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);
+}