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 62bcb1b..388f239 100644
--- a/arch/arm/plat-omap/include/mach/entry-macro.S
+++ b/arch/arm/plat-omap/include/mach/entry-macro.S
@@ -133,6 +133,34 @@
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
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