1 files changed, 103 insertions, 38 deletions

diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
index f80ae25a52e4..fc90d3ee0eba 100644
--- a/arch/arm/mach-davinci/time.c
+++ b/arch/arm/mach-davinci/time.c
@@ -46,14 +46,24 @@ enum {
 };
 
 /* Timer register offsets */
-#define PID12                        0x0
-#define TIM12                        0x10
-#define TIM34                        0x14
-#define PRD12                        0x18
-#define PRD34                        0x1c
-#define TCR                          0x20
-#define TGCR                         0x24
-#define WDTCR                        0x28
+#define PID12                   0x0
+#define TIM12                   0x10
+#define TIM34                   0x14
+#define PRD12                   0x18
+#define PRD34                   0x1c
+#define TCR                     0x20
+#define TGCR                    0x24
+#define WDTCR                   0x28
+
+/* Offsets of the 8 compare registers */
+#define CMP12_0                 0x60
+#define CMP12_1                 0x64
+#define CMP12_2                 0x68
+#define CMP12_3                 0x6c
+#define CMP12_4                 0x70
+#define CMP12_5                 0x74
+#define CMP12_6                 0x78
+#define CMP12_7                 0x7c
 
 /* Timer register bitfields */
 #define TCR_ENAMODE_DISABLE          0x0
@@ -85,6 +95,7 @@ struct timer_s {
         unsigned int id;
         unsigned long period;
         unsigned long opts;
+        unsigned long flags;
         void __iomem *base;
         unsigned long tim_off;
         unsigned long prd_off;
@@ -94,9 +105,13 @@ struct timer_s {
 static struct timer_s timers[];
 
 /* values for 'opts' field of struct timer_s */
-#define TIMER_OPTS_DISABLED   0x00
-#define TIMER_OPTS_ONESHOT    0x01
-#define TIMER_OPTS_PERIODIC   0x02
+#define TIMER_OPTS_DISABLED             0x01
+#define TIMER_OPTS_ONESHOT              0x02
+#define TIMER_OPTS_PERIODIC             0x04
+#define TIMER_OPTS_STATE_MASK           0x07
+
+#define TIMER_OPTS_USE_COMPARE          0x80000000
+#define USING_COMPARE(t)                ((t)->opts & TIMER_OPTS_USE_COMPARE)
 
 static char *id_to_name[] = {
         [T0_BOT]        = "timer0_0",
@@ -107,24 +122,41 @@ static char *id_to_name[] = {
 
 static int timer32_config(struct timer_s *t)
 {
-        u32 tcr = __raw_readl(t->base + TCR);
-
-        /* disable timer */
-        tcr &= ~(TCR_ENAMODE_MASK << t->enamode_shift);
-        __raw_writel(tcr, t->base + TCR);
-
-        /* reset counter to zero, set new period */
-        __raw_writel(0, t->base + t->tim_off);
-        __raw_writel(t->period, t->base + t->prd_off);
-
-        /* Set enable mode */
-        if (t->opts & TIMER_OPTS_ONESHOT) {
-                tcr |= TCR_ENAMODE_ONESHOT << t->enamode_shift;
-        } else if (t->opts & TIMER_OPTS_PERIODIC) {
-                tcr |= TCR_ENAMODE_PERIODIC << t->enamode_shift;
+        u32 tcr;
+        struct davinci_soc_info *soc_info = davinci_get_soc_info();
+
+        if (USING_COMPARE(t)) {
+                struct davinci_timer_instance *dtip =
+                                soc_info->timer_info->timers;
+                int event_timer = ID_TO_TIMER(timers[TID_CLOCKEVENT].id);
+
+                /*
+                 * Next interrupt should be the current time reg value plus
+                 * the new period (using 32-bit unsigned addition/wrapping
+                 * to 0 on overflow).  This assumes that the clocksource
+                 * is setup to count to 2^32-1 before wrapping around to 0.
+                 */
+                __raw_writel(__raw_readl(t->base + t->tim_off) + t->period,
+                        t->base + dtip[event_timer].cmp_off);
+        } else {
+                tcr = __raw_readl(t->base + TCR);
+
+                /* disable timer */
+                tcr &= ~(TCR_ENAMODE_MASK << t->enamode_shift);
+                __raw_writel(tcr, t->base + TCR);
+
+                /* reset counter to zero, set new period */
+                __raw_writel(0, t->base + t->tim_off);
+                __raw_writel(t->period, t->base + t->prd_off);
+
+                /* Set enable mode */
+                if (t->opts & TIMER_OPTS_ONESHOT)
+                        tcr |= TCR_ENAMODE_ONESHOT << t->enamode_shift;
+                else if (t->opts & TIMER_OPTS_PERIODIC)
+                        tcr |= TCR_ENAMODE_PERIODIC << t->enamode_shift;
+
+                __raw_writel(tcr, t->base + TCR);
         }
-
-        __raw_writel(tcr, t->base + TCR);
         return 0;
 }
 
@@ -222,8 +254,11 @@ static void __init timer_init(void)
                 /* Register interrupt */
                 t->irqaction.name = t->name;
                 t->irqaction.dev_id = (void *)t;
-                if (t->irqaction.handler != NULL)
+
+                if (t->irqaction.handler != NULL) {
+                        irq = USING_COMPARE(t) ? dtip[i].cmp_irq : irq;
                         setup_irq(irq, &t->irqaction);
+                }
 
                 timer32_config(&timers[i]);
         }
@@ -268,15 +303,18 @@ static void davinci_set_mode(enum clock_event_mode mode,
         switch (mode) {
         case CLOCK_EVT_MODE_PERIODIC:
                 t->period = davinci_clock_tick_rate / (HZ);
-                t->opts = TIMER_OPTS_PERIODIC;
+                t->opts &= ~TIMER_OPTS_STATE_MASK;
+                t->opts |= TIMER_OPTS_PERIODIC;
                 timer32_config(t);
                 break;
         case CLOCK_EVT_MODE_ONESHOT:
-                t->opts = TIMER_OPTS_ONESHOT;
+                t->opts &= ~TIMER_OPTS_STATE_MASK;
+                t->opts |= TIMER_OPTS_ONESHOT;
                 break;
         case CLOCK_EVT_MODE_UNUSED:
         case CLOCK_EVT_MODE_SHUTDOWN:
-                t->opts = TIMER_OPTS_DISABLED;
+                t->opts &= ~TIMER_OPTS_STATE_MASK;
+                t->opts |= TIMER_OPTS_DISABLED;
                 break;
         case CLOCK_EVT_MODE_RESUME:
                 break;
@@ -295,12 +333,40 @@ static void __init davinci_timer_init(void)
 {
         struct clk *timer_clk;
         struct davinci_soc_info *soc_info = &davinci_soc_info;
-
+        unsigned int clockevent_id;
+        unsigned int clocksource_id;
         static char err[] __initdata = KERN_ERR
                 "%s: can't register clocksource!\n";
 
-        timers[TID_CLOCKEVENT].id = soc_info->timer_info->clockevent_id;
-        timers[TID_CLOCKSOURCE].id = soc_info->timer_info->clocksource_id;
+        clockevent_id = soc_info->timer_info->clockevent_id;
+        clocksource_id = soc_info->timer_info->clocksource_id;
+
+        timers[TID_CLOCKEVENT].id = clockevent_id;
+        timers[TID_CLOCKSOURCE].id = clocksource_id;
+
+        /*
+         * If using same timer for both clock events & clocksource,
+         * a compare register must be used to generate an event interrupt.
+         * This is equivalent to a oneshot timer only (not periodic).
+         */
+        if (clockevent_id == clocksource_id) {
+                struct davinci_timer_instance *dtip =
+                                soc_info->timer_info->timers;
+                int event_timer = ID_TO_TIMER(clockevent_id);
+
+                /* Only bottom timers can use compare regs */
+                if (IS_TIMER_TOP(clockevent_id))
+                        pr_warning("davinci_timer_init: Invalid use"
+                                " of system timers.  Results unpredictable.\n");
+                else if ((dtip[event_timer].cmp_off == 0)
+                                || (dtip[event_timer].cmp_irq == 0))
+                        pr_warning("davinci_timer_init:  Invalid timer instance"
+                                " setup.  Results unpredictable.\n");
+                else {
+                        timers[TID_CLOCKEVENT].opts |= TIMER_OPTS_USE_COMPARE;
+                        clockevent_davinci.features = CLOCK_EVT_FEAT_ONESHOT;
+                }
+        }
 
         /* init timer hw */
         timer_init();
@@ -312,7 +378,7 @@ static void __init davinci_timer_init(void)
         davinci_clock_tick_rate = clk_get_rate(timer_clk);
 
         /* setup clocksource */
-        clocksource_davinci.name = id_to_name[timers[TID_CLOCKSOURCE].id];
+        clocksource_davinci.name = id_to_name[clocksource_id];
         clocksource_davinci.mult =
                 clocksource_khz2mult(davinci_clock_tick_rate/1000,
                                      clocksource_davinci.shift);
@@ -325,8 +391,7 @@ static void __init davinci_timer_init(void)
                                          clockevent_davinci.shift);
         clockevent_davinci.max_delta_ns =
                 clockevent_delta2ns(0xfffffffe, &clockevent_davinci);
-        clockevent_davinci.min_delta_ns =
-                clockevent_delta2ns(1, &clockevent_davinci);
+        clockevent_davinci.min_delta_ns = 50000; /* 50 usec */
 
         clockevent_davinci.cpumask = cpumask_of(0);
         clockevents_register_device(&clockevent_davinci);