Initial import

1 files changed, 226 insertions, 0 deletions

diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c
new file mode 100644
index 000000000..261258f71
--- /dev/null
+++ b/arch/arm/plat-orion/time.c
@@ -0,0 +1,226 @@
+/*
+ * arch/arm/plat-orion/time.c
+ *
+ * Marvell Orion SoC timer handling.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ *
+ * Timer 0 is used as free-running clocksource, while timer 1 is
+ * used as clock_event_device.
+ */
+
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/sched_clock.h>
+#include <plat/time.h>
+
+/*
+ * MBus bridge block registers.
+ */
+#define BRIDGE_CAUSE_OFF	0x0110
+#define BRIDGE_MASK_OFF		0x0114
+#define  BRIDGE_INT_TIMER0	 0x0002
+#define  BRIDGE_INT_TIMER1	 0x0004
+
+
+/*
+ * Timer block registers.
+ */
+#define TIMER_CTRL_OFF		0x0000
+#define  TIMER0_EN		 0x0001
+#define  TIMER0_RELOAD_EN	 0x0002
+#define  TIMER1_EN		 0x0004
+#define  TIMER1_RELOAD_EN	 0x0008
+#define TIMER0_RELOAD_OFF	0x0010
+#define TIMER0_VAL_OFF		0x0014
+#define TIMER1_RELOAD_OFF	0x0018
+#define TIMER1_VAL_OFF		0x001c
+
+
+/*
+ * SoC-specific data.
+ */
+static void __iomem *bridge_base;
+static u32 bridge_timer1_clr_mask;
+static void __iomem *timer_base;
+
+
+/*
+ * Number of timer ticks per jiffy.
+ */
+static u32 ticks_per_jiffy;
+
+
+/*
+ * Orion's sched_clock implementation. It has a resolution of
+ * at least 7.5ns (133MHz TCLK).
+ */
+
+static u64 notrace orion_read_sched_clock(void)
+{
+	return ~readl(timer_base + TIMER0_VAL_OFF);
+}
+
+/*
+ * Clockevent handling.
+ */
+static int
+orion_clkevt_next_event(unsigned long delta, struct clock_event_device *dev)
+{
+	unsigned long flags;
+	u32 u;
+
+	if (delta == 0)
+		return -ETIME;
+
+	local_irq_save(flags);
+
+	/*
+	 * Clear and enable clockevent timer interrupt.
+	 */
+	writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
+
+	u = readl(bridge_base + BRIDGE_MASK_OFF);
+	u |= BRIDGE_INT_TIMER1;
+	writel(u, bridge_base + BRIDGE_MASK_OFF);
+
+	/*
+	 * Setup new clockevent timer value.
+	 */
+	writel(delta, timer_base + TIMER1_VAL_OFF);
+
+	/*
+	 * Enable the timer.
+	 */
+	u = readl(timer_base + TIMER_CTRL_OFF);
+	u = (u & ~TIMER1_RELOAD_EN) | TIMER1_EN;
+	writel(u, timer_base + TIMER_CTRL_OFF);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static void
+orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev)
+{
+	unsigned long flags;
+	u32 u;
+
+	local_irq_save(flags);
+	if (mode == CLOCK_EVT_MODE_PERIODIC) {
+		/*
+		 * Setup timer to fire at 1/HZ intervals.
+		 */
+		writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD_OFF);
+		writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL_OFF);
+
+		/*
+		 * Enable timer interrupt.
+		 */
+		u = readl(bridge_base + BRIDGE_MASK_OFF);
+		writel(u | BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF);
+
+		/*
+		 * Enable timer.
+		 */
+		u = readl(timer_base + TIMER_CTRL_OFF);
+		writel(u | TIMER1_EN | TIMER1_RELOAD_EN,
+		       timer_base + TIMER_CTRL_OFF);
+	} else {
+		/*
+		 * Disable timer.
+		 */
+		u = readl(timer_base + TIMER_CTRL_OFF);
+		writel(u & ~TIMER1_EN, timer_base + TIMER_CTRL_OFF);
+
+		/*
+		 * Disable timer interrupt.
+		 */
+		u = readl(bridge_base + BRIDGE_MASK_OFF);
+		writel(u & ~BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF);
+
+		/*
+		 * ACK pending timer interrupt.
+		 */
+		writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
+
+	}
+	local_irq_restore(flags);
+}
+
+static struct clock_event_device orion_clkevt = {
+	.name		= "orion_tick",
+	.features	= CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+	.rating		= 300,
+	.set_next_event	= orion_clkevt_next_event,
+	.set_mode	= orion_clkevt_mode,
+};
+
+static irqreturn_t orion_timer_interrupt(int irq, void *dev_id)
+{
+	/*
+	 * ACK timer interrupt and call event handler.
+	 */
+	writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF);
+	orion_clkevt.event_handler(&orion_clkevt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction orion_timer_irq = {
+	.name		= "orion_tick",
+	.flags		= IRQF_TIMER,
+	.handler	= orion_timer_interrupt
+};
+
+void __init
+orion_time_set_base(void __iomem *_timer_base)
+{
+	timer_base = _timer_base;
+}
+
+void __init
+orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask,
+		unsigned int irq, unsigned int tclk)
+{
+	u32 u;
+
+	/*
+	 * Set SoC-specific data.
+	 */
+	bridge_base = _bridge_base;
+	bridge_timer1_clr_mask = _bridge_timer1_clr_mask;
+
+	ticks_per_jiffy = (tclk + HZ/2) / HZ;
+
+	/*
+	 * Set scale and timer for sched_clock.
+	 */
+	sched_clock_register(orion_read_sched_clock, 32, tclk);
+
+	/*
+	 * Setup free-running clocksource timer (interrupts
+	 * disabled).
+	 */
+	writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
+	writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
+	u = readl(bridge_base + BRIDGE_MASK_OFF);
+	writel(u & ~BRIDGE_INT_TIMER0, bridge_base + BRIDGE_MASK_OFF);
+	u = readl(timer_base + TIMER_CTRL_OFF);
+	writel(u | TIMER0_EN | TIMER0_RELOAD_EN, timer_base + TIMER_CTRL_OFF);
+	clocksource_mmio_init(timer_base + TIMER0_VAL_OFF, "orion_clocksource",
+		tclk, 300, 32, clocksource_mmio_readl_down);
+
+	/*
+	 * Setup clockevent timer (interrupt-driven).
+	 */
+	setup_irq(irq, &orion_timer_irq);
+	orion_clkevt.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&orion_clkevt, tclk, 1, 0xfffffffe);
+}