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Diffstat (limited to 'arch/arm/mach-davinci/time.c')
-rw-r--r--arch/arm/mach-davinci/time.c141
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);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-19 13:11:37 +0000