From b1ba4c50963db865b57092cd2ff9676e629aacf1 Mon Sep 17 00:00:00 2001
From: Florian Fainelli <florian@openwrt.org>
Date: Sat, 4 Apr 2015 18:01:07 +0000
Subject: mcs814x: add support for 3.18

Signed-off-by: Florian Fainelli <florian@openwrt.org>

SVN-Revision: 45273
---
 .../files-3.18/arch/arm/mach-mcs814x/timer.c       | 132 +++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 target/linux/mcs814x/files-3.18/arch/arm/mach-mcs814x/timer.c

(limited to 'target/linux/mcs814x/files-3.18/arch/arm/mach-mcs814x/timer.c')

diff --git a/target/linux/mcs814x/files-3.18/arch/arm/mach-mcs814x/timer.c b/target/linux/mcs814x/files-3.18/arch/arm/mach-mcs814x/timer.c
new file mode 100644
index 0000000000..ff9d44aa6e
--- /dev/null
+++ b/target/linux/mcs814x/files-3.18/arch/arm/mach-mcs814x/timer.c
@@ -0,0 +1,132 @@
+/*
+ * Moschip MCS814x timer routines
+ *
+ * Copyright (C) 2012, Florian Fainelli <florian@openwrt.org>
+ *
+ * Licensed under GPLv2
+ */
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include <asm/mach/time.h>
+#include <mach/mcs814x.h>
+
+/* Timer block registers */
+#define TIMER_VAL	0x00
+#define TIMER_CTL	0x04
+#define  TIMER_CTL_EN	0x01
+#define  TIMER_CTL_DBG	0x02
+
+static u32 last_reload;
+static u32 timer_correct;
+static u32 clock_rate;
+static u32 timer_reload_value;
+static void __iomem *mcs814x_timer_base;
+
+static inline u32 ticks2usecs(u32 x)
+{
+	return x / (clock_rate / 1000000);
+}
+
+/*
+ * Returns number of ms since last clock interrupt.  Note that interrupts
+ * will have been disabled by do_gettimeoffset()
+ */
+static u32 mcs814x_gettimeoffset(void)
+{
+	u32 ticks = readl_relaxed(mcs814x_timer_base + TIMER_VAL);
+
+	if (ticks < last_reload)
+		return ticks2usecs(ticks + (u32)(0xffffffff - last_reload));
+	else
+		return ticks2usecs(ticks - last_reload);
+}
+
+
+static irqreturn_t mcs814x_timer_interrupt(int irq, void *dev_id)
+{
+	u32 count = readl_relaxed(mcs814x_timer_base + TIMER_VAL);
+
+	/* take into account delay up to this moment */
+	last_reload = count + timer_correct + timer_reload_value;
+
+	if (last_reload < timer_reload_value) {
+		last_reload = timer_reload_value;
+	} else {
+		if (timer_correct == 0)
+			timer_correct = readl_relaxed(mcs814x_timer_base + TIMER_VAL) - count;
+	}
+	writel_relaxed(last_reload, mcs814x_timer_base + TIMER_VAL);
+
+	timer_tick();
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction mcs814x_timer_irq = {
+	.name		= "mcs814x-timer",
+	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= mcs814x_timer_interrupt,
+};
+
+static struct of_device_id mcs814x_timer_ids[] = {
+	{ .compatible = "moschip,mcs814x-timer" },
+	{ /* sentinel */ },
+};
+
+static void __init mcs814x_of_timer_init(void)
+{
+	struct device_node *np;
+	const unsigned int *intspec;
+
+	np = of_find_matching_node(NULL, mcs814x_timer_ids);
+	if (!np)
+		panic("unable to find compatible timer node in dtb");
+
+	mcs814x_timer_base = of_iomap(np, 0);
+	if (!mcs814x_timer_base)
+		panic("unable to remap timer cpu registers");
+
+	intspec = of_get_property(np, "interrupts", NULL);
+	if (!intspec)
+		panic("no interrupts property for timer");
+
+	mcs814x_timer_irq.irq = be32_to_cpup(intspec);
+}
+
+void __init mcs814x_timer_init(void)
+{
+	struct clk *clk;
+
+	arch_gettimeoffset = mcs814x_gettimeoffset;
+
+	clk = clk_get_sys("timer0", NULL);
+	if (IS_ERR_OR_NULL(clk))
+		panic("unable to get timer0 clock");
+
+	clock_rate = clk_get_rate(clk);
+
+	mcs814x_of_timer_init();
+
+	pr_info("Timer frequency: %d (kHz)\n", clock_rate / 1000);
+
+	timer_reload_value = 0xffffffff - (clock_rate / HZ);
+
+	/* disable timer */
+	writel_relaxed(~TIMER_CTL_EN, mcs814x_timer_base + TIMER_CTL);
+	writel_relaxed(timer_reload_value, mcs814x_timer_base + TIMER_VAL);
+	last_reload = timer_reload_value;
+
+	setup_irq(mcs814x_timer_irq.irq, &mcs814x_timer_irq);
+	/* enable timer, stop timer in debug mode */
+	writel_relaxed(TIMER_CTL_EN | TIMER_CTL_DBG,
+		mcs814x_timer_base + TIMER_CTL);
+}
-- 
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