MIPS: JZ4740: Add timer support

Add support for the timer/counter unit on a JZ4740 SoC.  This code is used
as a common base for the JZ4740 clocksource/clockevent implementation and
PWM support.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1396/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 48 insertions, 0 deletions

diff --git a/arch/mips/jz4740/timer.c b/arch/mips/jz4740/timer.c
new file mode 100644
index 000000000000..b2c015129055
--- /dev/null
+++ b/arch/mips/jz4740/timer.c
@@ -0,0 +1,48 @@
+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  JZ4740 platform timer support
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under  the terms of the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include "timer.h"
+
+#include <asm/mach-jz4740/base.h>
+
+void __iomem *jz4740_timer_base;
+
+void jz4740_timer_enable_watchdog(void)
+{
+        writel(BIT(16), jz4740_timer_base + JZ_REG_TIMER_STOP_CLEAR);
+}
+
+void jz4740_timer_disable_watchdog(void)
+{
+        writel(BIT(16), jz4740_timer_base + JZ_REG_TIMER_STOP_SET);
+}
+
+void __init jz4740_timer_init(void)
+{
+        jz4740_timer_base = ioremap(JZ4740_TCU_BASE_ADDR, 0x100);
+
+        if (!jz4740_timer_base)
+                panic("Failed to ioremap timer registers");
+
+        /* Disable all timer clocks except for those used as system timers */
+        writel(0x000100fc, jz4740_timer_base + JZ_REG_TIMER_STOP_SET);
+
+        /* Timer irqs are unmasked by default, mask them */
+        writel(0x00ff00ff, jz4740_timer_base + JZ_REG_TIMER_MASK_SET);
+}