1 files changed, 98 insertions, 0 deletions
diff --git a/kernel/arch/mips/mti-sead3/sead3-time.c b/kernel/arch/mips/mti-sead3/sead3-time.c
new file mode 100644
index 000000000..e1d69895f
--- /dev/null
+++ b/kernel/arch/mips/mti-sead3/sead3-time.c
@@ -0,0 +1,98 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc.  All rights reserved.
+ */
+#include <linux/init.h>
+#include <linux/irqchip/mips-gic.h>
+
+#include <asm/cpu.h>
+#include <asm/setup.h>
+#include <asm/time.h>
+#include <asm/irq.h>
+#include <asm/mips-boards/generic.h>
+
+static void __iomem *status_reg = (void __iomem *)0xbf000410;
+
+/*
+ * Estimate CPU frequency.  Sets mips_hpt_frequency as a side-effect.
+ */
+static unsigned int __init estimate_cpu_frequency(void)
+{
+	unsigned int prid = read_c0_prid() & (PRID_COMP_MASK | PRID_IMP_MASK);
+	unsigned int tick = 0;
+	unsigned int freq;
+	unsigned int orig;
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	orig = readl(status_reg) & 0x2;		      /* get original sample */
+	/* wait for transition */
+	while ((readl(status_reg) & 0x2) == orig)
+		;
+	orig = orig ^ 0x2;			      /* flip the bit */
+
+	write_c0_count(0);
+
+	/* wait 1 second (the sampling clock transitions every 10ms) */
+	while (tick < 100) {
+		/* wait for transition */
+		while ((readl(status_reg) & 0x2) == orig)
+			;
+		orig = orig ^ 0x2;			      /* flip the bit */
+		tick++;
+	}
+
+	freq = read_c0_count();
+
+	local_irq_restore(flags);
+
+	mips_hpt_frequency = freq;
+
+	/* Adjust for processor */
+	if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) &&
+		(prid != (PRID_COMP_MIPS | PRID_IMP_25KF)))
+		freq *= 2;
+
+	freq += 5000;	     /* rounding */
+	freq -= freq%10000;
+
+	return freq ;
+}
+
+void read_persistent_clock(struct timespec *ts)
+{
+	ts->tv_sec = 0;
+	ts->tv_nsec = 0;
+}
+
+int get_c0_perfcount_int(void)
+{
+	if (gic_present)
+		return gic_get_c0_perfcount_int();
+	if (cp0_perfcount_irq >= 0)
+		return MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
+	return -1;
+}
+
+unsigned int get_c0_compare_int(void)
+{
+	if (gic_present)
+		return gic_get_c0_compare_int();
+	return MIPS_CPU_IRQ_BASE + cp0_compare_irq;
+}
+
+void __init plat_time_init(void)
+{
+	unsigned int est_freq;
+
+	est_freq = estimate_cpu_frequency();
+
+	pr_debug("CPU frequency %d.%02d MHz\n", (est_freq / 1000000),
+		(est_freq % 1000000) * 100 / 1000000);
+
+	mips_scroll_message();
+}