[PATCH] ARM: 2771/1: Dynamic Tick support for OMAP, take 4
Patch from Tony Lindgren
This patch adds support for Dynamic Tick Timer for OMAP.
This patch is an updated version of ARM patch 2642/1 to
make it work with the already integrated generic ARM
dyntick support.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-omap/pm.c b/arch/arm/mach-omap/pm.c
index 00fac15..6b03ccd 100644
--- a/arch/arm/mach-omap/pm.c
+++ b/arch/arm/mach-omap/pm.c
@@ -41,7 +41,9 @@
#include <linux/pm.h>
#include <asm/io.h>
+#include <asm/mach/time.h>
#include <asm/mach-types.h>
+
#include <asm/arch/omap16xx.h>
#include <asm/arch/pm.h>
#include <asm/arch/mux.h>
@@ -80,13 +82,13 @@
return;
}
mask32 = omap_readl(ARM_SYSST);
- local_fiq_enable();
- local_irq_enable();
-#if defined(CONFIG_OMAP_32K_TIMER) && defined(CONFIG_NO_IDLE_HZ)
- /* Override timer to use VST for the next cycle */
- omap_32k_timer_next_vst_interrupt();
-#endif
+ /*
+ * Since an interrupt may set up a timer, we don't want to
+ * reprogram the hardware timer with interrupts enabled.
+ * Re-enable interrupts only after returning from idle.
+ */
+ timer_dyn_reprogram();
if ((mask32 & DSP_IDLE) == 0) {
__asm__ volatile ("mcr p15, 0, r0, c7, c0, 4");
@@ -102,6 +104,8 @@
func_ptr();
}
+ local_fiq_enable();
+ local_irq_enable();
}
/*
diff --git a/arch/arm/mach-omap/time.c b/arch/arm/mach-omap/time.c
index 589e8b2..dd34e9f 100644
--- a/arch/arm/mach-omap/time.c
+++ b/arch/arm/mach-omap/time.c
@@ -4,7 +4,7 @@
* OMAP Timers
*
* Copyright (C) 2004 Nokia Corporation
- * Partial timer rewrite and additional VST timer support by
+ * Partial timer rewrite and additional dynamic tick timer support by
* Tony Lindgen <tony@atomide.com> and
* Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>
*
@@ -261,7 +261,6 @@
* so with HZ = 100, TVR = 327.68.
*/
#define OMAP_32K_TIMER_TICK_PERIOD ((32768 / HZ) - 1)
-#define MAX_SKIP_JIFFIES 25
#define TIMER_32K_SYNCHRONIZED 0xfffbc410
#define JIFFIES_TO_HW_TICKS(nr_jiffies, clock_rate) \
@@ -347,6 +346,42 @@
return IRQ_HANDLED;
}
+#ifdef CONFIG_NO_IDLE_HZ
+/*
+ * Programs the next timer interrupt needed. Called when dynamic tick is
+ * enabled, and to reprogram the ticks to skip from pm_idle. Note that
+ * we can keep the timer continuous, and don't need to set it to run in
+ * one-shot mode. This is because the timer will get reprogrammed again
+ * after next interrupt.
+ */
+void omap_32k_timer_reprogram(unsigned long next_tick)
+{
+ omap_32k_timer_start(JIFFIES_TO_HW_TICKS(next_tick, 32768) + 1);
+}
+
+static struct irqaction omap_32k_timer_irq;
+extern struct timer_update_handler timer_update;
+
+static int omap_32k_timer_enable_dyn_tick(void)
+{
+ /* No need to reprogram timer, just use the next interrupt */
+ return 0;
+}
+
+static int omap_32k_timer_disable_dyn_tick(void)
+{
+ omap_32k_timer_start(OMAP_32K_TIMER_TICK_PERIOD);
+ return 0;
+}
+
+static struct dyn_tick_timer omap_dyn_tick_timer = {
+ .enable = omap_32k_timer_enable_dyn_tick,
+ .disable = omap_32k_timer_disable_dyn_tick,
+ .reprogram = omap_32k_timer_reprogram,
+ .handler = omap_32k_timer_interrupt,
+};
+#endif /* CONFIG_NO_IDLE_HZ */
+
static struct irqaction omap_32k_timer_irq = {
.name = "32KHz timer",
.flags = SA_INTERRUPT | SA_TIMER,
@@ -355,6 +390,11 @@
static __init void omap_init_32k_timer(void)
{
+
+#ifdef CONFIG_NO_IDLE_HZ
+ omap_timer.dyn_tick = &omap_dyn_tick_timer;
+#endif
+
setup_irq(INT_OS_TIMER, &omap_32k_timer_irq);
omap_timer.offset = omap_32k_timer_gettimeoffset;
omap_32k_last_tick = omap_32k_sync_timer_read();