#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/mach/time.h>
#include <asm/hardware/arm_twd.h>
#include <asm/hardware/gic.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
-#define TWD_BASE(cpu) (__io_address(REALVIEW_TWD_BASE) + \
- ((cpu) * REALVIEW_TWD_SIZE))
+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
+
+#define TWD_BASE(cpu) (twd_base_addr + (cpu) * twd_size)
+
+/* set up by the platform code */
+void __iomem *twd_base_addr;
+unsigned int twd_size;
static unsigned long mpcore_timer_rate;
+static void local_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *clk)
+{
+ void __iomem *base = TWD_BASE(smp_processor_id());
+ 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, base + TWD_TIMER_CONTROL);
+}
+
+static int local_timer_set_next_event(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ void __iomem *base = TWD_BASE(smp_processor_id());
+ unsigned long ctrl = __raw_readl(base + TWD_TIMER_CONTROL);
+
+ __raw_writel(evt, base + TWD_TIMER_COUNTER);
+ __raw_writel(ctrl | TWD_TIMER_CONTROL_ENABLE, base + TWD_TIMER_CONTROL);
+
+ return 0;
+}
+
/*
* local_timer_ack: checks for a local timer interrupt.
*
- * If a local timer interrupt has occured, acknowledge and return 1.
+ * If a local timer interrupt has occurred, acknowledge and return 1.
* Otherwise, return 0.
*/
int local_timer_ack(void)
return 0;
}
-void __cpuinit local_timer_setup(unsigned int cpu)
+static void __cpuinit twd_calibrate_rate(unsigned int cpu)
{
void __iomem *base = TWD_BASE(cpu);
- unsigned int load, offset;
+ unsigned long load, count;
u64 waitjiffies;
- unsigned int count;
/*
* If this is the first time round, we need to work out how fast
load = mpcore_timer_rate / HZ;
__raw_writel(load, base + TWD_TIMER_LOAD);
- __raw_writel(0x7, base + TWD_TIMER_CONTROL);
-
- /*
- * Now maneuver our local tick into the right part of the jiffy.
- * Start by working out where within the tick our local timer
- * interrupt should go.
- */
- offset = ((mpcore_timer_rate / HZ) / (NR_CPUS + 1)) * (cpu + 1);
-
- /*
- * gettimeoffset() will return a number of us since the last tick.
- * Convert this number of us to a local timer tick count.
- * Be careful of integer overflow whilst keeping maximum precision.
- *
- * with HZ=100 and 1MHz (fpga) ~ 1GHz processor:
- * load = 1 ~ 10,000
- * mpcore_timer_rate/10000 = 100 ~ 100,000
- *
- * so the multiply value will be less than 10^9 always.
- */
- load = (system_timer->offset() * (mpcore_timer_rate / 10000)) / 100;
-
- /* Add on our offset to get the load value */
- load = (load + offset) % (mpcore_timer_rate / HZ);
+}
- __raw_writel(load, base + TWD_TIMER_COUNTER);
+/*
+ * Setup the local clock events for a CPU.
+ */
+void __cpuinit local_timer_setup(unsigned int cpu)
+{
+ struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
+ unsigned long flags;
+
+ twd_calibrate_rate(cpu);
+
+ 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 = IRQ_LOCALTIMER;
+ clk->cpumask = cpumask_of_cpu(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 */
- __raw_writel(1 << IRQ_LOCALTIMER,
- __io_address(REALVIEW_GIC_DIST_BASE) + GIC_DIST_ENABLE_SET);
+ local_irq_save(flags);
+ get_irq_chip(IRQ_LOCALTIMER)->unmask(IRQ_LOCALTIMER);
+ local_irq_restore(flags);
+
+ clockevents_register_device(clk);
}
/*
{
__raw_writel(0, TWD_BASE(cpu) + 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(unsigned int cpu)
+{
+ struct clock_event_device *clk = &per_cpu(local_clockevent, cpu);
+
+ clk->name = "dummy_timer";
+ clk->features = CLOCK_EVT_FEAT_DUMMY;
+ clk->rating = 200;
+ clk->set_mode = dummy_timer_set_mode;
+ clk->broadcast = smp_timer_broadcast;
+ clk->cpumask = cpumask_of_cpu(cpu);
+
+ clockevents_register_device(clk);
+}
+
+#endif /* !CONFIG_LOCAL_TIMERS */
git.samba.org / sfrench / cifs-2.6.git / blobdiff