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authorDavid S. Miller <davem@sunset.davemloft.net>2006-03-01 17:32:46 -0800
committerDavid S. Miller <davem@sunset.davemloft.net>2006-03-20 01:14:10 -0800
commit8ba706a95bb92c3b14b812f6d507890336d19136 (patch)
tree2456134d50898a7bd8efda4adcfa636ab0ea43cf /arch
parentb830ab665ad96c6b20d51a89b35cbc09ab5a2c29 (diff)
downloadlwn-8ba706a95bb92c3b14b812f6d507890336d19136.tar.gz
lwn-8ba706a95bb92c3b14b812f6d507890336d19136.zip
[SPARC64]: Add mini-RTC driver for Starfire and SUN4V.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch')
-rw-r--r--arch/sparc64/kernel/time.c279
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);