From b3402cf50efead37dd9553b90fbf1486e09fb78e Mon Sep 17 00:00:00 2001 From: Tony Lindgren Date: Wed, 29 Jun 2005 19:59:48 +0100 Subject: [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 Signed-off-by: Russell King --- arch/arm/mach-omap/pm.c | 16 ++++++++++------ arch/arm/mach-omap/time.c | 44 ++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 52 insertions(+), 8 deletions(-) diff --git a/arch/arm/mach-omap/pm.c b/arch/arm/mach-omap/pm.c index 00fac155df2a6..6b03ccdc1e926 100644 --- a/arch/arm/mach-omap/pm.c +++ b/arch/arm/mach-omap/pm.c @@ -41,7 +41,9 @@ #include #include +#include #include + #include #include #include @@ -80,13 +82,13 @@ void omap_pm_idle(void) 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 @@ void omap_pm_idle(void) 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 589e8b2740ddf..dd34e9f4c4139 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 and * Tuukka Tikkanen * @@ -261,7 +261,6 @@ unsigned long long sched_clock(void) * 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 @@ static irqreturn_t omap_32k_timer_interrupt(int irq, void *dev_id, 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 struct irqaction omap_32k_timer_irq = { 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(); -- cgit 1.2.3-korg