plat-orion: share time handling code

Split off Orion time handling code into plat-orion/.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Reviewed-by: Tzachi Perelstein <tzachi@marvell.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Nicolas Pitre <nico@marvell.com>

1 files changed, 203 insertions, 0 deletions

diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c
new file mode 100644
index 0000000..28b5285
--- /dev/null
+++ b/arch/arm/plat-orion/time.c
@@ -0,0 +1,203 @@
+/*
+ * 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/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <asm/mach/time.h>
+#include <asm/arch/hardware.h>
+
+/*
+ * Number of timer ticks per jiffy.
+ */
+static u32 ticks_per_jiffy;
+
+
+/*
+ * Timer block registers.
+ */
+#define TIMER_CTRL		(TIMER_VIRT_BASE + 0x0000)
+#define  TIMER0_EN		0x0001
+#define  TIMER0_RELOAD_EN	0x0002
+#define  TIMER1_EN		0x0004
+#define  TIMER1_RELOAD_EN	0x0008
+#define TIMER0_RELOAD		(TIMER_VIRT_BASE + 0x0010)
+#define TIMER0_VAL		(TIMER_VIRT_BASE + 0x0014)
+#define TIMER1_RELOAD		(TIMER_VIRT_BASE + 0x0018)
+#define TIMER1_VAL		(TIMER_VIRT_BASE + 0x001c)
+
+
+/*
+ * Clocksource handling.
+ */
+static cycle_t orion_clksrc_read(void)
+{
+	return 0xffffffff - readl(TIMER0_VAL);
+}
+
+static struct clocksource orion_clksrc = {
+	.name		= "orion_clocksource",
+	.shift		= 20,
+	.rating		= 300,
+	.read		= orion_clksrc_read,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+
+
+/*
+ * 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_INT_TIMER1, BRIDGE_CAUSE);
+
+	u = readl(BRIDGE_MASK);
+	u |= BRIDGE_INT_TIMER1;
+	writel(u, BRIDGE_MASK);
+
+	/*
+	 * Setup new clockevent timer value.
+	 */
+	writel(delta, TIMER1_VAL);
+
+	/*
+	 * Enable the timer.
+	 */
+	u = readl(TIMER_CTRL);
+	u = (u & ~TIMER1_RELOAD_EN) | TIMER1_EN;
+	writel(u, TIMER_CTRL);
+
+	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, TIMER1_RELOAD);
+		writel(ticks_per_jiffy - 1, TIMER1_VAL);
+
+		/*
+		 * Enable timer interrupt.
+		 */
+		u = readl(BRIDGE_MASK);
+		writel(u | BRIDGE_INT_TIMER1, BRIDGE_MASK);
+
+		/*
+		 * Enable timer.
+		 */
+		u = readl(TIMER_CTRL);
+		writel(u | TIMER1_EN | TIMER1_RELOAD_EN, TIMER_CTRL);
+	} else {
+		/*
+		 * Disable timer.
+		 */
+		u = readl(TIMER_CTRL);
+		writel(u & ~TIMER1_EN, TIMER_CTRL);
+
+		/*
+		 * Disable timer interrupt.
+		 */
+		u = readl(BRIDGE_MASK);
+		writel(u & ~BRIDGE_INT_TIMER1, BRIDGE_MASK);
+
+		/*
+		 * ACK pending timer interrupt.
+		 */
+		writel(~BRIDGE_INT_TIMER1, BRIDGE_CAUSE);
+
+	}
+	local_irq_restore(flags);
+}
+
+static struct clock_event_device orion_clkevt = {
+	.name		= "orion_tick",
+	.features	= CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC,
+	.shift		= 32,
+	.rating		= 300,
+	.cpumask	= CPU_MASK_CPU0,
+	.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_INT_TIMER1, BRIDGE_CAUSE);
+	orion_clkevt.event_handler(&orion_clkevt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction orion_timer_irq = {
+	.name		= "orion_tick",
+	.flags		= IRQF_DISABLED | IRQF_TIMER,
+	.handler	= orion_timer_interrupt
+};
+
+void __init orion_time_init(unsigned int irq, unsigned int tclk)
+{
+	u32 u;
+
+	ticks_per_jiffy = (tclk + HZ/2) / HZ;
+
+
+	/*
+	 * Setup free-running clocksource timer (interrupts
+	 * disabled.)
+	 */
+	writel(0xffffffff, TIMER0_VAL);
+	writel(0xffffffff, TIMER0_RELOAD);
+	u = readl(BRIDGE_MASK);
+	writel(u & ~BRIDGE_INT_TIMER0, BRIDGE_MASK);
+	u = readl(TIMER_CTRL);
+	writel(u | TIMER0_EN | TIMER0_RELOAD_EN, TIMER_CTRL);
+	orion_clksrc.mult = clocksource_hz2mult(tclk, orion_clksrc.shift);
+	clocksource_register(&orion_clksrc);
+
+
+	/*
+	 * Setup clockevent timer (interrupt-driven.)
+	 */
+	setup_irq(irq, &orion_timer_irq);
+	orion_clkevt.mult = div_sc(tclk, NSEC_PER_SEC, orion_clkevt.shift);
+	orion_clkevt.max_delta_ns = clockevent_delta2ns(0xfffffffe, &orion_clkevt);
+	orion_clkevt.min_delta_ns = clockevent_delta2ns(1, &orion_clkevt);
+	clockevents_register_device(&orion_clkevt);
+}