Merge branch 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  clocksource: convert mips to generic i8253 clocksource
  clocksource: convert x86 to generic i8253 clocksource
  clocksource: convert footbridge to generic i8253 clocksource
  clocksource: add common i8253 PIT clocksource
  blackfin: convert to clocksource_register_hz
  mips: convert to clocksource_register_hz/khz
  sparc: convert to clocksource_register_hz/khz
  alpha: convert to clocksource_register_hz
  microblaze: convert to clocksource_register_hz/khz
  ia64: convert to clocksource_register_hz/khz
  x86: Convert remaining x86 clocksources to clocksource_register_hz/khz
  Make clocksource name const

6 files changed, 97 insertions, 13 deletions

diff --git a/drivers/Kconfig b/drivers/Kconfig
index 177c7d156933..557a469c7aa6 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -119,4 +119,7 @@ source "drivers/platform/Kconfig"
 source "drivers/clk/Kconfig"
 
 source "drivers/hwspinlock/Kconfig"
+
+source "drivers/clocksource/Kconfig"
+
 endmenu
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 7066e801b9d3..051474c65b78 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -84,8 +84,6 @@ static struct clocksource clocksource_hpet = {
         .rating         = 250,
         .read           = read_hpet,
         .mask           = CLOCKSOURCE_MASK(64),
-        .mult           = 0,            /* to be calculated */
-        .shift          = 10,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 static struct clocksource *hpet_clocksource;
@@ -934,9 +932,7 @@ int hpet_alloc(struct hpet_data *hdp)
         if (!hpet_clocksource) {
                 hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc;
                 CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr);
-                clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq,
-                                                clocksource_hpet.shift);
-                clocksource_register(&clocksource_hpet);
+                clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq);
                 hpetp->hp_clocksource = &clocksource_hpet;
                 hpet_clocksource = &clocksource_hpet;
         }
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
new file mode 100644
index 000000000000..110aeeb52f9a
--- /dev/null
+++ b/drivers/clocksource/Kconfig
@@ -0,0 +1,2 @@
+config CLKSRC_I8253
+        bool
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index be61ece6330b..cfb6383b543a 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC)	+= cs5535-clockevt.o
 obj-$(CONFIG_SH_TIMER_CMT)      += sh_cmt.o
 obj-$(CONFIG_SH_TIMER_MTU2)     += sh_mtu2.o
 obj-$(CONFIG_SH_TIMER_TMU)      += sh_tmu.o
+obj-$(CONFIG_CLKSRC_I8253)      += i8253.o
diff --git a/drivers/clocksource/cyclone.c b/drivers/clocksource/cyclone.c
index 64e528e8bfa6..72f811f73e9c 100644
--- a/drivers/clocksource/cyclone.c
+++ b/drivers/clocksource/cyclone.c
@@ -29,8 +29,6 @@ static struct clocksource clocksource_cyclone = {
         .rating         = 250,
         .read           = read_cyclone,
         .mask           = CYCLONE_TIMER_MASK,
-        .mult           = 10,
-        .shift          = 0,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
@@ -108,12 +106,8 @@ static int __init init_cyclone_clocksource(void)
         }
         cyclone_ptr = cyclone_timer;
 
-        /* sort out mult/shift values: */
-        clocksource_cyclone.shift = 22;
-        clocksource_cyclone.mult = clocksource_hz2mult(CYCLONE_TIMER_FREQ,
-                                                clocksource_cyclone.shift);
-
-        return clocksource_register(&clocksource_cyclone);
+        return clocksource_register_hz(&clocksource_cyclone,
+                                        CYCLONE_TIMER_FREQ);
 }
 
 arch_initcall(init_cyclone_clocksource);
diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c
new file mode 100644
index 000000000000..225c1761b372
--- /dev/null
+++ b/drivers/clocksource/i8253.c
@@ -0,0 +1,88 @@
+/*
+ * i8253 PIT clocksource
+ */
+#include <linux/clocksource.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/spinlock.h>
+#include <linux/timex.h>
+
+#include <asm/i8253.h>
+
+/*
+ * Since the PIT overflows every tick, its not very useful
+ * to just read by itself. So use jiffies to emulate a free
+ * running counter:
+ */
+static cycle_t i8253_read(struct clocksource *cs)
+{
+        static int old_count;
+        static u32 old_jifs;
+        unsigned long flags;
+        int count;
+        u32 jifs;
+
+        raw_spin_lock_irqsave(&i8253_lock, flags);
+        /*
+         * Although our caller may have the read side of xtime_lock,
+         * this is now a seqlock, and we are cheating in this routine
+         * by having side effects on state that we cannot undo if
+         * there is a collision on the seqlock and our caller has to
+         * retry.  (Namely, old_jifs and old_count.)  So we must treat
+         * jiffies as volatile despite the lock.  We read jiffies
+         * before latching the timer count to guarantee that although
+         * the jiffies value might be older than the count (that is,
+         * the counter may underflow between the last point where
+         * jiffies was incremented and the point where we latch the
+         * count), it cannot be newer.
+         */
+        jifs = jiffies;
+        outb_pit(0x00, PIT_MODE);       /* latch the count ASAP */
+        count = inb_pit(PIT_CH0);       /* read the latched count */
+        count |= inb_pit(PIT_CH0) << 8;
+
+        /* VIA686a test code... reset the latch if count > max + 1 */
+        if (count > LATCH) {
+                outb_pit(0x34, PIT_MODE);
+                outb_pit(PIT_LATCH & 0xff, PIT_CH0);
+                outb_pit(PIT_LATCH >> 8, PIT_CH0);
+                count = PIT_LATCH - 1;
+        }
+
+        /*
+         * It's possible for count to appear to go the wrong way for a
+         * couple of reasons:
+         *
+         *  1. The timer counter underflows, but we haven't handled the
+         *     resulting interrupt and incremented jiffies yet.
+         *  2. Hardware problem with the timer, not giving us continuous time,
+         *     the counter does small "jumps" upwards on some Pentium systems,
+         *     (see c't 95/10 page 335 for Neptun bug.)
+         *
+         * Previous attempts to handle these cases intelligently were
+         * buggy, so we just do the simple thing now.
+         */
+        if (count > old_count && jifs == old_jifs)
+                count = old_count;
+
+        old_count = count;
+        old_jifs = jifs;
+
+        raw_spin_unlock_irqrestore(&i8253_lock, flags);
+
+        count = (PIT_LATCH - 1) - count;
+
+        return (cycle_t)(jifs * PIT_LATCH) + count;
+}
+
+static struct clocksource i8253_cs = {
+        .name           = "pit",
+        .rating         = 110,
+        .read           = i8253_read,
+        .mask           = CLOCKSOURCE_MASK(32),
+};
+
+int __init clocksource_i8253_init(void)
+{
+        return clocksource_register_hz(&i8253_cs, PIT_TICK_RATE);
+}