1 files changed, 252 insertions, 0 deletions
diff --git a/arch/arm/mach-prima2/timer.c b/arch/arm/mach-prima2/timer.c
new file mode 100644
index 000000000000..b7a6091ce791
--- /dev/null
+++ b/arch/arm/mach-prima2/timer.c
@@ -0,0 +1,252 @@
+/*
+ * System timer for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <mach/map.h>
+#include <asm/mach/time.h>
+
+#define SIRFSOC_TIMER_COUNTER_LO	0x0000
+#define SIRFSOC_TIMER_COUNTER_HI	0x0004
+#define SIRFSOC_TIMER_MATCH_0		0x0008
+#define SIRFSOC_TIMER_MATCH_1		0x000C
+#define SIRFSOC_TIMER_MATCH_2		0x0010
+#define SIRFSOC_TIMER_MATCH_3		0x0014
+#define SIRFSOC_TIMER_MATCH_4		0x0018
+#define SIRFSOC_TIMER_MATCH_5		0x001C
+#define SIRFSOC_TIMER_STATUS		0x0020
+#define SIRFSOC_TIMER_INT_EN		0x0024
+#define SIRFSOC_TIMER_WATCHDOG_EN	0x0028
+#define SIRFSOC_TIMER_DIV		0x002C
+#define SIRFSOC_TIMER_LATCH		0x0030
+#define SIRFSOC_TIMER_LATCHED_LO	0x0034
+#define SIRFSOC_TIMER_LATCHED_HI	0x0038
+
+#define SIRFSOC_TIMER_WDT_INDEX		5
+
+#define SIRFSOC_TIMER_LATCH_BIT	 BIT(0)
+
+#define SIRFSOC_TIMER_REG_CNT 11
+
+static const u32 sirfsoc_timer_reg_list[SIRFSOC_TIMER_REG_CNT] = {
+	SIRFSOC_TIMER_MATCH_0, SIRFSOC_TIMER_MATCH_1, SIRFSOC_TIMER_MATCH_2,
+	SIRFSOC_TIMER_MATCH_3, SIRFSOC_TIMER_MATCH_4, SIRFSOC_TIMER_MATCH_5,
+	SIRFSOC_TIMER_INT_EN, SIRFSOC_TIMER_WATCHDOG_EN, SIRFSOC_TIMER_DIV,
+	SIRFSOC_TIMER_LATCHED_LO, SIRFSOC_TIMER_LATCHED_HI,
+};
+
+static u32 sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT];
+
+static void __iomem *sirfsoc_timer_base;
+static void __init sirfsoc_of_timer_map(void);
+
+/* timer0 interrupt handler */
+static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *ce = dev_id;
+
+	WARN_ON(!(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_STATUS) & BIT(0)));
+
+	/* clear timer0 interrupt */
+	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
+
+	ce->event_handler(ce);
+
+	return IRQ_HANDLED;
+}
+
+/* read 64-bit timer counter */
+static cycle_t sirfsoc_timer_read(struct clocksource *cs)
+{
+	u64 cycles;
+
+	/* latch the 64-bit timer counter */
+	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
+	cycles = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_HI);
+	cycles = (cycles << 32) | readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
+
+	return cycles;
+}
+
+static int sirfsoc_timer_set_next_event(unsigned long delta,
+	struct clock_event_device *ce)
+{
+	unsigned long now, next;
+
+	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
+	now = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
+	next = now + delta;
+	writel_relaxed(next, sirfsoc_timer_base + SIRFSOC_TIMER_MATCH_0);
+	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
+	now = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_LATCHED_LO);
+
+	return next - now > delta ? -ETIME : 0;
+}
+
+static void sirfsoc_timer_set_mode(enum clock_event_mode mode,
+	struct clock_event_device *ce)
+{
+	u32 val = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		WARN_ON(1);
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		writel_relaxed(val | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
+		break;
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		writel_relaxed(val & ~BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_INT_EN);
+		break;
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_RESUME:
+		break;
+	}
+}
+
+static void sirfsoc_clocksource_suspend(struct clocksource *cs)
+{
+	int i;
+
+	writel_relaxed(SIRFSOC_TIMER_LATCH_BIT, sirfsoc_timer_base + SIRFSOC_TIMER_LATCH);
+
+	for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
+		sirfsoc_timer_reg_val[i] = readl_relaxed(sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
+}
+
+static void sirfsoc_clocksource_resume(struct clocksource *cs)
+{
+	int i;
+
+	for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
+		writel_relaxed(sirfsoc_timer_reg_val[i], sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
+
+	writel_relaxed(sirfsoc_timer_reg_val[i - 2], sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
+	writel_relaxed(sirfsoc_timer_reg_val[i - 1], sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
+}
+
+static struct clock_event_device sirfsoc_clockevent = {
+	.name = "sirfsoc_clockevent",
+	.rating = 200,
+	.features = CLOCK_EVT_FEAT_ONESHOT,
+	.set_mode = sirfsoc_timer_set_mode,
+	.set_next_event = sirfsoc_timer_set_next_event,
+};
+
+static struct clocksource sirfsoc_clocksource = {
+	.name = "sirfsoc_clocksource",
+	.rating = 200,
+	.mask = CLOCKSOURCE_MASK(64),
+	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+	.read = sirfsoc_timer_read,
+	.suspend = sirfsoc_clocksource_suspend,
+	.resume = sirfsoc_clocksource_resume,
+};
+
+static struct irqaction sirfsoc_timer_irq = {
+	.name = "sirfsoc_timer0",
+	.flags = IRQF_TIMER,
+	.irq = 0,
+	.handler = sirfsoc_timer_interrupt,
+	.dev_id = &sirfsoc_clockevent,
+};
+
+/* Overwrite weak default sched_clock with more precise one */
+unsigned long long notrace sched_clock(void)
+{
+	static int is_mapped;
+
+	/*
+	 * sched_clock is called earlier than .init of sys_timer
+	 * if we map timer memory in .init of sys_timer, system
+	 * will panic due to illegal memory access
+	 */
+	if (!is_mapped) {
+		sirfsoc_of_timer_map();
+		is_mapped = 1;
+	}
+
+	return sirfsoc_timer_read(NULL) * (NSEC_PER_SEC / CLOCK_TICK_RATE);
+}
+
+static void __init sirfsoc_clockevent_init(void)
+{
+	clockevents_calc_mult_shift(&sirfsoc_clockevent, CLOCK_TICK_RATE, 60);
+
+	sirfsoc_clockevent.max_delta_ns =
+		clockevent_delta2ns(-2, &sirfsoc_clockevent);
+	sirfsoc_clockevent.min_delta_ns =
+		clockevent_delta2ns(2, &sirfsoc_clockevent);
+
+	sirfsoc_clockevent.cpumask = cpumask_of(0);
+	clockevents_register_device(&sirfsoc_clockevent);
+}
+
+/* initialize the kernel jiffy timer source */
+static void __init sirfsoc_timer_init(void)
+{
+	unsigned long rate;
+
+	/* timer's input clock is io clock */
+	struct clk *clk = clk_get_sys("io", NULL);
+
+	BUG_ON(IS_ERR(clk));
+
+	rate = clk_get_rate(clk);
+
+	BUG_ON(rate < CLOCK_TICK_RATE);
+	BUG_ON(rate % CLOCK_TICK_RATE);
+
+	writel_relaxed(rate / CLOCK_TICK_RATE / 2 - 1, sirfsoc_timer_base + SIRFSOC_TIMER_DIV);
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_LO);
+	writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_HI);
+	writel_relaxed(BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_STATUS);
+
+	BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE));
+
+	BUG_ON(setup_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq));
+
+	sirfsoc_clockevent_init();
+}
+
+static struct of_device_id timer_ids[] = {
+	{ .compatible = "sirf,prima2-tick" },
+	{},
+};
+
+static void __init sirfsoc_of_timer_map(void)
+{
+	struct device_node *np;
+	const unsigned int *intspec;
+
+	np = of_find_matching_node(NULL, timer_ids);
+	if (!np)
+		panic("unable to find compatible timer node in dtb\n");
+	sirfsoc_timer_base = of_iomap(np, 0);
+	if (!sirfsoc_timer_base)
+		panic("unable to map timer cpu registers\n");
+
+	/* Get the interrupts property */
+	intspec = of_get_property(np, "interrupts", NULL);
+	BUG_ON(!intspec);
+	sirfsoc_timer_irq.irq = be32_to_cpup(intspec);
+
+	of_node_put(np);
+}
+
+struct sys_timer sirfsoc_timer = {
+	.init = sirfsoc_timer_init,
+};