1 files changed, 111 insertions, 33 deletions

diff --git a/arch/arm/mach-realview/localtimer.c b/arch/arm/mach-realview/localtimer.c
index c7bdf04ab094..50604360479f 100644
--- a/arch/arm/mach-realview/localtimer.c
+++ b/arch/arm/mach-realview/localtimer.c
@@ -14,19 +14,75 @@
 #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.
  *
@@ -45,12 +101,11 @@ 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
@@ -88,36 +143,36 @@ void __cpuinit local_timer_setup(unsigned int cpu)
         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);
 }
 
 /*
@@ -127,3 +182,26 @@ void __cpuexit local_timer_stop(unsigned int cpu)
 {
         __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 */