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Commit e24b0bfa authored by Johan Hovold's avatar Johan Hovold Committed by Linus Torvalds
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Revert "drivers/rtc/rtc-at91rm9200.c: use a variable for storing IMR"

This reverts commit 0ef1594c.

This patch introduced a few races which cannot be easily fixed with a
small follow-up patch. Furthermore, the SoC with the broken hardware
register, which this patch intended to add support for, can only be used
with device trees, which this driver currently does not support.

[ Here is the discussion that led to this "revert" patch:
  https://lkml.org/lkml/2013/4/3/176

 ]

Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c4c80f63
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+19 −31
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ static DECLARE_COMPLETION(at91_rtc_updated);
static unsigned int at91_alarm_year = AT91_RTC_EPOCH;
static void __iomem *at91_rtc_regs;
static int irq;
static u32 at91_rtc_imr;

/*
 * Decode time/date into rtc_time structure
@@ -109,11 +108,9 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm)
	cr = at91_rtc_read(AT91_RTC_CR);
	at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);

	at91_rtc_imr |= AT91_RTC_ACKUPD;
	at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD);
	wait_for_completion(&at91_rtc_updated);	/* wait for ACKUPD interrupt */
	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);
	at91_rtc_imr &= ~AT91_RTC_ACKUPD;

	at91_rtc_write(AT91_RTC_TIMR,
			  bin2bcd(tm->tm_sec) << 0
@@ -145,7 +142,7 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
	tm->tm_year = at91_alarm_year - 1900;

	alrm->enabled = (at91_rtc_imr & AT91_RTC_ALARM)
	alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM)
			? 1 : 0;

	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
@@ -171,7 +168,6 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
	tm.tm_sec = alrm->time.tm_sec;

	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
	at91_rtc_imr &= ~AT91_RTC_ALARM;
	at91_rtc_write(AT91_RTC_TIMALR,
		  bin2bcd(tm.tm_sec) << 0
		| bin2bcd(tm.tm_min) << 8
@@ -184,7 +180,6 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)

	if (alrm->enabled) {
		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
		at91_rtc_imr |= AT91_RTC_ALARM;
		at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
	}

@@ -201,12 +196,9 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)

	if (enabled) {
		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
		at91_rtc_imr |= AT91_RTC_ALARM;
		at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);
	} else {
	} else
		at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);
		at91_rtc_imr &= ~AT91_RTC_ALARM;
	}

	return 0;
}
@@ -215,10 +207,12 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 */
static int at91_rtc_proc(struct device *dev, struct seq_file *seq)
{
	unsigned long imr = at91_rtc_read(AT91_RTC_IMR);

	seq_printf(seq, "update_IRQ\t: %s\n",
			(at91_rtc_imr & AT91_RTC_ACKUPD) ? "yes" : "no");
			(imr & AT91_RTC_ACKUPD) ? "yes" : "no");
	seq_printf(seq, "periodic_IRQ\t: %s\n",
			(at91_rtc_imr & AT91_RTC_SECEV) ? "yes" : "no");
			(imr & AT91_RTC_SECEV) ? "yes" : "no");

	return 0;
}
@@ -233,7 +227,7 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id)
	unsigned int rtsr;
	unsigned long events = 0;

	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_imr;
	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR);
	if (rtsr) {		/* this interrupt is shared!  Is it ours? */
		if (rtsr & AT91_RTC_ALARM)
			events |= (RTC_AF | RTC_IRQF);
@@ -297,7 +291,6 @@ static int __init at91_rtc_probe(struct platform_device *pdev)
	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
					AT91_RTC_SECEV | AT91_RTC_TIMEV |
					AT91_RTC_CALEV);
	at91_rtc_imr = 0;

	ret = request_irq(irq, at91_rtc_interrupt,
				IRQF_SHARED,
@@ -336,7 +329,6 @@ static int __exit at91_rtc_remove(struct platform_device *pdev)
	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |
					AT91_RTC_SECEV | AT91_RTC_TIMEV |
					AT91_RTC_CALEV);
	at91_rtc_imr = 0;
	free_irq(irq, pdev);

	rtc_device_unregister(rtc);
@@ -349,35 +341,31 @@ static int __exit at91_rtc_remove(struct platform_device *pdev)

/* AT91RM9200 RTC Power management control */

static u32 at91_rtc_bkpimr;

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
	 * necessarily doing PM like we are...
	 */
	at91_rtc_bkpimr = at91_rtc_imr & (AT91_RTC_ALARM|AT91_RTC_SECEV);
	if (at91_rtc_bkpimr) {
		if (device_may_wakeup(dev)) {
	at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR)
			& (AT91_RTC_ALARM|AT91_RTC_SECEV);
	if (at91_rtc_imr) {
		if (device_may_wakeup(dev))
			enable_irq_wake(irq);
		} else {
			at91_rtc_write(AT91_RTC_IDR, at91_rtc_bkpimr);
			at91_rtc_imr &= ~at91_rtc_bkpimr;
		}
		else
			at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr);
	}
	return 0;
}

static int at91_rtc_resume(struct device *dev)
{
	if (at91_rtc_bkpimr) {
		if (device_may_wakeup(dev)) {
	if (at91_rtc_imr) {
		if (device_may_wakeup(dev))
			disable_irq_wake(irq);
		} else {
			at91_rtc_imr |= at91_rtc_bkpimr;
			at91_rtc_write(AT91_RTC_IER, at91_rtc_bkpimr);
		}
		else
			at91_rtc_write(AT91_RTC_IER, at91_rtc_imr);
	}
	return 0;
}
+1 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@
#define	AT91_RTC_SCCR		0x1c			/* Status Clear Command Register */
#define	AT91_RTC_IER		0x20			/* Interrupt Enable Register */
#define	AT91_RTC_IDR		0x24			/* Interrupt Disable Register */
#define	AT91_RTC_IMR		0x28			/* Interrupt Mask Register */

#define	AT91_RTC_VER		0x2c			/* Valid Entry Register */
#define		AT91_RTC_NVTIM		(1 <<  0)		/* Non valid Time */