Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/arch/arm/mach-footbridge/isa-timer.c b/arch/arm/mach-footbridge/isa-timer.c
new file mode 100644
index 0000000..a4fefa0
--- /dev/null
+++ b/arch/arm/mach-footbridge/isa-timer.c
@@ -0,0 +1,94 @@
+/*
+ * linux/arch/arm/mach-footbridge/isa-timer.c
+ *
+ * Copyright (C) 1998 Russell King.
+ * Copyright (C) 1998 Phil Blundell
+ */
+#include <linux/init.h>
+#include <linux/interrupt.h>
+
+#include <asm/io.h>
+#include <asm/irq.h>
+
+#include <asm/mach/time.h>
+
+#include "common.h"
+
+/*
+ * ISA timer tick support
+ */
+#define mSEC_10_from_14 ((14318180 + 100) / 200)
+
+static unsigned long isa_gettimeoffset(void)
+{
+ int count;
+
+ static int count_p = (mSEC_10_from_14/6); /* for the first call after boot */
+ static unsigned long jiffies_p = 0;
+
+ /*
+ * cache volatile jiffies temporarily; we have IRQs turned off.
+ */
+ unsigned long jiffies_t;
+
+ /* timer count may underflow right here */
+ outb_p(0x00, 0x43); /* latch the count ASAP */
+
+ count = inb_p(0x40); /* read the latched count */
+
+ /*
+ * We do this guaranteed double memory access instead of a _p
+ * postfix in the previous port access. Wheee, hackady hack
+ */
+ jiffies_t = jiffies;
+
+ count |= inb_p(0x40) << 8;
+
+ /* Detect timer underflows. If we haven't had a timer tick since
+ the last time we were called, and time is apparently going
+ backwards, the counter must have wrapped during this routine. */
+ if ((jiffies_t == jiffies_p) && (count > count_p))
+ count -= (mSEC_10_from_14/6);
+ else
+ jiffies_p = jiffies_t;
+
+ count_p = count;
+
+ count = (((mSEC_10_from_14/6)-1) - count) * (tick_nsec / 1000);
+ count = (count + (mSEC_10_from_14/6)/2) / (mSEC_10_from_14/6);
+
+ return count;
+}
+
+static irqreturn_t
+isa_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ write_seqlock(&xtime_lock);
+ timer_tick(regs);
+ write_sequnlock(&xtime_lock);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction isa_timer_irq = {
+ .name = "ISA timer tick",
+ .handler = isa_timer_interrupt,
+ .flags = SA_INTERRUPT,
+};
+
+static void __init isa_timer_init(void)
+{
+ isa_rtc_init();
+
+ /* enable PIT timer */
+ /* set for periodic (4) and LSB/MSB write (0x30) */
+ outb(0x34, 0x43);
+ outb((mSEC_10_from_14/6) & 0xFF, 0x40);
+ outb((mSEC_10_from_14/6) >> 8, 0x40);
+
+ setup_irq(IRQ_ISA_TIMER, &isa_timer_irq);
+}
+
+struct sys_timer isa_timer = {
+ .init = isa_timer_init,
+ .offset = isa_gettimeoffset,
+};