u5500: add MTIMER clocksource

ST-Ericsson ID: 368260
ST-Ericsson Linux next: NA
ST-Ericsson FOSS-OUT ID: Trivial

Depends-On: I5307cb7f58fdf890896d641a8e4f49098a90b68e

Change-Id: I9ef4ff1c63f6ec9293ece4013f13cf3caa707d9d
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/34307
Reviewed-by: QATOOLS
Reviewed-by: QABUILD

1 files changed, 52 insertions, 0 deletions

diff --git a/drivers/clocksource/db5500-mtimer.c b/drivers/clocksource/db5500-mtimer.c
new file mode 100644
index 00000000000..641279707a8
--- /dev/null
+++ b/drivers/clocksource/db5500-mtimer.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2011
+ *
+ * License Terms: GNU General Public License v2
+ */
+
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/clockchips.h>
+#include <linux/clksrc-db5500-mtimer.h>
+
+#include <asm/sched_clock.h>
+
+#define MTIMER_PRIMARY_COUNTER		0x18
+
+static void __iomem *db5500_mtimer_base;
+
+#ifdef CONFIG_CLKSRC_DB5500_MTIMER_SCHED_CLOCK
+static DEFINE_CLOCK_DATA(cd);
+
+unsigned long long notrace sched_clock(void)
+{
+	u32 cyc;
+
+	if (unlikely(!db5500_mtimer_base))
+		return 0;
+
+	cyc = readl_relaxed(db5500_mtimer_base + MTIMER_PRIMARY_COUNTER);
+
+	return cyc_to_sched_clock(&cd, cyc, (u32)~0);
+}
+
+static void notrace db5500_mtimer_update_sched_clock(void)
+{
+	u32 cyc = readl_relaxed(db5500_mtimer_base + MTIMER_PRIMARY_COUNTER);
+	update_sched_clock(&cd, cyc, (u32)~0);
+}
+#endif
+
+void __init db5500_mtimer_init(void __iomem *base)
+{
+	db5500_mtimer_base = base;
+
+	clocksource_mmio_init(base + MTIMER_PRIMARY_COUNTER, "mtimer", 32768,
+			      400, 32, clocksource_mmio_readl_up);
+
+#ifdef CONFIG_CLKSRC_DB5500_MTIMER_SCHED_CLOCK
+	init_sched_clock(&cd, db5500_mtimer_update_sched_clock,
+			 32, 32768);
+#endif
+}