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path: root/drivers/clocksource/timer-stm32.c
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Diffstat (limited to 'drivers/clocksource/timer-stm32.c')
-rw-r--r--drivers/clocksource/timer-stm32.c56
1 files changed, 44 insertions, 12 deletions
diff --git a/drivers/clocksource/timer-stm32.c b/drivers/clocksource/timer-stm32.c
index 928ac281f937..882037f1d8d6 100644
--- a/drivers/clocksource/timer-stm32.c
+++ b/drivers/clocksource/timer-stm32.c
@@ -24,14 +24,18 @@
#define TIM_DIER 0x0c
#define TIM_SR 0x10
#define TIM_EGR 0x14
+#define TIM_CNT 0x24
#define TIM_PSC 0x28
#define TIM_ARR 0x2c
+#define TIM_CCR1 0x34
#define TIM_CR1_CEN BIT(0)
+#define TIM_CR1_UDIS BIT(1)
#define TIM_CR1_OPM BIT(3)
#define TIM_CR1_ARPE BIT(7)
#define TIM_DIER_UIE BIT(0)
+#define TIM_DIER_CC1IE BIT(1)
#define TIM_SR_UIF BIT(0)
@@ -40,33 +44,57 @@
#define TIM_PSC_MAX USHRT_MAX
#define TIM_PSC_CLKRATE 10000
+static void stm32_clock_event_disable(struct timer_of *to)
+{
+ writel_relaxed(0, timer_of_base(to) + TIM_DIER);
+}
+
+static void stm32_clock_event_enable(struct timer_of *to)
+{
+ writel_relaxed(TIM_CR1_UDIS | TIM_CR1_CEN, timer_of_base(to) + TIM_CR1);
+}
+
static int stm32_clock_event_shutdown(struct clock_event_device *clkevt)
{
struct timer_of *to = to_timer_of(clkevt);
- writel_relaxed(0, timer_of_base(to) + TIM_CR1);
+ stm32_clock_event_disable(to);
return 0;
}
-static int stm32_clock_event_set_periodic(struct clock_event_device *clkevt)
+static int stm32_clock_event_set_next_event(unsigned long evt,
+ struct clock_event_device *clkevt)
{
struct timer_of *to = to_timer_of(clkevt);
+ unsigned long now, next;
+
+ next = readl_relaxed(timer_of_base(to) + TIM_CNT) + evt;
+ writel_relaxed(next, timer_of_base(to) + TIM_CCR1);
+ now = readl_relaxed(timer_of_base(to) + TIM_CNT);
+
+ if ((next - now) > evt)
+ return -ETIME;
- writel_relaxed(timer_of_period(to), timer_of_base(to) + TIM_ARR);
- writel_relaxed(TIM_CR1_ARPE | TIM_CR1_CEN, timer_of_base(to) + TIM_CR1);
+ writel_relaxed(TIM_DIER_CC1IE, timer_of_base(to) + TIM_DIER);
return 0;
}
-static int stm32_clock_event_set_next_event(unsigned long evt,
- struct clock_event_device *clkevt)
+static int stm32_clock_event_set_periodic(struct clock_event_device *clkevt)
+{
+ struct timer_of *to = to_timer_of(clkevt);
+
+ stm32_clock_event_enable(to);
+
+ return stm32_clock_event_set_next_event(timer_of_period(to), clkevt);
+}
+
+static int stm32_clock_event_set_oneshot(struct clock_event_device *clkevt)
{
struct timer_of *to = to_timer_of(clkevt);
- writel_relaxed(evt, timer_of_base(to) + TIM_ARR);
- writel_relaxed(TIM_CR1_ARPE | TIM_CR1_OPM | TIM_CR1_CEN,
- timer_of_base(to) + TIM_CR1);
+ stm32_clock_event_enable(to);
return 0;
}
@@ -78,6 +106,11 @@ static irqreturn_t stm32_clock_event_handler(int irq, void *dev_id)
writel_relaxed(0, timer_of_base(to) + TIM_SR);
+ if (clockevent_state_periodic(clkevt))
+ stm32_clock_event_set_periodic(clkevt);
+ else
+ stm32_clock_event_shutdown(clkevt);
+
clkevt->event_handler(clkevt);
return IRQ_HANDLED;
@@ -108,9 +141,10 @@ static void __init stm32_clockevent_init(struct timer_of *to)
to->clkevt.name = to->np->full_name;
to->clkevt.features = CLOCK_EVT_FEAT_PERIODIC;
+ to->clkevt.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
to->clkevt.set_state_shutdown = stm32_clock_event_shutdown;
to->clkevt.set_state_periodic = stm32_clock_event_set_periodic;
- to->clkevt.set_state_oneshot = stm32_clock_event_shutdown;
+ to->clkevt.set_state_oneshot = stm32_clock_event_set_oneshot;
to->clkevt.tick_resume = stm32_clock_event_shutdown;
to->clkevt.set_next_event = stm32_clock_event_set_next_event;
@@ -129,12 +163,10 @@ static void __init stm32_clockevent_init(struct timer_of *to)
prescaler = prescaler < TIM_PSC_MAX ? prescaler : TIM_PSC_MAX;
to->clkevt.rating = 100;
}
- writel_relaxed(0, timer_of_base(to) + TIM_ARR);
writel_relaxed(prescaler - 1, timer_of_base(to) + TIM_PSC);
writel_relaxed(TIM_EGR_UG, timer_of_base(to) + TIM_EGR);
writel_relaxed(0, timer_of_base(to) + TIM_SR);
- writel_relaxed(TIM_DIER_UIE, timer_of_base(to) + TIM_DIER);
/* Adjust rate and period given the prescaler value */
to->of_clk.rate = DIV_ROUND_CLOSEST(to->of_clk.rate, prescaler);