1 files changed, 96 insertions, 0 deletions
diff --git a/target/linux/oxnas/files/drivers/clocksource/oxnas_rps_timer.c b/target/linux/oxnas/files/drivers/clocksource/oxnas_rps_timer.c
new file mode 100644
index 0000000000..7c8c4cf435
--- /dev/null
+++ b/target/linux/oxnas/files/drivers/clocksource/oxnas_rps_timer.c
@@ -0,0 +1,96 @@
+/*
+ * arch/arm/mach-ox820/rps-time.c
+ *
+ * Copyright (C) 2009 Oxford Semiconductor Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <linux/clockchips.h>
+#include <linux/clk.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/sched_clock.h>
+#include <mach/hardware.h>
+
+enum {
+	TIMER_LOAD = 0,
+	TIMER_CURR = 4,
+	TIMER_CTRL = 8,
+	TIMER_CLRINT = 0xC,
+
+	TIMER_BITS = 24,
+
+	TIMER_MAX_VAL = (1 << TIMER_BITS) - 1,
+
+	TIMER_PERIODIC = (1 << 6),
+	TIMER_ENABLE = (1 << 7),
+
+	TIMER_DIV1  = (0 << 2),
+	TIMER_DIV16  = (1 << 2),
+	TIMER_DIV256  = (2 << 2),
+
+	TIMER1_OFFSET = 0,
+	TIMER2_OFFSET = 0x20,
+
+};
+
+static u64 notrace rps_read_sched_clock(void)
+{
+	return ~readl_relaxed(RPSA_TIMER2_VAL);
+}
+
+static void __init rps_clocksource_init(void __iomem *base, ulong ref_rate)
+{
+	int ret;
+	ulong clock_rate;
+	/* use prescale 16 */
+	clock_rate = ref_rate / 16;
+
+	iowrite32(TIMER_MAX_VAL, base + TIMER_LOAD);
+	iowrite32(TIMER_PERIODIC | TIMER_ENABLE | TIMER_DIV16,
+			base + TIMER_CTRL);
+
+	ret = clocksource_mmio_init(base + TIMER_CURR, "rps_clocksource_timer",
+					clock_rate, 250, TIMER_BITS,
+					clocksource_mmio_readl_down);
+	if (ret)
+		panic("can't register clocksource\n");
+
+	sched_clock_register(rps_read_sched_clock, TIMER_BITS, clock_rate);
+}
+
+static void __init rps_timer_init(struct device_node *np)
+{
+	struct clk *refclk;
+	unsigned long ref_rate;
+	void __iomem *base;
+
+	refclk = of_clk_get(np, 0);
+
+	if (IS_ERR(refclk) || clk_prepare_enable(refclk))
+		panic("rps_timer_init: failed to get refclk\n");
+	ref_rate = clk_get_rate(refclk);
+
+	base = of_iomap(np, 0);
+	if (!base)
+		panic("rps_timer_init: failed to map io\n");
+
+	rps_clocksource_init(base + TIMER2_OFFSET, ref_rate);
+}
+
+CLOCKSOURCE_OF_DECLARE(nas782x, "plxtech,nas782x-rps-timer", rps_timer_init);