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authorLennert Buytenhek <buytenh@wantstofly.org>2008-03-27 21:51:40 +0300
committerNicolas Pitre <nico@marvell.com>2008-03-27 21:51:40 +0300
commit2bac1de2031aa4cad88a437d4410ec289da4f7dc (patch)
tree1f9abbf6f3d428bbdcbfc93337e3e2e28e3d81c9 /arch/arm/plat-orion/time.c
parentabc0197d7a74e51a1581ce9971d7c2c0f2adadaf (diff)
downloadlinux-2bac1de2031aa4cad88a437d4410ec289da4f7dc.tar.xz
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>
Diffstat (limited to 'arch/arm/plat-orion/time.c')
-rw-r--r--arch/arm/plat-orion/time.c203
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 000000000000..28b5285446e8
--- /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);
+}