This patch adds SMP platform specific parts for local(mpu) timer support for OMAP4430 platform. Each Cortex-a9 core has it's own local timer in the MPU domain. These timers are not in wakeup domain. Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> --- arch/arm/mach-omap2/timer-gp.c | 11 ++ arch/arm/mach-omap2/timer-mpu.c | 214 +++++++++++++++++++++++++ arch/arm/plat-omap/include/mach/common.h | 3 + arch/arm/plat-omap/include/mach/entry-macro.S | 28 ++++ arch/arm/plat-omap/include/mach/irqs.h | 2 + 5 files changed, 258 insertions(+), 0 deletions(-) create mode 100644 arch/arm/mach-omap2/timer-mpu.c diff --git a/arch/arm/mach-omap2/timer-gp.c b/arch/arm/mach-omap2/timer-gp.c index 080868d..08c6ded 100644 --- a/arch/arm/mach-omap2/timer-gp.c +++ b/arch/arm/mach-omap2/timer-gp.c @@ -36,6 +36,7 @@ #include <asm/mach/time.h> #include <mach/dmtimer.h> +#include <mach/common.h> static struct omap_dm_timer *gptimer; static struct clock_event_device clockevent_gpt; @@ -187,6 +188,16 @@ static void __init omap2_gp_clocksource_init(void) static void __init omap2_gp_timer_init(void) { +#ifdef CONFIG_LOCAL_TIMERS + twd_base = IO_ADDRESS(OMAP44XX_LOCAL_TWD_BASE); +#endif +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST + /* + * The dummy clock device has to be registered before the main device + * so that the latter will broadcast the clock events + */ + local_timer_setup(); +#endif omap_dm_timer_init(); omap2_gp_clockevent_init(); diff --git a/arch/arm/mach-omap2/timer-mpu.c b/arch/arm/mach-omap2/timer-mpu.c new file mode 100644 index 0000000..bb91b24 --- /dev/null +++ b/arch/arm/mach-omap2/timer-mpu.c @@ -0,0 +1,214 @@ +/* + * The MPU local timer source file. In OMAP4, both cortex-a9 cores have + * own timer in it's MPU domain. These timers will be driving the + * linux kernel SMP tick framework when active. These timers are not + * part of the wake up domain. + * + * Copyright (C) 2009 Texas Instruments, Inc. + * + * Author: + * Santosh Shilimkar <santosh.shilimkar@xxxxxx> + * + * This file is based on arm realview smp platform file. + * Copyright (C) 2002 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/smp.h> +#include <linux/jiffies.h> +#include <linux/percpu.h> +#include <linux/clockchips.h> +#include <linux/irq.h> + +#include <asm/hardware/arm_twd.h> +#include <asm/hardware/gic.h> +#include <asm/irq.h> + +#include <mach/hardware.h> +#include <mach/common.h> + +static DEFINE_PER_CPU(struct clock_event_device, local_clockevent); + +/* + * Used on SMP for either the local timer or IPI_TIMER + */ +void local_timer_interrupt(void) +{ + struct clock_event_device *clk = &__get_cpu_var(local_clockevent); + + clk->event_handler(clk); +} + +#ifdef CONFIG_LOCAL_TIMERS + +/* set up by the platform code */ +void __iomem *twd_base; + +static unsigned long mpcore_timer_rate; + +static void local_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *clk) +{ + unsigned long ctrl; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* timer load already set up */ + ctrl = TWD_TIMER_CONTROL_ENABLE | TWD_TIMER_CONTROL_IT_ENABLE + | TWD_TIMER_CONTROL_PERIODIC; + break; + case CLOCK_EVT_MODE_ONESHOT: + /* period set, and timer enabled in 'next_event' hook */ + ctrl = TWD_TIMER_CONTROL_IT_ENABLE | TWD_TIMER_CONTROL_ONESHOT; + break; + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + default: + ctrl = 0; + } + + __raw_writel(ctrl, twd_base + TWD_TIMER_CONTROL); +} + +static int local_timer_set_next_event(unsigned long evt, + struct clock_event_device *unused) +{ + unsigned long ctrl = __raw_readl(twd_base + TWD_TIMER_CONTROL); + + __raw_writel(evt, twd_base + TWD_TIMER_COUNTER); + __raw_writel(ctrl | TWD_TIMER_CONTROL_ENABLE, + twd_base + TWD_TIMER_CONTROL); + + return 0; +} + +/* + * local_timer_ack: checks for a local timer interrupt. + * + * If a local timer interrupt has occurred, acknowledge and return 1. + * Otherwise, return 0. + */ +int local_timer_ack(void) +{ + if (__raw_readl(twd_base + TWD_TIMER_INTSTAT)) { + __raw_writel(1, twd_base + TWD_TIMER_INTSTAT); + return 1; + } + + return 0; +} + +static void __cpuinit twd_calibrate_rate(void) +{ + unsigned long load, count; + u64 waitjiffies; + + /* + * If this is the first time round, we need to work out how fast + * the timer ticks + */ + if (mpcore_timer_rate == 0) { + printk(KERN_INFO "Calibrating local timer... "); + + /* Wait for a tick to start */ + waitjiffies = get_jiffies_64() + 1; + + while (get_jiffies_64() < waitjiffies) + udelay(10); + + /* OK, now the tick has started, let's get the timer going */ + waitjiffies += 5; + + /* enable, no interrupt or reload */ + __raw_writel(0x1, twd_base + TWD_TIMER_CONTROL); + + /* maximum value */ + __raw_writel(0xFFFFFFFFU, twd_base + TWD_TIMER_COUNTER); + + while (get_jiffies_64() < waitjiffies) + udelay(10); + + count = __raw_readl(twd_base + TWD_TIMER_COUNTER); + + mpcore_timer_rate = (0xFFFFFFFFU - count) * (HZ / 5); + + printk("%lu.%02luMHz.\n", mpcore_timer_rate / 1000000, + (mpcore_timer_rate / 100000) % 100); + } + + load = mpcore_timer_rate / HZ; + + __raw_writel(load, twd_base + TWD_TIMER_LOAD); +} + +/* + * Setup the local clock events for a CPU. + */ +void __cpuinit local_timer_setup(void) +{ + unsigned int cpu = smp_processor_id(); + struct clock_event_device *clk = &per_cpu(local_clockevent, cpu); + unsigned long flags; + + twd_calibrate_rate(); + + clk->name = "local_timer"; + clk->features = CLOCK_EVT_FEAT_PERIODIC + | CLOCK_EVT_FEAT_ONESHOT; + clk->rating = 350; + clk->set_mode = local_timer_set_mode; + clk->set_next_event = local_timer_set_next_event; + clk->irq = INT_44XX_LOCALTIMER_IRQ; + clk->cpumask = cpumask_of(cpu); + clk->shift = 20; + clk->mult = div_sc(mpcore_timer_rate, + NSEC_PER_SEC, clk->shift); + clk->max_delta_ns = clockevent_delta2ns(0xffffffff, clk); + clk->min_delta_ns = clockevent_delta2ns(0xf, clk); + + /* Make sure our local interrupt controller has this enabled */ + local_irq_save(flags); + get_irq_chip(INT_44XX_LOCALTIMER_IRQ)->unmask(INT_44XX_LOCALTIMER_IRQ); + local_irq_restore(flags); + + clockevents_register_device(clk); +} + +/* + * take a local timer down + */ +void __cpuexit local_timer_stop(void) +{ + __raw_writel(0, twd_base + TWD_TIMER_CONTROL); +} + +#else /* CONFIG_LOCAL_TIMERS */ + +static void dummy_timer_set_mode(enum clock_event_mode mode, + struct clock_event_device *clk) +{ +} + +void __cpuinit local_timer_setup(void) +{ + unsigned int cpu = smp_processor_id(); + struct clock_event_device *clk = &per_cpu(local_clockevent, cpu); + + clk->name = "dummy_timer"; + clk->features = CLOCK_EVT_FEAT_DUMMY; + clk->rating = 200; + clk->mult = 1; + clk->set_mode = dummy_timer_set_mode; + clk->broadcast = smp_timer_broadcast; + clk->cpumask = cpumask_of(cpu); + + clockevents_register_device(clk); +} + +#endif /* !CONFIG_LOCAL_TIMERS */ diff --git a/arch/arm/plat-omap/include/mach/common.h b/arch/arm/plat-omap/include/mach/common.h index 4b18833..99381df 100644 --- a/arch/arm/plat-omap/include/mach/common.h +++ b/arch/arm/plat-omap/include/mach/common.h @@ -30,6 +30,9 @@ #include <linux/i2c.h> struct sys_timer; +#ifdef CONFIG_LOCAL_TIMERS /* Base address of mpu timer */ +extern void __iomem *twd_base; +#endif extern void omap_map_common_io(void); extern struct sys_timer omap_timer; diff --git a/arch/arm/plat-omap/include/mach/entry-macro.S b/arch/arm/plat-omap/include/mach/entry-macro.S index cf4c532..347189d 100644 --- a/arch/arm/plat-omap/include/mach/entry-macro.S +++ b/arch/arm/plat-omap/include/mach/entry-macro.S @@ -135,6 +135,34 @@ cmpne \irqnr, \tmp cmpcs \irqnr, \irqnr .endm + + /* We assume that irqstat (the raw value of the IRQ acknowledge + * register) is preserved from the macro above. + * If there is an IPI, we immediately signal end of interrupt + * on the controller, since this requires the original irqstat + * value which we won't easily be able to recreate later. + */ + + .macro test_for_ipi, irqnr, irqstat, base, tmp + bic \irqnr, \irqstat, #0x1c00 + cmp \irqnr, #16 + it cc + strcc \irqstat, [\base, #GIC_CPU_EOI] + it cs + cmpcs \irqnr, \irqnr + .endm + + /* As above, this assumes that irqstat and base are preserved */ + + .macro test_for_ltirq, irqnr, irqstat, base, tmp + bic \irqnr, \irqstat, #0x1c00 + mov \tmp, #0 + cmp \irqnr, #29 + itt eq + moveq \tmp, #1 + streq \irqstat, [\base, #GIC_CPU_EOI] + cmp \tmp, #0 + .endm #endif .macro irq_prio_table diff --git a/arch/arm/plat-omap/include/mach/irqs.h b/arch/arm/plat-omap/include/mach/irqs.h index 5bc331e..e8f84a0 100644 --- a/arch/arm/plat-omap/include/mach/irqs.h +++ b/arch/arm/plat-omap/include/mach/irqs.h @@ -427,6 +427,8 @@ #define IRQ_GIC_START 32 +#define INT_44XX_LOCALTIMER_IRQ 29 +#define INT_44XX_LOCALWDT_IRQ 30 #define INT_44XX_BENCH_MPU_EMUL (3 + IRQ_GIC_START) #define INT_44XX_SSM_ABORT_IRQ (6 + IRQ_GIC_START) -- 1.5.4.7 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html