[POWERPC] Implement {read,update}_persistent_clock
authorTony Breeds <tony@bakeyournoodle.com>
Fri, 21 Sep 2007 03:26:02 +0000 (13:26 +1000)
committerPaul Mackerras <paulus@samba.org>
Wed, 3 Oct 2007 01:48:42 +0000 (11:48 +1000)
With these functions implemented we cooperate better with the generic
timekeeping code.  This obsoletes the need for the timer sysdev as a bonus.

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
arch/powerpc/Kconfig
arch/powerpc/kernel/time.c
arch/powerpc/sysdev/Makefile
arch/powerpc/sysdev/timer.c [deleted file]

index 45e86c751f118e78f998dececf0c418460224125..6468cd9d72e4bdfa876d82b7970d9077f093041a 100644 (file)
@@ -26,6 +26,9 @@ config MMU
        bool
        default y
 
+config GENERIC_CMOS_UPDATE
+       def_bool y
+
 config GENERIC_HARDIRQS
        bool
        default y
index d95e68c0a6b34324b4ddd394bd71a525d54b4f0d..b94e4dffba1920beb3ea431721dd94dffbd53bb1 100644 (file)
 #include <asm/iseries/hv_call_xm.h>
 #endif
 
-/* keep track of when we need to update the rtc */
-time_t last_rtc_update;
 #ifdef CONFIG_PPC_ISERIES
 static unsigned long __initdata iSeries_recal_titan;
 static signed long __initdata iSeries_recal_tb;
 #endif
 
-/* The decrementer counts down by 128 every 128ns on a 601. */
-#define DECREMENTER_COUNT_601  (1000000000 / HZ)
-
 #define XSEC_PER_SEC (1024*1024)
 
 #ifdef CONFIG_PPC64
@@ -348,39 +343,6 @@ void udelay(unsigned long usecs)
 }
 EXPORT_SYMBOL(udelay);
 
-static __inline__ void timer_check_rtc(void)
-{
-        /*
-         * update the rtc when needed, this should be performed on the
-         * right fraction of a second. Half or full second ?
-         * Full second works on mk48t59 clocks, others need testing.
-         * Note that this update is basically only used through 
-         * the adjtimex system calls. Setting the HW clock in
-         * any other way is a /dev/rtc and userland business.
-         * This is still wrong by -0.5/+1.5 jiffies because of the
-         * timer interrupt resolution and possible delay, but here we 
-         * hit a quantization limit which can only be solved by higher
-         * resolution timers and decoupling time management from timer
-         * interrupts. This is also wrong on the clocks
-         * which require being written at the half second boundary.
-         * We should have an rtc call that only sets the minutes and
-         * seconds like on Intel to avoid problems with non UTC clocks.
-         */
-        if (ppc_md.set_rtc_time && ntp_synced() &&
-           xtime.tv_sec - last_rtc_update >= 659 &&
-           abs((xtime.tv_nsec/1000) - (1000000-1000000/HZ)) < 500000/HZ) {
-               struct rtc_time tm;
-               to_tm(xtime.tv_sec + 1 + timezone_offset, &tm);
-               tm.tm_year -= 1900;
-               tm.tm_mon -= 1;
-               if (ppc_md.set_rtc_time(&tm) == 0)
-                       last_rtc_update = xtime.tv_sec + 1;
-               else
-                       /* Try again one minute later */
-                       last_rtc_update += 60;
-        }
-}
-
 /*
  * This version of gettimeofday has microsecond resolution.
  */
@@ -689,7 +651,6 @@ void timer_interrupt(struct pt_regs * regs)
                        tb_last_jiffy = tb_next_jiffy;
                        do_timer(1);
                        timer_recalc_offset(tb_last_jiffy);
-                       timer_check_rtc();
                }
                write_sequnlock(&xtime_lock);
        }
@@ -801,11 +762,6 @@ int do_settimeofday(struct timespec *tv)
        set_normalized_timespec(&xtime, new_sec, new_nsec);
        set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
 
-       /* In case of a large backwards jump in time with NTP, we want the 
-        * clock to be updated as soon as the PLL is again in lock.
-        */
-       last_rtc_update = new_sec - 658;
-
        ntp_clear();
 
        new_xsec = xtime.tv_nsec;
@@ -881,12 +837,35 @@ void __init generic_calibrate_decr(void)
 #endif
 }
 
-unsigned long get_boot_time(void)
+int update_persistent_clock(struct timespec now)
+{
+       struct rtc_time tm;
+
+       if (!ppc_md.set_rtc_time)
+               return 0;
+
+       to_tm(now.tv_sec + 1 + timezone_offset, &tm);
+       tm.tm_year -= 1900;
+       tm.tm_mon -= 1;
+
+       return ppc_md.set_rtc_time(&tm);
+}
+
+unsigned long read_persistent_clock(void)
 {
        struct rtc_time tm;
+       static int first = 1;
+
+       /* XXX this is a litle fragile but will work okay in the short term */
+       if (first) {
+               first = 0;
+               if (ppc_md.time_init)
+                       timezone_offset = ppc_md.time_init();
 
-       if (ppc_md.get_boot_time)
-               return ppc_md.get_boot_time();
+               /* get_boot_time() isn't guaranteed to be safe to call late */
+               if (ppc_md.get_boot_time)
+                       return ppc_md.get_boot_time() -timezone_offset;
+       }
        if (!ppc_md.get_rtc_time)
                return 0;
        ppc_md.get_rtc_time(&tm);
@@ -898,14 +877,10 @@ unsigned long get_boot_time(void)
 void __init time_init(void)
 {
        unsigned long flags;
-       unsigned long tm = 0;
        struct div_result res;
        u64 scale, x;
        unsigned shift;
 
-        if (ppc_md.time_init != NULL)
-                timezone_offset = ppc_md.time_init();
-
        if (__USE_RTC()) {
                /* 601 processor: dec counts down by 128 every 128ns */
                ppc_tb_freq = 1000000000;
@@ -980,19 +955,14 @@ void __init time_init(void)
        /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
        boot_tb = get_tb_or_rtc();
 
-       tm = get_boot_time();
-
        write_seqlock_irqsave(&xtime_lock, flags);
 
        /* If platform provided a timezone (pmac), we correct the time */
         if (timezone_offset) {
                sys_tz.tz_minuteswest = -timezone_offset / 60;
                sys_tz.tz_dsttime = 0;
-               tm -= timezone_offset;
         }
 
-       xtime.tv_sec = tm;
-       xtime.tv_nsec = 0;
        do_gtod.varp = &do_gtod.vars[0];
        do_gtod.var_idx = 0;
        do_gtod.varp->tb_orig_stamp = tb_last_jiffy;
@@ -1010,9 +980,6 @@ void __init time_init(void)
 
        time_freq = 0;
 
-       last_rtc_update = xtime.tv_sec;
-       set_normalized_timespec(&wall_to_monotonic,
-                               -xtime.tv_sec, -xtime.tv_nsec);
        write_sequnlock_irqrestore(&xtime_lock, flags);
 
        /* Not exact, but the timer interrupt takes care of this */
index ed41dc0a310f35816c8647a436711d9dcfd4108c..b0ea8e9495e8319d6f2f16a9dcc9a6b7c8ec1c9c 100644 (file)
@@ -21,11 +21,6 @@ obj-$(CONFIG_MV64X60)                += $(mv64x60-y) mv64x60_pic.o mv64x60_dev.o \
 obj-$(CONFIG_RTC_DRV_CMOS)     += rtc_cmos_setup.o
 obj-$(CONFIG_AXON_RAM)         += axonram.o
 
-# contains only the suspend handler for time
-ifeq ($(CONFIG_RTC_CLASS),)
-obj-$(CONFIG_PM)               += timer.o
-endif
-
 ifeq ($(CONFIG_PPC_MERGE),y)
 obj-$(CONFIG_PPC_INDIRECT_PCI) += indirect_pci.o
 obj-$(CONFIG_PPC_I8259)                += i8259.o
diff --git a/arch/powerpc/sysdev/timer.c b/arch/powerpc/sysdev/timer.c
deleted file mode 100644 (file)
index e81e7ec..0000000
+++ /dev/null
@@ -1,81 +0,0 @@
-/*
- * Common code to keep time when machine suspends.
- *
- * Copyright 2007      Johannes Berg <johannes@sipsolutions.net>
- *
- * GPLv2
- */
-
-#include <linux/time.h>
-#include <linux/sysdev.h>
-#include <asm/rtc.h>
-
-static unsigned long suspend_rtc_time;
-
-/*
- * Reset the time after a sleep.
- */
-static int timer_resume(struct sys_device *dev)
-{
-       struct timeval tv;
-       struct timespec ts;
-       struct rtc_time cur_rtc_tm;
-       unsigned long cur_rtc_time, diff;
-
-       /* get current RTC time and convert to seconds */
-       get_rtc_time(&cur_rtc_tm);
-       cur_rtc_time = mktime(cur_rtc_tm.tm_year + 1900,
-                             cur_rtc_tm.tm_mon + 1,
-                             cur_rtc_tm.tm_mday,
-                             cur_rtc_tm.tm_hour,
-                             cur_rtc_tm.tm_min,
-                             cur_rtc_tm.tm_sec);
-
-       diff = cur_rtc_time - suspend_rtc_time;
-
-       /* adjust time of day by seconds that elapsed while
-        * we were suspended */
-       do_gettimeofday(&tv);
-       ts.tv_sec = tv.tv_sec + diff;
-       ts.tv_nsec = tv.tv_usec * NSEC_PER_USEC;
-       do_settimeofday(&ts);
-
-       return 0;
-}
-
-static int timer_suspend(struct sys_device *dev, pm_message_t state)
-{
-       struct rtc_time suspend_rtc_tm;
-       WARN_ON(!ppc_md.get_rtc_time);
-
-       get_rtc_time(&suspend_rtc_tm);
-       suspend_rtc_time = mktime(suspend_rtc_tm.tm_year + 1900,
-                                 suspend_rtc_tm.tm_mon + 1,
-                                 suspend_rtc_tm.tm_mday,
-                                 suspend_rtc_tm.tm_hour,
-                                 suspend_rtc_tm.tm_min,
-                                 suspend_rtc_tm.tm_sec);
-
-       return 0;
-}
-
-static struct sysdev_class timer_sysclass = {
-       .resume = timer_resume,
-       .suspend = timer_suspend,
-       set_kset_name("timer"),
-};
-
-static struct sys_device device_timer = {
-       .id = 0,
-       .cls = &timer_sysclass,
-};
-
-static int time_init_device(void)
-{
-       int error = sysdev_class_register(&timer_sysclass);
-       if (!error)
-               error = sysdev_register(&device_timer);
-       return error;
-}
-
-device_initcall(time_init_device);