1 files changed, 217 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..44027f34a88a
--- /dev/null
+++ b/arch/arm/mach-prima2/timer.c
@@ -0,0 +1,217 @@
+/*
+ * 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)
+
+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 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,
+};
+
+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 = 0;
+
+        /*
+         * 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,
+};