Initial import

1 files changed, 247 insertions, 0 deletions

diff --git a/arch/arm/mach-mmp/time.c b/arch/arm/mach-mmp/time.c
new file mode 100644
index 000000000..10bfa03e5
--- /dev/null
+++ b/arch/arm/mach-mmp/time.c
@@ -0,0 +1,247 @@
+/*
+ * linux/arch/arm/mach-mmp/time.c
+ *
+ *   Support for clocksource and clockevents
+ *
+ * Copyright (C) 2008 Marvell International Ltd.
+ * All rights reserved.
+ *
+ *   2008-04-11: Jason Chagas <Jason.chagas@marvell.com>
+ *   2008-10-08: Bin Yang <bin.yang@marvell.com>
+ *
+ * The timers module actually includes three timers, each timer with up to
+ * three match comparators. Timer #0 is used here in free-running mode as
+ * the clock source, and match comparator #1 used as clock event device.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/clockchips.h>
+
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#include <mach/addr-map.h>
+#include <mach/regs-timers.h>
+#include <mach/regs-apbc.h>
+#include <mach/irqs.h>
+#include <mach/cputype.h>
+#include <asm/mach/time.h>
+
+#include "clock.h"
+
+#ifdef CONFIG_CPU_MMP2
+#define MMP_CLOCK_FREQ		6500000
+#else
+#define MMP_CLOCK_FREQ		3250000
+#endif
+
+#define TIMERS_VIRT_BASE	TIMERS1_VIRT_BASE
+
+#define MAX_DELTA		(0xfffffffe)
+#define MIN_DELTA		(16)
+
+static void __iomem *mmp_timer_base = TIMERS_VIRT_BASE;
+
+/*
+ * FIXME: the timer needs some delay to stablize the counter capture
+ */
+static inline uint32_t timer_read(void)
+{
+	int delay = 100;
+
+	__raw_writel(1, mmp_timer_base + TMR_CVWR(1));
+
+	while (delay--)
+		cpu_relax();
+
+	return __raw_readl(mmp_timer_base + TMR_CVWR(1));
+}
+
+static u64 notrace mmp_read_sched_clock(void)
+{
+	return timer_read();
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *c = dev_id;
+
+	/*
+	 * Clear pending interrupt status.
+	 */
+	__raw_writel(0x01, mmp_timer_base + TMR_ICR(0));
+
+	/*
+	 * Disable timer 0.
+	 */
+	__raw_writel(0x02, mmp_timer_base + TMR_CER);
+
+	c->event_handler(c);
+
+	return IRQ_HANDLED;
+}
+
+static int timer_set_next_event(unsigned long delta,
+				struct clock_event_device *dev)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+
+	/*
+	 * Disable timer 0.
+	 */
+	__raw_writel(0x02, mmp_timer_base + TMR_CER);
+
+	/*
+	 * Clear and enable timer match 0 interrupt.
+	 */
+	__raw_writel(0x01, mmp_timer_base + TMR_ICR(0));
+	__raw_writel(0x01, mmp_timer_base + TMR_IER(0));
+
+	/*
+	 * Setup new clockevent timer value.
+	 */
+	__raw_writel(delta - 1, mmp_timer_base + TMR_TN_MM(0, 0));
+
+	/*
+	 * Enable timer 0.
+	 */
+	__raw_writel(0x03, mmp_timer_base + TMR_CER);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static void timer_set_mode(enum clock_event_mode mode,
+			   struct clock_event_device *dev)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	switch (mode) {
+	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		/* disable the matching interrupt */
+		__raw_writel(0x00, mmp_timer_base + TMR_IER(0));
+		break;
+	case CLOCK_EVT_MODE_RESUME:
+	case CLOCK_EVT_MODE_PERIODIC:
+		break;
+	}
+	local_irq_restore(flags);
+}
+
+static struct clock_event_device ckevt = {
+	.name		= "clockevent",
+	.features	= CLOCK_EVT_FEAT_ONESHOT,
+	.rating		= 200,
+	.set_next_event	= timer_set_next_event,
+	.set_mode	= timer_set_mode,
+};
+
+static cycle_t clksrc_read(struct clocksource *cs)
+{
+	return timer_read();
+}
+
+static struct clocksource cksrc = {
+	.name		= "clocksource",
+	.rating		= 200,
+	.read		= clksrc_read,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init timer_config(void)
+{
+	uint32_t ccr = __raw_readl(mmp_timer_base + TMR_CCR);
+
+	__raw_writel(0x0, mmp_timer_base + TMR_CER); /* disable */
+
+	ccr &= (cpu_is_mmp2()) ? (TMR_CCR_CS_0(0) | TMR_CCR_CS_1(0)) :
+		(TMR_CCR_CS_0(3) | TMR_CCR_CS_1(3));
+	__raw_writel(ccr, mmp_timer_base + TMR_CCR);
+
+	/* set timer 0 to periodic mode, and timer 1 to free-running mode */
+	__raw_writel(0x2, mmp_timer_base + TMR_CMR);
+
+	__raw_writel(0x1, mmp_timer_base + TMR_PLCR(0)); /* periodic */
+	__raw_writel(0x7, mmp_timer_base + TMR_ICR(0));  /* clear status */
+	__raw_writel(0x0, mmp_timer_base + TMR_IER(0));
+
+	__raw_writel(0x0, mmp_timer_base + TMR_PLCR(1)); /* free-running */
+	__raw_writel(0x7, mmp_timer_base + TMR_ICR(1));  /* clear status */
+	__raw_writel(0x0, mmp_timer_base + TMR_IER(1));
+
+	/* enable timer 1 counter */
+	__raw_writel(0x2, mmp_timer_base + TMR_CER);
+}
+
+static struct irqaction timer_irq = {
+	.name		= "timer",
+	.flags		= IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= timer_interrupt,
+	.dev_id		= &ckevt,
+};
+
+void __init timer_init(int irq)
+{
+	timer_config();
+
+	sched_clock_register(mmp_read_sched_clock, 32, MMP_CLOCK_FREQ);
+
+	ckevt.cpumask = cpumask_of(0);
+
+	setup_irq(irq, &timer_irq);
+
+	clocksource_register_hz(&cksrc, MMP_CLOCK_FREQ);
+	clockevents_config_and_register(&ckevt, MMP_CLOCK_FREQ,
+					MIN_DELTA, MAX_DELTA);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id mmp_timer_dt_ids[] = {
+	{ .compatible = "mrvl,mmp-timer", },
+	{}
+};
+
+void __init mmp_dt_init_timer(void)
+{
+	struct device_node *np;
+	int irq, ret;
+
+	np = of_find_matching_node(NULL, mmp_timer_dt_ids);
+	if (!np) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	irq = irq_of_parse_and_map(np, 0);
+	if (!irq) {
+		ret = -EINVAL;
+		goto out;
+	}
+	mmp_timer_base = of_iomap(np, 0);
+	if (!mmp_timer_base) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	timer_init(irq);
+	return;
+out:
+	pr_err("Failed to get timer from device tree with error:%d\n", ret);
+}
+#endif