1 files changed, 535 insertions, 0 deletions

diff --git a/drivers/char/genrtc.c b/drivers/char/genrtc.c
new file mode 100644
index 000000000000..d3a2bc36129b
--- /dev/null
+++ b/drivers/char/genrtc.c
@@ -0,0 +1,535 @@
+/*
+ *      Real Time Clock interface for
+ *              - q40 and other m68k machines,
+ *              - HP PARISC machines
+ *              - PowerPC machines
+ *      emulate some RTC irq capabilities in software
+ *
+ *      Copyright (C) 1999 Richard Zidlicky
+ *
+ *      based on Paul Gortmaker's rtc.c device and
+ *           Sam Creasey Generic rtc driver
+ *
+ *      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/dev/rtc
+ *      pseudo-file for status information.
+ *
+ *      The ioctls can be used to set the interrupt behaviour where
+ *      supported.
+ *
+ *      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.
+ *
+
+ *      1.01 fix for 2.3.X                    rz@linux-m68k.org
+ *      1.02 merged with code from genrtc.c   rz@linux-m68k.org
+ *      1.03 make it more portable            zippel@linux-m68k.org
+ *      1.04 removed useless timer code       rz@linux-m68k.org
+ *      1.05 portable RTC_UIE emulation       rz@linux-m68k.org
+ *      1.06 set_rtc_time can return an error trini@kernel.crashing.org
+ *      1.07 ported to HP PARISC (hppa)       Helge Deller <deller@gmx.de>
+ */
+
+#define RTC_VERSION     "1.07"
+
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/miscdevice.h>
+#include <linux/fcntl.h>
+
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/poll.h>
+#include <linux/proc_fs.h>
+#include <linux/workqueue.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/rtc.h>
+
+/*
+ *      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(gen_rtc_wait);
+
+/*
+ *      Bits in gen_rtc_status.
+ */
+
+#define RTC_IS_OPEN             0x01    /* means /dev/rtc is in use     */
+
+static unsigned char gen_rtc_status;    /* bitmapped status byte.       */
+static unsigned long gen_rtc_irq_data;  /* our output to the world      */
+
+/* months start at 0 now */
+static unsigned char days_in_mo[] =
+{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+static int irq_active;
+
+#ifdef CONFIG_GEN_RTC_X
+static struct work_struct genrtc_task;
+static struct timer_list timer_task;
+
+static unsigned int oldsecs;
+static int lostint;
+static unsigned long tt_exp;
+
+static void gen_rtc_timer(unsigned long data);
+
+static volatile int stask_active;              /* schedule_work */
+static volatile int ttask_active;              /* timer_task */
+static int stop_rtc_timers;                    /* don't requeue tasks */
+static DEFINE_SPINLOCK(gen_rtc_lock);
+
+static void gen_rtc_interrupt(unsigned long arg);
+
+/*
+ * Routine to poll RTC seconds field for change as often as possible,
+ * after first RTC_UIE use timer to reduce polling
+ */
+static void genrtc_troutine(void *data)
+{
+        unsigned int tmp = get_rtc_ss();
+        
+        if (stop_rtc_timers) {
+                stask_active = 0;
+                return;
+        }
+
+        if (oldsecs != tmp){
+                oldsecs = tmp;
+
+                timer_task.function = gen_rtc_timer;
+                timer_task.expires = jiffies + HZ - (HZ/10);
+                tt_exp=timer_task.expires;
+                ttask_active=1;
+                stask_active=0;
+                add_timer(&timer_task);
+
+                gen_rtc_interrupt(0);
+        } else if (schedule_work(&genrtc_task) == 0)
+                stask_active = 0;
+}
+
+static void gen_rtc_timer(unsigned long data)
+{
+        lostint = get_rtc_ss() - oldsecs ;
+        if (lostint<0) 
+                lostint = 60 - lostint;
+        if (time_after(jiffies, tt_exp))
+                printk(KERN_INFO "genrtc: timer task delayed by %ld jiffies\n",
+                       jiffies-tt_exp);
+        ttask_active=0;
+        stask_active=1;
+        if ((schedule_work(&genrtc_task) == 0))
+                stask_active = 0;
+}
+
+/* 
+ * call gen_rtc_interrupt function to signal an RTC_UIE,
+ * arg is unused.
+ * Could be invoked either from a real interrupt handler or
+ * from some routine that periodically (eg 100HZ) monitors
+ * whether RTC_SECS changed
+ */
+static void gen_rtc_interrupt(unsigned long arg)
+{
+        /*  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.  */
+
+        gen_rtc_irq_data += 0x100;
+        gen_rtc_irq_data &= ~0xff;
+        gen_rtc_irq_data |= RTC_UIE;
+
+        if (lostint){
+                printk("genrtc: system delaying clock ticks?\n");
+                /* increment count so that userspace knows something is wrong */
+                gen_rtc_irq_data += ((lostint-1)<<8);
+                lostint = 0;
+        }
+
+        wake_up_interruptible(&gen_rtc_wait);
+}
+
+/*
+ *      Now all the various file operations that we export.
+ */
+static ssize_t gen_rtc_read(struct file *file, char __user *buf,
+                        size_t count, loff_t *ppos)
+{
+        DECLARE_WAITQUEUE(wait, current);
+        unsigned long data;
+        ssize_t retval;
+
+        if (count != sizeof (unsigned int) && count != sizeof (unsigned long))
+                return -EINVAL;
+
+        if (file->f_flags & O_NONBLOCK && !gen_rtc_irq_data)
+                return -EAGAIN;
+
+        add_wait_queue(&gen_rtc_wait, &wait);
+        retval = -ERESTARTSYS;
+
+        while (1) {
+                set_current_state(TASK_INTERRUPTIBLE);
+                data = xchg(&gen_rtc_irq_data, 0);
+                if (data)
+                        break;
+                if (signal_pending(current))
+                        goto out;
+                schedule();
+        }
+
+        /* first test allows optimizer to nuke this case for 32-bit machines */
+        if (sizeof (int) != sizeof (long) && count == sizeof (unsigned int)) {
+                unsigned int uidata = data;
+                retval = put_user(uidata, (unsigned long __user *)buf);
+        }
+        else {
+                retval = put_user(data, (unsigned long __user *)buf);
+        }
+        if (!retval)
+                retval = sizeof(unsigned long);
+ out:
+        current->state = TASK_RUNNING;
+        remove_wait_queue(&gen_rtc_wait, &wait);
+
+        return retval;
+}
+
+static unsigned int gen_rtc_poll(struct file *file,
+                                 struct poll_table_struct *wait)
+{
+        poll_wait(file, &gen_rtc_wait, wait);
+        if (gen_rtc_irq_data != 0)
+                return POLLIN | POLLRDNORM;
+        return 0;
+}
+
+#endif
+
+/*
+ * Used to disable/enable interrupts, only RTC_UIE supported
+ * We also clear out any old irq data after an ioctl() that
+ * meddles with the interrupt enable/disable bits.
+ */
+
+static inline void gen_clear_rtc_irq_bit(unsigned char bit)
+{
+#ifdef CONFIG_GEN_RTC_X
+        stop_rtc_timers = 1;
+        if (ttask_active){
+                del_timer_sync(&timer_task);
+                ttask_active = 0;
+        }
+        while (stask_active)
+                schedule();
+
+        spin_lock(&gen_rtc_lock);
+        irq_active = 0;
+        spin_unlock(&gen_rtc_lock);
+#endif
+}
+
+static inline int gen_set_rtc_irq_bit(unsigned char bit)
+{
+#ifdef CONFIG_GEN_RTC_X
+        spin_lock(&gen_rtc_lock);
+        if ( !irq_active ) {
+                irq_active = 1;
+                stop_rtc_timers = 0;
+                lostint = 0;
+                INIT_WORK(&genrtc_task, genrtc_troutine, NULL);
+                oldsecs = get_rtc_ss();
+                init_timer(&timer_task);
+
+                stask_active = 1;
+                if (schedule_work(&genrtc_task) == 0){
+                        stask_active = 0;
+                }
+        }
+        spin_unlock(&gen_rtc_lock);
+        gen_rtc_irq_data = 0;
+        return 0;
+#else
+        return -EINVAL;
+#endif
+}
+
+static int gen_rtc_ioctl(struct inode *inode, struct file *file,
+                         unsigned int cmd, unsigned long arg)
+{
+        struct rtc_time wtime;
+        struct rtc_pll_info pll;
+        void __user *argp = (void __user *)arg;
+
+        switch (cmd) {
+
+        case RTC_PLL_GET:
+            if (get_rtc_pll(&pll))
+                    return -EINVAL;
+            else
+                    return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0;
+
+        case RTC_PLL_SET:
+                if (!capable(CAP_SYS_TIME))
+                        return -EACCES;
+                if (copy_from_user(&pll, argp, sizeof(pll)))
+                        return -EFAULT;
+            return set_rtc_pll(&pll);
+
+        case RTC_UIE_OFF:       /* disable ints from RTC updates.       */
+                gen_clear_rtc_irq_bit(RTC_UIE);
+                return 0;
+
+        case RTC_UIE_ON:        /* enable ints for RTC updates. */
+                return gen_set_rtc_irq_bit(RTC_UIE);
+
+        case RTC_RD_TIME:       /* Read the time/date from RTC  */
+                /* this doesn't get week-day, who cares */
+                memset(&wtime, 0, sizeof(wtime));
+                get_rtc_time(&wtime);
+
+                return copy_to_user(argp, &wtime, sizeof(wtime)) ? -EFAULT : 0;
+
+        case RTC_SET_TIME:      /* Set the RTC */
+            {
+                int year;
+                unsigned char leap_yr;
+
+                if (!capable(CAP_SYS_TIME))
+                        return -EACCES;
+
+                if (copy_from_user(&wtime, argp, sizeof(wtime)))
+                        return -EFAULT;
+
+                year = wtime.tm_year + 1900;
+                leap_yr = ((!(year % 4) && (year % 100)) ||
+                           !(year % 400));
+
+                if ((wtime.tm_mon < 0 || wtime.tm_mon > 11) || (wtime.tm_mday < 1))
+                        return -EINVAL;
+
+                if (wtime.tm_mday < 0 || wtime.tm_mday >
+                    (days_in_mo[wtime.tm_mon] + ((wtime.tm_mon == 1) && leap_yr)))
+                        return -EINVAL;
+
+                if (wtime.tm_hour < 0 || wtime.tm_hour >= 24 ||
+                    wtime.tm_min < 0 || wtime.tm_min >= 60 ||
+                    wtime.tm_sec < 0 || wtime.tm_sec >= 60)
+                        return -EINVAL;
+
+                return set_rtc_time(&wtime);
+            }
+        }
+
+        return -EINVAL;
+}
+
+/*
+ *      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 gen_rtc_open(struct inode *inode, struct file *file)
+{
+        if (gen_rtc_status & RTC_IS_OPEN)
+                return -EBUSY;
+
+        gen_rtc_status |= RTC_IS_OPEN;
+        gen_rtc_irq_data = 0;
+        irq_active = 0;
+
+        return 0;
+}
+
+static int gen_rtc_release(struct inode *inode, struct file *file)
+{
+        /*
+         * Turn off all interrupts once the device is no longer
+         * in use and clear the data.
+         */
+
+        gen_clear_rtc_irq_bit(RTC_PIE|RTC_AIE|RTC_UIE);
+
+        gen_rtc_status &= ~RTC_IS_OPEN;
+        return 0;
+}
+
+
+#ifdef CONFIG_PROC_FS
+
+/*
+ *      Info exported via "/proc/rtc".
+ */
+
+static int gen_rtc_proc_output(char *buf)
+{
+        char *p;
+        struct rtc_time tm;
+        unsigned int flags;
+        struct rtc_pll_info pll;
+
+        p = buf;
+
+        flags = get_rtc_time(&tm);
+
+        p += sprintf(p,
+                     "rtc_time\t: %02d:%02d:%02d\n"
+                     "rtc_date\t: %04d-%02d-%02d\n"
+                     "rtc_epoch\t: %04u\n",
+                     tm.tm_hour, tm.tm_min, tm.tm_sec,
+                     tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 1900);
+
+        tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
+
+        p += sprintf(p, "alarm\t\t: ");
+        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:", tm.tm_min);
+        else
+                p += sprintf(p, "**:");
+
+        if (tm.tm_sec <= 59)
+                p += sprintf(p, "%02d\n", tm.tm_sec);
+        else
+                p += sprintf(p, "**\n");
+
+        p += sprintf(p,
+                     "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",
+                     (flags & RTC_DST_EN) ? "yes" : "no",
+                     (flags & RTC_DM_BINARY) ? "no" : "yes",
+                     (flags & RTC_24H) ? "yes" : "no",
+                     (flags & RTC_SQWE) ? "yes" : "no",
+                     (flags & RTC_AIE) ? "yes" : "no",
+                     irq_active ? "yes" : "no",
+                     (flags & RTC_PIE) ? "yes" : "no",
+                     0L /* freq */,
+                     (flags & RTC_BATT_BAD) ? "bad" : "okay");
+        if (!get_rtc_pll(&pll))
+            p += sprintf(p,
+                         "PLL adjustment\t: %d\n"
+                         "PLL max +ve adjustment\t: %d\n"
+                         "PLL max -ve adjustment\t: %d\n"
+                         "PLL +ve adjustment factor\t: %d\n"
+                         "PLL -ve adjustment factor\t: %d\n"
+                         "PLL frequency\t: %ld\n",
+                         pll.pll_value,
+                         pll.pll_max,
+                         pll.pll_min,
+                         pll.pll_posmult,
+                         pll.pll_negmult,
+                         pll.pll_clock);
+        return p - buf;
+}
+
+static int gen_rtc_read_proc(char *page, char **start, off_t off,
+                             int count, int *eof, void *data)
+{
+        int len = gen_rtc_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;
+}
+
+static int __init gen_rtc_proc_init(void)
+{
+        struct proc_dir_entry *r;
+
+        r = create_proc_read_entry("driver/rtc", 0, NULL, gen_rtc_read_proc, NULL);
+        if (!r)
+                return -ENOMEM;
+        return 0;
+}
+#else
+static inline int gen_rtc_proc_init(void) { return 0; }
+#endif /* CONFIG_PROC_FS */
+
+
+/*
+ *      The various file operations we support.
+ */
+
+static struct file_operations gen_rtc_fops = {
+        .owner          = THIS_MODULE,
+#ifdef CONFIG_GEN_RTC_X
+        .read           = gen_rtc_read,
+        .poll           = gen_rtc_poll,
+#endif
+        .ioctl          = gen_rtc_ioctl,
+        .open           = gen_rtc_open,
+        .release        = gen_rtc_release,
+};
+
+static struct miscdevice rtc_gen_dev =
+{
+        .minor          = RTC_MINOR,
+        .name           = "rtc",
+        .fops           = &gen_rtc_fops,
+};
+
+static int __init rtc_generic_init(void)
+{
+        int retval;
+
+        printk(KERN_INFO "Generic RTC Driver v%s\n", RTC_VERSION);
+
+        retval = misc_register(&rtc_gen_dev);
+        if (retval < 0)
+                return retval;
+
+        retval = gen_rtc_proc_init();
+        if (retval) {
+                misc_deregister(&rtc_gen_dev);
+                return retval;
+        }
+
+        return 0;
+}
+
+static void __exit rtc_generic_exit(void)
+{
+        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);