ptr = hpet_rtc_interrupt;
+ } else {
+ rtc_int_handler_ptr = rtc_interrupt;
+ }
+
+ if(request_irq(RTC_IRQ, rtc_int_handler_ptr, SA_INTERRUPT, "rtc", NULL)) {
+ /* Yeah right, seeing as irq 8 doesn't even hit the bus. */
+ printk(KERN_ERR "rtc: IRQ %d is not free.\n", RTC_IRQ);
+ release_region(RTC_PORT(0), RTC_IO_EXTENT);
+ return -EIO;
+ }
+ hpet_rtc_timer_init();
+
+#endif
+
+#endif /* __sparc__ vs. others */
+
+ if (misc_register(&rtc_dev)) {
+#ifdef RTC_IRQ
+ free_irq(RTC_IRQ, NULL);
+#endif
+ release_region(RTC_PORT(0), RTC_IO_EXTENT);
+ return -ENODEV;
+ }
+
+ ent = create_proc_entry("driver/rtc", 0, NULL);
+ if (!ent) {
+#ifdef RTC_IRQ
+ free_irq(RTC_IRQ, NULL);
+#endif
+ release_region(RTC_PORT(0), RTC_IO_EXTENT);
+ misc_deregister(&rtc_dev);
+ return -ENOMEM;
+ }
+ ent->proc_fops = &rtc_proc_fops;
+
+#if defined(__alpha__) || defined(__mips__)
+ rtc_freq = HZ;
+
+ /* Each operating system on an Alpha uses its own epoch.
+ Let's try to guess which one we are using now. */
+
+ uip_watchdog = jiffies;
+ if (rtc_is_updating() != 0)
+ while (jiffies - uip_watchdog < 2*HZ/100) {
+ barrier();
+ cpu_relax();
+ }
+
+ spin_lock_irq(&rtc_lock);
+ year = CMOS_READ(RTC_YEAR);
+ ctrl = CMOS_READ(RTC_CONTROL);
+ spin_unlock_irq(&rtc_lock);
+
+ if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
+ BCD_TO_BIN(year); /* This should never happen... */
+
+ if (year < 20) {
+ epoch = 2000;
+ guess = "SRM (post-2000)";
+ } else if (year >= 20 && year < 48) {
+ epoch = 1980;
+ guess = "ARC console";
+ } else if (year >= 48 && year < 72) {
+ epoch = 1952;
+ guess = "Digital UNIX";
+#if defined(__mips__)
+ } else if (year >= 72 && year < 74) {
+ epoch = 2000;
+ guess = "Digital DECstation";
+#else
+ } else if (year >= 70) {
+ epoch = 1900;
+ guess = "Standard PC (1900)";
+#endif
+ }
+ if (guess)
+ printk(KERN_INFO "rtc: %s epoch (%lu) detected\n", guess, epoch);
+#endif
+#ifdef RTC_IRQ
+ if (rtc_has_irq == 0)
+ goto no_irq2;
+
+ init_timer(&rtc_irq_timer);
+ rtc_irq_timer.function = rtc_dropped_irq;
+ spin_lock_irq(&rtc_lock);
+ rtc_freq = 1024;
+ if (!hpet_set_periodic_freq(rtc_freq)) {
+ /* Initialize periodic freq. to CMOS reset default, which is 1024Hz */
+ CMOS_WRITE(((CMOS_READ(RTC_FREQ_SELECT) & 0xF0) | 0x06), RTC_FREQ_SELECT);
+ }
+ spin_unlock_irq(&rtc_lock);
+no_irq2:
+#endif
+
+ (void) init_sysctl();
+
+ printk(KERN_INFO "Real Time Clock Driver v" RTC_VERSION "\n");
+
+ return 0;
+}
+
+static void __exit rtc_exit (void)
+{
+ cleanup_sysctl();
+ remove_proc_entry ("driver/rtc", NULL);
+ misc_deregister(&rtc_dev);
+
+#ifdef __sparc__
+ if (rtc_has_irq)
+ free_irq (rtc_irq, &rtc_port);
+#else
+ release_region (RTC_PORT (0), RTC_IO_EXTENT);
+#ifdef RTC_IRQ
+ if (rtc_has_irq)
+ free_irq (RTC_IRQ, NULL);
+#endif
+#endif /* __sparc__ */
+}
+
+module_init(rtc_init);
+module_exit(rtc_exit);
+
+#ifdef RTC_IRQ
+/*
+ * At IRQ rates >= 4096Hz, an interrupt may get lost altogether.
+ * (usually during an IDE disk interrupt, with IRQ unmasking off)
+ * Since the interrupt handler doesn't get called, the IRQ status
+ * byte doesn't get read, and the RTC stops generating interrupts.
+ * A timer is set, and will call this function if/when that happens.
+ * To get it out of this stalled state, we just read the status.
+ * At least a jiffy of interrupts (rtc_freq/HZ) will have been lost.
+ * (You *really* shouldn't be trying to use a non-realtime system
+ * for something that requires a steady > 1KHz signal anyways.)
+ */
+
+static void rtc_dropped_irq(unsigned long data)
+{
+ unsigned long freq;
+
+ spin_lock_irq (&rtc_lock);
+
+ if (hpet_rtc_dropped_irq()) {
+ spin_unlock_irq(&rtc_lock);
+ return;
+ }
+
+ /* Just in case someone disabled the timer from behind our back... */
+ if (rtc_status & RTC_TIMER_ON)
+ mod_timer(&rtc_irq_timer, jiffies + HZ/rtc_freq + 2*HZ/100);
+
+ rtc_irq_data += ((rtc_freq/HZ)<<8);
+ rtc_irq_data &= ~0xff;
+ rtc_irq_data |= (CMOS_READ(RTC_INTR_FLAGS) & 0xF0); /* restart */
+
+ freq = rtc_freq;
+
+ spin_unlock_irq(&rtc_lock);
+
+ printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", freq);
+
+ /* Now we have new data */
+ wake_up_interruptible(&rtc_wait);
+
+ kill_fasync (&rtc_async_queue, SIGIO, POLL_IN);
+}
+#endif
+
+/*
+ * Info exported via "/proc/driver/rtc".
+ */
+
+static int rtc_proc_show(struct seq_file *seq, void *v)
+{
+#define YN(bit) ((ctrl & bit) ? "yes" : "no")
+#define NY(bit) ((ctrl & bit) ? "no" : "yes")
+ struct rtc_time tm;
+ unsigned char batt, ctrl;
+ unsigned long freq;
+
+ spin_lock_irq(&rtc_lock);
+ batt = CMOS_READ(RTC_VALID) & RTC_VRT;
+ ctrl = CMOS_READ(RTC_CONTROL);
+ freq = rtc_freq;
+ spin_unlock_irq(&rtc_lock);
+
+
+ rtc_get_rtc_time(&tm);
+
+ /*
+ * There is no way to tell if the luser has the RTC set for local
+ * time or for Universal Standard Time (GMT). Probably local though.
+ */
+ seq_printf(seq,
+ "rtc_time\t: %02d:%02d:%02d\n"
+ "rtc_date\t: %04d-%02d-%02d\n"
+ "rtc_epoch\t: %04lu\n",
+ tm.tm_hour, tm.tm_min, tm.tm_sec,
+ tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
+
+ get_rtc_alm_time(&tm);
+
+ /*
+ * 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.
+ */
+ seq_puts(seq, "alarm\t\t: ");
+ if (tm.tm_hour <= 24)
+ seq_printf(seq, "%02d:", tm.tm_hour);
+ else
+ seq_puts(seq, "**:");
+
+ if (tm.tm_min <= 59)
+ seq_printf(seq, "%02d:", tm.tm_min);
+ else
+ seq_puts(seq, "**:");
+
+ if (tm.tm_sec <= 59)
+ seq_printf(seq, "%02d\n", tm.tm_sec);
+ else
+ seq_puts(seq, "**\n");
+
+ seq_printf(seq,
+ "DST_enable\t: %s\n"
+ "BCD\t\t: %s\n"
+ "24hr\t\t: %s\n"
+ "square_wave\t: %s\n"
+ "alarm_IRQ\t: %s\n"
+ "update_IRQ\t: %s\n"
+ "periodic_IRQ\t: %s\n"
+ "periodic_freq\t: %ld\n"
+ "batt_status\t: %s\n",
+ YN(RTC_DST_EN),
+ NY(RTC_DM_BINARY),
+ YN(RTC_24H),
+ YN(RTC_SQWE),
+ YN(RTC_AIE),
+ YN(RTC_UIE),
+ YN(RTC_PIE),
+ freq,
+ batt ? "okay" : "dead");
+
+ return 0;
+#undef YN
+#undef NY
+}
+
+static int rtc_proc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, rtc_proc_show, NULL);
+}
+
+void rtc_get_rtc_time(struct rtc_time *rtc_tm)
+{
+ unsigned long uip_watchdog = jiffies;
+ unsigned char ctrl;
+#ifdef CONFIG_MACH_DECSTATION
+ unsigned int real_year;
+#endif
+
+ /*
+ * 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 (rtc_is_updating() != 0)
+ while (jiffies - uip_watchdog < 2*HZ/100) {
+ barrier();
+ cpu_relax();
+ }
+
+ /*
+ * 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_irq(&rtc_lock);
+ rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
+ rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
+ rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
+ rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
+ rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
+ rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
+#ifdef CONFIG_MACH_DECSTATION
+ real_year = CMOS_READ(RTC_DEC_YEAR);
+#endif
+ ctrl = CMOS_READ(RTC_CONTROL);
+ spin_unlock_irq(&rtc_lock);
+
+ if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
+ {
+ BCD_TO_BIN(rtc_tm->tm_sec);
+ BCD_TO_BIN(rtc_tm->tm_min);
+ BCD_TO_BIN(rtc_tm->tm_hour);
+ BCD_TO_BIN(rtc_tm->tm_mday);
+ BCD_TO_BIN(rtc_tm->tm_mon);
+ BCD_TO_BIN(rtc_tm->tm_year);
+ }
+
+#ifdef CONFIG_MACH_DECSTATION
+ rtc_tm->tm_year += real_year - 72;
+#endif
+
+ /*
+ * 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 += (epoch - 1900)) <= 69)
+ rtc_tm->tm_year += 100;
+
+ rtc_tm->tm_mon--;
+}
+
+static void get_rtc_alm_time(struct rtc_time *alm_tm)
+{
+ unsigned char ctrl;
+
+ /*
+ * Only the values that we read from the RTC are set. That
+ * means only tm_hour, tm_min, and tm_sec.
+ */
+ spin_lock_irq(&rtc_lock);
+ alm_tm->tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
+ alm_tm->tm_min = CMOS_READ(RTC_MINUTES_ALARM);
+ alm_tm->tm_hour = CMOS_READ(RTC_HOURS_ALARM);
+ ctrl = CMOS_READ(RTC_CONTROL);
+ spin_unlock_irq(&rtc_lock);
+
+ if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
+ {
+ BCD_TO_BIN(alm_tm->tm_sec);
+ BCD_TO_BIN(alm_tm->tm_min);
+ BCD_TO_BIN(alm_tm->tm_hour);
+ }
+}
+
+#ifdef RTC_IRQ
+/*
+ * Used to disable/enable interrupts for any one of UIE, AIE, PIE.
+ * Rumour has it that if you frob the interrupt enable/disable
+ * bits in RTC_CONTROL, you should read RTC_INTR_FLAGS, to
+ * ensure you actually start getting interrupts. Probably for
+ * compatibility with older/broken chipset RTC implementations.
+ * We also clear out any old irq data after an ioctl() that
+ * meddles with the interrupt enable/disable bits.
+ */
+
+static void mask_rtc_irq_bit(unsigned char bit)
+{
+ unsigned char val;
+
+ spin_lock_irq(&rtc_lock);
+ if (hpet_mask_rtc_irq_bit(bit)) {
+ spin_unlock_irq(&rtc_lock);
+ return;
+ }
+ val = CMOS_READ(RTC_CONTROL);
+ val &= ~bit;
+ CMOS_WRITE(val, RTC_CONTROL);
+ CMOS_READ(RTC_INTR_FLAGS);
+
+ rtc_irq_data = 0;
+ spin_unlock_irq(&rtc_lock);
+}
+
+static void set_rtc_irq_bit(unsigned char bit)
+{
+ unsigned char val;
+
+ spin_lock_irq(&rtc_lock);
+ if (hpet_set_rtc_irq_bit(bit)) {
+ spin_unlock_irq(&rtc_lock);
+ return;
+ }
+ val = CMOS_READ(RTC_CONTROL);
+ val |= bit;
+ CMOS_WRITE(val, RTC_CONTROL);
+ CMOS_READ(RTC_INTR_FLAGS);
+
+ rtc_irq_data = 0;
+ spin_unlock_irq(&rtc_lock);
+}
+#endif
+
+MODULE_AUTHOR("Paul Gortmaker");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(RTC_MINOR);