Messages in this thread Patch in this message | | | From | Alexandre Belloni <> | Subject | [PATCH 1/3] clocksource: atmel-st: Remove irq handler when clock event is unused | Date | Fri, 17 Jul 2015 21:33:26 +0200 |
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Setup and remove the interrupt handler in clock event mode selection. This avoids calling the (shared) interrupt handler when the device is not used.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> --- drivers/clocksource/timer-atmel-st.c | 43 +++++++++++++++++++++++++++++------- 1 file changed, 35 insertions(+), 8 deletions(-)
diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c index 41b7b6dc1d0d..a498b7446006 100644 --- a/drivers/clocksource/timer-atmel-st.c +++ b/drivers/clocksource/timer-atmel-st.c @@ -31,6 +31,7 @@ static unsigned long last_crtr; static u32 irqmask; +static int irq; static struct clock_event_device clkevt; static struct regmap *regmap_st; @@ -121,17 +122,45 @@ static int clkevt32k_shutdown(struct clock_event_device *evt) clkdev32k_disable_and_flush_irq(); irqmask = 0; regmap_write(regmap_st, AT91_ST_IER, irqmask); + + if (clockevent_state_periodic(evt) || clockevent_state_oneshot(evt)) + free_irq(irq, regmap_st); + + return 0; +} + +static int atmel_st_request_irq(struct clock_event_device *dev) +{ + int ret; + + if (clockevent_state_periodic(dev) || clockevent_state_oneshot(dev)) + return 0; + + ret = request_irq(irq, at91rm9200_timer_interrupt, + IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL, + "at91_tick", regmap_st); + if (ret) { + pr_alert("Unable to setup IRQ\n"); + return ret; + } + return 0; } static int clkevt32k_set_oneshot(struct clock_event_device *dev) { + int ret; + clkdev32k_disable_and_flush_irq(); /* * ALM for oneshot irqs, set by next_event() * before 32 seconds have passed. */ + ret = atmel_st_request_irq(dev); + if (ret) + return ret; + irqmask = AT91_ST_ALMS; regmap_write(regmap_st, AT91_ST_RTAR, last_crtr); regmap_write(regmap_st, AT91_ST_IER, irqmask); @@ -140,9 +169,15 @@ static int clkevt32k_set_oneshot(struct clock_event_device *dev) static int clkevt32k_set_periodic(struct clock_event_device *dev) { + int ret; + clkdev32k_disable_and_flush_irq(); /* PIT for periodic irqs; fixed rate of 1/HZ */ + ret = atmel_st_request_irq(dev); + if (ret) + return ret; + irqmask = AT91_ST_PITS; regmap_write(regmap_st, AT91_ST_PIMR, RM9200_TIMER_LATCH); regmap_write(regmap_st, AT91_ST_IER, irqmask); @@ -198,7 +233,6 @@ static struct clock_event_device clkevt = { static void __init atmel_st_timer_init(struct device_node *node) { unsigned int val; - int irq, ret; regmap_st = syscon_node_to_regmap(node); if (IS_ERR(regmap_st)) @@ -214,13 +248,6 @@ static void __init atmel_st_timer_init(struct device_node *node) if (!irq) panic(pr_fmt("Unable to get IRQ from DT\n")); - /* Make IRQs happen for the system timer */ - ret = request_irq(irq, at91rm9200_timer_interrupt, - IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL, - "at91_tick", regmap_st); - if (ret) - panic(pr_fmt("Unable to setup IRQ\n")); - /* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used * directly for the clocksource and all clockevents, after adjusting * its prescaler from the 1 Hz default. -- 2.1.4
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