[SPARC64]: Add mini-RTC driver for Starfire and SUN4V.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 279 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/time.c b/arch/sparc64/kernel/time.c
index f6275adbc811..d50ebeae144a 100644
--- a/arch/sparc64/kernel/time.c
+++ b/arch/sparc64/kernel/time.c
@@ -30,6 +30,8 @@
 #include <linux/cpufreq.h>
 #include <linux/percpu.h>
 #include <linux/profile.h>
+#include <linux/miscdevice.h>
+#include <linux/rtc.h>
 
 #include <asm/oplib.h>
 #include <asm/mostek.h>
@@ -45,6 +47,7 @@
 #include <asm/smp.h>
 #include <asm/sections.h>
 #include <asm/cpudata.h>
+#include <asm/uaccess.h>
 
 DEFINE_SPINLOCK(mostek_lock);
 DEFINE_SPINLOCK(rtc_lock);
@@ -702,6 +705,14 @@ static u32 starfire_get_time(void)
         return unix_tod;
 }
 
+static int starfire_set_time(u32 val)
+{
+        /* Do nothing, time is set using the service processor
+         * console on this platform.
+         */
+        return 0;
+}
+
 static u32 hypervisor_get_time(void)
 {
         register unsigned long func asm("%o5");
@@ -731,6 +742,33 @@ retry:
         return 0;
 }
 
+static int hypervisor_set_time(u32 secs)
+{
+        register unsigned long func asm("%o5");
+        register unsigned long arg0 asm("%o0");
+        int retries = 10000;
+
+retry:
+        func = HV_FAST_TOD_SET;
+        arg0 = secs;
+        __asm__ __volatile__("ta        %4"
+                             : "=&r" (func), "=&r" (arg0)
+                             : "0" (func), "1" (arg0),
+                               "i" (HV_FAST_TRAP));
+        if (arg0 == HV_EOK)
+                return 0;
+        if (arg0 == HV_EWOULDBLOCK) {
+                if (--retries > 0) {
+                        udelay(100);
+                        goto retry;
+                }
+                printk(KERN_WARNING "SUN4V: tod_set() timed out.\n");
+                return -EAGAIN;
+        }
+        printk(KERN_WARNING "SUN4V: tod_set() not supported.\n");
+        return -EOPNOTSUPP;
+}
+
 void __init clock_probe(void)
 {
         struct linux_prom_registers clk_reg[2];
@@ -1221,3 +1259,244 @@ static int set_rtc_mmss(unsigned long nowtime)
                 return retval;
         }
 }
+
+#define RTC_IS_OPEN             0x01    /* means /dev/rtc is in use     */
+static unsigned char mini_rtc_status;   /* bitmapped status byte.       */
+
+/* months start at 0 now */
+static unsigned char days_in_mo[] =
+{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+#define FEBRUARY        2
+#define STARTOFTIME     1970
+#define SECDAY          86400L
+#define SECYR           (SECDAY * 365)
+#define leapyear(year)          ((year) % 4 == 0 && \
+                                 ((year) % 100 != 0 || (year) % 400 == 0))
+#define days_in_year(a)         (leapyear(a) ? 366 : 365)
+#define days_in_month(a)        (month_days[(a) - 1])
+
+static int month_days[12] = {
+        31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+/*
+ * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
+ */
+static void GregorianDay(struct rtc_time * tm)
+{
+        int leapsToDate;
+        int lastYear;
+        int day;
+        int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
+
+        lastYear = tm->tm_year - 1;
+
+        /*
+         * Number of leap corrections to apply up to end of last year
+         */
+        leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;
+
+        /*
+         * This year is a leap year if it is divisible by 4 except when it is
+         * divisible by 100 unless it is divisible by 400
+         *
+         * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
+         */
+        day = tm->tm_mon > 2 && leapyear(tm->tm_year);
+
+        day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
+                   tm->tm_mday;
+
+        tm->tm_wday = day % 7;
+}
+
+static void to_tm(int tim, struct rtc_time *tm)
+{
+        register int    i;
+        register long   hms, day;
+
+        day = tim / SECDAY;
+        hms = tim % SECDAY;
+
+        /* Hours, minutes, seconds are easy */
+        tm->tm_hour = hms / 3600;
+        tm->tm_min = (hms % 3600) / 60;
+        tm->tm_sec = (hms % 3600) % 60;
+
+        /* Number of years in days */
+        for (i = STARTOFTIME; day >= days_in_year(i); i++)
+                day -= days_in_year(i);
+        tm->tm_year = i;
+
+        /* Number of months in days left */
+        if (leapyear(tm->tm_year))
+                days_in_month(FEBRUARY) = 29;
+        for (i = 1; day >= days_in_month(i); i++)
+                day -= days_in_month(i);
+        days_in_month(FEBRUARY) = 28;
+        tm->tm_mon = i;
+
+        /* Days are what is left over (+1) from all that. */
+        tm->tm_mday = day + 1;
+
+        /*
+         * Determine the day of week
+         */
+        GregorianDay(tm);
+}
+
+/* Both Starfire and SUN4V give us seconds since Jan 1st, 1970,
+ * aka Unix time.  So we have to convert to/from rtc_time.
+ */
+static inline void mini_get_rtc_time(struct rtc_time *time)
+{
+        unsigned long flags;
+        u32 seconds;
+
+        spin_lock_irqsave(&rtc_lock, flags);
+        seconds = 0;
+        if (this_is_starfire)
+                seconds = starfire_get_time();
+        else if (tlb_type == hypervisor)
+                seconds = hypervisor_get_time();
+        spin_unlock_irqrestore(&rtc_lock, flags);
+
+        to_tm(seconds, time);
+}
+
+static inline int mini_set_rtc_time(struct rtc_time *time)
+{
+        u32 seconds = mktime(time->tm_year + 1900, time->tm_mon + 1,
+                             time->tm_mday, time->tm_hour,
+                             time->tm_min, time->tm_sec);
+        unsigned long flags;
+        int err;
+
+        spin_lock_irqsave(&rtc_lock, flags);
+        err = -ENODEV;
+        if (this_is_starfire)
+                err = starfire_set_time(seconds);
+        else  if (tlb_type == hypervisor)
+                err = hypervisor_set_time(seconds);
+        spin_unlock_irqrestore(&rtc_lock, flags);
+
+        return err;
+}
+
+static int mini_rtc_ioctl(struct inode *inode, struct file *file,
+                          unsigned int cmd, unsigned long arg)
+{
+        struct rtc_time wtime;
+        void __user *argp = (void __user *)arg;
+
+        switch (cmd) {
+
+        case RTC_PLL_GET:
+                return -EINVAL;
+
+        case RTC_PLL_SET:
+                return -EINVAL;
+
+        case RTC_UIE_OFF:       /* disable ints from RTC updates.       */
+                return 0;
+
+        case RTC_UIE_ON:        /* enable ints for RTC updates. */
+                return -EINVAL;
+
+        case RTC_RD_TIME:       /* Read the time/date from RTC  */
+                /* this doesn't get week-day, who cares */
+                memset(&wtime, 0, sizeof(wtime));
+                mini_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 mini_set_rtc_time(&wtime);
+            }
+        }
+
+        return -EINVAL;
+}
+
+static int mini_rtc_open(struct inode *inode, struct file *file)
+{
+        if (mini_rtc_status & RTC_IS_OPEN)
+                return -EBUSY;
+
+        mini_rtc_status |= RTC_IS_OPEN;
+
+        return 0;
+}
+
+static int mini_rtc_release(struct inode *inode, struct file *file)
+{
+        mini_rtc_status &= ~RTC_IS_OPEN;
+        return 0;
+}
+
+
+static struct file_operations mini_rtc_fops = {
+        .owner          = THIS_MODULE,
+        .ioctl          = mini_rtc_ioctl,
+        .open           = mini_rtc_open,
+        .release        = mini_rtc_release,
+};
+
+static struct miscdevice rtc_mini_dev =
+{
+        .minor          = RTC_MINOR,
+        .name           = "rtc",
+        .fops           = &mini_rtc_fops,
+};
+
+static int __init rtc_mini_init(void)
+{
+        int retval;
+
+        if (tlb_type != hypervisor && !this_is_starfire)
+                return -ENODEV;
+
+        printk(KERN_INFO "Mini RTC Driver\n");
+
+        retval = misc_register(&rtc_mini_dev);
+        if (retval < 0)
+                return retval;
+
+        return 0;
+}
+
+static void __exit rtc_mini_exit(void)
+{
+        misc_deregister(&rtc_mini_dev);
+}
+
+
+module_init(rtc_mini_init);
+module_exit(rtc_mini_exit);