v4.19.13 snapshot.
diff --git a/arch/arm/mach-footbridge/isa-timer.c b/arch/arm/mach-footbridge/isa-timer.c
new file mode 100644
index 0000000..82f4559
--- /dev/null
+++ b/arch/arm/mach-footbridge/isa-timer.c
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/arch/arm/mach-footbridge/isa-timer.c
+ *
+ * Copyright (C) 1998 Russell King.
+ * Copyright (C) 1998 Phil Blundell
+ */
+#include <linux/clockchips.h>
+#include <linux/i8253.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/spinlock.h>
+#include <linux/timex.h>
+
+#include <asm/irq.h>
+#include <asm/mach/time.h>
+
+#include "common.h"
+
+static irqreturn_t pit_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *ce = dev_id;
+ ce->event_handler(ce);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction pit_timer_irq = {
+ .name = "pit",
+ .handler = pit_timer_interrupt,
+ .flags = IRQF_TIMER | IRQF_IRQPOLL,
+ .dev_id = &i8253_clockevent,
+};
+
+void __init isa_timer_init(void)
+{
+ clocksource_i8253_init();
+
+ setup_irq(i8253_clockevent.irq, &pit_timer_irq);
+ clockevent_i8253_init(false);
+}