From 603b1a232604dcd19a28eaddf70eee9fbe3edc88 Mon Sep 17 00:00:00 2001 From: Boris BREZILLON Date: Mon, 2 Mar 2015 10:18:14 +0100 Subject: rtc: at91sam9: rework wakeup and interrupt handling The IRQ line used by the RTC device is usually shared with the system timer (PIT) on at91 platforms. Since timers are registering their handlers with IRQF_NO_SUSPEND, we should expect being called in suspended state, and properly wake the system up when this is the case. Set IRQF_COND_SUSPEND flag when registering the IRQ handler to inform irq core that it can safely be called while the system is suspended. Signed-off-by: Boris Brezillon Reviewed-by: Alexandre Belloni Acked-by: Nicolas Ferre Acked-by: Mark Rutland Signed-off-by: Rafael J. Wysocki --- drivers/rtc/rtc-at91sam9.c | 73 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 61 insertions(+), 12 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c index 2183fd2750ab..5ccaee32df72 100644 --- a/drivers/rtc/rtc-at91sam9.c +++ b/drivers/rtc/rtc-at91sam9.c @@ -23,6 +23,7 @@ #include #include #include +#include #include /* @@ -77,6 +78,9 @@ struct sam9_rtc { unsigned int gpbr_offset; int irq; struct clk *sclk; + bool suspended; + unsigned long events; + spinlock_t lock; }; #define rtt_readl(rtc, field) \ @@ -271,14 +275,9 @@ static int at91_rtc_proc(struct device *dev, struct seq_file *seq) return 0; } -/* - * IRQ handler for the RTC - */ -static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) +static irqreturn_t at91_rtc_cache_events(struct sam9_rtc *rtc) { - struct sam9_rtc *rtc = _rtc; u32 sr, mr; - unsigned long events = 0; /* Shared interrupt may be for another device. Note: reading * SR clears it, so we must only read it in this irq handler! @@ -290,18 +289,54 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) /* alarm status */ if (sr & AT91_RTT_ALMS) - events |= (RTC_AF | RTC_IRQF); + rtc->events |= (RTC_AF | RTC_IRQF); /* timer update/increment */ if (sr & AT91_RTT_RTTINC) - events |= (RTC_UF | RTC_IRQF); + rtc->events |= (RTC_UF | RTC_IRQF); + + return IRQ_HANDLED; +} + +static void at91_rtc_flush_events(struct sam9_rtc *rtc) +{ + if (!rtc->events) + return; - rtc_update_irq(rtc->rtcdev, 1, events); + rtc_update_irq(rtc->rtcdev, 1, rtc->events); + rtc->events = 0; pr_debug("%s: num=%ld, events=0x%02lx\n", __func__, - events >> 8, events & 0x000000FF); + rtc->events >> 8, rtc->events & 0x000000FF); +} - return IRQ_HANDLED; +/* + * IRQ handler for the RTC + */ +static irqreturn_t at91_rtc_interrupt(int irq, void *_rtc) +{ + struct sam9_rtc *rtc = _rtc; + int ret; + + spin_lock(&rtc->lock); + + ret = at91_rtc_cache_events(rtc); + + /* We're called in suspended state */ + if (rtc->suspended) { + /* Mask irqs coming from this peripheral */ + rtt_writel(rtc, MR, + rtt_readl(rtc, MR) & + ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN)); + /* Trigger a system wakeup */ + pm_system_wakeup(); + } else { + at91_rtc_flush_events(rtc); + } + + spin_unlock(&rtc->lock); + + return ret; } static const struct rtc_class_ops at91_rtc_ops = { @@ -421,7 +456,8 @@ static int at91_rtc_probe(struct platform_device *pdev) /* register irq handler after we know what name we'll use */ ret = devm_request_irq(&pdev->dev, rtc->irq, at91_rtc_interrupt, - IRQF_SHARED, dev_name(&rtc->rtcdev->dev), rtc); + IRQF_SHARED | IRQF_COND_SUSPEND, + dev_name(&rtc->rtcdev->dev), rtc); if (ret) { dev_dbg(&pdev->dev, "can't share IRQ %d?\n", rtc->irq); return ret; @@ -482,7 +518,12 @@ static int at91_rtc_suspend(struct device *dev) rtc->imr = mr & (AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN); if (rtc->imr) { if (device_may_wakeup(dev) && (mr & AT91_RTT_ALMIEN)) { + unsigned long flags; + enable_irq_wake(rtc->irq); + spin_lock_irqsave(&rtc->lock, flags); + rtc->suspended = true; + spin_unlock_irqrestore(&rtc->lock, flags); /* don't let RTTINC cause wakeups */ if (mr & AT91_RTT_RTTINCIEN) rtt_writel(rtc, MR, mr & ~AT91_RTT_RTTINCIEN); @@ -499,10 +540,18 @@ static int at91_rtc_resume(struct device *dev) u32 mr; if (rtc->imr) { + unsigned long flags; + if (device_may_wakeup(dev)) disable_irq_wake(rtc->irq); mr = rtt_readl(rtc, MR); rtt_writel(rtc, MR, mr | rtc->imr); + + spin_lock_irqsave(&rtc->lock, flags); + rtc->suspended = false; + at91_rtc_cache_events(rtc); + at91_rtc_flush_events(rtc); + spin_unlock_irqrestore(&rtc->lock, flags); } return 0; -- cgit v1.2.3 From dd1f1f391dd7f3a39a3983df2ca076871111cec9 Mon Sep 17 00:00:00 2001 From: Boris BREZILLON Date: Mon, 2 Mar 2015 10:18:15 +0100 Subject: rtc: at91rm9200: rework wakeup and interrupt handling The IRQ line used by the RTC device is usually shared with the system timer (PIT) on at91 platforms. Since timers are registering their handlers with IRQF_NO_SUSPEND, we should expect being called in suspended state, and properly wake the system up when this is the case. Set IRQF_COND_SUSPEND flag when registering the IRQ handler to inform irq core that it can safely be called while the system is suspended. Signed-off-by: Boris Brezillon Reviewed-by: Alexandre Belloni Acked-by: Nicolas Ferre Acked-by: Mark Rutland Signed-off-by: Rafael J. Wysocki --- drivers/rtc/rtc-at91rm9200.c | 62 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 48 insertions(+), 14 deletions(-) (limited to 'drivers/rtc') diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index 70a5d94cc766..b4f7744f6751 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include "rtc-at91rm9200.h" @@ -54,6 +55,10 @@ static void __iomem *at91_rtc_regs; static int irq; static DEFINE_SPINLOCK(at91_rtc_lock); static u32 at91_rtc_shadow_imr; +static bool suspended; +static DEFINE_SPINLOCK(suspended_lock); +static unsigned long cached_events; +static u32 at91_rtc_imr; static void at91_rtc_write_ier(u32 mask) { @@ -290,7 +295,9 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) struct rtc_device *rtc = platform_get_drvdata(pdev); unsigned int rtsr; unsigned long events = 0; + int ret = IRQ_NONE; + spin_lock(&suspended_lock); rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read_imr(); if (rtsr) { /* this interrupt is shared! Is it ours? */ if (rtsr & AT91_RTC_ALARM) @@ -304,14 +311,22 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) at91_rtc_write(AT91_RTC_SCCR, rtsr); /* clear status reg */ - rtc_update_irq(rtc, 1, events); + if (!suspended) { + rtc_update_irq(rtc, 1, events); - dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", __func__, - events >> 8, events & 0x000000FF); + dev_dbg(&pdev->dev, "%s(): num=%ld, events=0x%02lx\n", + __func__, events >> 8, events & 0x000000FF); + } else { + cached_events |= events; + at91_rtc_write_idr(at91_rtc_imr); + pm_system_wakeup(); + } - return IRQ_HANDLED; + ret = IRQ_HANDLED; } - return IRQ_NONE; /* not handled */ + spin_lock(&suspended_lock); + + return ret; } static const struct at91_rtc_config at91rm9200_config = { @@ -401,8 +416,8 @@ static int __init at91_rtc_probe(struct platform_device *pdev) AT91_RTC_CALEV); ret = devm_request_irq(&pdev->dev, irq, at91_rtc_interrupt, - IRQF_SHARED, - "at91_rtc", pdev); + IRQF_SHARED | IRQF_COND_SUSPEND, + "at91_rtc", pdev); if (ret) { dev_err(&pdev->dev, "IRQ %d already in use.\n", irq); return ret; @@ -454,8 +469,6 @@ static void at91_rtc_shutdown(struct platform_device *pdev) /* AT91RM9200 RTC Power management control */ -static u32 at91_rtc_imr; - static int at91_rtc_suspend(struct device *dev) { /* this IRQ is shared with DBGU and other hardware which isn't @@ -464,21 +477,42 @@ static int at91_rtc_suspend(struct device *dev) at91_rtc_imr = at91_rtc_read_imr() & (AT91_RTC_ALARM|AT91_RTC_SECEV); if (at91_rtc_imr) { - if (device_may_wakeup(dev)) + if (device_may_wakeup(dev)) { + unsigned long flags; + enable_irq_wake(irq); - else + + spin_lock_irqsave(&suspended_lock, flags); + suspended = true; + spin_unlock_irqrestore(&suspended_lock, flags); + } else { at91_rtc_write_idr(at91_rtc_imr); + } } return 0; } static int at91_rtc_resume(struct device *dev) { + struct rtc_device *rtc = dev_get_drvdata(dev); + if (at91_rtc_imr) { - if (device_may_wakeup(dev)) + if (device_may_wakeup(dev)) { + unsigned long flags; + + spin_lock_irqsave(&suspended_lock, flags); + + if (cached_events) { + rtc_update_irq(rtc, 1, cached_events); + cached_events = 0; + } + + suspended = false; + spin_unlock_irqrestore(&suspended_lock, flags); + disable_irq_wake(irq); - else - at91_rtc_write_ier(at91_rtc_imr); + } + at91_rtc_write_ier(at91_rtc_imr); } return 0; } -- cgit v1.2.3