Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / arm / mach-rpc / time.c

diff --git a/kernel/arch/arm/mach-rpc/time.c b/kernel/arch/arm/mach-rpc/time.c
new file mode 100644 (file)
index 0000000..2689771
--- /dev/null
+++ b/kernel/arch/arm/mach-rpc/time.c
@@ -0,0 +1,92 @@
+/*
+ *  linux/arch/arm/common/time-acorn.c
+ *
+ *  Copyright (c) 1996-2000 Russell King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  Changelog:
+ *   24-Sep-1996       RMK     Created
+ *   10-Oct-1996       RMK     Brought up to date with arch-sa110eval
+ *   04-Dec-1997       RMK     Updated for new arch/arm/time.c
+ *   13=Jun-2004       DS      Moved to arch/arm/common b/c shared w/CLPS7500
+ */
+#include <linux/timex.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <mach/hardware.h>
+#include <asm/hardware/ioc.h>
+
+#include <asm/mach/time.h>
+
+#define RPC_CLOCK_FREQ 2000000
+#define RPC_LATCH DIV_ROUND_CLOSEST(RPC_CLOCK_FREQ, HZ)
+
+static u32 ioc_timer_gettimeoffset(void)
+{
+       unsigned int count1, count2, status;
+       long offset;
+
+       ioc_writeb (0, IOC_T0LATCH);
+       barrier ();
+       count1 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
+       barrier ();
+       status = ioc_readb(IOC_IRQREQA);
+       barrier ();
+       ioc_writeb (0, IOC_T0LATCH);
+       barrier ();
+       count2 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
+
+       offset = count2;
+       if (count2 < count1) {
+               /*
+                * We have not had an interrupt between reading count1
+                * and count2.
+                */
+               if (status & (1 << 5))
+                       offset -= RPC_LATCH;
+       } else if (count2 > count1) {
+               /*
+                * We have just had another interrupt between reading
+                * count1 and count2.
+                */
+               offset -= RPC_LATCH;
+       }
+
+       offset = (RPC_LATCH - offset) * (tick_nsec / 1000);
+       return DIV_ROUND_CLOSEST(offset, RPC_LATCH) * 1000;
+}
+
+void __init ioctime_init(void)
+{
+       ioc_writeb(RPC_LATCH & 255, IOC_T0LTCHL);
+       ioc_writeb(RPC_LATCH >> 8, IOC_T0LTCHH);
+       ioc_writeb(0, IOC_T0GO);
+}
+
+static irqreturn_t
+ioc_timer_interrupt(int irq, void *dev_id)
+{
+       timer_tick();
+       return IRQ_HANDLED;
+}
+
+static struct irqaction ioc_timer_irq = {
+       .name           = "timer",
+       .handler        = ioc_timer_interrupt
+};
+
+/*
+ * Set up timer interrupt.
+ */
+void __init ioc_timer_init(void)
+{
+       arch_gettimeoffset = ioc_timer_gettimeoffset;
+       ioctime_init();
+       setup_irq(IRQ_TIMER0, &ioc_timer_irq);
+}